Author Topic: BFR Shakedown Cruise?  (Read 11675 times)

Offline speedevil

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Re: BFR Shakedown Cruise?
« Reply #40 on: 06/28/2018 04:44 pm »
Getting back on the topic of a shake-down cruise.

Imho, it's quite possible that the first time a BFS is ready to go interplanetary is not in sync with the next the Earth-Mars close approach.  Development timelines being what they are, you might find yourself with a BFS that's ready to go, but no Mars to go to.  Plenty of shorter missions other than going to Mars that are worth doing, especially if you want to accumulate flight time before bringing the paying public onboard.

The moon looks really quite good in this respect.
Free returns are a nice stepping stone out beyond LEO, and then you have 'zero risk' missions without landing all the way up to throwing out 20 tons 100m over the surface, with essentially no hardware development of the BFS, and with long enough transits that the thermal environment becomes similar to interplanetary space. (where the earth thermal radiation is wholly negligible)

Durations are short enough that margins for multiple redundancies can mitigate failures.

Much of this testing needs to happen anyway.
(fuel transfer, ...)

Adding landing - and you get the possibility of somewhere around 100 tons on the surface for every 7 BFR launches or so for $35M each cost to SpaceX, and things get unpredictable as there are so many plausible opportunities.



Offline marsbase

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Re: BFR Shakedown Cruise?
« Reply #41 on: 06/28/2018 09:59 pm »
Adding landing - and you get the possibility of somewhere around 100 tons on the surface for every 7 BFR launches

Ok, I'm a little slow here.  Can you innumerate the 7 launches and their function in getting the 100 ton payload to the Moon?

Offline oiorionsbelt

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Re: BFR Shakedown Cruise?
« Reply #42 on: 06/28/2018 11:42 pm »
BFS to the Moon and back without ISRU on the Moon equals 5 or 6 refueling missions in high ecliptic elliptic  orbit.
« Last Edit: 06/28/2018 11:44 pm by oiorionsbelt »

Offline speedevil

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Re: BFR Shakedown Cruise?
« Reply #43 on: 06/29/2018 10:36 am »
Adding landing - and you get the possibility of somewhere around 100 tons on the surface for every 7 BFR launches

Ok, I'm a little slow here.  Can you innumerate the 7 launches and their function in getting the 100 ton payload to the Moon?

Launch BFS, refill in LEO, small burn to eliptic orbit, refill, get to lunar orbit, offload fuel to prepositioned tanker, land, offload cargo, ascend, retank, back to earth. See this post on the ITS to the moon thread

« Last Edit: 06/29/2018 10:39 am by speedevil »

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