Crew size for Mars missions

Dayton Kitchens · 2006-12-19 08:48:52

We could do so much more with a crew of 20. Or 50.

why not wait until we can put Aldrins Mars Cyclers into operation?

ftlwright · 2006-12-19 13:23:44

We could do so much more with a crew of 20. Or 50.
why not wait until we can put Aldrins Mars Cyclers into operation?

Zubrin has no crew medic nor a dedicated mission commander. The engineers are in charge of keeping them alive; while at least one mission scientist is needed. I can understand the argument for 5, but 4? Too many compromises, no margin.

Dayton Kitchens · 2006-12-19 13:37:50

We could do so much more with a crew of 20. Or 50.
why not wait until we can put Aldrins Mars Cyclers into operation?
Zubrin has no crew medic nor a dedicated mission commander. The engineers are in charge of keeping them alive; while at least one mission scientist is needed. I can understand the argument for 5, but 4? Too many compromises, no margin.

Sending a dedicated crew medic makes no sense. Just choose a biologist that has training in medicine.

And you don't need to waste a crew member on someone who just "commands".

Make the commander one of the engineers.

Dayton Kitchens · 2006-12-19 13:39:36

Remember, U.S. nuclear submarines even with crews of more than 100 don't have a fully trained doctor aboard.

Their medics are supposed to be able to perform appendectomies by themselves. Its certain that a biologist with cross training and medicine could do that much with guidance from Earth.

SpaceNut · 2006-12-20 07:32:39

Crew size 4 versus 6 for Mars missions has a direct impact on "Whats does NASAs Manned Mars Architecture Look Like Now?" since this not only effects the mass the ships will need to lift but there overall size and shape which can have a snowballing effect.

My understanding of GCNs overall objections to "3 Ares V, Mars Semi-Direct" is that a single Ares V launched from Earth can't deliver large enough of a Hab module to the surface of Mars.

Regardless of what the plan is called the size of the hab also must carry the supplies for the journey out and back. As GCNRevenger contends that it is to small by volume of which I can accept this. So I wonder if this means that the hab should be a 2 piece unit to give the volume and space for all supplies.

What about a "four Ares V rocket" Mars Semi-Direct Mission?
Four man crew of course.

I think GCNRevenger proposed a 6 vehicle approach for the crew of 6 plus but for either case you still need a taxi to orbit in order to complete the process of assembly so that will mean 1 Ares I.

Not sure what the out come of the cost per vehicle will be but once they are available it would be a good bet that this many would be between 2 or 3 years worth of manned budgets of the combined amount of ISS and shuttle just for the first mission.

Dayton Kitchens · 2006-12-20 07:38:08

Forget the Ares I launched "taxi".

Just launch the outbound crew in the Hab.

It has got to be capable of supporting them for two years anyway.

I know what people will say "no launch escape system for the Hab".

Who cares?

In what, more than 250 launches of manned missions by the U.S. and Russia, there have been TWO thats two disasters on launch.

In the Soviet one, a launch escape system saved the crew. The other was Challenger.

If we can launch 120 shuttle missions with no launch escape system, then launching a Mars crew without one once every two years should be no big deal.

SpaceNut · 2006-12-20 08:07:06

Forget the Ares I launched "taxi".
Just launch the outbound crew in the Hab.

That would mean we could do away with the Ares I only if the Ares V was man rated but at this point it is not on the planning board.

As for

I know what people will say "no launch escape system for the Hab".
Who cares?
In what, more than 250 launches of manned missions by the U.S. and Russia, there have been TWO thats two disasters on launch.
In the Soviet one, a launch escape system saved the crew. The other was Challenger.
If we can launch 120 shuttle missions with no launch escape system, then launching a Mars crew without one once every two years should be no big deal.

I think that if one had been integrated into the first shuttles accident that it would have saved there lives but the second it would not have. Having the option is a small price to pay for saving lives.

