Is Falcon Heavy not a better option for this? Especially in reusable format, it can put significant payloads into LEO without expending any cores. So if you need a few hundred tons in LEO for a manned Mars mission, Falcon Heavy could put it there far more cheaply than any other launch system could.
Quote from: M.E.T. on 04/30/2017 05:20 pmIs Falcon Heavy not a better option for this? Especially in reusable format, it can put significant payloads into LEO without expending any cores. So if you need a few hundred tons in LEO for a manned Mars mission, Falcon Heavy could put it there far more cheaply than any other launch system could.The bottleneck with using FH is fairing size. As originally envisaged, Mars Direct relies on a 10m+ PLF to enable entry vehicles that have suitable ballistic coefficient to enable EDL without recourse to hypersonic retropropulsion.The BFR would be a great starting point for a Mars Direct launcher, but as RonM says you still need a second stage/EDS. And it's pretty hard to make your EDS reusable, by definition.
The traditional Mars Direct by Robert Zubrin and David Baker had Direct vehicles of about 45 tons being sent on Trans-Mars Injection. This is about what the SLS Block II with 'Dark Knights' solid boosters could achieve with an Exploration Upper Stage. If the core stage was redesigned for 5x RS-25E and the EUS had slightly higher thrust engines, this could raise the Direct Vehicle's masses to about 50 tons.
Quote from: MATTBLAK on 05/01/2017 07:08 amThe traditional Mars Direct by Robert Zubrin and David Baker had Direct vehicles of about 45 tons being sent on Trans-Mars Injection. This is about what the SLS Block II with 'Dark Knights' solid boosters could achieve with an Exploration Upper Stage. If the core stage was redesigned for 5x RS-25E and the EUS had slightly higher thrust engines, this could raise the Direct Vehicle's masses to about 50 tons.That means developing RS-25E, Dark Knights, the LUS (as opposed to EUS), and more tower mods for SLS. And this is all at NASA expense, I do not think this will happen. Also, it is all disposable. The thread OP was about using the ITS booster. Rather than developing all these SLS components, would it be less expensive to employ the reusable ITS booster, strengthen the SLS core, place J-2X or BE-3U (both of which do or will exist anyway) on it, and use that as the combination second stage/Earth Departure Stage? Further, my guess is that gives you a lot of margin, with a lot less for NASA to develop. Senators in SLS states would be happy. Trump might get a landing w/in 8 years. SpaceX can work on their big booster. Somebody gets to build a new HydroLox engine that has already been designed. Those SLS cores actually go somewhere instead of nowhere. The same ITS boosters get reused with the new ITS spaceship, saving a lot of money. Who knows, maybe Robotbeat's OTS (mini-ITS) might even be used as the lander, giving SX a small scale prototype to work with. The public sees that Mars is possible on a somewhat reasonable budget and comes to embrace significant progress in space exploration, perhaps even becoming enthusiastic about it. The sortie missions serve as precursors to the flights of the bigger ITS spacecraft and the later possible beginning of colonization. Once the big ITS ships are operational, the SLS can be gracefully retired, while NASA and Trump take credit for working with the private sector and getting us to Mars. I think Trump might be happy to cooperate with Musk like this. He could finally say he did something. And it would be a very bold something.
The ITS booster isn't going to exist without the ITS spaceship. If the ITS spaceship exists what's point in developing the Mars Direct departure, transit, EDL and Earth return hardware? It's all grossly out-classed by the ITS ship. The Mars Direct surface ops and refueling hardware would still be useful, but could at that point just be delivered to the surface by ITS.
We probably need to have a new thread about Mars Direct redesigned for alternate launch vehicles such as New Glenn, Vulcan/ACES and Falcon Heavy (latest iteration; with and without propellant cross feed).
Quote from: envy887 on 05/01/2017 02:03 pmThe ITS booster isn't going to exist without the ITS spaceship. If the ITS spaceship exists what's point in developing the Mars Direct departure, transit, EDL and Earth return hardware? It's all grossly out-classed by the ITS ship. The Mars Direct surface ops and refueling hardware would still be useful, but could at that point just be delivered to the surface by ITS.Every now and then I do seem to see hints that SpaceX is building the ITS spaceship first rather than the booster. Doing the opposite would make better sense to me. I will admit though, if the spaceship is up and running and operating with the same engines it would serve as a SSTO LEO launcher which could be where Elon seeks to get most of his money; the booster solo would be overkill for a small-payload-rich v.s. large-payload-poor economy.
I don't want to diss your idea - which isn't awful - but it is extremely unlikely. Why? I think Elon would view it in 'Not Invented Here' terms or as a kludge of different components and technologies. It is also highly unlikely that Boeing, P&W Rocketdyne, NASA and SpaceX would or could all get 'in bed' with each other to enforce such a concept.
Yes but this is not the 1960s, nor those other eras.
