TG Guides (1)

SECTION 2 WHAT HAS SPACE EXPLORATION BROUGHT DOWN TO EARTH? LAPTOPS & NON-REFLECTIVE SCREENS Until the 1970s, few people had access to a life-support functions to posting status updates on computer as they were very expensive and could social media! The ISS used IBM/Lenovo ThinkPad take up an entire room. As technology laptops until 2016 when they transitioned to HP developed, office users began to access larger ones instead. computers via smaller terminals, then later they were given their own desktop PCs. However, Many of the features found in the first laptop used in these were still very heavy and non-portable. space are still in use today. This changed in 1982 with the release of the GRiD Compass laptop computer which would Non-Reflective Screens become the first laptop to be used in space. If you’ve used a mobile phone, you will have noticed Laptops in Space that it is hard to see what’s on the screen in bright sunlight. This is partly because the screen is reflective, acting like a mirror to the sun meaning you have to increase your brightness and energy usage to clearly read the screen. To minimize energy loss, NASA developed a non-reflective coating (film) to screens. This film was originally used to coat the windows of the Gemini 2-man spacecraft in 1963 before it found use on computer screens Astronaut John Creighton posing with a GRiD Compass Display screens for computers used to almost always laptop aboard a Space Shuttle Discovery mission in 1985. have a glass screen surface that was highly reflective. A screen overlay would reduce this reflectiveness Anything taken into space needs to be as (glare). Modern laptop screens don’t use glass as an lightweight and portable as possible. Space vehicles outer layer and anti-reflectiveness is built into the are cramped, and any extra weight adds a significant screen itself. A layer on the screen surface is cost to a mission. The GRiD Compass laptop was ‘roughened’ so it disperses the light that hits the used in NASA shuttle missions from 1983 because it screen, preventing reflection. was 20% the weight of its nearest competitor, had a rugged magnesium case, was small and portable (for the time!), had a bright display and had memory that would be more reliable in space. The laptop was the first to have a closing lid with the screen attached to it (like modern laptops) but didn’t have a battery so it had to be plugged in. NASA and other space programs have used laptops Display screens on the ISS. The screens have been ever since. On the International Space Station designed to reduce (but not eliminate) glare. laptops are used for everything from controlling vital APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE 10

SECTION 2 WHAT HAS SPACE EXPLORATION BROUGHT DOWN TO EARTH? PORTABLE HAND TOOLS If you have a cordless vacuum cleaner or any task. The drill had to be highly efficient at cutting battery powered hand tools in your household, through hard pieces in the lunar surface and it then you own a piece of technology that was needed to be lightweight and compact. It also had originally designed to help astronauts on the to have its own power source, as it was to be used moon. away from the main lunar module. NASA engineers were concerned about trailing wires because In a Collecting Moon Rock Samples low gravity environment these wires could easily entangle and trap an astronaut. US astronauts visited the moon on several occasions during the Apollo space program between 1969 and Development 1972. One of the most important tasks performed was the collection of lunar rock and soil samples for Cordless tools were available before NASA asked for later analysis on Earth. It was relatively easy to obtain the lunar drill to be developed, but the data this from the surface, but NASA scientists also obtained from this project was used to improve needed samples from up to 3 metres below the power consumption and the weight of tools ground. developed for consumers. The Dustbuster cordless vacuum was designed in 1979 as an easy to carry portable alternative to a vacuum cleaner and was created as a result of the technology developed for the Apollo missions. Astronaut Richard Linnehan is pictured in 2016 repairing a control unit inside the Hubble Space Telescope. He used cordless tools like the one attached to his spacesuit. An astronaut on the moon using the large cordless hand Since then cordless tools have become even more drill developed by Black and Decker. refined and easy to use. Better battery technology has given tools much more power and range than To facilitate this, NASA hired the Black and Decker before. Dustbuster technology helped pioneer larger tool company to develop and manufacture a cordless vacuum cleaners that are now used instead cordless drill that could be used to complete this of a corded model in many households. 11 APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE

SECTION 2 WHAT HAS SPACE EXPLORATION BROUGHT DOWN TO EARTH? MEMORY FOAM Memory foam works by becoming soft enough to mould around a person or body shape. It does this by becoming softer with body heat. When the heat and pressure is removed the foam returns to its original shape. Memory foam is perhaps one of the most famous To solve this problem the engineers developed a inventions developed from space technology special foam that could absorb lots of energy while and is widely used in many things today. It has a still staying soft. It also moulded to an astronauts number of commercial and medical applications, shape, ‘bouncing back’ to its original shape after use. including cushioning for shoes, prosthetics and NASA still uses memory foam in the space program seating pads for wheelchairs. But the most today, for everything from seats to floors. common application is in pillows and mattresses, as its softness and responsiveness Memory foam was initially expensive and very make it ideal for sleeping. difficult to produce, but as manufacturing techniques improved, costs fell. Memory foam In the 1960s, a group of NASA engineers were asked mattresses were initially used in medicine to help to design a customized seat for each astronaut that improve the comfort and health of patients who would relieve pressure from the massive needed to spend long periods in bed. Mattresses gravitational (G) forces the astronauts endured started to appear on public sale in 1991. during take-off and landing. Making a customised seat for each astronaut would not only have been Memory foam is now used in lots of different ways. very expensive, but it would not have been practical More unusual applications include racing car seats in the longer term. for shock absorbing purposes and in bulletproof vests to cushion the blow from a bullet. APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE 12

SECTION 2 WHAT HAS SPACE EXPLORATION BROUGHT DOWN TO EARTH? FIND OUT MORE If you’re interested in any of topics that have been covered in this section then you can use the links below to conduct your own research. You can click on the links if you are viewing this document electronically. FIREFIGHTING 1 A space.com article about the Apollo 1 Fire bit.ly/2A57a25 2 NASA information about protective PBI fabric bit.ly/2Mx3fhh 3 An article on how satellites can help put out or prevent fires bit.ly/2Y4JJxJ ROBOTIC ARMS 1 A NASA article about the applications of robotic arms rb.gy/zeqpfd 2 BBC news article about robotic arms in the NHS bbc.in/2UgDjdR 3 Space.com article about robotic arms and medicine bit.ly/372cwqY LAPTOPS & NON-REFLECTIVE SCREENS 1 Information about the first laptop in space s.si.edu/2UemX5n 2 NASA magazine article about anti-glare coatings rb.gy/a4rhlx 3 Differences between matt and glossy screens bit.ly/3cIOz9u PORTABLE HAND TOOLS 1 NASA magazine article about cordless tools rb.gy/fwtw6q 2 The links between NASA, the Moon and cordless tools bit.ly/3dE7fZd 3 Repairing the Hubble Space Telescope with cordless tools bit.ly/3eNSJya MEMORY FOAM 1 Where does memory foam come from? bit.ly/372PX5k 2 Facts about NASA memory foam technology bit.ly/2XAawTC 3 NASA information about an application of memory foam rb.gy/ynrymw 13 APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE

APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE SECTION 3 HOW DO WE LOOK FROM SPACE? APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE 14

SECTION 3 HOW DO WE LOOK FROM SPACE? INTRODUCTION Many of the things in our daily lives that we take life, so they are replaced constantly by newer models for granted are only possible because of with more advanced features. thousands of satellites that are orbiting the Earth. Each satellite has one or two specific Satellites work by communicating with the ground functions and are a key component in helping us via radio signals. Ground stations often have a very to watch television, navigate from place to place, large antenna, a transmitter and a receiver. Bigger forecast the weather, protect the environment, ground stations will have moveable antenna’s to make international phone calls and even access track a satellite’s movements. In the case of the Internet. communications satellites, data is transmitted from the ground and is received by the satellite which Satellites are placed into orbit around the Earth by retransmits the data to be received somewhere else. rockets that launch them into space. The first ever satellite was launched by the USSR in 1957 and there This section looks at some common uses of satellites, are now around 3000 in operation. Technology exploring the impact they have on our daily lives and moves quickly and satellites have a limited operating how they further our understanding of the Earth and space. Pictured is NASA’s Wide-field Infrared Survey Explorer (WISE) space telescope. It is an example of an astronomy satellite. WISE spots comets and asteroids that have been nudged by the gravitational attraction of the planets in our solar system into orbits that allow them to pass near Earth. Some of these have been identified as potentially hazardous asteroids. 15 APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE

