How Computers Revolutionized Space Travel

When Alan Shepard became the first American
in space in 1961, he rode in a Mercury capsule packed with the world’s most cutting-edge
technology. It had almost everything you’d expect a
spaceship to have, from a heat shield to plenty of oxygen. But it was missing one really big thing: a
computer! Somehow, our first mission to space relied
on Newton’s good ‘ole “what goes up, must come down” idea about gravity. Thankfully, we’ve come a long way since
those early days. And as computers have gotten more powerful,
they’ve completely transformed how we explore the solar system. And along the way, the space industry gave
computer science a boost, too. By the time NASA was getting serious about
landing on the Moon, everyone knew the Mercury system wouldn’t cut it. Mission control in Houston provided most Apollo
flight control data, but there were still critical times when the astronauts couldn’t
rely on Earth. And the most important time was during lunar
landing. Because the Moon is so far and signals can
only travel so fast, there’s a round-trip communication delay of about two and half
seconds between Earth and the Moon. Which was just way too long during landing. So each Apollo mission needed computers capable
of doing everything necessary to reach the lunar surface. The problem was that computers back then fit
in whole rooms, not on desks, and the Apollo missions needed something with as little mass
as possible. So computer engineering had to step it up. NASA assigned this huge task to MIT, which
proposed using a new technology: the integrated circuit. In the 1950s, computers were being made with
transistors, tiny electronic switches that form the foundation of digital circuits. But all the wires needed to connect them together
still left a bulky, sometimes unreliable end result — which is not good if you only get
one chance to land on the Moon! Integrated circuits solve this problem by
printing the transistor and its wiring directly on a thin sheet of silicon, which increases
reliability and decreases weight. Using integrated circuits in the Apollo Guidance
Computer was a huge risk because they’d never been tried outside a prototype — but
they worked! The final computers weighed only about 32
kilograms — or about as much as a golden retriever — and each one performed flawlessly
in flight. To build them, MIT also bought basically the
whole world’s supply of integrated circuits, which really helped out the computer industry. In 1961, a single circuit cost about $32,
and each Apollo computer used them by the thousands. With all that demand, the price plummeted
to just a buck-twenty-five a decade later, and today every computerized product on Earth
is built from integrated circuits. Thanks, Apollo! Of course, we had plenty of robotic missions
in the 1960s, too. And since those didn’t have astronauts,
they definitely needed computers. But they were super basic! Back then, they weren’t even called computers;
instead these so-called sequencers just stored a list of commands and the time they should
be executed. Once the mission was in flight, everything
was totally out of our hands. The first mission to break this mold didn’t
come until 1969, when Mariner 6 and 7 flew past Mars. The Mariner 6 flyby happened first, and then
scientists could use the data it collected to reprogram Mariner 7 mid-flight. That way, when Mariner 7 showed up at Mars
five days later, it could get an even better data return. Now, almost 50 years later, our flight sequencing
has gotten a lot more complicated, thanks to more powerful computers. When Cassini made its final dives between
Saturn and its rings this fall, it was executing the last commands of a 294-orbit mission. Something that complicated could never have
been planned out years in advance, so it was critical that mission controllers could update
the computer along the way. Cassini’s flight computer is simple compared
to what’s in your phone, but it successfully flipped and spun the spacecraft to make sure
every instrument was pointed in the right place at the right time. And all those flips and turns have taught
us a lot about Saturn’s moons, weather, and more. Modern computers are also enabling missions
we wouldn’t have dreamed of in the past — like the Sky Crane that dropped the Curiosity
rover on Mars in 2012. Curiosity is way too big for an airbag-style
landing, like what we used for the Opportunity rover, so engineers built the parachute, rocket,
and winch combo of the Sky Crane to lower it to the ground. Like with the Apollo landings, there’s a
communications delay between Earth and Mars, so everything was up to the flight computer. But unlike a sequencer, the computer had split-second
decisions to make. After being dropped from the parachute, the
Sky Crane had just moments to find its elevation and velocity, determine its orientation, account
for the local wind speed, and fire its rockets to get balanced. And it had to decide when to lower Curiosity
and when to cut it loose. All before anyone on Earth even knew it was
entering the atmosphere. Spoilers: It worked! And now Curiosity is living a happy, productive
life on Mars. Without computers powerful enough to collect
that data and make those decisions, Curiosity may have never made it to Mars in the first
place. And luckily there’s no sign this innovation
will slow down. Opportunity and Curiosity can already pick
some of their own objects to study, and Curiosity can drive itself over short distances like
a self-driving car. That’s a heck of a long way to come in sixty
years, and there’s no telling what will come next. Thanks for watching this episode of SciShow
Space, brought to you by our awesome patrons on Patreon who make everything we do possible! If you want to learn more about the human
computers who helped Alan Shepherd and other Mercury astronauts get to space, check out
one of my all time favorite SciShow Space videos on Katherine Johnson.

