4 ms·

There is a claim that answers your question in the very beginning of the article. >Currently, all of the fuel needed for a mission is carried up with the rocke

• rbanffy 15y ago
  That doesn't make much sense. You can send a booster stage to orbit, complete with engine, cluster boosters (or add already full tanks) if needed and dock the spacecraft (which can be assembled in orbit too) in place. There is no reason to send empty "fuel depots" to orbit or to transfer cryogenic fuel and oxidizer in zero-G.
  • electromagnetic 15y ago
    I think the point is to minimize launches. 2 launches per mission as you suggest is eventually going to cost more. If it takes 10 launches to initially set up and 1 every say 5 fuel ups, then it's only going to be 12 launches before it breaks even. Given the Space Shuttles did 135 missions, doing 135 additional launches definitely isn't cost effective. Not to mention you wouldn't have to re-enter a vehicle or do another launch if you wanted to extend a mission. It would pave way for transfer and potentially one day freight transfers in space. Also it gives the potential for "Oh Space X you need fuel, well look who has a fuel depot bitches."
    • rbanffy 15y ago
      The number of launches should be more or less the same, since the mass that gets to orbit is more or less the same. With the advantage pending towards placing already full tanks in orbit because you don't have to launch a separate tank plus the apparatus needed for the fuel transfer. Unless this "surprise you need fuel" thing becomes common, something very unlikely because you usually know what you are going to do in orbit, this "fuel depot" thing makes no sense at all.