4 ms·

Why can't you aerodynamically fly up to high altitudes and then start rocketing?

Pfhreak 7y ago
You can, but it introduces its own set of complexities. The plane needs to carry a massive payload, and doesn't really get you much delta v. The problem is not how do we get up high, but rather how do we get going really, really, really fast.
- techdragon 7y ago
  There is in fact a remarkably useful set of well developed air launch rockets that help provide a nice “benchmark” for comparison with air launching satellites/etc using rockets. Anti-SATellite (ASAT) weapons are making similar engineering trade offs but aiming at a different set of capabilities, optimising for smaller sizes, being “rack ready” in the event war breaks out, and so on. Unlike the more modern ship launched SM3 that is part of the Ageis system, the older ASM-135 https://en.wikipedia.org/wiki/ASM-135_ASAT https://en.wikipedia.org/wiki/ASM-135_ASAT was designed to be air launched in a supersonic zoom climb to get maximum speed and altitude from the aircraft in order to maximise its capabilities. For an even better comparison, you can compare air launches ASAT missiles with sounding rockets, they have a greater similarity in their trajectories/launch profiles, so it’s easier to see what the air launch “gains” over the ground launch.
  - mlyle 7y ago
    There's always also e.g. Orbital Pegasus.
- benj111 7y ago
  Rockets tend to throttle down at lower altitudes so they're not accelerating through thick atmosphere though? So Delta V isnt much of a loss.
  - rocqua 7y ago
    When not burning sideways, you have the issue of gravity drag. Specifically, all the force spent firing downwards is wasted on fighting gravity rather than gaining speed. The reason rockets go up is to get above the atmosphere. Without an atmosphere, you'd launch rockets sideways.
jccooper 7y ago
It doesn't help much. Most of the work in achieving orbit is in gaining speed "sideways". Your average orbital launch achieves high airplane altitudes in the first 15-20 seconds out of a 500 second flight. It's easier to build a slightly bigger rocket than to add a giant airplane to the system.

You can, but it introduces its own set of complexities. The plane needs to carry a massive payload, and doesn't really get you much delta v. The problem is not how do we get up high, but rather how do we get going really, really, really fast.

techdragon 7y ago
There is in fact a remarkably useful set of well developed air launch rockets that help provide a nice “benchmark” for comparison with air launching satellites/etc using rockets. Anti-SATellite (ASAT) weapons are making similar engineering trade offs but aiming at a different set of capabilities, optimising for smaller sizes, being “rack ready” in the event war breaks out, and so on. Unlike the more modern ship launched SM3 that is part of the Ageis system, the older ASM-135 https://en.wikipedia.org/wiki/ASM-135_ASAT https://en.wikipedia.org/wiki/ASM-135_ASAT was designed to be air launched in a supersonic zoom climb to get maximum speed and altitude from the aircraft in order to maximise its capabilities. For an even better comparison, you can compare air launches ASAT missiles with sounding rockets, they have a greater similarity in their trajectories/launch profiles, so it’s easier to see what the air launch “gains” over the ground launch.
- mlyle 7y ago
  There's always also e.g. Orbital Pegasus.
benj111 7y ago
Rockets tend to throttle down at lower altitudes so they're not accelerating through thick atmosphere though? So Delta V isnt much of a loss.
- rocqua 7y ago
  When not burning sideways, you have the issue of gravity drag. Specifically, all the force spent firing downwards is wasted on fighting gravity rather than gaining speed. The reason rockets go up is to get above the atmosphere. Without an atmosphere, you'd launch rockets sideways.

jccooper 7y ago

It doesn't help much. Most of the work in achieving orbit is in gaining speed "sideways". Your average orbital launch achieves high airplane altitudes in the first 15-20 seconds out of a 500 second flight. It's easier to build a slightly bigger rocket than to add a giant airplane to the system.