Stuff still has to pay for itself, one way or another. When government projects don’t bring in a return commiserate with their cost, people complain about waste (see the California $100B High Speed Rail project).
Sure, governments could do it anyway… but it wouldn’t be worth it. Maybe later when automated construction or some such can bring the price down.
And yet here we are with the stunning success of the Ingenuity helicopter, built on a relative shoestring budget–most of which went into the parts that couldn’t be COTS. The parts that were COTS, most of which were never designed to go into space at all, let alone Mars, performed admirably.
The inclinometer was a $5 part you can buy from Digikey. The IMU was $30 from the same source. Bog-standard Sony li-ion cells, a Qualcomm SOC found in cheap-ass cell phones, some equally cheap cameras units, etc.
Almost all worked perfectly fine on Mars, the craft only failing after a bad landing. They had neither the money nor the mass budget to meaningfully “bring it up to an adequate standard of reliability” for Mars, whatever that would even mean in this context (it has no real radiation shielding, for example). It was accepted to be a high-risk mission but it turned out that all the COTS stuff just plain worked with no special handholding (ok, the inclination sensor did stop working eventually, but that wasn’t a mission-killer).
No, that’s a myth. Public corporations are required by law (among other things) to be transparent about their governance and financials, so that the public understands what they’re investing in. That is the real reason SpaceX hasn’t gone public, Musk doesn’t want you to have the information to tell if he’s lying or not.
This begins to sound more and more like Carl Sagan’s epistemic argument of “I have an invisible dragon in my garage.” Whenever you ask a new question about how to detect if the dragon is really there, it turns out the dragon has some interesting property rendering it immune to observation. You see, it’s invisible. It makes no sound, has no smell, it emits no infrared, etc. This is how the Mars colony will remain in perpetuity. This is why it can be anything you want to believe, provided that you don’t actually need to observe it in reality.
I seriously doubt anyone’s saying “this is too much Mars, too fast, it’s too scary, we can’t handle it.” More like, “we know you’ve not done the work to get there in 7 years, stop pretending like you are.”
But more than that, do you honestly, credibly see Musk listening to any public criticism telling him to slow down? It’s unlikely criticism would cause him to moderate, more likely he would accelerate. So I chalk this story up as a Musk-head wives’ tale to assuage anxieties about why the Mars program doesn’t really seem to be working on anything specifically Mars-related. “boo hoo, Elon slowed things down because the public wants us to go slower.” Yeah, that’s not happening, sorry.
Also, from a billionaire’s perspective, a 260 day journey from disgruntled lesser humans with 3D printed guns and a serious grudge against corporations.
It might be more accurate to say no immediately lethal or debilitating effects. Everyone spending an extended time in orbit does, in fact, show effects from the radiation. Vision changes being one common one. Or maybe that’s from the microgravity. Or both. Or some unforeseen impact of living in a sealed tin can with other people that probably smells like old socks/locker room with minimal fresh food and other environmental strangeness. It’s actually not very certain.
That said - I could certainly see “long treks through the Marinaris Valley” or “summiting Olympus Mons”. Although civilian limits are currently 1 millisievert per year and our Mars colonists would blow through that in less than two days occupational exposures up to 50 milliseiverts per year are allowed. Arguably, being a Mars colonist is an “occupation”. At 0.7 mSv/day that gives you 71 days out on the surface before blowing the occupational limits. You have to get to hundreds of mSv before showing symptoms (generally in the neighborhood of 500). Of course, the additional radiation will raise cancer risks, as well as increase cataract formation, but none of that will bar people reproducing sufficiently fast to maintain a population IF there is sufficient resources to support life otherwise.
As far as that civilian limit of 1 mSv/year… A CT scan typically doses you with 20 mSv. Clearly, there’s a risk vs. benefit calculation here, and adjustments in permitted levels may need to be adjusted for a Mars environment, but it wouldn’t be sudden death (most of the time) to be on the surface.
Yes, you’d probably want to bury living quarters and the rest of where humans spend most of their time, but it will certainly be feasible to spend time on the surface without constant heavy shielding. Even if there are reasons to shield whenever possible.
Depends on how you go about the LARPing. NASA did LARPing for Moon missions in desert areas, as an example, and will “LARP” zero-g procedures in a giant tank of water prior to sending people into space to do a job. Can’t rehearse everything on the surface of the Earth but you can do enough to make it easier for people to do things in space or on another solid body. The concept is sound, it’s how you go about it that determines if it’s actually useful.
