What If we HAD to get to Mars on Short Notice

GCNRevenger · 2007-01-12 15:21:11

...at the rate things are progressing the past 30 years, I'd say if we had to get to Mars on short notice we'd be screwed.
Getting there is a hard problem but not as hard as getting back. It's doable one way relatively quickly, say in 10 years given the funding. The "hold and and build" model is one approach. The first crew of six on Mars would stay indefinitely, they would be resupplied regularly as they built up infrastructure and explored. The capability to return two crew would be possible in the first cycle. Additional crew would be added as the base expanded. The plan would be to maintain a permanent presence and slowly grow it as capabilities were established. Some of the initial crew might never return to Earth.

What are you talking about? Thats a crazy idea

C M Edwards · 2007-01-12 16:00:06

...at the rate things are progressing the past 30 years, I'd say if we had to get to Mars on short notice we'd be screwed.
Getting there is a hard problem but not as hard as getting back. It's doable one way relatively quickly, say in 10 years given the funding. The "hold and and build" model is one approach. The first crew of six on Mars would stay indefinitely, they would be resupplied regularly as they built up infrastructure and explored. The capability to return two crew would be possible in the first cycle. Additional crew would be added as the base expanded. The plan would be to maintain a permanent presence and slowly grow it as capabilities were established. Some of the initial crew might never return to Earth.
What are you talking about? Thats a crazy idea

No it's not... once you have a secure, permanent base large enough to absorb such shift changes.

Trying to start off that way is insanely risky, though.

cIclops · 2007-01-12 16:08:17

No it's not... once you have a secure, permanent base large enough to absorb such shift changes.
Trying to start off that way is insanely risky, though.

Where's the risk? The biggest one is medical, namely physical adaptation to 1/3 g and psychological isolation. The later will be managed by a clear commitment to base expansion and careful screening of crew. Lunar base studies should provide the missing data point between 0 and 1g and eliminate much of the gravity adaptation risk. There is probably far more risk in returning to Earth than staying. Eventually all crew will have the opportunity to return, just not all at the same time.

If we are serious about settling Mars, then why not start sooner rather than later, it solves so many problems.

cIclops · 2007-01-12 16:53:09

So the architecture would look like this:

Cycle 1:
o HAB to surface
o full crew (6) land near HAB
o Cargo to surface

Cycle 2:
o ERV into Mars orbit
o Crew(2) land near base in lander/ascender
o 2 crew return to orbit in ascender and take ERV back to Earth
o Cargo to surface

Cycle 3:
repeat Cycle 2 or Cycle 1

Michael Bloxham · 2007-01-12 17:55:33

I don't think its insane, just potentially rather pointless.

I think GCNR knows his stuff. Perhaps it's a shame that the Mars Society is so one-sided when it comes to MD or DRM (whether this is official or not, I don't know), especially in light of Zubrins contributions to DRM. However, I think everyone could benefit from being a little more open-minded. Just in case there's still room for improvement.

cIclops · 2007-01-13 05:24:50

I don't think its insane, just potentially rather pointless.
I think GCNR knows his stuff. Perhaps it's a shame that the Mars Society is so one-sided when it comes to MD or DRM (whether this is official or not, I don't know), especially in light of Zubrins contributions to DRM. However, I think everyone could benefit from being a little more open-minded. Just in case there's still room for improvement.

So starting the human exploration and settlement of Mars as soon as technically possible is "rather pointless"?

The prime difference with other plans is extending the time crew stay on the surface and synchronizing their return with the 26 month optimal transit geometry.
This has several advantages:

1. Makes human missions feasible with the current Constellation system (provided the problem of accurately landing large mass packages can be solved)

2. Establishes a continuous human presence on Mars rather than a series of disconnected 18 month visits.

3. Minimizes and spreads the cost and risk by avoiding the development of an horrendously expensive return capability for 6 crew from the very beginning.

4. Greatly simplifies the architecture and focuses development and funding on surface capabilities (international partners provide surface projects in exchange for seats to Mars)

5. Minimizes boiloff of the ERV and ascender fuel by returning them directly rather than loitering in orbit or on the surface.

6. Provides the time and through time the budget (and motivation) necessary to develop new technologies to enhance surface and transportation capabilities

7. Presence of people on the surface will multiply the effectiveness of surface technology (ISRU, greenhouse, power) by on site maintenance

8. Evacuation mode possible by sending several ERVs.

C M Edwards · 2007-01-13 16:29:51

3. Minimizes and spreads the cost and risk by avoiding the development of an horrendously expensive return capability for 6 crew from the very beginning.
[...]
8. Evacuation mode possible by sending several ERVs.

Yep, that's the risky part of small ERV's.

Once you have a base that's stable enough that you're reasonably sure you won't have to abandon it at any time in the coming year, then you can talk about not having sufficient ERV capability on site to get everybody home at once.

Of course, two-person ERV's are slightly more desirable mass-wise, and its extremely desirable to use them periodically rather than leave them lying around until the limit of their shelf life. That's the good part of this scheme. However, it is absolutely imperative that sufficient transportation for a complete and immediate evacuation of all hands be available for at least the first few years.