SECTION 3 HOW DO WE LOOK FROM SPACE? ENVIRONMENTAL MONITORING Pictured is a European Space Agency (ESA) Sentiel-2 environmental monitoring satellite. There are two Sentiel-2 satellites in orbit which are placed 180° apart from each other. Sentinel-2A was launched in 2015 and Sentinel-2B was launched in 2017. These satellites are providing global coverage of the Earth’s land surface every 5 days. Photo: ESA Environmental monitoring satellites are typically Uses of Environmental Satellites: used for weather forecasting, disaster monitoring and continuous observation of the WEATHER FORECASTING global environment. The USA launched the first Temperature, wind speed and direction, water weather satellite, TIROS-1, in 1960. It was a vapour, cloud cover, precipitation (snow & rain), simple satellite with two cameras and only spent storms, and hurricanes/cyclones. 78 days in orbit. Since then there have been continuous improvements in the instruments MONITORING OF THE SEA and technology found in this type of satellite. Sea surface temperature, sea level height, ocean currents, and ocean winds. It is also possible to Satellites are able to view environmental features monitor accidents, such as large oil spills and such as clouds and mountains from above, making phenomenon that affect global weather patterns, them perfect for observing the global environment. If like the jet stream in the Atlantic Ocean or the El they are fitted with the right equipment they can Niño in the Pacific. even visualise things the human eye can’t detect like changes in temperature, wind speed/direction, and MONITORING OF THE LAND ocean currents. New satellites with better sensors Land surface temperature, winds, vegetation and tracking capabilities are being released all the cover, bodies of water, human settlements, soil time and in the next ten years our capability to moisture, depth and extent of snow and ice. observe the global environment will improve dramatically. APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE 16

SECTION 3 HOW DO WE LOOK FROM SPACE? GLOBAL COMMUNICATIONS Most communication satellites essentially handheld devices. Most communication satellites are ‘bounce’ signals from one place on Earth to geostationary. This means they are placed in a special another. In 1960 a satellite called Echo 1A was orbit which follows the rotation of the Earth. You can launched by NASA and demonstrated that radio find out more about this in the Exploring Space waves could be relayed into space and back. In Subject Guide. 1962 Telstar 1, the first real communication satellite, was launched. Telstar 1 could relay telephone circuits and a single TV channel. Telstar 1 relayed the first television pictures between two The Astra 2G satellite was launched in 2014 and continents through space the day after it was launched. broadcasts TV channels for Sky and Freesat. It is part of It was only functional for around seven months, but is the Astra group of five satellites which broadcast over still orbiting the Earth. 2600 channels across Europe, Asia and Australia. Communication satellites launched today are much A disadvantage of putting communication satellites more sophisticated. They can transmit and receive in this special geostationary orbit is that it takes a much more data than the first satellites and play a long time for them to send and receive data as they vital role in the global telecommunications system. are so far away from Earth. This makes things like satellite internet slower and less useful. To combat this, companies are putting communication satellites in much lower orbits that are ten times closer to Earth like the Starlink satellite pictured below. Doing this presents its own problems; hundreds of satellites are needed like this to provide global coverage. A typical satellite link involves the transmission of a Startlink satellites are designed to provide worldwide signal from an Earth station to a satellite. The satellite internet access and are placed in a very low orbit. then receives and amplifies the signal before retransmitting it back to Earth, where it is received and reamplified by Earth stations and receivers. Satellite receivers on the ground can include direct- to-home (DTH) satellite equipment, mobile reception equipment in aircraft, satellite telephones, and 17 APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE

SECTION 3 HOW DO WE LOOK FROM SPACE? ASTRONOMY Astronomers have been looking at space through anything into space. Despite this, space telescopes telescopes for over 400 years. The first have helped scientists discover much more about observatory to use an optical telescope was the universe than they ever thought possible. constructed by Galileo Galilei in 1609. It was not until much more recently that we have had the One of the most famous astronomy satellites is the technology to put a telescope into space. There Hubble Space Telescope. It has helped scientists are numerous advantages of doing this and determine the age of the universe (around 13.8 many astronomy satellites are in orbit today. billion years) and helped establish the rate at which the universe is expanding, as well as discovering that Astronomy satellites are put into space to gather every major galaxy has a black hole at its centre. data and images that are not affected by the Earth’s atmosphere. This gives scientists a much clearer view When you look into space and see stars you are of planets, stars and far away galaxies. The looking at the stars as they were in the past, because atmosphere blocks certain kinds of light and their light takes time to reach Earth. Even the light radiation, some of which would be useful for from the sun takes eight minutes to travel to Earth. scientists to see and study. One of the ways to Space telescopes look at galaxies much further away overcome this is to launch a telescope into space. than this; the Hubble space telescope has photographed galaxies 100 million light years away. Putting a telescope in orbit has its limitations. As well as being very difficult to repair, telescopes can’t be  built too big or heavy as it is very expensive to launch NASA’s Four Great Observatories: HUBBLE SPACE TELESCOPE Launched in 1990, this telescope measures visible light and produces high resolution images of distant space objects. COMPTON GAMMA RAY OBSERVATORY Launched in 1991, it measures Gamma rays and other electromagnetic energy. It re-entered the Earth's atmosphere in the year 2000. The Hubble Space Telescope is one of the most well CHANDRA X-RAY OBSERVATORY known astronomy satellites and also one of the largest and most versatile. The telescope has studied more than Launched in 1999, this satellite measures x-rays 40 000 cosmic objects, providing views that astronomers and can spot black holes, quasars, and high- are unable to capture from the ground. It is one of temperature gases. NASA’s Four Great Observatories. SPITZER SPACE TELESCOPE Launched in 2003, it measures infrared light and has made a number of discoveries, including finding another ring around Saturn. APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE 18

SECTION 3 HOW DO WE LOOK FROM SPACE? SATELLITE NAVIGATION If you have ever used a smartphone it will have Different navigation constellations provide different probably communicated with a navigation levels of location accuracy. The GPS system from the satellite. Smartphones take advantage of a large USA was the first system that the public were able to network of navigation satellites to determine use and its location accuracy is between five and ten your location, even when you aren’t actively metres. other systems, like Galileo which can provide using it. A group of satellites is called a location accuracy of 1m, are much more accurate. constellation, and several different regions have Military and commercial users can access more launched their own navigation constellations accurate information from satellite constellations. including Europe, the USA, Russia and China. Galileo, for example, can have increased accuracy from 1m to 1cm. Satellite navigation signals are detected by a GPS receiver. These are found in things like car navigation Navigation Satellite Constellations: systems and smartphones. For it to work the receiver must detect the signal from at least four or five GPS 32 satellites. Full coverage was satellites in the same constellation. The receiver (USA) achieved in 1994. Accuracy 3 to 4 m. works out the distance from each of these satellites to deduce its own location. Modern receivers will GLONASS 24 satellites. Introduced in 1982 look to more than one satellite constellation to get (Russia) and upgraded 2011. Accuracy 3 m. the most accurate location information and will often connect to all four main satellite navigation GALILEO 30 satellites. Full coverage was constellations. (Europe) achieved in 2019. Accuracy 1m. BEIDOU 35 satellites. Full coverage was (China) achieved in 2020. Accuracy 5 m. Pictured is an artist’s impression of Galileo Satellite navigation satellites in orbit. Galileo is the name for Europe’s satellite navigation system which has 30 satellites in orbit and is available for anyone to access. 19 APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE

SECTION 3 HOW DO WE LOOK FROM SPACE? RECONNAISSANCE A reconnaissance satellite or ‘spy satellite’ is a With the advent of digital imaging, it is much easier low-orbiting satellite that collects information to obtain data from reconnaissance satellites. Military about things on the ground. It might do this forces around the world still routinely use optically (by taking photos or videos) or via reconnaissance satellites for tactical information that radar. If you have visited Google Maps almost all they cannot acquire easily from the ground. Because the aerial photos you viewed on the site would of their versatility they are now also used in other have been taken with a reconnaissance satellite. projects such as missile early warning detection, nuclear explosion detection, electronic The first reconnaissance satellites were produced for reconnaissance (signals intelligence which intercepts military applications but were limited in their use stray radio waves) and radar imaging. However, because images had to be stored on film. In the USA many military uses are classified. 140 Corona ‘spy’ satellites were launched between 1960 and 1972. They had large banks of film and More modern satellites have the capability to would pass over enemy territory like the USSR and capture detailed images which have an image take photos. When the film was used up it would be resolution of less than 30 cm. This means that each dropped in a controlled fall using parachutes. An pixel in a 30 cm image captures an area on the aircraft would then try to catch the film using a sling! ground of 30 x 30 cm, which makes smaller objects visible. The Landsat 8 reconnaissance satellite was launched by This photograph was created by using high resolution NASA in February 2013. It has an image resolution of 30 satellite imagery and combining it with terrain (height) metres and routinely photographs all areas of the Earth. data to create a 3D image. Image: Maptiler Some map providers like Google Maps, Apple Maps and Microsoft Bing Maps use data from reconnaissance satellites to provide free-to-view 2D imagery of the Earth, at varying resolutions depending on the location. More popular areas will often have better resolution imagery than remote locations. These map providers will also use another type of satellite to know your location. See Satellite Navigation to find out more about this. APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE 20