I agree that there are some health uncertainties there, but the microgravity is almost certainly the dominant one when it comes to people living on the ISS. In particular because we can compare against people on Earth with similar levels of radiation exposure and they don’t have the same problems.
There is the problem that, in all likelihood, the first trips to Mars won’t have any sort of artificial (centrifugal) gravity while on the ship. Just too complicated and risky for the time being. So people will have 6ish months of microgravity exposure before arriving, and when they land they won’t have a team of medical specialists to help them recover, or even help them off the ship. So they’ll have to do everything in their power to stay in shape, although there will still be residual issues.
Beyond that, it’s unknown how people deal with 37% gravity. Maybe I’m optimistic, but my intuition is that it’s enough to avoid almost all of the gravity-related health effects, even in the long term. People can walk around almost normally, there’s a consistent “up” vector, etc. They’ll be able to use all of their muscle power, which means they’ll be able to jump to great heights and lift heavy weights. Will that actually pan out? Only one way to be sure. Though depending on the schedules, we may have some data from the Moon first. If people do ok in 1/6 gee, they’ll do fine in 1/3.
I agree, and I honestly don’t know enough about their efforts to say how useful they are. They aren’t trying to replicate a fully closed life support system. But research into the social isolation aspects, communication delays, difficulties in living in a small habitat, etc. might prove useful.
I am confident that they’ll at least try to put two Starships making the journey at the ends of a mutual tether. Doubtless there will be complications but it should be an (eventually) solvable engineering problem. Heck, if they can solve any secondary and tertiary problems like stability, it might even be done on that high-orbit dress rehearsal I mentioned upthread.
Eventually, maybe–but not the first or even the twentieth flight. Would be cool, certainly. Plus all kinds of opportunity for folks on the North ship to plot against those on the South ship, and vice versa, each figuring out how to fling the other into deep space so that their own people can claim all of Mars for themselves…
Everyone always says this, and I don’t know why. Tell any terrestrial construction company “Take this capsule, and make some cables that it can hang from safely for a few years”, and they’d tell you “No problem, that’s easy”. Even if you tell them “put a winch on it so it can be raised or lowered at will”, that’s still easy. And that’s if you want a full g on the capsule: If a third of a g (what the astronauts/colonists/explorers will be getting on the surface of Mars) is good enough, then it gets that much easier.
As an aside, long-term exposure to gravity in between zero and Earth is something else that there’s been basically no research on. Maybe it has no health impact. Maybe it has a health impact, but it’s minor. Maybe it’s almost as bad for health as protracted zero g. Maybe it’s actually better for you than Earth gravity. We just don’t know, and that’s another thing we should research (in Earth orbit with centrifuges) before we launch a protracted Mars mission.
As I get older and less robust, I am almost sure that the gravity regime on Earth is far too high, and I’d like to opt for one slightly lower, if that’s on offer, thank you very much. Back problems, leg problems, problems with falls and lifting weights; Mars sounds pretty good to me in that respect, if maybe a bit too low.
Sure, you need more stress when you are young, to increase bone density; but I’m sure this could be replicated with suitable exercise equipment and so on. I’m almost certain that when we do finally get round to building rotating space habitats, the optimum gravity will be 0.8 gees (or even less).
While I haven’t studied this in detail my recollection from reading over the years is that the only way to reliably increase bone density is living for an extended time under greater gravity. If I recall some experiments were done with raising chickens under 2g’s. Just exercising more doesn’t seem to work that well, we’ve been trying to come up with an exercise regime that could be done in microgravity to sustain bone and muscle and we haven’t managed it yet despite a few decades of trying. The best we’ve done is slow down the deterioration.
To be very clear we already know that even moderately short times in space (station trip lengths) have significant negative health impacts.
We don’t know how much of that is low gravity, how much low magnetic fields, how much radiation exposure, how those interact, or if there are other factors.
But that’s microgravity. We have almost no data on lunar or Martian gravity. There’s been just one centrifuge experiment on the ISS with mice. And it is better than microgravity, but not as good as Earth gravity.
Still, it’s just mice, and they were in very tiny cages, and they only tested a few things. IIRC they also only tested lunar gravity vs. a 1 g and 0 g control.
