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About the resupply missions in "The Martian".



 
 
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  #1  
Old November 16th 15, 11:06 PM posted to sci.space.policy
Bob Haller
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Default About the resupply missions in "The Martian".

if we cut the travel time to mars by 90%, the consuables are now 90% less.

since we dont have the $$ for hhumans to go to mars right now. were better off building vasmir, design a mars orbital station, design a mars lander station, basically design the infrastructure we will need.

I believe attempting to stop terrorism will kill any humans explore mars programs for the forseable future.

however we could send the parts for a mars base buried under mars regolith by unmanned dozers, etc etc, while vasmir is tested.

since having quick travel within our solar system can open not just mars to exploration

and running a vasmir full out, could it get us to another solar system?
  #2  
Old November 17th 15, 03:47 AM posted to sci.space.policy
Greg \(Strider\) Moore
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Default About the resupply missions in "The Martian".

"bob haller" wrote in message
...

if we cut the travel time to mars by 90%, the consuables are now 90% less.


You're facing similar issues to SST.

Sure you get faster, but the costs are much higher.

since we dont have the $$ for hhumans to go to mars right now. were better
off building vasmir, design a mars orbital station, design a mars lander
station, basically design the infrastructure we will need.

I believe attempting to stop terrorism will kill any humans explore mars
programs for the forseable future.


It's amazing we got to the moon during the Cold War and Vietnam war. I mean
this country is simply incapable of doing multiple things at once.


however we could send the parts for a mars base buried under mars regolith
by unmanned dozers, etc etc, while vasmir is tested.


Or do that while we're preparing for a standard Hoffman style orbit.

since having quick travel within our solar system can open not just mars to
exploration


So will fairy dust.

and running a vasmir full out, could it get us to another solar system?


Bob, seriously, do the ****ing math. Just think about it.

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

  #3  
Old November 17th 15, 11:57 AM posted to sci.space.policy
Jeff Findley[_6_]
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Default About the resupply missions in "The Martian".

In article ,
says...

if we cut the travel time to mars by 90%, the consuables are now 90% less.


Except we really don't know how to do that within our budget. Liquid
fueled LOX/methane engines will be far cheaper to develop.

since we dont have the $$ for hhumans to go to mars right now. were better off building vasmir, design a mars orbital station, design a mars lander station, basically design the infrastructure we will need.


Except what are you going to use to power those VASMIR engines? Again,
they require huge amounts of electricity in order to scale up to the
thrust levels needed for a manned mission. VASMIR engines are no magic
bullet, despite the salesmanship of the researchers who want more money
to work on their engines that they know really aren't all that suitable
for a manned mission.

I believe attempting to stop terrorism will kill any humans explore mars programs for the forseable future.


Just because you can't focus on more than one task at a time doesn't
mean that the US, as a country, can't.

however we could send the parts for a mars base buried under mars regolith by unmanned dozers, etc etc, while vasmir is tested.


Which would mean you would already have a conventional propulsion system
which works, and you're just waiting on sending people so it will be
"safe". This is a chicken **** approach to manned space travel which
****es on the history of Mercury, Gemini, Apollo, and even the Space
Shuttle. None of those were ever anywhere close to "safe", yet we flew
them anyway.

The astronauts know the risks and take them because they also know the
benefits. Not everyone is as scared as you.

since having quick travel within our solar system can open not just mars to exploration


And Star Trek's warp drive would open up travel to other solar systems.
Engineers don't build manned spacecraft on wishes.

and running a vasmir full out, could it get us to another solar

system?

VASMIR can't even get people to Mars. Why not wish for warp drive
instead?

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
  #4  
Old November 17th 15, 12:03 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 2,307
Default About the resupply missions in "The Martian".

In article om,
says...

On 2015-11-16 17:06, bob haller wrote:
if we cut the travel time to mars by 90%, the consuables are now 90% less.


Anything more than a weekend camping trip to the moon will involve a lot
of regenerative systems on the transit ship and mars base.

Since water is the heaviest of consumables, water reclamation system
will greatly reduce the need to carry water since a good proportion of
consumed water gets put back into the water tanks.

so whether the trip is 1 month or 6 months, you are likely to see the
same types of systems (since the mars base will also have similar
systems and draw from the transit ship's supplies). Not sure reducing
trip length wil reduce mass of water by that much.


And while the ISS has not yet gotten to a point where they can grow
enough food to reduce its dependence from earth supplies, I think they
did grow and eat a head of lettuce once. If they can perfect this to a
scale where it can reduce the need to store all food, this is also mass
that is saved.


Do you have any idea how much air, water, nutrients, lights, and power
would be necessary to grow enough food to actually feed a crew? You
might be able to do this by growing the right kinds of algae in tanks,
but you're not going to be eating fresh salads every night, that's for
sure.

In the overall mass budget, food is not that big of an issue. NASA and
the US Military have known for decades how to make storable food that
stays good for years. Campers and "preppers" order such food right off
the Internet these days.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
  #5  
Old November 17th 15, 12:16 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 2,307
Default About the resupply missions in "The Martian".

In article ,
says...

VASIMR can't get transit times to Mars down to 30 days, no matter how
big a reactor you throw at it. A 200 MW system will get you there in
39 days. You're not going to do much better than that, no matter what
you do.


Which would be great if we had a small enough, light enough, not too
radioactive, 200 MW power system to throw at the problem. Developing
that might just be hideously expensive. Consider that we're talking
about a government organization that has yet to get SLS off the ground,
despite the many years and many billions of dollars spent and despite
the fact that its propulsion systems are based on 1970s tech.

For perspective, ISS generates on the order of 100 kilowatts of power.
Can anyone imagine a manned spacecraft with more than three orders of
magnitude larger solar panels than ISS?

Pushing VASMIR for manned missions without a viable power source in
sight is a huge bait and switch. Unfortunately, it seems like many in
the media, like Bob, don't "run the numbers". Because if they did,
they would be shocked to find that we really can't make VASMIR work for
a manned mission, because we just don't have an extension cord long
enough to keep it powered.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
 




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