On 5/21/2019 2:15 PM, Niklas Holsti wrote:

So that's the suggestion. Comments are welcome...


This very type of configuration of Starships has been discussed here
before. It is not an unrealistic approach. However I was unaware that
the SpaceX plan called for two Starships to make the journey all the way
to Mars. Two Superheavys (or whatever SpaceX is calling the BFR these
days) where planned but one of them was not a Starship destined for Mars
but a fueling pod for the Starship that was. That's the plan I remember.

But frankly I think Mars is a long way off. In fact the Moon is becoming
a major distraction. And that actually makes sense since all this
hardware can be tested out far more easily on lunar missions. There is a
push within NASA to refocus on the Moon and a lunar base, by any means
possible. If that means contracting with private enterprise to do it, so
be it. We will have to wait and see how Starship does in this regard.

We are along a familiar trajectory here. Same one as was taken for
recoverable Falcon 9 stages. I think Starship will focus on P2P
suborbital trajectories first to establish launch and return procedures
that must work anyway. Then a push to orbit, then a push beyond. Opening
out the envelope becomes easier the further along the curve you get.
However the first part of that curve is the hardest. Or would appear so
from where we stand today. What is interesting, to me, is how much
SpaceX is going to rely on automation before committing crew to the
Starship. At what point will they crew the vehicle? After it completely
passes all P2P and orbital tests or before? Will crew be considered an
essential part of Starship operation or not? (i.e. will Starship require
pilots or provide crew with a flat screen they can follow the action
on?) If the past is any indication I'd say no. At least not in the
initial stages.

Your bolas configuration could be tried out in LEO. If such a plan were
part of a SpaceX requirement this would make a lot of sense. It could
provide an orbital gravity lab "on the cheap" in the sense that it
doesn't require "bending steel" that a specialized orbital lab would.

But you bolas configuration points to a far far deeper question than the
mere mechanics of generating artificial g in space.

The data points we'd get from the physiological effects of long term
operations on the lunar surface might also make the need for a gravity
lab moot. If humans can do "fine" in lunar gravity, there would be no
rational supposition that Mars would be worse. At least until we get to
Mars. I put the word fine in quotes because there are going to be
physiological effects. The key question is whether we define those
effects as debilitating. Some might consider the inability to return to
Earth as disabling. Others might not. Same with Mars. The key in all
cases is whether medically humans can adapt to a sudden change in 'g'
long term. Is life in space like smoking? If you are guaranteed to die
after 15 years in lunar surface conditions, will that be a deterrent? Or
would the experience of a (short) life in space on the moon be worth
every otherwise lost year? Let's hope we're not forced into that kind of
choice, but right now there is no reason to say it can't happen. We need
more data.

Dave