The Technical Legacy of Apollo
That ‘one small step for man, one giant leap for mankind’ was much greater than a human foot placed upon another world. As I write this, humans have not set foot on the Moon again, or on another planet — yet.
In the years since Apollo, space exploration has mostly been done remotely from Earth, using the Hubble Space Telescope, the Very Large Array in space or by scientists in the International Space Station.
This hasn’t just been due to the expense — the Mars rovers that have sent us back extraordinary close-up photos and test results from another planet were far cheaper than it would cost to keep a human safe in Mars’ environment for that length of time. The expense of keeping astronauts alive through the long voyage to Mars, through the radiation of space and the dangers of descent, would be enormous.
Apollo 1 cost the astronauts their lives. The crew of Apollo 13 nearly died. Those on Apollo 11 knew they had perhaps a 50/50 chance of surviving both landing on and taking off from the Moon’s surface. They could have been stranded there until they died, days later, horribly, from lack of oxygen. Yet they went, and the world watched.
It was a different era.
Today, as back then, people starve, they die in floods and fires. Refugees drown in their attempt to reach safety. We do not hold that life is any more precious now than back in the days of the Apollo program or, at least, not the lives of people who are not like us. But we do not want our heroes to die. Every time astronauts died — nearly always publicly, watched by masses of people on TV screens — public support for the space program declined. While there are still many who would gladly risk their lives, engaging in space exploration or settlement, these days it must be deemed to be ‘safe’.
Instead of manned missions, there have been remote sensing devices sent to the Moon, Mars, a comet and asteroids.
As I write this in September 2018, Japan has successfully landed two small rovers on the surface of an asteroid, in a history-making mission that could provide clues to the origin of our solar system. The Ryugu asteroid is about 1 kilometre wide and 280 million kilometres from Earth. The rovers are 18 centimetres round, 7 centimetres high and weigh about 1.1 kilograms. They are moving around the surface, ‘hopping’ because of the weak gravity. Scientists hope that, by looking at what the asteroid is made of, the mission could help explain the history of our planet and the universe.
They may also find elements that are valuable on Earth.
Most of the space work since the Apollo missions has been commercial, using the technology and knowledge generated by those missions to build a world that’s very different from the one I grew up in.
Even in 1969, much of the world did not have phone coverage. You needed telephone lines — in many places, each call had to be booked through an operator — as there were no mobile phones. Information came from giant encyclopaedias or libraries of textbooks. Even finding a single fact, like an address or the date of an event, would mean travelling to the Post Office to look up telephone books, or a trip to the library for hours, or even days, of work. This has been replaced now by a few taps on a keyboard to consult the World Wide Web.
If you travelled beyond your own neighbourhood, you carried a map, or many maps, to find out where to go. Phone calls were expensive — it was far cheaper to write a letter even though it might take days, or even months, to reach its destination. Shopping meant travelling into the town centre to browse from shop to shop. You might gossip with a friend on the phone but, unless they were nearby, it was expensive and long-distance calls might take hours to get through.
Today? We chat across the world on social media, get our news online, and watch movies streamed to our TV, computer or mobile phone screen via satellite. Satellites have changed the way we live. Every day, we use space technology, from mobile and satellite phones to the internet, and from wi-fi to the GPS systems that guide our cars or aircraft. All this is a gift from those early space missions, giving us the basis for modern technology.
Even the biometrics that measured the heart rate and other health signs of the astronauts have led to major advances in medical imaging, allowing doctors to diagnose problems without surgery or to send images almost instantaneously to specialists, who can study them and give their opinion. We are firmly in the space age.
THE MEN WHO REALLY DID INVENT THE INTERNET
Did you log on to your computer today? Or log off?
For centuries, sea captains kept ships’ logs. Many of those people who sent men to the Moon had a background in naval or military technology. They used the phrases ‘logged on’ and ‘logged off’ as they spoke to each other and to the astronauts.
With the Apollo spacecraft and their tracking stations across the planet, humankind was communicating for the first time over vast distances via keyboard — sending text, voices and even images. Whoever ‘logged on’ to the system could read the records and be part of the project.
This was where the internet began. As the tracking stations communicated with each other, Mission Control and the astronauts in space, they cast a vast ‘net’ across the planet. The system was classified — it was top-secret technology in a time when the United States and the USSR were conducting a Cold War.
Credit for ‘the beginning of the internet’ is usually given to the ARPANET (Advanced Research Projects Agency Network) project, directed by Bob Taylor and managed by Lawrence Roberts. The first internet message was sent over the ARPANET in 1969, from the Computer Science laboratory of Professor Leonard Kleinrock at the University of California, Los Angeles (UCLA), to the Stanford Research Institute (SRI).
By then, however, space trackers had been using a similar system for several years. The system gradually became more sophisticated even though, during those early years, it was restricted to those involved in the Apollo missions.
BROADBAND INTERNET CONNECTIONS
Apollo spacecraft signals were complex with varying types such as voice, telemetry data, biomedical, ranging (a special signal where they send out a signal with a code and the spacecraft returns so they can measure the distance) and scientific instruments that collected information to be analysed from Earth.
By combining all these signals into one single broadband radio channel, it meant that a single large dish antenna replaced a variety of smaller dedicated antennas. Using broadband techniques enabled much larger amounts of information to be transmitted. Broadband services are taken for granted these days, as we download complete movies and news on our mobile phones, and play computer games online with friends at distant locations in real time.
