6
$\begingroup$

Why does SpaceX not develop a second stage that can be used to meet with a first stage to pick up payload and refuel, thus transporting goods to orbit repeatedly instead of being used only once?

$\endgroup$
2
  • $\begingroup$ If the first stage is handing over fuel and payload to the second stage, only significant thing being utilized from the second stage are the engine, tank and the plumbing. By mass, the savings are probably minuscule ? Can you edit add to the question the amount of mass the first stage hands over to the second stage and the mass of the second stage just before receiving stuff from the first stage ? Would the first stage need to dock wit the second stage ? What would be the additional mass required for the docking mechanism and fuel, paylod transfer mechanisms ? $\endgroup$
    – AJN
    Jul 10 at 8:24
  • 2
    $\begingroup$ The question is quite lacking in description. Please edit in the things you have already thought about including masses, mechanisms, orbits/trajectories involved. $\endgroup$
    – AJN
    Jul 10 at 8:28
6
$\begingroup$

Because the first stage isn't designed to get to orbit.

$\endgroup$
4
  • 3
    $\begingroup$ ...or, the 2nd stage would expend almost all of it's fuel shuttling back and forth between orbital velocity and a suborbital rendez-vous velocity with the suborbital first stage. $\endgroup$
    – uhoh
    Jul 10 at 8:28
  • 3
    $\begingroup$ @uhoh I suppose you can in theory abuse the atmosphere to cut the shuttling cost, but I wouldn't want to touch a system were phrases like "docking during reentry", "repeated mandatory split second launch windows" and "suborbital propellant cross feed" can be heard. $\endgroup$ Jul 10 at 12:50
  • 1
    $\begingroup$ @SE-stopfiringthegoodguys then don't touch it! Docking is in no way necessary to transfer stuff. Here, catch! $\endgroup$
    – uhoh
    Jul 10 at 13:34
  • 2
    $\begingroup$ Oh no it slipped! Wasn't anything valuable, right? $\endgroup$ Jul 10 at 13:37

Not the answer you're looking for? Browse other questions tagged or ask your own question.