For example, a Falcon 9 v1.0 could get 10 tonnes to LEO. If it had been re-usable - your choice would have been eithera) only get 7 tonnes to LEO (expensive in terms of payload), orb) build a bigger Falcon 9 v1.1 that can get 10 tonnes to LEO (expensive in terms of bigger rocket & more fuel)
I know it's guesswork, but if the comment that "the whole rocket could land on mars" is right, then there is no centre stage to RTLS, right?
I believe that the listed F9 v1.1 payload of 13,150 kg (14.5 tons) to LEO already has first-stage RTLS built into the number.
I think the whole MCT lands, not the whole rocket -- it's not single-stage-to-Mars.
Quote from: Vultur on 05/09/2014 03:41 amI think the whole MCT lands, not the whole rocket -- it's not single-stage-to-Mars.Fair point. I certainly don't think all the boosters go to Mars.
Kind of chicken or egg. We don't know what the MCT total mass and size is, so we don't know what capability might be needed to launch it. I would guess squatty is better, since I posit that MCT has to be ginormous, like A380 size!I guess around 150mT reusable single core, but I think that is too small for their ambitions, unless they have a Heavy version after that. I favor single core over tri core. It would be safe to assume that it has to be more capable than SLS Block(x) and any Chinese or Russia paper rocket.
... it suggests that the fewer components in the fleet, the easier the launch rate is to accomplish. Achieving efficient throughput outweighs infrastructure cost and architecture cost where volume is high. This argues for a two stage design rather than a Heavy, despite the additional cost of the two stage design.
original post was... Colonist numbers and the optimum Mars launch window will drive the BFR/MCT design. Musk has stated a target colony size of 80,000. Actually he has given higher figures but lets take the more ‘conservative’ number as the target.The MCT target capacity is 100 colonists, so to get our 80,000 we need 800 launches. ...
Quote from: SteveKelsey on 05/12/2014 08:16 am... it suggests that the fewer components in the fleet, the easier the launch rate is to accomplish. Achieving efficient throughput outweighs infrastructure cost and architecture cost where volume is high. This argues for a two stage design rather than a Heavy, despite the additional cost of the two stage design.Interesting observation, Steve. I'm a bit agnostic on the stages/single-core-vs-tri-core question, but your broader point about cost-efficient throughput trumping infrastructure capital cost and development cost when flight volume is high is a good one for us to keep in mind.EM said that the BFR will be based on the Facon Heavy design.Welcome to the forum.
In this admittedly invented context it suggests that the fewer components in the fleet, the easier the launch rate is to accomplish. Achieving efficient throughput outweighs infrastructure cost and architecture cost where volume is high. This argues for a two stage design rather than a Heavy, despite the additional cost of the two stage design.
I'm not sure if this is a different perspective - but I'm trying to imagine the MCT launching from Mars in one configuration, and from Earth in a different configuration. It would seem boosters from Earth is the easiest way to allow for the increased requirements from earth. (But maybe the first stage could look different on each planet? Or one less stage on Mars?)
......... and I would expect the two stage to win out all other things being equal.
I think it's fairly clear that the MCT will be using depots. They significantly decrease the size of the rocket needed, and they would allow SpaceX to actually benefit from rapid reuse for mars missions.