Overnight to Mars

[Roboramma]

All that's left is engineering folks. Is this actually more feasible than having astronauts spend months in low gravity?

We've already basically solved the problems of living in micro-gravity for months. We know how to maintain human health in the environment, at least well enough.
The exposure to cosmic rays and radiation from the sun is possibly a bigger issue, and could be more motivation for speeding up the trip. I think we have reasonable solutions and the increased cancer risk, while serious, isn't enough to make a mars trip unfeasible. But don't actually have practical experience with dealing with that particular hazard.

Laser propulsion seems like a good idea and something worth more research and development.

 

[Gord_in_Toronto]

We've already basically solved the problems of living in micro-gravity for months. We know how to maintain human health in the environment, at least well enough.
The exposure to cosmic rays and radiation from the sun is possibly a bigger issue, and could be more motivation for speeding up the trip. I think we have reasonable solutions and the increased cancer risk, while serious, isn't enough to make a mars trip unfeasible. But don't actually have practical experience with dealing with that particular hazard.

Laser propulsion seems like a good idea and something worth more research and development.

The link I gave earlier in this thread says that the issues had not been resolved:
https://www.space.com/spaceflight-destroys-red-blood-cells

The damage is irreversible.

As to what happens in the future (if there is a future), it comes down to a race between medical science and engineering. Place your money here.

 

[theprestige]

"NASA and China plan to mount crewed missions to Mars in the next decade"

I'd like to see their plans for mounting an uncrewed return trip mission to Mars in the next decade. I don't see why this has to be an Apollo-era "all of our test flights have to be crewed because we can't figure out how to do it any other way" type effort.

 

[RecoveringYuppy]

"NASA and China plan to mount crewed missions to Mars in the next decade"

I thought Musk was going first?

Where did you get that quote? Earliest dates I can find are NASA 2037 and China for 2033. And neither is certain.

 

[Puppycow]

Where did you get that quote? Earliest dates I can find are NASA 2037 and China for 2033. And neither is certain.

Maybe by "the next decade" they meant the 2030s.

Personally, I would be surprised if there really is a manned mission to Mars by anyone before 2040. If it does happen, I think it will be very high risk.

 

[Roboramma]

The link I gave earlier in this thread says that the issues had not been resolved:
https://www.space.com/spaceflight-destroys-red-blood-cells

The damage is irreversible.

It's not crippling. It's not deadly. People have lived in space for months on end, and are still leading relatively healthy lives. Anemia isn't something that's going to prevent people from going to Mars. The length of the trip from earth to Mars is equal to the length of time that we've already had people living on the ISS. Since we've already done it, I don't see it being a dealbreaker here.

 

[arthwollipot]

It's not crippling. It's not deadly. People have lived in space for months on end, and are still leading relatively healthy lives. Anemia isn't something that's going to prevent people from going to Mars. The length of the trip from earth to Mars is equal to the length of time that we've already had people living on the ISS. Since we've already done it, I don't see it being a dealbreaker here.

The ISS is within the Earth's magnetosphere. The trip to Mars isn't. The problem with going to Mars isn't microgravity, it's high-energy cosmic rays causing cancer and other severe damage. And according to NASA, the only way - the only way - to protect astronauts from this is to make the trip as quickly as possible and try to treat the damage when they return.

Source: the Skeptic's Guide to the Universe podcast, where they refer to talks by NASA astronauts at the most recent NECSS conference. I don't have links.

 

[Roboramma]

The ISS is within the Earth's magnetosphere. The trip to Mars isn't. The problem with going to Mars isn't microgravity, it's high-energy cosmic rays causing cancer and other severe damage. And according to NASA, the only way - the only way - to protect astronauts from this is to make the trip as quickly as possible and try to treat the damage when they return.

Source: the Skeptic's Guide to the Universe podcast, where they refer to talks by NASA astronauts at the most recent NECSS conference. I don't have links.

It's weird that you're telling me this when I made that exact point myself:

The exposure to cosmic rays and radiation from the sun is possibly a bigger issue, and could be more motivation for speeding up the trip. I think we have reasonable solutions and the increased cancer risk, while serious, isn't enough to make a mars trip unfeasible. But we don't actually have practical experience with dealing with that particular hazard.

 

[GlennB]

Where did you get that quote? Earliest dates I can find are NASA 2037 and China for 2033. And neither is certain.

https://www.universetoday.com/tag/mission-to-mars/

But the 2030's are 'next decade'.

 

[RecoveringYuppy]

Maybe by "the next decade" they meant the 2030s.

Personally, I would be surprised if there really is a manned mission to Mars by anyone before 2040. If it does happen, I think it will be very high risk.

Personally I think there is little reason for people to go to Mars. I think we should develop near Earth first. And develop it more than NASA currently has plans for (they plan a small moon base prior to going to Mars).

I think the risk is too high for the current time it takes and the current mass we can launch from Earth. We're going to need to go faster, and/or artificial gravity, and/or massive radiation shields.

Can't find anything authoritative on how to parse "next decade", but most sources seem to think that would mean 10 years from now.

https://forum.wordreference.com/threads/in-the-next-decade.3557799/

 

[arthwollipot]

It's weird that you're telling me this when I made that exact point myself:

Consider it me agreeing with you. Or maybe I just skim-read the thread and commented where I felt like it.

 

[Roboramma]

Consider it me agreeing with you.

Always a wise choice.

 

[Doghouse Reilly]

The link I gave earlier in this thread says that the issues had not been resolved:
https://www.space.com/spaceflight-destroys-red-blood-cells

The damage is irreversible.

As to what happens in the future (if there is a future), it comes down to a race between medical science and engineering. Place your money here.