SECTION 3 HOW DO WE LOOK FROM SPACE? FIND OUT MORE If you’re interested in any of topics that have been covered in this section then you can use the links below to conduct your own research. You can click on the links if you are viewing this document electronically. ENVIRONMENTAL MONITORING SATELLITES 1 Information about the EU’s Copernicus Monitoring Programme rb.gy/3oqlml 2 How Things Work: Environmental Satellites bit.ly/2Ug0q8e 3 Information about NASA’s GEOS satellite network. rb.gy/eueoiw GLOBAL COMMUNICATION SATELLITES 1 Information about how communication satellites work bit.ly/2XD39en 2 Facts about Sputnik 1, the first communications satellite bit.ly/2A7oMKK 3 Facts about the SpaceX satellite internet project bit.ly/3cHSdjz ASTRONOMY SATELLITES 1 NASA article about the Great Observatories rb.gy/8gltzh 2 Website from the ESA all about the Hubble Space Telescope bit.ly/2z7EkgX 3 Why do we put telescopes in space? bit.ly/3eQLLs0 SATELLITE NAVIGATION 1 ESA article about how satellite navigation works bit.ly/3f8b0Xh 2 About the different types of satellite navigation systems bit.ly/2z9APXx 3 Article about the Galileo satellite navigation constellation bit.ly/3gX1acd RECONNAISSANCE SATELLITES 1 The history of spy satellites bit.ly/2XDFgTW 2 How does Google Maps work? bit.ly/2ANiJLu 3 Article about satellite imagery bit.ly/2XAXXri 21 APPLICATIONS OF SPACE TECHNOLOGY SUBJECT GUIDE

SPACE: THE BRONZE SPACE HOW TO GUIDE #31 SYLLABUS ABOUT THE BRONZE SPACE SYLLABUS If you have completed the Blue Space: Applications of MODULE 2: THE MOON Space Technology course and are looking for a new challenge, then The Open University OpenLearn This module is all about the moon. You will learn Launch Pad Space Award for the Air Cadets now has a about: new bronze level.  The influence the moon has on tides and gravity. This course has been developed for cadets to complete  Things we have brought down from the moon. in small groups, however it can also be completed at  How to use moon craters to determine the age of a home. The bronze syllabus is split into two modules, both of which can be found on Ultilearn. You must surface. complete both modules.  If the moon ever had water on it. .Ask your staff members for your Ultilearn logon  How we could live on the moon. information if you have forgotten your password. See How To Guide #1-Classification Training and How To COMPLETING THE COURSE Guide #11-Blue Space to find out how to access Ultilearn. Both modules are interactive and based online with videos, activities and tutorials helping you to enhance MODULE 1: EXPLORING SPACE your understanding of the topic. You will be assessed on this topic by answering some This module is all about exploring space and the questions and completing some activities online. You challenges it brings. You will learn about: can do this in a small group or on your own.  The history of rockets and how they work. All activities are marked automatically so you don’t  What’s in the space around the earth. need to wait for your results.  Space Debris and the plans to clean it up. After completing this course you will receive an Open  Some Space ‘firsts’, like the first animal in space, the University branded certificate. first women in space, the first Briton in space and the first space tourist. HQ RAFAC Training Team Version 1

THE OPEN UNIVERSITY OPENLEARN LAUNCH PAD SPACE AWARD FOR AIR CADETS BRONZE LEVEL EXPLORING SPACE SUBJECT GUIDE EXPLORING SPACE SUBJECT GUIDE 1

CONTENTS 4 5 SECTION 1 THE DEVELOPMENT OF ROCKETS 7 9 Introduction 10 The First Rockets 11 Early Rocket Development Rockets and the War Years 13 Launching Into Space 14 Find Out More 15 16 SECTION 2 HOW DO ROCKET ENGINES WORK? 17 Introduction 19 Solid Fuel Rockets 20 Liquid Fuel Rockets 21 Ion Propulsion 22 Find Out More 23 24 SECTION 3 WHAT’S IN THE SPACE AROUND THE EARTH? 26 Introduction 27 Why is Space Debris a Problem? 28 Damage from Space Debris 29 Cleaning up Space 30 Satellites in Orbit 31 Find Out More SECTION 4 PIONEERS OF SPACE EXPLORATION Introduction Laika the Space Dog Valentina Tereshkova Helen Sharman Dennis Tito Find Out More 2 EXPLORING SPACE SUBJECT GUIDE

EXPLORING SPACE SUBJECT GUIDE SECTION 1 THE DEVELOPMENT OF ROCKETS EXPLORING SPACE SUBJECT GUIDE 3

SECTION 1 THE DEVELOPMENT OF ROCKETS INTRODUCTION In their simplest form, rockets are just chambers pressure inside the bird grew until eventually the of gas under pressure. An opening in the steam escaped, propelling the bird forwards. The chamber allows this gas to escape, providing bird travelled along a suspended wire and could thrust which propels the rocket in the opposite travel hundreds of meters. This pigeon is sometimes direction. In rockets that are used in space, this referred to as the first robot. gas is created by burning solid or liquid propellants. This is in contrast to both internal The Aeolipile combustion engines and jet engines which need the oxygen in the air for propulsion. About two hundred years after the Flying Pigeon Greek engineer Hero of Alexandria created another The Development of Rockets section begins by steam powered device called the Aeolipile. His looking at some of the earliest stages of rocket device was essentially a metal sphere mounted on development. It then goes on to explore rocket top of a bowl of water. When the water was heated, designs through time before describing rockets the steam produced travelled up two pipes into the that have been used in recent history and those sphere. Two more pipes on the outside of the sphere in use today. allowed this steam to escape when the pressure inside was high enough. This created thrust which As with many technical developments the early uses caused the sphere to rotate. of rockets were linked to warfare and battle. The following pages in this section give a brief history of the development of rocket technology. The Flying Pigeon One of the first devices to successfully employ the principles of rocketry was a steam powered pigeon! It was designed by Greek philosopher Archytas, sometime around 400 B.C. Archytas created a lightweight wooden pigeon with large wings. The hollow inside of the bird was connected to a heated, airtight boiler. As the boiler created steam the Archytas’s flying pigeon. Photo: ancient-origins.net A replica of Hero’s Aeolipile. 4 EXPLORING SPACE SUBJECT GUIDE

SECTION 1 THE DEVELOPMENT OF ROCKETS THE FIRST ROCKETS It is believed that the Chinese were the first to being used to propel these new rockets. develop the kind of rocket that we are familiar with today. They produced an early form of The 14th & 15th Centuries gunpowder using saltpetre, sulphur and charcoal dust around the 1st Century and used this to The Mongols, after having rockets used against them produce explosions during religious ceremonies in multiple battles, worked out how to create them and celebrations. They later used this gunpowder themselves. They were probably responsible for the mixture in rockets. spread of rockets throughout Europe during this time. There were reports of many experiments with The 11th to 14th Centuries rockets during the 13th-15th centuries. The first rockets developed by the Chinese were An English Monk called Roger Bacon improved the bamboo tubes filled with gunpowder. They were lit formulation of gunpowder which helped to and then launched with bows. They were called considerably increase the range of rockets. In France, Chinese Fire Arrows. Evolutions of this design rockets were used extensively during this time. In included sharp points at the end of the rocket like an 1410, author Jean Froissart outlined designs for arrow, sometimes with poisoned tips. They later rockets launched in tubes. This design is seen as the discovered that the rockets didn’t need to be forerunner of the modern bazooka. Joanes de propelled by a bow and could be launched by Fontana of Italy designed a surface-running rocket- themselves. By the 14th Century gunpowder was powered torpedo for setting enemy ships on fire. The Chinese using rockets to deter invading Mongols in 1232. This is one of the first recorded uses of rockets in warfare. EXPLORING SPACE SUBJECT GUIDE 5

SECTION 1 THE DEVELOPMENT OF ROCKETS The 16th Century Rockets began to fall out of favour as instruments of war but were used more and more in firework displays. The desire for fireworks to become bigger and reach higher altitudes encouraged innovation in the field and German fireworks maker Johann Schmidlap developed the first multi-stage rocket, known as the step rocket. A large initial rocket carried the firework and a smaller, secondary rocket. When the large rocket burned out, the smaller one ignited to take the firework to a higher altitude. This principle of multi-stage rocketry is still used to propel spacecraft into space today. Wan-Hu and his flying rocket chair. Johann Schmidlap’s “step rocket”. Photo: ESA Wan-Hu sat on the chair on the day of the flight and gave the command to light the rockets. Forty-seven The First Transportation Rocket rocket assistants, each armed with his own torch, lit the fuses. There was a tremendous roar A Chinese official named Wan-Hu introduced rockets accompanied by billowing clouds of smoke. When as a means of transportation. He assembled a rocket- the smoke cleared, Wan-Hu and his flying chair were powered flying chair , attaching two large kites to gone. No one knows for sure what happened to the chair and 47 fire-arrow rockets to the kites. Wan-Hu. Legend has it that Wan-Hu was propelled into Space but this is unlikely. He and his chair were blown to pieces as the rockets used were as likely to explode as to propel him upwards without incident. Fireworks became popular in the 16th Century as the use of rockets in war declined. 6 EXPLORING SPACE SUBJECT GUIDE

