In article ,
says...

$3 to $5 billion per year to keep two (2) American
astronauts in space all year long is just too
expensive. What the ISS has primarily returned
is evidence bone loss for long duration space flight
shows the whole colonizing Mars dream isn't practical.

Bull****. This is an engineering problem, not a medical problem. Why
NASA continues to treat it as a medical problem baffles me.

Not until we can build spacecraft large enough to
supply artificial gravity and that means a sea-change
in cost to orbit.

Not that hard. All you need to do is attach your transfer stage to your
habitat module by a long cable and spin it up. Again, this is an
engineering problem that is not very difficult to solve.

The next space station, manned space flight
in general, should wait until that day
arrives. We're not even close yet.

Waiting for "artificial gravity" stupid since it's something we could do
today given the motivation. NASA isn't doing anything meaningful
towards sending people to Mars. Just look at where the money is being
spent. There are no Mars landers being designed and built. There is no
habitat being built big enough for a Mars trip. There are no in-situ
propellant production experiments being run on Mars (could be used to
fuel an unmanned sample return mission). SLS/Orion is the only big
thing NASA is spending money on and neither, by themselves, will take
people to Mars. Orion doesn't even have a good enough heat shield for a
direct reentry of a returning Mars mission.

The biggest problem with going to Mars, or anywhere beyond LEO, is the
high cost to launch anything into LEO. LEO is "half way to anywhere" in
terms of delta-V. Low launch costs will open up spaceflight like we've
never seen before.

Until then we should spend our space budget
on more ambitious unmanned missions to Mars
not this pipe-dream of sending people there.

Toasters are fine, but can't do 1/100th what a person in an EVA suit
plus a pressurized laboratory module can do. Add a rover to that and
people can do amazing things in a very short time.

At best we'd put a couple people on Mars
for a couple weeks, a symbolic event not
scientific, but at enormous costs and
more importantly enormous time, that
starves the budget for all else.

Cost is high because launch costs are high. Again, solve the launch
cost problem and everything else becomes easier and cheaper.

Let Musk have his 'fifteen minutes' on
Mars, the US space program should make
sense, and the ISS, current or future
versions, doesn't make sense.

ISS makes sense in that NASA is learning how to build and maintain a
large-ish habitat that needs to operate for years at a time. They need
to know how to do that in order to send people beyond LEO. ISS is very
expensive, but at least now it's "fully assembled" from the US point of
view. Plus it gives a purpose for commercial cargo and commercial crew,
which are lowering the cost of access to space for US astronauts.

SLS/Orion is certainly not going to lower costs. If you want to cancel
something at NASA that's expensive and completely useless, cancel
SLS/Orion.

Jeff
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