Re: An opportunity for VMS

david20@xxxxxxxxxxxxxxxx wrote:
The ISS is expected to be 453.6 metric tons in weight, bigger than a 5 bedroom
house and measure 110 meters end-to-end.

The specifications of the habitat module for the Mars direct mission are
available at http://en.wikipedia.org/wiki/Mars_Habitat_Unit
Adding the figures up the total weight including crew is
45.49 Tonnes

ie about a tenth that of the ISS.


The space station is the currently at bare minimum to support 3 persons
for 6 months. In fact, it gets resupplies every 2 to 3 months.

If you really think that you can encase a crew for 6 months in a
telephone booth for a voyage to mars, you are crazy. And by the way,
where is the weight or engines, attitude control, solar panels, fuel
tanks, O2 and N2 tanks ? Water ?

Just because you can use a computer to create neat images of a concept
doesn't make that concept workable.

And remember that you need to have enough supplies to return to earth.
One can argue that you'll send those supplies ahead of time and meet in
mars orbit. But even with that, the main ship will require barebones
supplies to keep the crew alive to earth should that rendez-vous fail in mars.

Furthermore, right now, when something breaks on the ISS, generally the
russians can send a replacement part within roughly 2 months. But some
of the bigger parts require the shuttle (such as the failed control
moment gyros) and those took years to ship up. On a mission to mars,
they won,t have that luxury. They either need full inventory of spare
parts, or ability to repair faulty ones. And this experience is being
gained on the ISS right now (especially on the russian side who are less
affraid to thinker with stuff, while on the USA side, they prefer to
just shut the unit down and not let the crews thinker with it).

Right now, when station crews return to earth, they need to have only
enough strength to push a few buttons and make a phone call on an
irridium phone to provide their lat/long, and then wait for the recovery
crews to get there and pull them out of the soyuz and lay them up on
lounge chairs. When they land on mars, they will be required to be
more or less fully functional. And that means a far more rigorous
exercise regime while on transit to mars, and thus more exercise
equipment. (and also less time to do any work to maintain the ship).

While one would not expect the whole ship to land on mars and the
artists' concept of the "mars direct" ship may seem to be workable for
the mars landing, it isn't for the whole trip to/from mars.
.

Relevant Pages

  • ESA prepares for a human mission to Mars (Forwarded)
    ... ESA prepares for a human mission to Mars ... a crew of six will be sent on a 500 day ...
    (sci.space.news)
  • Re: An opportunity for VMS
    ... Adding the figures up the total weight including crew is ... Mars Habitat units being tested on Earth by the Mars society. ... the main ship will require barebones ...
    (comp.os.vms)
  • Re: Two questions on Saturn V
    ... Mars or the Moon using 1960s technology. ... American nuclear-powered orbital launch vehicle. ... meters long and 6.7 meters in diameter ... the crew from radiation and also from solar storms by pointing the ...
    (sci.space.history)
  • Re: Space Policy: Why Mars should be our top priority.
    ... Anyway, it would be a really fun thread to figure out what NASA could and couldn't do in regards to a Mars flight using 1970 technology, and throwing the amount of money and ASAP political will at the problem that Apollo had. ... Every time you remove even one crew member, you save a tremendous amount of weigh required to keep them alive on the trip to Mars and back. ... Of course they had a monkey along also....but the original intention was to drop that monkey onto the surface of Mars and just leave it there to see how it finally croaked. ...
    (sci.space.policy)
  • Re: Does Mars need women? Russians say no
    ... Of course the solution to all this is simple...we need a Mars ship with ... with the ship's crew quarters and lander at one end and the reactor at ... rotation that would be big enough not to cause nausea as the crew moved ...
    (sci.space.history)