@peterh Agreed. But SPaceX says one or two refuelling is needed to go to the Moon, and 6 t go to Mars. No one ever said you need full refuel to go anywhere in particular.

@geoffc Another thing: soyuz fan says: starship hull can survive at most 2-3 g, yet lesser if empty. This is an upper limit to the maximal acceleration on the landing trajectory. But aerobraking in Martian atmosphere, for a thing with starship geometry, nobsuch trajectory exists.

Ok. SpaceX clearly disagrees. No doubt Soyuz fan, who has no access to any data is correct and the engineers building it are totally wasting everyones time and money. Occams' Razor.

@geoffc Yes, he admits it. But he also says: no one has access to this data, only the spacex (and maybe NASA). So the only way to estimate, what the SpaceX really wants to, is by examining their current products/experiments. What they have already done. And then the result is this: StarShip will be a cheap LEO transfer vehicle, essentially a Space Shuttle replacement. All other might be or might be not ever real.

I am a SpaceX fan. But also rationality fan. And his arguments have a strong anti-spacex bias, but also very rational.

My opinion is this: even if we consider what the SpaceX have already done, I still see the strong possibility of an ISS replacement and a cheap moon lander.

Possibly his real goal is to stimulate a space exploration forum on a language with lesser native speakers than New York city, and this is why is he so critical.

@peterh That's the first I've heard of Google Sky Map ...

@peterh Well even if they only succeed at cheap launch to orbit, building a Mars transit vehicle is then just a detail that is less efficient.

@geoffc Ok, but all starship -> LEO needs also a super heavy launch. All Super Heavy launches need 3400t propellant. So a fully loaded starship on LEO costs (3400t+1200t)*13 = 60000t propellant. 60000t supercooled LOX/LH4. I think at this size, also the propellant cost becomes an important factor.

Although getting 100t, with humans, into the Martian surface, that looks really colonization-ish to me.

Although the first 100t will be likely the ISRU infrastructure. And that should be likely robotical, because it would not be funny if something would went bad and they could not get home.

Maybe it could be done by human-controlled robots from Low Martian Orbit. So they could control the robots real-time. Possibly it could be even from a higher Martian orbit, to spare fuel.

What they need: 1. find the ice deposits 2. install solar panels 3. install the ISRU machines 4. install the retank machines 5. mine the ice and put it into the ISRU 6. install the tanks 7. bind these together with a lot of cables and pipes. Doing these all with robots... afaik it would not be very easy

For the first human footstep on the Mars, maybe 2030 is yet a very brave prediction. And Musk dad can not play forever with the bitcoin, his following tweets probably won't be taken so seriously by the market. Tesla and Starlink has to make enough money for the spaceship programs. And Musk is already 49 years old. In 2035, he will be 64. If he won't control directly his wealth any more, on any reason (incl. death), the decision-makers of his companies will likely focus their efforts...

to the pure dollar production on the Earth. With other words, the whole SpaceX project depends on Musk, in persona.