That means several two-person ERV's, all available for use upon arrival.

The goal should always be - always - to enable the crew to stay as long as possible. Permanently, IMHO. But if they can't be ready to blast off as soon as they shake off the dust of their first surface jaunt, the mission archiectecture is not safe.

cIclops · 2007-01-13 17:00:58

Once you have a base that's stable enough that you're reasonably sure you won't have to abandon it at any time in the coming year, then you can talk about not having sufficient ERV capability on site to get everybody home at once.
Of course, two-person ERV's are slightly more desirable mass-wise, and its extremely desirable to use them periodically rather than leave them lying around until the limit of their shelf life. That's the good part of this scheme. However, it is absolutely imperative that sufficient transportation for a complete and immediate evacuation of all hands be available for at least the first few years.

Why is "immediate evacuation of all hands" necessary? If an emergency happens shortly after Earth departure there is no immediate evacuation possible for over a year (the time to swingby Mars back to Earth). So that's one year minimum that is part of any Mars mission plan.

What disaster scenario would require the immediate evacuation of all crew from the surface? Of course there would have to be sufficient backup power, habitable shelter and supplies available as there would be in Antarctica or any remote location. People at the Mars base are not in the same situation as on ISS where depressurization, extensive fire or total loss of power or attitude control would mean abandoning the vehicle. Millions of people each year fly in aircraft without any form of immediate evacuation. A Mars base is not an aircraft or a spacecraft, it won't crash or explode. Backup emergency facilities will be available while repairs are made, that's one big advantage of a planetary base. Crew have somewhere to go: the surface.

Immediate evacuation of the surface isn't a survival option either for much of the time in the DRM or MD plan. The return vehicle wouldn't have the endurance to reach Earth, the crew would just slowly die in space. The best form of evacuation of the HAB is to a nearby emergency shelter.

Dayton Kitchens · 2007-01-13 17:19:12

I agree.

The ability to return all the humans on Mars in one vehicle at one time isn't necessarily a vital part of a manned program. Though it might require some change to peoples way of thinking.

And to be honest, I think you might have to make your crew two sets of married couples at least.

cIclops · 2007-01-13 17:25:25

And to be honest, I think you might have to make your crew two sets of married couples at least.

If that was a mandatory requirement for the crew, immediate evacuation from the surface might become necessary

C M Edwards · 2007-01-13 21:05:48

Ciclops, I think that this could be an important point, so I'm going to parse it out...

Why is "immediate evacuation of all hands" necessary? If an emergency happens shortly after Earth departure there is no immediate evacuation possible for over a year (the time to swingby Mars back to Earth). So that's one year minimum that is part of any Mars mission plan.

The time for a free return trajectory on the six month transit advocated in Mars Direct is two years, and I think its similar for DRM. That's six months hapless in space (from a propulsion perspective), followed immediately upon landing by an opportunity to hop an ERV and return to Earth in nine months rather than eighteen - if an ERV is available. If something bad enough to abort the mission but not bad enough to abort the landing occured during that transit (say, losing half the crew, half the food, half the laundry, or whatever), it might be nice to have the option of returning the crew nine months early.

Of course there would have to be sufficient backup power, habitable shelter and supplies available as there would be in Antarctica or any remote location. People at the Mars base are not in the same situation as on ISS where depressurization, extensive fire or total loss of power or attitude control would mean abandoning the vehicle. Millions of people each year fly in aircraft without any form of immediate evacuation. A Mars base is not an aircraft or a spacecraft, it won't crash or explode. Backup emergency facilities will be available while repairs are made, that's one big advantage of a planetary base.

A mars base would exist in vacuum, just like the ISS, and be subject to the same problems. However, the ISS has an escape vehicle, and an airplane can descend. However, if the problem is with the pressure vessel of the base, but on a timescale allowing evacuation, the best solution isn't to flee back to Earth but to move to a new pressure vessel. If a backup living quarters can be provided, the majority of mechanical problems become something better handled by repairs, not aborting the mission.

Crew have somewhere to go: the surface.

Where the ERV's are waiting....

The return vehicle wouldn't have the endurance to reach Earth, the crew would just slowly die in space.

The Mars Direct plan calls for the ERV to be fully fueled and ready to go before the crew ever reaches the surface. DRM likewise calls for the return vehicle to be ready and waiting. Neither plan allows for an ERV still lacking the endurance to reach earth by the time the first crew arrives - although the Mars Direct ERV's life support supplies are too small to handle the additional three months necessary for an immediate return launch.

The best form of evacuation of the HAB is to a nearby emergency shelter.

The best form, yes. Now we just need to convince mother nature that disasters this couldn't deal with are not worth her trouble.

The shortfall with the Mars Direct ERV's supplies is telling, IMHO, although it's not as bad as omitting the crew's clothing and other oversights of the Mars Direct mass budget, and does reflect exactly the sort of planning philosophy you are advocating. It can be done.

But it's hardly the safest design for the task.