Grypd · 2006-12-20 08:43:23

There are real engineering reasons apart from safety that ensure that the crew will not be sent up in the Hab. The basics are if we send crew then we have to take mass from space that should really be used for stores or other essentals. This is further reduced if we then have to man rate the actual launch.

We also, apart from the prime safety reason of having the crew launch in a vehicle that they can escape in. Get the advantage of the potential use of it as a lifeboat and of course as a means to increase the supply delivery.

GCNRevenger · 2006-12-20 22:55:48

Six (preferably with option for eight sans science) crewmen is a good number; NASA's DRM plan is probably the biggest Mars mission affordable with present day technology, and is also the smallest plan that could credibly lead to a permanent base. And that changes all the rules when you only have to get crew & cargo to Mars orbit and back instead of the surface. Its the right size.

As for sending the crew up in a HAB instead of on a taxi vehicle (Ares-I probably), thats just classic "SUCK IT UP SOLDIER!" attitude, which isn't pertinent nor welcome.

What happens if the launch succeeds, the acceptability of the risk debate aside, if the HAB itself, docking with the EDS, or TMI fails? How is the crew supposed to get back down from orbit? Having a taxi vehicle docked or still in orbit with a full Moon-Earth sized tank of fuel is an extra safety feature worth the cost.

Dayton Kitchens · 2006-12-21 09:08:18

Six (preferably with option for eight sans science) crewmen is a good number; NASA's DRM plan is probably the biggest Mars mission affordable with present day technology, and is also the smallest plan that could credibly lead to a permanent base. And that changes all the rules when you only have to get crew & cargo to Mars orbit and back instead of the surface. Its the right size.
As for sending the crew up in a HAB instead of on a taxi vehicle (Ares-I probably), thats just classic "SUCK IT UP SOLDIER!" attitude, which isn't pertinent nor welcome.

What do you have against the "Suck it up soldier" attitude anyway?

If it gets Americans to Mars, then thats fine with me.

And why is a permanet base on Mars required anyway? You haven't even addressed that.

GCNRevenger · 2006-12-21 14:20:36

That attitude simply gets people killed needlessly, generally leading to bad planning & design choices, and is of questionable morality.

Getting Americans to Mars no matter what is a perfect way to make sure our journey there is ultimately for nothing. Wasting another two generations (if ever) waiting to get our heads screwed back on straight is crazy.

A permanent base is ultimately the goal of most anybody you'll find on this forum, since Mars is probably the best place to live in the solar system besides the Earth.

Anyway, Mars (especially if there is or was life) still presents on the greatest troves of space science, and its silly to think that even a dozen good manned missions will unlock what is worth learning.

A base also radically reduces the cost of getting to and from Mars, since a domestic supply of rocket fuel coupled to a reusable ascent vehicle eliminates all the mass and expense of getting down to the surface and back. Plus, with a surface HAB already present, then you only need one HAB per mission, reducing the launch manifest from six to two. And, if aerobraking at Earth is practical, even that HAB could be reuseable. It also makes it possible to send 5-10MT scale cargo missions with an Ares-I/Atlas-V class rocket.

Lastly, the reuseable lander/ascent vehicle can also be used as a long-range suborbital transport to cover about half the Martian globe, permitting short duration stays at many many more sites than missions all the way from Earth could manage.

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#1 2006-12-19 08:48:52

Re: Crew size for Mars missions

#2 2006-12-19 13:23:44

Re: Crew size for Mars missions

#3 2006-12-19 13:37:50

Re: Crew size for Mars missions

#4 2006-12-19 13:39:36

Re: Crew size for Mars missions

#5 2006-12-20 07:32:39

Re: Crew size for Mars missions

#6 2006-12-20 07:38:08

Re: Crew size for Mars missions

#7 2006-12-20 08:07:06

Re: Crew size for Mars missions

#8 2006-12-20 08:43:23

Re: Crew size for Mars missions

#9 2006-12-20 22:55:48

Re: Crew size for Mars missions

#10 2006-12-21 09:08:18

Re: Crew size for Mars missions

#11 2006-12-21 14:20:36

Re: Crew size for Mars missions

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