SECTION 1 THE DEVELOPMENT OF ROCKETS EARLY ROCKET DEVELOPMENT Scientist Isaac Newton’s understanding of Isaac Newton is said to have been sitting under an apple physical motion at the end of the 1600’s helped tree, when he saw an apple fall beside him. This inspired develop the foundations for modern space travel him to think about gravity and helped him to create his using rockets. However, it wasn’t until the three laws of motion. mid-1700’s rocket technology advanced from the basic Chinese designs. More durable materials These laws could be applied and used to explain began to be used, enabling them to become how rockets could be used in the vacuum of outer more effective when used in battle. space and have since been used to influence and improve rocket designs. Sir Isaac Newton Isaac Newton organized his understanding of physical motion into three scientific laws. These are:  Every object in a state of uniform motion will remain in that state of motion unless an external force acts on it.  Force equals mass times acceleration.  For every action there is an equal and opposite reaction. Sword rockets being used against the British in India in 1780. EXPLORING SPACE SUBJECT GUIDE 7

SECTION 1 THE DEVELOPMENT OF ROCKETS One of Congreve’s rockets being launched during the Napoleonic War Improved Rocket Designs Rockets of this type were used in the 1802-1815 Napoleonic wars and the 1812 war against the In the early 1700’s scientists in Russia and Germany United States. These rockets were still not particularly began experimenting with larger and more powerful accurate or powerful but were effective because of rocket designs, including making heavier rockets the sheer number used against the enemy. with masses of over 45kg. Some of these rockets were so powerful that they scoured deep holes in At the beginning of the 19th Century these rockets the ground before take-off. were subsequently altered to improve their accuracy. Studies showed that a rocket could be more India began making their rockets from iron in the accurate if it was spun, so small fins were attached second half of the 18th century. They discovered that on the bottom. Exhaust gases then hit these fins and doing this improved the stability and range of the cause the rocket to spin, like a bullet in flight. This rocket. These rockets had sharp blades attached to basic principle is still used today to improve a rockets the end of them, like the arrow heads of the earlier accuracy and stability. Chinese fire arrows. These were successfully used by Hyder Ali, Sultan of Mysore, against the British East The use of rockets for war waned after the middle of India Company during the 1780’s and 1790’s. the 19th Century as conventional artillery became better and more accurate. Breech loaded canons and The success of these barrages inspired the British to exploding warheads were found to be much more create rockets of their own and Colonel William effective and eventually the use of rockets as an Congreve drafted rocket designs for the British Army. instrument of war stopped. 8 EXPLORING SPACE SUBJECT GUIDE

SECTION 1 THE DEVELOPMENT OF ROCKETS ROCKETS AND THE WAR YEARS At the beginning of the 20th Century there was a of the V-2 rocket used against London in WWII. In the great interest in the prospect of interplanetary 1930’s and 1940s the Nazis were interested in using travel, driven in part by the popularity of science rockets as long-range weapons. Their V-2 had a range fiction writers such as Jules Verne and H.G. Wells. of 200 miles, with a top speed of 3500 miles per hour. Rocket development continued after World War 1 Over 3000 V-2s were launched against targets in and accelerated in the lead up to World War 2. London, Antwerp and Liege with an estimated 9,000 deaths. In the 1920s three key engineers were working on rockets. An early pioneer of space travel was a Russian, Konstantin Tsiolkovsky, who realised that propulsion in the near-vacuum of space would need an engine based on the rocket principle. He also proposed that a rocket might be built in stages, dropping each stage when its fuel was used so as not to carry unnecessary mass. In March 1926 , American A German V-2 Rocket, used against the British in WWII Dr Robert H Goddard with his liquid-fuelled rocket. As the war ended teams from the USA, UK and Soviet Photo: NASA Union rushed to capture key personnel and technology. The majority of the V-2 teams ended up Dr. Robert Goddard launched the world’s first liquid- working for the USA, while others went to the Soviet fuelled rocket on which modern rocket technology is Union. Both the USA and Soviet Union realized the based. A third great space pioneer, Hermann potential of rocketry as a military weapon and began Oberth of Germany, published a book in 1923 about a variety of experimental programs. The USA began a travel into outer space. This led to the development program with high-altitude rockets, one of Goddard's early ideas. A variety of medium and long-range ballistic missiles were developed later. These became the starting point of the USA space program. The technology behind Redstone, Atlas and Titan missiles helped launch astronauts into space. EXPLORING SPACE SUBJECT GUIDE 9

SECTION 1 THE DEVELOPMENT OF ROCKETS LAUNCHING INTO SPACE The first rocket capable of flying high enough to The USSR also sent the first animal into space a few travel to space was the German V-2 missile. After months later. A dog called Laika was launched into World War 2 and the acquisition of V-2 rocket space on the 3rd November 1957 inside the technology from the Germans, scientists from Sputnik-2 satellite. More information about Laika and both the USA and USSR (Russia) raced to be the the Sputnik-2 mission can be found in Section 4 of first nation that could successfully develop a this guide. rocket that could launch something into space. Both countries have many space ‘firsts’ but initial The USA milestones were achieved by the USSR. Despite being beaten by the USSR, the USA launched The USSR their first satellite on the 31st January 1958. Their Explorer 1 satellite was launched by a Jupiter-C In 1955 the USA announced that it would launch the rocket, a more powerful version of the German V-2. first artificial satellite into space to commemorate the International Geophysical Year in 1957. The USSR An Illustration of the Sputnik-1 satellite in orbit. wanted to launch their own satellite before the USA and began developing a rocket that could launch a satellite into space at the beginning of 1956. This satellite was designed to take measurements of the upper atmosphere and the edge of space. However, it was too complicated to develop in time and too heavy for the rocket designed to carry it. A smaller, simpler satellite was developed instead Explorer 1 was technically more advanced than called Sputnik-1. On the 4th October 1957 Sputnik-1 Sputnik-1 as it had equipment on-board to measure was launched into space, surprising the USA and the cosmic rays. Explorer 1, and sister satellites Explorer 3 rest of the world. It transmitted radio signals to Earth and Explorer 4, discovered the Van Allen Radiation and was in orbit for around three months. The Belts. These belts are two large areas of magnetically satellite was launched by a newly developed R-7 trapped, highly energetic, charged particles around rocket. Earth. An Illustration of the Sputnik-1 satellite in orbit. Rocket Development Since these two initial launches many more rockets have been launched into space. Astronauts have orbited the earth and landed on the moon and robot spacecraft have travelled to distant planets in our solar system. A wide array of powerful and versatile rockets have been built as the boundaries of space travel have been pushed. Rockets have evolved from simple weapons of war containing gunpowder to giant vehicles capable of travelling into outer space. 10 EXPLORING SPACE SUBJECT GUIDE

SECTION 1 THE DEVELOPMENT OF ROCKETS FIND OUT MORE If you’re interested in any of the topics that have been covered in this section then you can use the links below to conduct your own research. You can click on the links if you are viewing this document electronically. THE FIRST ROCKETS 1 The history of Chinese rockets. bit.ly/35tDfOp 2 Website about Chinese Fire Arrows. bit.ly/2GY2mib 3 A history of rocketry from their Chinese origins to today. bit.ly/3miOy1S 4 Another general history of rockets from their origins to today. bit.ly/33kqpPM EARLY ROCKET DEVELOPMENT 1 A comprehensive history about the history of early rockets. bit.ly/3mhcZN9 2 A history of rocketry from their Chinese Origins to today. bit.ly/3miOy1S 3 All about about Tipi Sultan and his Mysorean war rockets. bit.ly/2GN1hcL 4 Info about the Congreve War rockets. bit.ly/35Klmv1 ROCKETS AND THE WAR YEARS 1 All about Dr Robert H Goddard with his liquid-fuelled rocket. s.si.edu/2Ft4wWD 2 All About Konstantin Tsiolkovsky & Russian rocket development. bit.ly/33ommCb 3 Info about Germany and Rocket Development, bit.ly/35EfwLg 4 Article about the German V-2 Rocket. bbc.in/3metxW2 LAUNCHING INTO SPACE 1 Article about Sputnik-1 and the R-7 rocket that launched it. bit.ly/3mjGpKn 2 Information about the Explorer 1 Satellite and Jupiter C Rocket. rb.gy/wgbkle 3 Article about the ‘Space Race’. bit.ly/2FyHc9o 4 Info about NASA’s newest rocket, the Space Launch System. rb.gy/kukbpa EXPLORING SPACE SUBJECT GUIDE 11