RobS · 2007-01-14 03:29:44

The time for a free return trajectory on the six month transit advocated in Mars Direct is two years, and I think its similar for DRM. That's six months hapless in space (from a propulsion perspective), followed immediately upon landing by an opportunity to hop an ERV and return to Earth in nine months rather than eighteen - if an ERV is available.

I don't think you can "hop on an ERV" and return to Earth in nine months upon arrival at Mars. The time to depart Mars for the Earth occurs before the time to depart Earth for Mars, so by the time you reach Mars, you are already nine months too late to go straight back to Earth. The ERV would also have to follow an eighteen-month trajectory to reach Earth at that time.

-- RobS

SpaceNut · 2007-01-14 09:17:20

A senerio of the need for quick return would be a lot longer than 9 to get back since it is a 26 month cycle for launching to mars. Which has the 2 month launch within window for flights.

Its could be worse if it were necessary to leave after the nine month journey out for the journey to get back with the ERV would only have a 9 month supply of food in orbit.

Number04 · 2007-01-14 09:58:54

I for one think we should send people with the possibility of not coming back. The return trip would be the hardest leg and with people already there future Mars missions would be less likely to fall out of importance.

cIclops · 2007-01-14 10:43:56

I for one think we should send people with the possibility of not coming back. The return trip would be the hardest leg and with people already there future Mars missions would be less likely to fall out of importance.

Yes. Keeping those people alive on Mars will be a great motivation and it will make a fantastic media event ... even better than Reality TV. For a while anyway, maybe several years - look how long big brother has lasted. NASA should seriously look at the media aspect of this. There could be even more attention to selecting the first crew than the first astronauts or the Apollo crew. They can be presented as settlers, as people creating a New Earth, starting a new civilization. The importance of it will be obvious to everyone, especially the international dimension. They will be true new heros.

The biggest obstacle to human missions to Mars is not technical or even financial, it's building the will to do it among the politicians which means getting the public to want it.

C M Edwards · 2007-01-14 13:01:34

I for one think we should send people with the possibility of not coming back.

Amen! Which, I suppose, is the number one reason that we should refuse to go "on short notice" without some compensation far more impressive than mere prestige.

I take issue with the claim that the only attainable trajectory for premature return is >18 months transit, but in the end that's an issue of design philosophy, not mission philosophy. The real issue is whether to go with minimal preparation.

Dayton Kitchens · 2007-01-17 13:38:34

A question I was going to ask.

If you had the choices

Option 1-quick and dirty mission to Mars. Two missions to Mars minimum.
50% chance of a continuing series of missions indefinitely.

Option 2-Go big Mars program-80% chance the program will be canceled before
the first mission goes, but if its sustained, a far faster buildup of men
and material on the Martian surface with more advanced technology
used.

Which option would you choose.

C M Edwards · 2007-01-17 14:22:58

A question I was going to ask.
If you had the choices
Option 1-quick and dirty mission to Mars. Two missions to Mars minimum.
50% chance of a continuing series of missions indefinitely.

Option 2-Go big Mars program-80% chance the program will be canceled before
the first mission goes, but if its sustained, a far faster buildup of men
and material on the Martian surface with more advanced technology
used.
Which option would you choose.

My answer: Yes. 8)

Unfortunately, that's just a personal preferrence. We need to face the reality that the resources to do both may not be available. Therefore, we need to go with Option 2, because it would offer the most return for the flight time. This creates another requirement:

We need to make option 2 fit into the budget for option 1.

publiusr · 2007-05-04 16:20:28

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#51 2007-01-12 15:21:11

Re: What If we HAD to get to Mars on Short Notice

#52 2007-01-12 16:00:06

Re: What If we HAD to get to Mars on Short Notice

#53 2007-01-12 16:08:17

Re: What If we HAD to get to Mars on Short Notice

#54 2007-01-12 16:53:09

Re: What If we HAD to get to Mars on Short Notice

#55 2007-01-12 17:55:33

Re: What If we HAD to get to Mars on Short Notice

#56 2007-01-13 05:24:50

Re: What If we HAD to get to Mars on Short Notice

#57 2007-01-13 16:29:51

Re: What If we HAD to get to Mars on Short Notice

#58 2007-01-13 17:00:58

Re: What If we HAD to get to Mars on Short Notice

#59 2007-01-13 17:19:12

Re: What If we HAD to get to Mars on Short Notice

#60 2007-01-13 17:25:25

Re: What If we HAD to get to Mars on Short Notice

#61 2007-01-13 21:05:48

Re: What If we HAD to get to Mars on Short Notice

#62 2007-01-14 03:29:44

Re: What If we HAD to get to Mars on Short Notice

#63 2007-01-14 09:17:20

Re: What If we HAD to get to Mars on Short Notice

#64 2007-01-14 09:58:54

Re: What If we HAD to get to Mars on Short Notice

#65 2007-01-14 10:43:56

Re: What If we HAD to get to Mars on Short Notice

#66 2007-01-14 13:01:34

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#67 2007-01-17 13:38:34

Re: What If we HAD to get to Mars on Short Notice

#68 2007-01-17 14:22:58

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#69 2007-05-04 16:20:28

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