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It still blows my mind how they landed that rover on Mars. Heat shield to use the atmosphere to aerobreak. Then it opened the largest hypersonic parachute ever
by mabbo 6y ago
It still blows my mind how they landed that rover on Mars.
Heat shield to use the atmosphere to aerobreak. Then it opened the largest hypersonic parachute ever to slow it down further (dropping the heat shield after it opened). Then eventually it cut off the parachute, turned on rockets, and flew sideways so that it didn't run back into the parachute. THEN, to avoid spitting up too much dust during landing, it lowered the rover on a 21 foot tether down to the surface, while hovering above it, before flying away to crash somewhere safe.[0]
It's so ridiculous you'd think it came from a movie. And it worked.
[0]https://en.wikipedia.org/wiki/File:Curiosity%27s_Seven_Minutes_of_Terror.ogv https://en.wikipedia.org/wiki/File:Curiosity%27s_Seven_Minut...
- parhamn 6y agoGreat point. In a weird way it makes the whole relanding the boosters thing SpaceX did seem like it was obviously within the realm of our capabilities if we were ambitious enough. And it makes their next goal of 'catching rockets' seem less ridiculous too.
- Sharlin 6y agoIt was always within capacity, the question was just whether it made sense economically compared to dumb boosters. SpaceX was always an extremely-high-stakes gamble that did happen to pay off in the end.
- mlyle 6y agoYup. There were plans to give the Shuttle flyback boosters at various points, but each time it was thought it wouldn't pay off.
- blackrock 6y agoIt seems the Space Shuttle’s orange fuel tank should’ve been a flyback booster. It’s fuel was connected to the shuttle main engines via a tube. And the main engines were useless in space, once the tank was de-staged. The tank burned up in the atmosphere. But it would’ve been nice if it flew back and landed instead.
- mlyle 6y agoYou'd lose a lot of performance, then, because the tank would have to separate while still containing enough fuel to slow down and come home. You'd make a little bit of it back because the OMS wouldn't have to use thrust to circularize the orbit of the SSME mass or to deorbit it...
- nickik 6y agoYou would need to remove the Solid Boosters first to make it worth it. If you do that hydrogen becomes a bad choice. So you should have built an RP-1 or Methane single booster without solids and then you could have done it.
- nickik 6y agoThe whole shuttle designs was simply not a good one, it has a lot of compromises and false assumptions. The Soviet version where you simply have a space plane on the side of a independent booster was much better design that had much broader use case. It would have been much easier to build ISS if you had that capability. Remove the Solid Boosters and make the Core Booster better to further reduce risk. Once you are there you can just make the first stage land like SpaceX Falcon 9 does and have the Orbiter land like a plane. Even better to put the Space plane on top of the booster, rather then the side to reduce risk. And if your at that point, you realize you don't need the massive cross range capability, you can remove the massive wings. Then you are already pretty close to SpaceX Starship design.
- bumby 6y agoExactly, the DC-X was a reusable design from the early 1990s. The feasibility was there, the next hurdle was economics. https://en.m.wikipedia.org/wiki/McDonnell_Douglas_DC-X https://en.m.wikipedia.org/wiki/McDonnell_Douglas_DC-X
- helmholtz 6y agoIf you haven't watched Roving Mars (about Spirit and Opportunity), it's a must watch as well.
- potency 6y agoThat's incredible, thanks for sharing.
- jonnycomputer 6y agothat video is great!
- GeorgeTirebiter 6y agohttps://youtu.be/7gUI18dJx8k https://youtu.be/7gUI18dJx8k
- torpfactory 6y agoThe really crazy part is that they never did a full up integrated test of all those systems together and in sequence before arriving at Mars.
- layoric 6y agoI was at a local radio telescope for the “live” event when it landed. Another crazy part was due to the time delay, by the time they were receiving info about entering the Mars atmosphere, it was was already over in reality and we all just had to wait those “minutes of hell” to find out what had happened.
- nine_k 6y agoThere's no such thing as "in the same time" at distances where light propagation delays are comparable to the duration of the event.
- p1mrx 6y agoEarth and Mars are practically stationary, and Occam's razor would say to assume that light travels at the same speed in all directions, even if we can't prove it. So the time of events on Mars has an "obvious", if technically not unique, solution.
- layoric 6y agoFor perceiving the events happening, sure, that was my point. These time differences are nearly always imperceptible but at distances of planets it truly becomes a way of looking into the past. But to be clear, events happen concurrently, eg NASA knew _when_ relative to earth time and _perceived_ events, each stage was "happening" local to Mars vs Earth (assuming it all went well). They made videos about this "7 minutes of terror", I forgot the name of them but linking here [0] [0] https://youtu.be/Ki_Af_o9Q9s https://youtu.be/Ki_Af_o9Q9s
- fireattack 6y agoIt's weird that as a featured media on Commons, no one has bothered to add subtitles (YouTube do have them, and the source site has transcript too).
