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.
It'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.
Most 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.
> Keep the ISS of course, as a relatively less expensive way of studying the effects of low-G on the human body
The ISS is actually very expensive.
> If NASA had an unlimited budget, then by all means do it all.
NASA is not free to decide these things by themselves.
It is true that the robotic side has been more successful, but that is simply because human spaceflight has been totally mismanaged for the last 50 years. It is not inherently the case.
The new Mars rover was about as expensive as the complete development of Orbital human flight at SpaceX. And for that SpaceX was also able to finish the most advanced reusable rocket and make it human rated.
Actually getting humans onto Mars together with robots to work locally will actually produce a much bigger bang for the buck. Having local labs, local control of robots, human scientists directly on sight. It would also advanced the technology for transportation, agriculture, medicine and so on.
Specially with SpaceX already development the technology need to build a base on Mars, not taking advantage of it and only sending rovers out there, is in my opinion a bad policy. Its both bad from a scientific and from a political view.
Endlessly doing low-G research and getting more details on Marsian stones, is simply not on the same level as human permanently occupying Mars. And a Mars base is in my opinion not outside of the current budget if it were spent in a smarter way.
>not taking advantage of it and only sending rovers out there, is in my opinion a bad policy
I wonder much of this choice is due to political risk. A policy to send humans to Mars would have to span multiple administrations and risk being put on the chopping block due to multiple re-prioritizations. Maybe they think a less optimal sure bet is better?
Its not as simple. The political transitions are part of it. However the politics of NASA are complicated.
One of the major issues is simply that NASA for human-space flight could in the past not build on top of commercial rockets and NASA has been terrible at developing launch vehicles.
Simply put, Marshall Space flight center, Boeing and Alabama is where the money is going. There simply is no accountability. The money just keeps flowing there year after year no matter what is achieved or not achieved. No matter if the president changes or not, no matter if you are going to Moon, Mars or an Asteroid.
Before that the Shuttle was all consuming program that limited you to LEO, partly because you have very little budget left over as long as you had Shuttle operating.
This is likely not gone change unless there are some real power shifts in congress.
I agree, but also think this is part of the design. Both government orgs like NASA and the contractors who support them spread their jobs/money across enough Congressional districts to reduce the risk of reduction in funding. Haven’t you ever wondered why NASA designed a naturally inefficient system by spreading the country? Programs in Marshall also stretch their tentacles into Johnson, Glenn, etc. I wonder if part of the blowback is that it makes it less palatable to prioritize big, bold projects (also factoring in how bad estimating these projects is and the fact they will have inevitable overruns). It’s not actually an inability to hold people accountable, it’s that they don’t want that accountability because it puts their districts at risk. Listening to a few talks by the NASA administrator led me to believe political risk is at the forefront of their mind
> If NASA had an unlimited budget, then by all means do it all. But unfortunately that's not the reality right now.
It doesn't feel like NASA has a budget at all. Sure, they probably know how much discretionary cash they can spend this year, but for large projects, don't they pitch them to Congress and get them approved or denied?
Congress has effectively an unlimited budget, so if NASA have multiple exciting ideas, they "just" have to sell them each to the real bosses.
>But the fact of the matter, is that they just don’t excite us the same way as sending a human to explore it ourselves.
Yeah, I don't think sending humans excites enough people anymore to generate the broad political support required for doing that. Over the past ~20yrs, America has cannibalized our middle class to enrich the 1%. Expensive, manned Mars missions are an absurd luxury to the many who can't afford healthcare, whose small business has gone bankrupt due to COVID, or has to wait in food lines to feed their family.
It's quite possibly the case now that manned Mars missions will have to be handled by the private sector, which as someone above commented, is already working towards that.
Great 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.
It 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.
It 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.
You'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...
The 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.
I 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.
I 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.
The 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?
Thanks for that link. I think I have read something similar in the distant past but read through it again.
