it would take between 8 and 12 launches of an augmented SLS to get a fully fueled manned Mars vehicle into space and prepared for departure to Mars.Only if they do it wrong. This is somewhere in the neighborhood of 10 billion for a single mission. This is never going to happen since it would be following a much better plan.
Human missions to deep space destinations require large amounts of mass in LEO because we need to protect and preserve the lives of the crew, take all consumables and fuel for the journey, and carry the equipment and supporting machines needed to carry out the mission objectives.No. We only need enough mass to get the job done. More mass is more cost. Most equipment should be sent ahead and waiting. Nothing need be stationed in LEO.
No existing commercial launch vehicle (nor any anticipated in the near future) has the launch capacity of the SLS.The SLS doesn't have any launch capacity yet. Other vehicles with greater capacity could actually become reality sooner.
as no Falcon Heavy has yet to fly, we have no idea of what its cost would be.$90m already published.
[FH] would consist of 27 engines, all of which must burn for the same duration and thrust level.Not exactly. The central core, with crossfeed will burn longer and engine out is part of the design. The N-1 failures means nothing.
[The purpose of SLS] was to make sure that the vehicle would be built and to assure that our national capability in this area would not be lost.You have just entered the spin zone! Translation, it's about old space jobs over new space jobs.
[SLS] exists and it will provide a capability that we can use to go back to the Moon and to the planets beyond.No it doesn't exist. No it doesn't provide a capability without new equipment they haven't even started. Orion can only splash down on earth and perhaps not even then from some sources.
Dragon 2 exists and can land anywhere including on mars. FH is made from existing cores and will be flying soon. It has been delayed by other priorities but that situation has drawn to a close.
Zubrin reviews Spudis.