EXPLORING SPACE SUBJECT GUIDE SECTION 2 HOW DO ROCKET ENGINES WORK? 12 EXPLORING SPACE SUBJECT GUIDE

SECTION 2 HOW DO ROCKET ENGINES WORK? INTRODUCTION A rocket engine uses stored rocket propellants as A rocket engine pushes on its exhaust and the the reaction mass for forming a high-speed exhaust pushes back on the rocket. The force of the propulsive jet of fluid, usually high-temperature particles being ejected from the back of the engine gas. Rocket engines are reaction engines, equals the same amount of force on the rocket producing thrust by ejecting mass rearward. Most making it move forward. As long as its rocket engine rocket engines use the combustion of reactive fires, a spacecraft will gain speed. In space, if the chemicals to supply the necessary energy. rocket stops ejecting material then the craft will continue at whatever speed it had reached In the emptiness of space there is insufficient air indefinitely, unless it encounters some object or an either for conventional flight or for engines that use engine fires again. oxygen taken from the air. Therefore, you can't actually fly through empty space, you get pushed There are three main types of rocket engines through it. On Earth, flight involves: currently used in space:  Aerodynamic lift acting against gravity.  Solid-fuel + chemical energy  Thrust opposing aerodynamic drag.  Liquid-fuel + chemical energy Forward thrust and orientation is therefore provided  Pressurised gas + electrical energy by the rocket engines instead in space. Only solid-fuel and liquid-fuel rocket engines A rocket engine uses the propellant which is inside currently have a high enough power output to be of it to eject material out of the back of the engine at used for launching objects into orbit. Gas-powered significant speed. The energy source and propellant rockets are useful once out in space and away from type define the type of rocket engine. Isaac Newton the pull of gravity. developed three laws of motion which describe how objects move in response to forces. His third law states that for every force that acts, there is an equal and opposite reaction. Rockets use this principle to propel themselves through both the air and space. A SpaceX Falcon Heavy rocket launching the Arabsat-6A satellite EXPLORING SPACE SUBJECT GUIDE 13

SECTION 2 HOW DO ROCKET ENGINES WORK? SOLID FUEL ROCKETS Virgin Galactic SpaceShipTwo (SS2). The spacecraft is carried underneath another aircraft until it reaches the upper atmosphere. It then uses it’s solid fuel engine to propel it upwards and forwards into space. Solid fuel is the oldest and simplest type of rocket boosters. The fuel was initially ignited by heat. propellant. It has been used in rockets for Exhaust gases and fine particles then formed in the thousands of years since the Chinese discovered exothermic (heat producing) chemical reactions that gunpowder. followed, propelling the rocket upward. A modern form of solid propellant uses a mixture of fuel, like powdered aluminium, and a solid chemical oxidiser like ammonium perchlorate. This mixture is loaded in the combustion chamber awaiting ignition. The centre of the engine is normally hollow to increase the burning surface area and the rate at which gases are ejected through the exit nozzle. A diagram detailing the parts of a solid fuel rocket. The Space Shuttle was launched with solid fuel rockets. The two tall external rocket engines on the side of One of the disadvantages of this kind of the NASA Space Shuttle were solid fuel rocket monopropellant rocket (the fuel and oxidiser are both in the same state) is that once it starts to burn there is no way to stop it until the fuel supply runs out, just like a firework. To combat this problem, hybrid engines have been developed. These can be closed down when needed by stopping the flow of the oxidiser. A hybrid rocket engine like this is used on the Virgin Galactic SpaceShip Two (SS2). 14 EXPLORING SPACE SUBJECT GUIDE

SECTION 2 HOW DO ROCKET ENGINES WORK? LIQUID FUEL ROCKETS In liquid fuelled rocket engines, the fuel and the easier for the rocket to be fuelled-up and on standby. oxidizer are liquids. These liquids need to be stored separately. They are stored in separate In the engines of liquid rockets the fuel and oxidizer tanks and are pumped into a combustion are thoroughly mixed so that the fuel burns properly. chamber. As the fuel is burned in the combustion chamber the engine produces gases at a high temperature and pressure. These gases expand out of a narrow nozzle which generates the thrust necessary to lift the rocket. The Ariane 5 Rocket at lift-off. Photo: ESA The Proton Rocket at lift-off. Photo: Spaceflight Insider The European Space Agency (ESA) Ariane 5 rocket A liquid-fuel rocket engine is a sophisticated uses liquid fuel during launch. Liquid Hydrogen fuel machine comprising storage tanks, pumps, valves, is stored in the rocket at –253°C and in another tank injectors and piping making these types of rockets liquid oxygen is stored at –183°C and is used as an more complicated than a solid fuel rocket. However, oxidiser. The storage tanks need to be very well the advantages of liquid fuel rockets is that they are insulated to maintain the temperature of the liquids very easy to control. The thrust, and therefore the inside, adding weight to the rocket. speed, of the rocket is controlled by controlling the amount of fuel and oxygen that is pumped into the The Russian Proton rocket uses liquids that can be combustion chamber. stored at ambient temperature. Which makes it EXPLORING SPACE SUBJECT GUIDE 15

SECTION 2 HOW DO ROCKET ENGINES WORK? ION PROPULSION Compressed gas can be used as the basis for rocket engines without the need for the on-board combustion of fuel and oxidiser. Gas-powered rockets are not powerful enough to be used effectively on Earth, but are useful when a spacecraft is in space. This system is known as Ion Propulsion. For a jet of gas to thrust a rocket forward a high flow Ion propulsion in use on a small satellite. Photo: Safran rate is needed. In solid and liquid fuel rockets a rapid chemical combustion reaction creates this gas at a efficient, unlike traditional chemical propulsion powerful enough rate to give the rocket the thrust it systems which are only around 35% efficient. The needs. most common propellant used in ion propelled rockets is Xenon. This gas is relatively easy to ionize Another way to increase the flow rate of gas is and has a high atomic mass helping to achieve a through electrical acceleration. Gas molecules are relatively high flow which is used to provide the first given a positive electrical charge. This is called thrust. This flow rate is still much lower than a ionisation. When this has been applied the molecules chemically propelled rocket which means that this can then be accelerated by a high voltage being system is best suited to spacecraft that are already in passed through them. space. This high voltage is applied across a short section of A common application of electrical thrusters is for the the gas to turn some of the gas molecules into ions repositioning of satellites. There is a slow but (charged molecules) converting the gas into an relentless friction on satellites caused by the residual electrically conducting plasma. For this to work in gas in the upper thermosphere and exosphere space a supply of electricity is needed. Ion engines Correcting for that friction or adjusting the and plasma thrusters use electrical energy to create orientation of a satellite are tasks that are well suited thrust from propellant. to the low thrust, zero combustion characteristics of an electrical propulsion system. Ion propulsion is attractive as it provides a very high ratio of thrust to rate of fuel use. It is over 90% Ion propulsion in action on NASA’s Dawn probe. 16 EXPLORING SPACE SUBJECT GUIDE

SECTION 2 HOW DO ROCKET ENGINES WORK? FIND OUT MORE If you’re interested in any of the topics that have been covered in this section then you can use the links below to conduct your own research. You can click on the links if you are viewing this document electronically. SOLID FUEL ROCKETS 1 A video about how solid fuel rockets work. bit.ly/33pGYdg 2 Information on how solid fuel rockets work. bit.ly/3bZQtno 3 Info about the advantages and disadvantages of different fuels. bit.ly/2Rn56ay LIQUID FUEL ROCKETS 1 A video about how liquid fuel rockets work. bit.ly/3kfcnFT 2 Information on how liquid fuel rockets work. bit.ly/32tpE7H 3 A comprehensive article about how rockets work. rb.gy/nzt6t5 ION PROPULSION 1 A video about how ion propulsion works. bit.ly/3mluawY 2 A NASA article about ion propulsion. rb.gy/a2vnhq 3 Can ion propulsion work on Earth? bit.ly/3bT88wU EXPLORING SPACE SUBJECT GUIDE 17

EXPLORING SPACE SUBJECT GUIDE SECTION 3 WHAT’S IN THE SPACE AROUND THE EARTH? 18 EXPLORING SPACE SUBJECT GUIDE

SECTION 3 WHAT’S IN THE SPACE AROUND THE EARTH? INTRODUCTION Over recent decades we have been populating In October 1957 the Soviet Union launched the very the space around the Earth with satellites. The first artificial communications satellite, Sputnik 1. What’s in the Space Around the Earth section Since then around 10 000 satellites have been looks at the rise of satellite technology, the launched into space. When a satellite has finished problem of unwanted space debris and how becoming useful it either burns up in the Earth’s countries can develop ways to reduce the atmosphere or becomes a piece of space debris number of objects orbiting the Earth. (space junk). Out of those 10 000 satellite launches only around 2700 are operational today. A heavenly or artificial body which orbits a planet is a satellite of that planet. The Moon (a heavenly body) Space debris is any unwanted object left by humans is the Earth’s only natural satellite, but we now have in space. It may be a large object like a dead satellite thousands of artificial satellites in orbit. Their many that has failed or been left in orbit at the end of it’s roles include communications, military intelligence, mission. Many more smaller pieces of debris, like weather information and navigation aids. broken up satellites or paint flecks that have fallen off a rocket also exist.  This photograph was taken from the International Space Station (ISS) and shows a view of the aurora borealis (northern lights). The auroras are normally only seen from earth in the areas close to the northern and southern poles. The ISS is an artificial satellite and has been occupied by astronauts continuously since October 2000. This sets a record for the longest continuous human presence in space. EXPLORING SPACE SUBJECT GUIDE 19