100 thoughts on “How Computers Revolutionized Space Travel

  1. And today people use these super powerful portable computers they carry on their pockets to exchange hatred, bigotry, fake news and nudes in the internet.


  2. Read Hidden Figures for a good look at how "computers" the name used for the women who worked on the airplanes and eventually NASAs equations to determine how planes or rockets would work.

  3. I like how we assume a robot alone in an inhospitable wasteland hurling through space being blasted by cosmic waves that are slowly degrading its components is happy. Sounds like a miserable prolonged death. Push me off the highest cliff you can find and be done with it, I'll be an astronaut exploring vast nothingness for all of 5 seconds before SPLAT , the end. Hell, you could even say it was all in the name of curiosity.

  4. Planet Express ship, Hal 9000, the ship's computer in Planet of the Apes, R2D2, Mother computer from Nostromo, the computer from Enterprise ship The Next Generation, TARS and CASE, and Data the android disliked this video.

  5. I cannot watch this presenter as she expresses extreme excitement constantly. I am upset, and simultaneously surprised by this nonsense.

  6. 2:05 Thousands of circuits at $32 each, NASA had to spend some serious cache.
    But it was worth it, every BIT of it.

  7. It would also be interesting to hear about how computers are protected from radiation in space. I'm sure our more powerful smart phones would be fried around Saturn!

  8. Left out the need for radiation hardened equipment and how cosmic rays could shred the processors and memory in all our ground gear.

  9. noobs.
    should have trained the Golden Retriever to land the Lander…actually should have trained 2; so if something went wrong with the lander -you could tell the 2nd one to 'fetch'.

  10. Next will be AI androids exploring the universe on their own and building infrastructure on alien worlds for
    humans to migrate to.

  11. Somebody only half listening to this will come away with the impression that they used computers made of golden retriever brains to get to the moon.

  12. The Apollo Program was also responsible for the development of Surface Mount Technology since Through Hole components were too bulky.

  13. The first man in space is supposed to be Uri Gagarin you know, I think that's more relevant than the first American man in space…

  14. You should do a video about the computers they're working on for a Venus rover. Silicon doesn't semiconduct at Venus temps so they have to use other materials.

  15. What's missing is how advances in computer algorithms are currently revolutionising space travel by enabling reuse of previously launched rocket boosters.

  16. PLEASE put a second of silence between your sentences! It won't make your presentation too long, and it goes a long way to allow absorption of information.

  17. [04:36] "[:no:]-telling what will come next"—asteroid micro-avoidance, error-detection-and-correction at the equipment level (we've done data-bit ED&C for decades, four, decades)…

  18. I am amazed and appalled that Cassini had less computing power than a cell phone. They should have at least the amount of computing power of a high grade pc.

  19. also the Space Race led to the development of the Advanced Research Projects Agency (ARPA, later DARPA) which led to ARPANET, predecessor to… the Internet!

  20. Fun fact: the Curiosity rover uses a radiation-hardened version of the same CPU that's in the Nintendo GameCube and the Wii: the RAD750. It runs about 2.5 times slower than the GameCube (PPC750CXe) or about 4 times slower than the Wii (PPC750CL), since it's a special version that favors reliability over speed, but is otherwise largely identical and can run the same software. Even the Wii U still used a multicore version of otherwise the same CPU! Apple also used the same CPU in PowerPC Macs, and called it the G3.

  21. How about the cosmic rays that flip bits in computers memory? Donw here on earth, it happens on rare occasions. But out in space that should happen almost all the time… or?

  22. Wasn't it the curiosity that controlled the skycrane? That is to say didn't the rover decide when it should be lowered/cut loose?

  23. It weighed 32 Kilograms which is about as much as a golden retriever weighs. Gahaha what??? It weighs as much as 3 wet guinea pigs. Hahaha

  24. And we have computers that are light years in advance of those systems…and yet we cant seem to recreate to trip to the Moon. According to scientific principle where it must be repeatable to be true…we haven't been to the Moon.

  25. Oh so without NASA or a government funded space program, we wouldn't have cell phones, computers, GPS, polymer plastics, next gen alloys (and basically everything we need today)
    …so why is there no funding?
    Any technologies discovered (using public money, like the human genome project) can be used by any private company right?

  26. Robotic missions used "sequencers". Yeah I prefer custom made Midi sequences and live playing with maybe some arpeggiator here and there.

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