- D13Fd 6y agoI found the wheel problems with Curiosity to be super interesting. They designed this incredible vehicle, and landed it in this incredible way, but making the wheels just a tiny bit too thin (in a well-justified pursuit of optimization) wound up limiting the scope of the mission when met with unexpected terrain. It shows just how small of a margin of error they have in making this all work.
- proactivesvcs 6y agoI think it was Curiosity's wheel treads which spelled out "JPL" in Morse. Such a gloriously geeky Easter egg!
- ibrault 6y agoYep! It was originally supposed to be the full logo but that got vetoed
- bmitc 6y agoI haven't read about this in a long time, but I have always been curious why the wheels weren't tested more on Earth and designed to be more hardy. Curiosity has apparently only traveled 12.5 miles, and that seems extremely low for such heavy damage. I would have guessed that tests on Earth would have logged many more miles than that, but I should look into their diagnosis of what went wrong.
- nickserv 6y agoThe rovers were extensively tested on Earth. However, Mars has lower gravity than Earth, which would of course have an impact on the wear on the wheels. Maybe there was an underestimation when applying the lessons on Earth to Mars gravity?
- StephanTLavavej 6y agohttps://www.planetary.org/articles/08190630-curiosity-wheel-damage https://www.planetary.org/articles/08190630-curiosity-wheel-... explains the root cause.
- shadowgovt 6y agoGet hype, because they're doing it again in February. ;) I believe its name is Perseverance.
- SkyMarshal 6y agoIt's really amazing work, and the knowledge and skills NASA and collaborators learned from doing that are invaluable. I honestly think for the next decade or two that NASA should double down on propulsion science, energy science, and robotics. Instead of trying to send a few men and biospheres to Mars, lets send a greater quantity of increasingly advanced robots/AI on increasingly challenging missions to study Mars and the Asteroid Belt. Use NASA's limited budget to advance theoretical and applied AI, robotics, and new propulsion/energy generation technologies for industrial use in space, with the ultimate goal of creating a fully robotic space mining and refining industry and supply chain back to Earth. Keep the ISS of course, as a relatively less expensive way of studying the effects of low-G on the human body, space agriculture, and human sustainability in space. But for anything beyond Earth orbit, let robots prepare the way for humanity. If NASA had an unlimited budget, then by all means do it all. But unfortunately that's not the reality right now. The robotic missions of the last several decades, from Mars Rovers, to Hubble, to probes of asteroids and the outer planets, have had such an amazing track record and ROI that they're worth doubling down on for the foreseeable future. The rapid advance of both AI and robotics is also expanding the mission capabilities of this technology, and its worth pushing that envelope hard for another decade or two. Finally, given limited budgets, we can send a greater quantity of robotic missions than we can manned missions. Quantity is an important factor in quality, as I think the tech world has learned in the last decade or two.
- ohazi 6y agoMost of the robotics expertise that you're attributing to NASA is actually JPL. JPL may technically be a NASA lab, but it has been managed by Caltech since 1958, unlike every other NASA center. JPL employees work for Caltech, not NASA. https://www.jpl.nasa.gov/about/history.php https://www.jpl.nasa.gov/about/history.php
- pauldino 6y agoJPL has been managed by Caltech for NASA since 1958, but JPL actually predates the formation of NASA (and has always been managed by Caltech).
- 6y ago
- rossdavidh 6y agoSomewhat over-the-top but still cool discussion of this by actual NASA tech folks, made before the landing actually happened: https://www.youtube.com/watch?v=h2I8AoB1xgU https://www.youtube.com/watch?v=h2I8AoB1xgU
- throwaway0a5e 6y agoMeh, the way I see it is some NASA people saw the Army drop a humvee from a blackhawk at an airshow and said "hey, let's try that" and then solved all the the prerequisite problems in order to make it happen. It's not a hard problem but pulling it off on Mars is an exercise in attention to detail. You have to get thousands of little things right to pull it off.
- bigiain 6y agoAll it takes is one tiny little error failing to convert pounds seconds to newton seconds, and your Climate Orbiter becomes a Ballistic Planetary Surface Hardness Probe...
- deleted 6y ago[deleted]
- rawoke083600 6y agoAmazing stuff! That lander is kinda super-saiyan-level-cart-pole ! Would love to know what sorta of algo's they use for lander ?
- dclowd9901 6y agoAll of this from millions of miles away. Absolutely astonishing. And it’s still running. NASA deserves so much more respect... and money.