Unfortunately, the only hope we have for real human data before a Mars mission is on the moon. The ISS is a dead man walking and isn’t going to get a human centrifuge in the next few years, and probably not even another rodent centrifuge that could produce better data.
Artemis will provide some data, though it’s such a short duration on the moon that it might be hard to conclude anything. We need a moon base.
Curious enough to find the study:
https://www.nature.com/articles/s41598-024-79315-0
It is also interesting that the “better” varied by organ.
It’s tough to come up with good exercises in zero g, but there’s a difference between zero g and low g. If you’re in low g, you can do things like wearing lead clothes to bring your total weight up to Earth normal. Is that good enough? We don’t know, because we’ve never tried it. But it’s definitely not good enough for zero g.
A lunar colony (or long-duration research base, or whatever) is another thing we ought to do before a Mars colony. The environment on the Moon is slightly less hostile than Mars, but if things go wrong, it’s a lot more realistic to do emergency response (resupply, evacuation, whatever) from a few days away than a few months away.
That’s the one. Thanks for digging it up.
I think it’s reasonably promising with respect to humans. It suggests that there is a kind of threshold effect, at least in some cases. The spleen lost mass in zero g but not 1/6. Bone and thymus were partially improved vs. microgravity. As Chronos suggests, weights can probably help somewhat with muscle/bone as long as there is some gravity. And IMO, much of that will be solved without extra effort by virtue of people engaging in heavier activity than on Earth (carrying heavier loads, jumping higher, etc.)
It’d be great if it were that easy, but complications have a way of arising. A cable would be much lighter and simpler than say a rigid truss but it introduces potential problems. At a minimum there probably needs to be shock absorption built into it: you don’t want a “crack the whip” situation, or either Starship swinging or twisting on the cable end. You definitely don’t want random vibrations from the ships to build up resonances. The sort of surprises that the real world loves to throw at engineers. Heck it was only comparatively recently that the Tennis racket theorem - Wikipedia made it’s way into the consciousness of people planning rotating habitats.
ETA: fun discussion, but I think we’ve moved quite a distance away from the OP, which was about the contention that not mastering closed environments here on Earth first meant that the Mars plans were faulty. Maybe a lot of this should be moved to The Great Ongoing Space Exploration Thread
Exactly my line of thinking. It would be one thing if it were as easy as hanging the ship by a cable. But even rigid-body dynamics in space get weird (as evidenced by your example of the tennis racquet theorem), let alone flexible-body dynamics. I’m sure there are ways to solve all these problems with dampers and such in all the right places, but it’s not trivial. Not to mention all the spin-up/down related issues.
One contention that always seems faulty to me is that Biosphere 2 failed because they could not maintain a breathable atmosphere by generating oxygen from photosynthesis inside a closed environment. Well, that makes no sense; Earth’s atmosphere is not a closed environment in that sense, since nearly all the oxygen we breathe has been accumulated over hundreds of millions of years of photosynthesis in the past, and the oxygen generated by our contemporary biosphere is trivial in comparison.
For demonstrate this, if we killed and burned all the plants on earth and in the oceans, this would only reduce the oxygen level in the atmosphere by a percent or so. It would mess up the CO2 levels, on the other hand.
If we ever create any closed ecological life support systems off Earth (and I’m sure we will, one day) we cannot afford to rely solely on the actions of photosynthesis to generate oxygen - that doesn’t work on Earth, today, and it wouldn’t work on Mars, or the Moon. In Antarctica, of course we have plenty to breathe.
IMO that logic is faulty.
Biosphere started with a normal Earth atmosphere’s supply of oxygen. The plants inside were not tasked with creating all the oxygen. Just with creating the amount the animals consumed once the airlocks were sealed. The animals in turn were tasked with consuming the amount the plants created. Which is no different than the real world.
Now in reality Earth’s CO2/O2 cycle is a lot more complex than the lie to 4th graders that “Plants consume CO2 & make oxygen; animals do the opposite.” There are many other major contributors to the total reality of Earth atmosphere O2/CO2 balance.
All of which would have to be duplicated in appropriate scale inside Biosphere, or else compensated for, deus ex machina style, by simply artificially adding or subtracting O2 and/or CO2 according to your calcs about the rest of Earth. Not according to “whatever it takes to maintain Earth-like percentages inside”.
In the case of Biosphere 2, they were unaware that newly poured concrete continues to absorb oxygen for years as it cures.