> There are [places] on Earth that do have these sharp ventifacts, but we hadn't seen them on Mars and we didn't test against them
This is whats so curious. In their testing on Earth after the fact, they found:
> Bedrock with lots of rocks: ~8 kilometers
> Lots of rocks, not on bedrock: 13-14 kilometers
> Bedrock with few rocks (think flagstones): 30-40 kilometers or more
It's just very surprising they didn't think to test on more varied Earth terrains, looking for worst case scenarios, where they would have clearly found this limitation. It is my understanding that the wheel damage became a major limiting factor of Curiosity's mission.
I 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.
For 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]
Earth 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.
Agreed, the amount of validation work that goes into these projects must be amazing, and even then the engineers have to essentially cross their fingers that no issues were missed. I think I’m spoiled in my job in that our software can at least be rolled back if we detect an issue after the fact (also much lower stakes).
Keep in mind that a lot of investments are made in ensuring that these things don't fail. Not saying its not a great achievement. But it helps to remember that for most software shops, reliability improvements are often treated as 2nd class compared with new feature development, which reflect the reality that most software shops don't really need quite that perfect amount of reliability.
This is a good point, which I think was reflected by in nickpeterson's comment as well. There's still a bit of a culture of "move fast and break things" in my line of software engineering that I don't think ever existed in space travel. (or at least hope not)
Absolutely spoiled. My team does a lot of testing in production. We can find real world faults quickly and easily, roll back, and save ourselves time and effort by failing in production intentionally. It’s about as easy as it gets, haha.
I have a theory that difference isn’t just quality level of the engineers, but the shared interest and stakes. Most things we attribute to engineering incompetence are really just carelessness because the stakes don’t appear high.
It's probably comparing apples to oranges. There are very talented software engineers and very talented non-software engineers. Regardless of the field, I think it's worth mentioning how extraordinary it is to take on an engineering feat that comes with so much risk. And while this isn't the case with the Curiosity rover, in my head I suppose I was thinking more of missions where human lives are at stake. I'm just a bit in awe at the courage and confidence someone must have to write code or design something and be comfortable that it will keep another human safe.
Meh, 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.
All 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...
Shoutout to Dr. Kathryn Weiss's great conference talk on Curiosity's Flight Software Architecture. I know of at least one other high availability robotic system that took a lot of inspiration from it.
Probably less so for Curiosity than the other Martian rovers. It's powered by an RTG rather than solar panels, so the only difference between day and night is the temperature fluctuations, which is still significant.
Panels wear slowly, but just from being hit by photons, blasted by dust, etc. - but that’s not the problem - batteries are. They don’t last forever, and every cycle takes a little out of their lifetime.
I recommend the stop motion video of the final two and a half minutes of the descent. Even with its low quality I think it's absolutely mind boggling because you're seeing the actual event.
I don't think I've lived in one place that long ever in my life. This is some amazing engineering, considering everything I own breaks after about 5 years.
What kind of stuff do you guys have that breaks? Sometimes I wish my stuff broke so I could upgrade it guilt-free, but it just doesn't happen. I have to find some unwilling victim to donate it to so it doesn't end up in a landfill.
The only thing I own that's broken in recent memory is this duvet cover I bought in 2008 that I've used every night since then... it developed some big holes after 13 years and I threw it away.
None of my tools, computer parts, furniture, etc. have broken. I've honestly never even broken a mobile phone, though I have dropped them a couple times.
I agree that computers from 10 years ago kind of suck when asked to run modern software. That's not "planned obsolescence", that's more like "software engineers made more complicated stuff more quickly; the downside is that you need a new $300 CPU instead of a decade-old $300 CPU". I'm okay with that.
I wasn't being too serious, but you're correct, usually things age out for other reasons, like old WiFi access points becoming obsolete or shoes getting worn, and the occasional cheap electronic crap from some startup that outsourced to China's lowest bidder.
Several years back NASA issued a warning on the slow progress of this mission. Their main objective was to traverse the sedimentary layers up Mt. Sharp. They havent really begun the climb yet. A long, dangerous sand dune caused a couple year delay. Plus lots of investigative stops along the way.
The power will last 20 years. The wheels are damaged from being too thin. If funding becomes tight, other missions will have precedence.
Interesting that they didn't go with what we base it in Western society, essentially the winter solstice. That said I've always thought the vernal equinox makes more sense.
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_Minut...