SECTION 3 WHAT’S IN THE SPACE AROUND THE EARTH? WHY IS SPACE DEBRIS A PROBLEM? Space debris or 'space junk' describes objects in with other objects producing even more smaller Earth orbit from defunct satellites, used rocket pieces of debris. If this continued it may start to engines and fragments from explosions or become unviable to launch anything new into space collisions. The United States Strategic Command because of the likelihood of damage. are tracking over 26 000 larger items of junk, including around 2700 operational satellites. The number of pieces of space debris orbiting earth of increased by over 50% in the last 5 years and even Apart from the Moon, anything orbiting the Earth is the smallest of objects can create significant there because it has been launched into space. damage. The Damage From Space Debris page Debris remains in orbit until it eventually re-enters within this section goes into this in further detail. the atmosphere. When this happens the object often burns up before it reaches the ground. This doesn’t always happen quickly for some objects, especially if they have been placed at a high altitude. For something at a lower altitude this often happens after a few years. Some items in geostationary (high) orbit will circle the Earth for thousands of years. It is estimated that there are around 130 million fragments of debris between 1 mm and 1 cm in size and almost one million pieces in the size range of 1 to 10 cm in orbit. There are also around 34 000 objects more than 10 cm in size. Larger objects cause more damage than smaller pieces but all pose a threat to active satellites in orbit. The Kessler Effect Statistics correct as of May 2020. For the most up to date values visit bit.ly/3bFgUgl In 1978, a NASA space debris expert called Don Kessler noticed the growing problem of space debris and predicted that, once past a critical mass, the total amount of space debris will keep on increasing. This is because when objects collide, they produce lots of smaller pieces of debris, which in turn collide Some events have led to a significant increase in the amount of debris in Space:  In 2009 two satellites collided, the then active Iridium 33 satellite and defunct Russian Kosmos-2251. They collided at 26 000 mph, producing over 2000 large pieces of debris.  Several countries have deployed missiles to destroy their own satellites. In 2007 China destroyed their Fengyun 1C weather satellite, creating around 5500 large pieces of debris. The USA destroyed their USA-193 satellite in 2008 and India destroyed their Microsat-R satellite in 2019. 20 EXPLORING SPACE SUBJECT GUIDE

SECTION 3 WHAT’S IN THE SPACE AROUND THE EARTH? DAMAGE FROM SPACE DEBRIS An artists impression of a small piece of space debris hitting an active satellite. Items in orbit travel very quickly. An item in low Larger pieces of space debris hitting the ISS could Earth orbit has an average impact velocity of have catastrophic consequences, tearing right 21 600 mph. That’s around 12 times faster than through its shielding. The ISS and some other the fastest bullet. This means that even the satellites are able to dodge these larger pieces by smallest piece of space debris can cause changing their position whilst in orbit. Ground based significant damage to active satellites and even facilities, like the Haystack observatory in the USA, astronauts and cosmonauts on the International use radar to monitor the position of larger pieces of Space Station (ISS). space junk. This information is shared throughout the world and is used to help predict where possible High speed collisions with smaller pieces of debris collisions might occur. can cause damage akin to sandblasting, especially to solar panels and optical components of telescopes To avoid space debris active satellites must move out that cannot be covered with a shielding. These small of the way. To do this they must use their limited fuel collisions happen fairly regularly on the ISS, but it is reserves. The risk is assessed carefully before such shielded to protect it from the smallest pieces by manoeuvres are performed. For the ISS, if there is a Whipple shielding which breaks up and disperses more than 1 in 10 000 chance of a collision then it is debris, spreading energy over a larger area. moved using control gyros and thrusters. The ISS has been damaged several times by smaller pieces of space debris. In 2007, a rotary joint in a solar panel was damaged by metal shavings and other space debris. A radiator cooling panel was damaged in 2009 which resulted in a leakage of coolant. In 2016, British Astronaut Tim Peake found a 7mm chip on the ISS’s Cupola window. The size of the object that hit the window is estimated to be only a few thousandths of a millimetre in diameter. EXPLORING SPACE SUBJECT GUIDE 21

SECTION 3 WHAT’S IN THE SPACE AROUND THE EARTH? CLEANING UP SPACE The European Space Agency (ESA) has described Earths atmosphere with solar sails tethers. There are the clean up of space as an urgent priority; debris plans to zap smaller pieces with lasers. levels have increased by over 50% in Low Earth Orbit (LEO) over the last 5 years with the trend set RemoveDEBRIS to continue if nothing is done. In June 2018, the UK’s RemoveDEBRIS satellite was To achieve this new guidelines have been deployed from the International Space Station. It was introduced to limit the production of new space equipped with separate harpoon and net systems to debris, but not all countries follow the same rules. In demonstrate two capture techniques. For target the LEO region the ESA recommends that satellites practice, the satellite takes aim at two CubeSats and other large pieces of space junk should re-enter playing the part of rouge space junk. The net and the Earth’s atmosphere within 25 years of the end of harpoon experiments were successful in retrieving their operational life by becoming de-orbited. the CubeSats, but the mission to release a drag sail Satellites often need to use their own fuel reserves to could not go ahead because of a problem with change course to be able to do this. another component within the satellite. Startlink satellites are placed in a very low orbit, meaning E.Deorbit they burn up in the atmosphere passively within around a year of the end of their life. Satellites like these form An ESA concept for a future mission is called ‘constellations’ and provide internet connectivity. e.Deorbit, which was initially designed to target an Some satellites in very low orbits can do this ESA-owned derelict satellite in low orbit, capture it, passively. Atmospheric drag means that these then safely burn it up in a controlled atmospheric satellites re-enter the atmosphere around a year after re-entry. Since then the project has been expanded the end of their operational life. Other satellites and now the plan includes the development of a should be expected to move to a ’graveyard orbit’ space servicing vehicle that can refuel, refurbish or where they will not interfere with operational reboost satellites already in orbit, extending their satellites. operational life. The e.Deorbit satellite is scheduled for launch in 2025. Recovering Existing Satellites The e.Deorbit satellite will have a robotic arm to drag debris out of orbit. It will also have a harpoon and net to Some organisations, including ESA, are focussing catch and drag larger objects. Photo: ESA their efforts on targeting dead satellites with the aim of catching them with robotic arms, spearing them with harpoons or dragging them down into the 22 EXPLORING SPACE SUBJECT GUIDE

SECTION 3 WHAT’S IN THE SPACE AROUND THE EARTH? SATELLITES IN ORBIT An orbit is the path that an object takes in space satellite television and weather monitoring satellites when it goes around a star, a planet or a moon are usually found in this orbit. due to its gravitational pull. The gravitational force of the Earth causes objects like satellites, Because of the distance these satellites are above the spacecraft and space debris to orbit around it. Earth compared to other orbits described later there is a noticeable delay when transmitting or receiving There are lots of things to consider when information, making them less suitable for time deciding what orbit would be the most suitable critical communications. for a satellite. This page looks at some of the most common orbits in use and the typical satellites Medium Earth Orbit (MEO) found within them. The term medium Earth orbit describes the range of Geostationary Orbit (GEO) orbits between low Earth orbit and geostationary orbit. Generally this is anything in orbit between Satellites in a geostationary orbit circle the Earth at 1000 and 35 000 km. The most common height for 35 786 km above the equator, keeping pace with the satellites in MEO is around 20 000 km. rotation of the Earth. They complete a full orbit in 24 hours and appear to observers on the ground as being fixed. Only three satellites of the same type in geostationary orbit are needed to achieve near global coverage (except for some largely uninhabited areas at high latitudes near the North and South Poles) if a satellite operator requires this. The Galileo satellite navigation constellation (pictured) can be found in MEO at 23 222 km. Photo: ESA GEO orbits lie above the equator and keep pace with the Navigation satellites are most often found in MEO rotation of the earth. Photo: ESA orbits and are carefully positioned so as many satellites as possible are available to view. Satellite GEO is used by satellites that need to stay over a Navigation receivers need to be able to receive a particular place on the Earth. This means that signal from at least 4 or 5 satellites to function communications antenna on the ground can be correctly. The use of MEO is relatively limited permanently positioned, as they do not need to track however because of the high radiation levels in this where the satellite is in the sky. Communication, area which limit a satellite’s usefulness and active life. EXPLORING SPACE SUBJECT GUIDE 23

SECTION 3 WHAT’S IN THE SPACE AROUND THE EARTH? Low Earth Orbit (LEO) A satellite in a low orbit can see less of the Earth’s surface at any one time than one in high orbit, so Items in low Earth orbit are relatively close to the more are needed for continuous coverage of any Earth’s surface, with orbits of between 200 and given area. Atmospheric conditions in LEO can affect 1000 km, although some satellites can be deployed the position of these satellites and most need to even lower than this. It is easier to launch a satellite ‘boost’ their orbit several times a year using their fuel into LEO and less power is needed to transmit data. reserves to make up for atmospheric drag. High resolution images can be taken using a satellite in this orbit because of how close they are to Earth. Despite these limitations, putting a satellite into LEO There is also much less of a delay (latency) between is a popular choice and more and more satellites are transmissions compared to satellites in higher orbits. being deployed in this region of space. LEO satellites can tilt their plane of orbit so they do not have to follow the equator, as illustrated in the diagram. This means there are more routes available to these satellites. Satellites in LEO orbit do not need to follow the equator Satellite constellations (large groups of satellites) in and can tilt their orbit. Photo: ESA LEO are becoming more frequent. Some companies have launched large numbers (sometimes in their The ISS is an example of a satellite in Low Earth Orbit, thousands) to provide global coverage for things like with an orbit altitude of 408km. This height was internet connectivity. We have already looked at how chosen as it is easier and cheaper for astronauts and crowded the LEO is and the implications this has for cosmonauts to get to and from the station because satellite operation. Some scientists have raised their of the shorter distance. concerns about launching this many satellites, especially when the operational life of most satellites in LEO is only 5-8 years. When they go out of service they have the potential to significantly add to the space debris problem if they are not all removed from orbit at the end of their life. The Hubble Space Telescope is in a LEO at 540 km. It captures high resolution images, allowing a deep view into space. 24 EXPLORING SPACE SUBJECT GUIDE

