4
$\begingroup$

enter image description here What could the Kozlov’s Aerosmena project blimp add to fuel saving if space rockets were launched from it? Where would you place the rocket and airship on this chart?

$\endgroup$
7
  • 6
    $\begingroup$ fuel usage per km is not a useful metric for space vehicles $\endgroup$ May 9, 2021 at 19:02
  • 2
    $\begingroup$ Rockets can travel as far as you are willing to wait, and the optimal time to reach a destination is driven by orbital mechanics, independent of vehicle. This chart is basically useless for space travel, it only means something for vehicles that spend their time crawling around on a planetary surface or through its oceans/atmosphere. $\endgroup$ May 9, 2021 at 19:26
  • 1
    $\begingroup$ To reiterate what has been said in many places. When you want to reach the orbit, gaining altitude is not the problem. The real problem is that you need to accelerate to the speed of 8 kilometers per second sideways. True, it is marginally easier to do that if you don't have to fight the extra drag of the thicker atmosphere the first few kilometers, but A) a rocket lifting off does not spend much time at low altitudes, B) its speed while there is "slow". $\endgroup$ May 10, 2021 at 7:24
  • 2
    $\begingroup$ @JyrkiLahtonen also, from what I could find, the maximum altitude of these blimps is only 3000 m. That's probably not when carrying their maximum payload. You're basically launching from a really expensive and weather-sensitive ground pad. $\endgroup$ May 10, 2021 at 13:00
  • 1
    $\begingroup$ @OrganicMarble This graphic has nothing to do with space travel - what is called "Stage" here are just different stages of engine development. $\endgroup$
    – asdfex
    May 11, 2021 at 7:49

1 Answer 1

5
$\begingroup$

If a rocket using cryogenic fuel and oxidizer is launched from a blimp, no fuel will be saved.

During the blimp flight from ground to launch height, the rocket will loose a lot of fuel by evaporation.

A rocket to reach an orbit at 400 km height and 8 km/s speed saves only very, very little fuel when launched from about 10 km height provided by a blimb.

So much more fuel is wasted by evaporation than saved by the increased launch height.

$\endgroup$
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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