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by wizzwizz4 674 days ago
Eh, this isn't actually that bad. It's quite easy, using a jet aircraft, to (via a ballistic trajectory) get into space. Surrounded by reaction mass as you are, the rocket equation isn't nearly so bad. You could conceivably dock with something in orbit, if you had elastic tethers or something to make the acceleration survivable. If you're much lighter than what you're docking with, you won't knock the satellite out of orbit.

Heck, you could even ignore the jet aspect, and go for full rocket. (An ICBM only weighs around 50 tonnes, after all.) Getting the heavy thing into orbit, though, requires proper, multi-stage rockets.
1 comments
hermitcrab 674 days ago
>It's quite easy, using a jet aircraft, to (via a ballistic trajectory) get into space

A jet engine requires atmosphere. Spaces requires no (or very little) atmosphere.

The edge of space is usually defined at 100km (the Karman line).

The highest altitude reach by an air breathing jet is around 37km. https://en.wikipedia.org/wiki/Flight_altitude_record

A scramjet might get to ~75km according to: https://aviation.stackexchange.com/questions/44837/what-is-t...

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wizzwizz4 674 days ago
That's the point at which the jet stops working, but by that point you can be going quite fast. If there isn't enough air to run the jet engine, there also isn't enough air to slow you down (much).
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hermitcrab 674 days ago
Assuming no air resistance and 10m/s^2 gravity. I calculate that you would have to be doing ~1,100m/s (~mach 3.2 at sea level) straight up at 37km to reach 100km. Or ~1,600m/s (~mach 4.7 at sea level) at 45 degrees to perpendicular.
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wizzwizz4 674 days ago
Seems about right. https://en.wikipedia.org/wiki/Project_HARP (1966) got 2100m/s from a ground-based cannon: this got the projectile to 179km.
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