SECTION 3 WHAT’S IN THE SPACE AROUND THE EARTH? FIND OUT MORE If you’re interested in any of the topics that have been covered in this section then you can use the links below to conduct your own research. You can click on the links if you are viewing this document electronically. SPACE DEBRIS 1 ESA sub-site all about space debris with lots of extra information. bit.ly/36xhbRp 2 Latest space debris statistics. bit.ly/2A7pMxT 3 A Natural History Museum article about space debris. bit.ly/3d25gxA 4 An Encyclopaedia Britannica entry about space debris. bit.ly/2TzGXzd DAMAGE FROM SPACE DEBRIS 1 About the Cupola window chip that Tim Peake discovered. bit.ly/3efssso 2 An article about space debris damage on a satellite. bit.ly/2A2tfOn 3 ESA article on assessing the risk of space debris. bit.ly/2XsgBQD 4 A Universe Today website page about avoiding space debris. bit.ly/2WYNIgg CLEANING UP SPACE 1 The latest, updated e.Deorbit news from the ESA. bit.ly/2ZyzUL8 2 Main University of Surrey page for the RemoveDEBRIS mission. bit.ly/3cZUS9s 3 Bloomberg.com article about ESA space junk clean up missions. rb.gy/jdilst 4 NASA statement on Space Debris. rb.gy/ylrox3 SATELLITES AND ORBITS 1 A detailed ESA page about types of orbits. bit.ly/2LTrW7h 2 A feature about satellite constellations and worries from NASA. bit.ly/36rlaik 3 NASA orbit catalogue. rb.gy/p4z8gb 4 Space.com article about satellite constellations. bit.ly/3eiXEXH EXPLORING SPACE SUBJECT GUIDE 25

EXPLORING SPACE SUBJECT GUIDE SECTION 4 PIONEERS OF SPACE EXPLORATION 26 EXPLORING SPACE SUBJECT GUIDE

SECTION 4 PIONEERS OF SPACE EXPLORATION INTRODUCTION At the end of WWII the Russians, the USA and the were sent into space and in 1961 Soviet Cosmonaut UK continued working and experimenting with Yuri Gagarin was the first human to orbit the earth. rockets. The space race had begun! The first In 1963, Soviet Cosmonaut Valentina Tereshkova attempts to use rockets for space travel began in was the first woman to go into space. the late 1950s and continues today. The Using Rockets for Exploration section looks at four Finally in 1969, the USA won the space race when space ‘firsts’, two of which took place before the American Astronauts set foot on the Moon, Neil first moon landing in 1969. Armstrong and Buzz Aldrin. Since then only 10 more people have ever walked on the moon and nobody To put an astronaut into space needed careful has visited since 1972. planning and experimentation. The working environment was harsh and nobody knew how it The first British citizen was sent into space in 1991. would affect someone exposed to it. Special Helen Sharman visited the Russian Mir space station equipment and advanced technologies were to conduct experiments. Only eight British citizens required, and many tests were carried out. In have ever been into space, with the latest being the particular, various animals were sent into space to European Space Agency (ESA) astronaut Tim Peake, test the risks and the new technologies before the first UK government funded Briton in space and risking the lives of a man. The first animal was aboard the International Space Station. launched into Space by Russia (the USSR) in 1957, just a month after the first satellite was put into orbit, It’s not just astronauts and cosmonauts that have Sputnik 1. been in orbit. It is now possible for ‘space tourists’ to visit space if they have the vast funds needed to do Like most high technology projects the cost was this. The first person to fund his own trip to do this high. Many people saw the cost of the space race was the American Dennis Tito in 2001. (between America and the USSR) as a waste of money particularly since Earth had many problems The rest of this section will focus in more detail on of its own. But it wasn’t long before the first humans the first animal in space, the first female in space, the first Briton in space and the first space tourist. From left: Laika, the first animal launched into space; Soviet Cosmonaut Valentina Tereshkova, first woman in space; Helen Sharman, the first Briton in space; Dennis Tito, the first ‘space tourist’. EXPLORING SPACE SUBJECT GUIDE 27

SECTION 4 PIONEERS OF SPACE EXPLORATION THE FIRST ANIMAL IN ORBIT LAIKA THE SPACE DOG Laika was a Soviet space dog who was one of the get an animal into orbit was rushed and Laika’s first animals in space and the first living thing to spacecraft was hastily constructed. No technology orbit the Earth. Laika’s journey into space in 1957 was available to enable the spacecraft to return to arguably gave scientists the vital information Earth. Laika was provided with enough food for which they needed to send humans into space. around 7 days. After that the plan was to euthanise her with poisoned food or for her to die painlessly Before Laika’s mission it was believed by some from a lack of oxygen. scientists that humans would not be able to survive either the launch into outer space, or the conditions Laika was terrified; as the rocket was launched her they would face. Launching a dog into space was heart rate became three-four times faster than designed to prove that something living could normal. She eventually calmed down and began survive space and the lack of gravity for long periods. eating her food but during launch some of the thermal insulation on the spacecraft came loose, Laika was a stray. Strays were chosen because meaning the temperature in the cabin increased to scientists thought that they would be better at over 40°C. Within 5 to 7 hours into the flight, no tolerating extreme conditions. Laika and other dogs signs of life were reported. Laika died of heat were quickly trained to manage cramped conditions exhaustion. by being put in progressively smaller cages over a period of 20 days. This caused them to become The USSR for many years denied the cause and time stressed and to physically deteriorate. The dogs were of Laika’s death and it wasn’t until much later that span in centrifuges and exposed to loud rocket the truth emerged of what actually happened. Oleg noises to simulate space travel. Gazenko, a scientist responsible for sending Laika into space later expressed regret and wrote: “The The journey was always to more time passes, the more I'm sorry about it. We be one-way. The race to shouldn't have done it ... We did not learn enough achieve another space ‘first’ from this mission to justify the death of the dog.” meant that the programme to 28 EXPLORING SPACE SUBJECT GUIDE

SECTION 4 PIONEERS OF SPACE EXPLORATION THE FIRST WOMAN IN SPACE VALENTINA TERESHKOVA Valentina Tereshkova was the first woman in logged more hours than the combined times of all space. In 1963 she spent 70 hours in orbit, circling the American astronauts who had flown before that the Earth 48 times in her space capsule Vostok 6. date. A camera placed inside her spacecraft She remains the only woman to fly solo in space, transmitted live TV pictures which were beamed all and the youngest at 26 years old. over the world. Tereshkova was a parachutist. She joined her local During her flight, a programming error in the parachuting club as soon as she was able to and spacecraft’s automatic navigation system caused the trained almost every weekend. It was her ship to begin to drift away from the Earth. Luckily, parachuting experience that helped secure her Tereshkova noticed this early on and scientists position as the first female in space. At the time, developed a new landing algorithm in time. This cosmonauts had to parachute from their capsules information was classified for more than 40 years, just before they hit the ground on the return to only being released after the fall of the Soviet Union. Earth. She trained with four other women for 18 At the end of the mission she parachuted safely, months and was tested on how she would react to despite high winds making her parachute difficult to being alone for long periods and how she would control. react to extreme and zero gravity. Tereshkova was the only one of these women to make it into space. After her mission Tereshkova became a role model for women all over the world and is still a national Tereshkova’s flight was scheduled for the 16 June hero and celebrity in Russia. In 2015 she was 1963. Her rocket was launched successfully and she interviewed by the BBC and said: ‘One cannot deny began her orbit. Within her single flight of nearly the great role women have played in the world three days she community. My flight was yet another impetus to continue this female contribution.’ She also issued a message to young women who wanted to follow in her footsteps: ‘Work hard and you will get there. I am very jealous of you!’ EXPLORING SPACE SUBJECT GUIDE 29

