On 19-10-05 23:38 , Alain Fournier wrote:
On Oct/5/2019 at 11:44, Niklas Holsti wrote :
On 19-10-03 19:18 , David Spain wrote:

There are a TON of issues remaining to get crewed Starships to Mars.

Nah, I would say two tons :-)

No matter how you slice it, there is complexity to artificial gravity. I
have the sneaking suspicion that EM thinks this can be short circuited
by routine exercise inside a Starship. If I can compensate for the
deleterious effects using exercise, drugs, or alcohol (lol) well...
'tight is right'. :-)

I agree that this seems to be the SpaceX plan. And it will probably
work, too, at least for the fast and quick transits that SpaceX will
probably start with.

I think that the SpaceX plan is a bit of a if you build it they will
come plan.

That is a larger plan than David and I discussed -- we were discussing
how SpaceX intends to handle the free-fall physiological problems, and
I've seen nothing form Musk or SpaceX that suggests they will have some
form of artificial gravity on SS.

Your view of the larger SpaceX plan agrees with what Musk has said (some
time ago, perhaps he has changed his mind) that SpaceX will focus on the
rocket and hope or trust that others will pitch in with life support,
Mars suits and habitats, etc. On the other hand, one often stated
explanation of SpaceX's success so far is that they have mostly designed
and built their own solutions in house, rather than subcontract, at
least not subcontract to the "space establishment" companies (and
instead engaging water-tower builders, for example). If SS/SH turns out
to work, perhaps SpaceX will be inspired and have the resources to solve
many of these N tons of other problems.

They want to build a rocket that can bring humans to Mars
cheaply. They figure that if they send a few people to Mars, even if
these few people can't do much on Mars because their spacesuit isn't
optimised for Mars and they are unfit to do work because of bone and
muscle loss, SpaceX still showed that Mars missions can be done. Others
will work on the N tons of details [ choose your value of N, but I agree
with you that one is a small value for N :-) ] that will make Mars
missions interesting and Mars colonisation possible.

Anyway that's my impression. Maybe they are working on all the details
and have solutions. But until now they haven't shown so.

Shown, no. But from what Musk has said of their plans, SpaceX will not
send humans to Mars before there is an operating ISRU propellant plant
there, with enough propellant stored for the return trip. ISRU
propellant production is one of the larger problems after the rocket.
Here some work on the Moon could be good practice, although the in-situ
resources on the Moon are different from those on Mars (no carbon
dioxide on the Moon, unless the polar ice turns out to be made of fizzy
water :-) ).

I would have hoped that some people would have started to be vocal about
the needs of Mars travellers by now. I mean there should be some company
somewhere telling SpaceX, we can make great Mars spacesuits, or we have
a great solution for disembarkation and embarkation from a cabin on a
rocket on Mars, or artificial gravity or ... Even NASA and other space
agencies should be calling SpaceX. Maybe there is some of that going on,
but they sure are quiet about it.

I suppose many of these people are still skeptical about SS/SH, either
of the technical success and/or of Musk's and SpaceX's resources to
finish a working SS/SH system (not long ago -- before SS Mk1 started
visibly building -- a prominent European space business leader called
SS/SH "science fiction"). And of course there is the
SLS-mandate-that-must-be-obeyed...

--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .