I agree with your overall point that this is harder than people think, however a lot of this Mars landing inaccuracy is due to so much of the descent being controlled by parachutes instead of being propulsive. If (and it’s hard) people like SpaceX can use propulsive descent for much more of the process, the accuracy will improve very quickly.
One reason for (cautious) optimism here is the tests SpaceX has been performing at propulsive deacceleration in the upper atmosphere when returning boosters, and their tech/data sharing agreements with NASA which cover their Mars landings. There are similarities to the atmospheric density of Mars at those altitudes, so some valuable experience is already underway. It’ll still take years and a lot of risk as you guys point out, though.
I think the drivers for when we might send people to Mars have about zilch to do with science or technology.
Right now all this is being done in the name of pure science, as there’s no actual material gains for going to the moon/mars/etc. And if we want to do science, robots are much hardier explorers than humans. So at the end of the day, the motivation (and thus funding) for going to Mars is going to depend on external factors. We did the moon mission to demonstrate rocketry/technical prowess in the context of a cold war. If another such situation arises where we want to flaunt American wealth and prowess at foreigners, it could get prioritized. Otherwise it’s a very expensive exercise with only symbolic gains.
Several people have mentioned radiation, both in transit and on Mars, but isn’t that a pretty easy problem to solve by storing the water for the mission in the outer shell of the craft? Water is great at damping radiation.
Absolutely, and fuel reserves can help with this too, but water and liquids are heavy and moving it to where it’s needed at every moment (e.g. temporarily switch from cosmic rays protection in all directions to emergency shielding from a solar flare) is hard in space without messing up something else. If larger ships can launch, it’s probably quite reasonable to do given enough weight allowance, but it will take time to get right.
Also, given the research into better materials/construction for shielding based on what we’ve learned on the ISS, we should be able to make the skin of the future ships better as well. Again, needs some more time.
JoshL
3695
Water is heavy. In fact, it doesn’t matter what you use as shielding, it’s going to be heavy. It is very expensive to move that much mass into orbit from Earth, which is why it is better if we can get it somewhere else (asteroids, the moon, etc), although water is hard to find.
The problem with using water is that then you’ve used up your shielding by the time you want to come back.
One nitpick here, used water doesn’t just disappear. You keep recycling the waste water on long-duration missions. We’re starting to learn how to do it on the ISS. We’ve gotten a lot better at it during the lifespan of the ISS already.
JoshL
3697
Fair point. Unless you use it as propellant :)
Yes, true.
The other thing which helps once you land is that regolith/“dirt” is a good way to shield against radiation as well. You just need to learn how to build things on the moon or Mars. We’re working on it slowly…
All of this is why the first real Mars mission should be assembled in space, or perhaps on the Moon. You either send up water over a period of time on many ships, or you find/mine/manufacture it on the Moon. That would be better than shipping from Earth, but either way, there is a significant period of time required to get enough of it up there to send a mission.
And we really do need to send a LOT of stuff on Mars before humans go. I’m personally in favor of not bothering trying to bring them back–if you are sending volunteers anyway, get volunteers willing to colonize, and land enough stuff ahead of time to make a permanent village type situation. Then you send enough people for a viable village. Set it somewhere they can start mining their own water, and hopefully other materials as well, and keep shipping them stuff. But don’t even try to figure out how to get them home. Return trips are a well-into-the-future thing.
One clarification about that for those who haven’t followed it, the Starship proposals are sort of assembling the mission in space. The ship isn’t, but the fuel at least is. The idea is that each Mars mission would take something like several Starship launches, one with the passengers and the interplanetary ship, but it burns all its fuel to get to orbit. The rest of the launches are special tanker Starships which use some of their fuel to get to orbit and transfer the rest to the primary ship.
SpaceX never proposed single launch to Mars. Their goal is to refuel to have a fuel-heavy burn to Mars which allow fast transit times (relatively.) It’s still hard to do, of course.
JoshL
3701
Is a return trip really harder than setting up a base that will allow people to live the rest of their lives on Mars? I mean, they both seem pretty hard.
Menzo
3702
I would imagine not. We have no idea how to make food on Mars right now. We have theories about making water.
That is a very interesting question!
Bah, we know how to grow potatoes! We just science the shit out of them!
There’s a scientific debate going on about things in the martian “soil” which we didn’t used to know about (Andy Weir, author of The Martian has lamented this recently.) We now know that on the one hand (like Menzo hints at) there’s a lot of water well distributed below the surface that we might be able to use. On the other hand, we now know of poisonous perchlorates in the soil which most plants wouldn’t like.
So, we need to solve how to cook the perchlorates out of the soil and extract the water we need from below the surface while we’re there (plus add Earth microbes like in The Martian.) Scientists seem to disagree on how hard this is. It needs a lot more investigation to even understand the difficulty.
Or just fly in water and supplies from Earth to grow things hydroponically (with good water reuse.) That might work at first given a lot of funding and shorter missions. I assume if NASA does things the traditional way that’s what we’d end up doing eventually.
Menzo
3706
And to learn what we need to know about Martian soil we need to send a rover to collect multiple samples and return it safely to earth. That’s 10 years from today, at best.
So SpaceX’s hardware runs on commonly available software apparently. The Core OS for the Falcon 9, Dragon, and Starllink satellites is a custom Linux distro, and the UI the Dragon crew uses on those screens is based off of Chromium. So just web apps of HTML, JavaScript etc. Pretty cool reading.
I’m 60, I’m planning on seeing humans land on Mars before I die, but I’ll admit Elon’s either going to have get better at hitting schedules or I’m going to have to live for a long time, and if he goes broke or gives up I’m screwed.
I don’t really want to see people go to Mars, because in my opinion it’s an enormous waste of resources. The only reason to go as @Tortilla said is symbolic - and I’m not really supporting blowing billions of dollars on symbols.
Mars is uninhabitable. It’s a definition. If you go outside you die. Even on the day the comet hits, or the hour that we trade nukes with Russia, Earth is habitable and Mars is not.
So no public dollars from my vote. But I suppose if it’s privately funded, go ahead. I doubt that will ever happen; four astronauts on Falcon 9 costs $57 million. Say 100 times that or $1.5 billion dollars per ticket. Maybe a few could afford it, but what’s the overlap of those with people that want a 40% chance of death, and a reputation for not using their wealth for better purposes?
My 2 cents. I’ll go play Offworld Trading Company - a good game that I never got into but mean to try again.