SECTION 4 PIONEERS OF SPACE EXPLORATION THE FIRST BRITON IN SPACE HELEN SHARMAN Helen Sharman was the first British astronaut to then they couldn’t choose her! Her mum had travel to space, the first British cosmonaut and previously told her: ‘If you don’t try something, then the first woman to visit the Mir space station in you’ll never know what might have happened!’ This 1991. She spent almost eight days in space, can-do attitude paid off. More than 13 000 mostly on the Mir space station, and conducted applicants applied for Project Juno and Sharman was medical and agricultural tests whilst in orbit. selected live on TV in 1989. Before becoming an astronaut Sharman was a Before the mission Sharman trained intensively for chemist working for Mars Confectionery. In 1989 she 18 months in Moscow, Russia with another was driving home from work and heard an advert on applicant, Tim Mace. The British funding contribution the radio for Project Juno, a space programme was to be provided by private companies, however funded by British companies and the Soviet Union. they couldn’t raise the money required for the The advert announced: ‘Astronauts wanted, no mission so the Soviets paid for it instead. The training experience required.’ Despite meeting the criteria was difficult, especially as much of it was delivered in Sharman wasn’t going to apply as she didn’t think Russian! For most of her training she assumed she’d she’d be chosen, however, by the time she returned be the backup, with Tim Mace as the lead, but was home she had delighted to discover that she was selected as lead changed her mind, three months before the launch. realising that if she didn’t On the 18 May 1991 Sharman travelled to Mir as part apply of the Soyuz TM-12 mission along with two other Soviet Cosmonauts. Whilst onboard Mir she conducted high temperature superconductor experiments and a number of medical and agricultural tests including studying the effects of pansies growing in a weightless environment. She also contacted nine British schools via radio. Sharman didn’t get much free time aboard Mir and her days were strictly regulated, waking up at 7am and going to bed at 11pm. She spent lots of the little free time she had looking out of the windows of Mir and later said: ‘There’s no greater beauty than looking at the Earth from up high.’ She returned to Earth on the 26 May 1991. After her mission Sharman dedicated the next eight years communicating science to the public. She is now the Operations Manger for the Department of Chemistry at Imperial College London. 30 EXPLORING SPACE SUBJECT GUIDE

SECTION 4 PIONEERS OF SPACE EXPLORATION THE FIRST SPACE TOURIST DENNIS TITO Dennis Tito is the first person to fund his own trip a tourist to take a ride to space. into space giving him the title of the first ‘space tourist’. He paid around $20 million to travel to Russia disagreed with NASA’s decision and Tito the International Space Station (ISS) in 2001 and trained in Moscow for about a year until he was spent 8 days in space. ready to travel to the Mir space station in 2001. Unfortunately this mission was cancelled when it Tito is from the USA. He studied a BSc in astronautics was finally decided to deorbit Mir in early 2001. and aeronautics at University and went on to gain an Instead, Tito joined two Cosmonauts on the Soyuz- MSc in engineering science. For a while he worked as TM32 mission to the ISS. This would have normally an aerospace engineer in NASA’s Jet Propulsion required weeks of training with NASA to become Laboratory helping to plan and monitor both the familiar with the American sections of the ISS, but Mariner 4 and Mariner 9 space probes to Mars. In Tito and his Russian mission partners were sent 1972 he founded a finance company and became home before any training could take place. NASA very successful in that industry but was he always stated that they did not want to work with Tito. held a special interest in space. Despite this refusal to provide training Tito spent 6 Tito had always wanted to travel to space and had days on the ISS and conducted some experiments been in negotiations with Russian Space Agencies that he said would be useful to his company. He also for several yeas before his mission. He was criticised by NASA who stated spent a significant amount of time enjoying the that they considered it view and experience. He hopes inappropriate for that many more people will get to experience space travel in the future. EXPLORING SPACE SUBJECT GUIDE 31

SECTION 4 PIONEERS OF SPACE EXPLORATION FIND OUT MORE If you’re interested in any of the topics that have been covered in this section then you can use the links below to conduct your own research. You can click on the links if you are viewing this document electronically. LAIKA, THE FIRST ANIMAL IN ORBIT 1 A comprehensive account of Laika’s journey. bit.ly/2WXqrv6 2 A space.com article written on the 60 year launch anniversary. bit.ly/2ZCXHcu 3 An article from the Independent Online about animals in space. bit.ly/2LVHNC2 4 An Encyclopaedia Britannica entry about Laika. bit.ly/2XuS7GO VALENTINA TERESHKOVA, THE FIRST WOMEN IN SPACE 1 A space.com article about Tereshkova’s life and legacy. bit.ly/3eaTmBw 2 A 2015 BBC News Interview with Tereshkova. bbc.in/3ee0U6x 3 An Interview with Tereshkova from the Guardian newspaper. bit.ly/2LRf1Cv 4 A short biography of Tereshkova’s life. bit.ly/2TyIYvx HELEN SHARMAN, THE FIRST BRITON IN SPACE 1 An interview with Sharman from the Independent Online. bit.ly/3cZK1Mz 2 An Interview with Sharman from the Guardian newspaper. bit.ly/2zp2VOw 3 A feature on Sharman from the Royal School of Chemistry. rsc.li/36osuew 4 A ‘Destination Space!’ Profile of Helen Sharman. bit.ly/36qQAFN DENNIS TITO, THE FIRST SPACE TOURIST 1 An Encyclopaedia Britannica entry about Tito. bit.ly/3eeT4K0 2 A BBC News Interview for the 10 year launch anniversary. bbc.in/2TxQAi1 3 A article from NBC news on 6 May 2001, the day of landing. rb.gy/1xamai 4 A space.com article about Dennis Tito’s journey to space bit.ly/2WUkP4y 32 EXPLORING SPACE SUBJECT GUIDE

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My ncklfjskalfjkfj INNOVATION FOR THE NEXT GENERATION HQ RAF Air Cadets TG Branch

HOW TO GUIDE #12 USING SPACE APPS ACCESS INTERACTIVE SPACE APPS There are many interesting mobile apps for both smart  if you are using a phone or tablet look through the phones and tablets that can be fun and interactive. list and click on the link for the one you are They are generally free. interested in. If you are using a PC or Mac, scan the You will find a folder in Ultilearn called ‘Interactive QR code provided with your phone or tablet. Mobile Training Apps’ with information on some of these. Check this folder regularly, as new apps will be  Download the app in the normal way. added as they are found. USING THE APPS HOW TO GET THE APPS  The apps will work in the normal way, but did you  Open Ultilearn via Cadet Portal or by visiting know that you can view them on other screens and https://learning.bader.mod.uk. Make sure you even share them? know your Ultilearn username and Password. Ask your squadron staff if you’re not sure what it is.  You can view apps on larger screens by linking your smart phone or tablet to a TV or desktop computer  If the Interactive Mobile Training Apps course monitor. Visit the Interactive Mobile Training isn’t displayed, click Explorer Register. This is near Apps course to find out how to do this. the top of the screen on the right hand side.  When you’ve done this you will be able to share  Find the course in the list and click the Register your screen over the internet with your instructors button. The course should now appear in the My or other cadets and friends. Courses Area. AIRBUS SPACE DATA HIGHWAY AR ADVENTURE IN SPACE 3D SPACE WALK SIMULATOR NASA HQ RAFAC Training Team Version 1

STAFF GUIDE #12 USING SPACE APPS ENHANCE YOUR CADETS TRAINING WITH APPS Following on from Staff Guide #8, the HQ RAFAC your screen directly within the Teams app. Training team has put together a list of some useful  If you do not want to do an interactive lesson, but space training apps that can be used to enhance the training provided to your cadets for STEM or The Open want to demonstrate an app working, you can University Launch Pad Space Syllabus. make a screen video of this on any device that does Cadets can find them in Ultilearn and staff can find this, which is most computers, smart phones or them in the Training Officers’ Area in Bader SharePoint tablets and then play the video within your lesson. under the ‘Interactive Mobile Training Apps’ section.  When normal sqn parade night lessons resume, you Both will be updated regularly when new apps are can connect your smart phone or tablet to a TV, found. monitor, or projector, to deliver these apps in the classroom. GETTING THE APPS CHECKLIST  Go to Ultilearn or Bader SharePoint. On SharePoint. links can be found in the Training Officer’s Area. Make sure each cadet has a valid Ultilearn  Find the Interactive Mobile Training Apps folder. username and password. Their username is the  Look through the list and click on the link for the long number next to their name on SMS. one you are interested in if you are on a phone or Pass on any password request emails to the cadet tablet. If you are using a PC, scan the QR code provided with your phone. concerned as soon as possible. These are  Download the app in the normal way. delivered to the OC email account. USING THE APPS SHARING BEST PRACTICE  Cadets can be encouraged to learn about space  Have you used any other apps that are not listed? topics using their own smart phone or tablet. Do you think they would be useful to enhance a cadet’s training?  You can view apps on larger screens by linking your smart phone or tablet to a TV or desktop computer  If you spot any useful apps then please let the HQ monitor by attaching a HDMI cable. You may need RAFAC training team know via the Progressive an inexpensive adapter to connect from the smart Training Syllabus section of the Virtual Parade Night phone or tablet in this way. Resources in Microsoft Teams, or email the link to [email protected].  You may also be able to attach your smart phone or tablet wirelessly to your TV or computer. Further  We would also like to hear from you if you have instructions on how to do this can be found within created a recorded video demonstrating the use of the Interactive Mobile Training Apps course on the app. Bader SharePoint.  If you are using your smart phone or tablet to deliver TEAMS lessons you will not need to connect to a laptop or desktop computer. You can share HQ RAFAC Training Team Version 1