The article you shared absolutely does not say the damage is irreversible, I don't think you read it carefully. It says that after 3-4 months SOME of the issues hadn't been fully resolved (but even those issues had been partially resolved), while some of the issues had been completely resolved. That's a very, very far cry from "the damage is irreversible."

 

[RecoveringYuppy]

The length of the trip from earth to Mars is equal to the length of time that we've already had people living on the ISS. Since we've already done it, I don't see it being a dealbreaker here.

Not quite, unless you're counting on sending the astronauts faster than most plans expect.

An astronaut is just a week or so away from setting the new American record and that will be less than a year (353 days) which is a bit short of the 21 months Mars might take.

https://en.wikipedia.org/wiki/Mark_T._Vande_Hei

The Russian record holder is at a bit over 14 months.

 

[BowlOfRed]

Not quite, unless you're counting on sending the astronauts faster than most plans expect.

The quote specifically said the length of the trip from earth to mars. That's normally planned for 9 months.

An astronaut is just a week or so away from setting the new American record and that will be less than a year (353 days) which is a bit short of the 21 months Mars might take.

3 months of that time would not be zero-g, but on the ~38% earth gravity of mars.

 

[RecoveringYuppy]

The quote specifically said the length of the trip from earth to mars. That's normally planned for 9 months.

But he was supporting his assertion that we have basically solved the problem of living in micro-gravity for months. Comparing it to a one-way trip is meaningless unless you have a way of teleporting back.

There's really no way you can call this problem solved now.

Seems perfectly fine to assume we can be ready in 15 years though. Either by learning to live longer in micro-gravity, or speeding up the trip, or a bit of both.

If a moon base is built first (which seems to be the plan favored by NASA) we'll have some significant experience at 1/6 G which would be useful for evaluating what might happen on Mars. But, obviously, we don't have that info now.

3 months of that time would not be zero-g, but on the ~38% earth gravity of mars.

Which we have zero experience with. No prudent plan can make the assumption that that isn't going to be as bad a zero g. Really, to be prudent we have to plan that it might be worse. Until we have that Moon base experience.

ETA: BTW I don't know how much these faster transit options would speed up the total mission time. Some (all?) of these faster mechanisms will still have launch window constraints. That would mean these speeds up can't be used solely to reduce to mission time. Some of the time saving would have to be used as longer time on Mars waiting for the window.

 

[Roboramma]

Not quite, unless you're counting on sending the astronauts faster than most plans expect.

An astronaut is just a week or so away from setting the new American record and that will be less than a year (353 days) which is a bit short of the 21 months Mars might take.

https://en.wikipedia.org/wiki/Mark_T._Vande_Hei

The Russian record holder is at a bit over 14 months.

Thanks, that's a valid correction.

But we disagree about this part:

3 months of that time would not be zero-g, but on the ~38% earth gravity of mars.

Which we have zero experience with. No prudent plan can make the assumption that that isn't going to be as bad a zero g. Really, to be prudent we have to plan that it might be worse. Until we have that Moon base experience.

We know what the actual health problems with zero gravity are (ie. bone density loss, etc.) and they are caused by, well, zero gravity, in ways that will necessarily be mitigated by low gravity.
If you were talking about issues with gestation, for instance, I'd agree that we really don't know, but bone loss? Yes, it's proportional to the gravity.
My expectation is that we could get significantly improved condition in the astronauts during their time on Mars such that even subtracting the time on Mars from the total isn't reasonable.

I do think you're right that it makes sense to actually test these expectations, for instance on the moon.

(It's also quite possible to include artificial gravity on the spacecraft that we send to Mars if this really is an issue, but it's probably not necessary.)

 

[RecoveringYuppy]

We know what the actual health problems with zero gravity are (ie. bone density loss, etc.) and they are caused by, well, zero gravity, in ways that will necessarily be mitigated by low gravity.

I didn't get impression that we understand the anemia problem mentioned upthread.

My expectation is that we could get significantly improved condition in the astronauts during their time on Mars such that even subtracting the time on Mars from the total isn't reasonable.

Well, that's my expectation too but I don't thinking trusting untested opinion is prudent even when they are my opinions.

But still that lead to 18 months to plan for. Would you agree that we don't currently know if that 3 months in partial gravity is enough to trigger any sort of recovery? Unless we confidently know that we have to plan for this as 18 continuous months rather than two 9 month stints with recovery in between.

(It's also quite possible to include artificial gravity on the spacecraft that we send to Mars if this really is an issue, but it's probably not necessary.)

Yeah, I mentioned that myself but note the we don't have any experience with 9 or 21 months of that either. And given the size limitations that are likely to exist for any craft in the next 20 years an artificial gravity solution is likely to require rapid rotation or only provide partial gravity. So that doesn't fall in the "completely solved" area for me yet either.

BTW There is also the radiation problem. There might be reason to think we understand how radiation affects the body since we can study that here on Earth. But I'm not sure how much we actually know about 21 months of cosmic ray exposure. I'm not sure that has been properly studied since accurate studies would raise ethical issues. But, further, is our understanding of the physiology of the micro-gravity problems sufficient to confidently say they won't be complicated when high radiation is thrown on top of the lack of gravity.

 

[theprestige]

There's also the problem of guaranteeing a successful liftoff from the Martian surface, for the return trip. That's the one problem I'm really interested in seeing them solve.

 

[RecoveringYuppy]

There's also the problem of guaranteeing a successful liftoff from the Martian surface, for the return trip. That's the one problem I'm really interested in seeing them solve.

Interesting choice. Why? That would be a problem I think we do understand well enough now. I expect one or two sample return missions will happen before we send people. I also see a way to mitigate risk by sending the ascent components to Mars on an earlier mission.