The internet as we know it only really began in the 1980s, when ‘servers’ began offering to connect the general public to the ever-growing ‘World Wide Web’ (www). By the mid-1990s, the way we communicated and worked had changed forever — thanks to the space program.
Some people went on to make their fortunes inventing technology, or creating new search engines or social network platforms with that technology. But the people who began it all remain anonymous. We worked for a modest salary, and our discoveries were the property of the government. I never heard any one of us say, ‘We should have made a fortune with that.’ We were fascinated with the technology itself, not with money or publicity.
In 1966, we decided to send a different kind of Christmas message from Honeysuckle Creek. Ron Hicks and I worked out that by using different shadings of print, we could use letters to create an image. So we did — ‘Miss Honeysuckle Creek, 1966’ was an image of a (fairly modest) naked woman taken from a Playboy Magazine. Her image was sent to every tracking station — and many space trackers remember having her pasted up on the inside of their locker doors. When you play with images sent electronically today, remember we began this way back then, with Miss Honeysuckle Creek.
So much of what we take for granted now with everyday medical procedures began in the Apollo era.
Biomedical information on each of the Apollo astronauts was taken via body sensors, then digitised through the onboard computer and transmitted in the telemetry data stream to Mission Control, via the worldwide network of tracking stations. The biomedical data was further processed in the tracking stations’ telemetry computers, and recorded on paper chart recorders while it was being transmitted to the flight surgeon’s console in Mission Control. In the Apollo missions, the biomedical data on each astronaut included heart rate, breathing rate, body temperature, water-cooling temperature and suit pressures. All this information was continuously available throughout the mission. Nowadays, such medical information can be transmitted in real time from doctors in remote locations to major hospitals or medical centres, so that experienced specialists can assess patients immediately.
Early video cameras were used on Earth-orbiting spacecraft. These were about the size of a large shoebox, heavy and bulky to handle. In the Apollo missions, they were usually fixed inside the crew cabin. For the first moon-landing mission, NASA required the astronauts to operate a handheld video camera while outside on the lunar surface. This camera had to be of rugged construction, lightweight, and be able to withstand an operating temperature range of –300°C to +300°C on the lunar surface. At the time, commercial television studios and outside-broadcast video cameras were about the size of a large travelling suitcase. They were very heavy and required a pneumatic mobile pedestal mount. They needed a thick, flexible cable attached to a backroom full of electronic equipment.
For Apollo 11, the Motorola Corporation produced a lightweight camera about the size of a chocolate box, which used a recently developed miniature vidicon picture tube. It had a small pole-stick handle for the astronauts to grip easily with their large awkward gloves, easy lens focusing and a simple push-button on/off switch. (Today, we use palm-held camcorders or even miniature cameras inside mobile phones.)
Three fuel cells provided all the electric power for the Apollo spacecraft (command module). A fuel cell operates via a chemical process, where oxygen and hydrogen are mixed to produce electricity and water. The fuel cells supplied enough electric power to operate all the equipment in the command module for the duration of the mission, including air conditioning/environment control, electronic communications, spacecraft radar, guidance computer and lighting. For the Apollo 11 mission, three fuel cells supplied power for the total distance travelled of 1.5 million kilometres. (Fuel cells have been proposed as an alternative to fossil fuel for our cars, and are now being used in some European countries.)
The first commercial business computers were large ‘dinosaur’ installations, which occupied one whole floor of an office building. Included in the installation were many rows of grey cabinets, each full of electronic equipment. The most impressive sight was the engineers’ control console with its hundreds of blinking lights and small switches. Also impressive was a row of magnetic-tape machines with their spools of tape whizzing backwards and forwards, as well as an assortment of noisy and cumbersome printing machines.
NASA required the computers on the Apollo spacecraft to control all the subsystems, provide an interface for the astronauts and communicate with the tracking station computers. Representatives from the computer industry asked NASA about the physical space available in each spacecraft, to which the officials replied — no bigger than 30 cubic centimetres. At the time, this was considered to be impossible.
Researchers at MIT were developing new silicon chips, which contained many hundreds of transistors in each. These miniature chips could be assembled together to perform all the logic functions of a large general-purpose valve-based computer.
NASA called on MIT to design the Apollo Guidance Computer (AGC) and oversee its manufacture, as well as to develop the appropriate hardwired programs for both the command and lunar modules.
These mini computers formed the basis for the revolutionary desktop personal computer, followed quickly by laptop versions, which all have vastly more power and speed than the old ‘mainframes’ of the 1960s.
The earliest Apollo missions were unmanned; they were mainly to test and verify the engineering design and operation of the command module spacecraft in Earth’s orbit. All of the manned space flight network tracking stations were upgraded for the Apollo program, with computer systems to enable transferring command and telemetry information between the Mission Control computers and the AGC in real time.
Each tracking station was equipped with two identical computer systems. One system received commands from flight engineers in Mission Control to perform different functions on board the spacecraft via the AGC. The second computer processed the telemetry data into specific formats, depending on what the testing and/or flight plan required. The limitations in transmission speeds of the undersea cables, as well as the satellite capacities availability at the time, meant this was necessary.
At each tracking station, two computer systems communicated directly with each other to validate all command information before transmitting it automatically to the spacecraft. When it received a valid command, the spacecraft’s AGC would insert an acceptance signal into the telemetry data, which was sent to the appropriate flight engineer in Mission Control via the tracking station. Operating like this, in this real-time mode, meant that the flight engineer in Mission Control would see the results of each command sent almost immediately.