What's interesting to me is how they seem to be trying to get the physics right in some places and just fail in other places. They make a big deal about having centrifugal pseudo-gravity in the crew quarters but being weightless elsewhere. Yet all the crying (so much crying) they do in the supposedly weightless regions of the ship, still has tears streaming down their faces.
Yes I noticed that too. I suspect either their science advisors missed that or, more likely, the cost of the CGI to make weightless tearing look accurate was too much money.
But in general I find the weightless scenes unconvincing. Of course the actors are actually suspended by cables which are later digitally removed, but the way their bodies are positioned rarely looks realistic to me; they are often horizontal with backs slightly arched or primarily vertical and hanging without moving.
The ship design with the two “crew quarters” pods rotating around the long axis of the vehicle is interesting but the deployment mechanism shown looks much too complex to implement in real life. Too many points of potential failure.
What really amuses me is that, if such a system could be made to work, surely it would be optimal to have the crew spend almost the entirely of their time in the artificial gravity environment and minimize the time in the main body of the ship? It would not be used just for sleeping and personal private time as the health benefits on a 6-8 month voyage would be tremendous. From the crew quarters the crew could easily monitor everything happening on the ship.
Or maybe — though this is not stated in any episode I have seen so far — the main body is radiation shielded but the crew quarters are not, so the crew cannot spend all their time there?
I don't think 1" of water would provide enough shielding, anyhow.
It most certainly would not, as
@Cosmacelf correctly pointed out.
The issue of the risk from additional radiation dosage during a trip to Mars is in dispute. Yes it would increase lifetime cancer risk, but not necessarily by a large amount. Effective shielding against solar flares (which are transient events) would certainly be important but that can be accomplished without shielding the entire crew compartment, just a subsection, as
@Cosmacelf also noted. I hope that SpaceX is already planning for such shielding in the Starship design.
The idea of inducing artificial gravity by spinning Starship does not seem to be an option; the vehicle radius is not large enough for that to be effective and a separate compartment farther out from the center has never been mentioned for Elon. It would be an extremely difficult engineering problem.
SpaceX can certainly draw on the large amount of data NASA has accumulated on the ISS about how to counteract the effects of microgravity on the human body, but it will be a very challenging issue to deal with during a trip to Mars. The only good news is that the much lower Martian gravity may be somewhat easier to adjust to after many months in zero-G.
