[AR] Re: Mini-rocket to space?
- From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
- To: Arocket List <arocket@xxxxxxxxxxxxx>
- Date: Sun, 28 Feb 2021 18:54:58 -0500 (EST)
On Sun, 28 Feb 2021, John Dom wrote:
I would prefer the gun launch principle where all launch energy and mass
is provided on the ground.
Reaching 100km with a gun is no big trick -- the WW1 Paris Guns could
probably have done that, perhaps with a somewhat lighter shell, if fired
near-vertically. But it needs a big up-front investment, so it doesn't
really make sense unless somebody's willing to pay to launch a lot of
payloads to that altitude.
Reaching orbit that way is another story. Gerald Bull's orbital-launch
gun designs required three-stage or even four-stage rocket shells, which
is ridiculous -- two good solid stages can reach orbit *without* the gun,
as witness Athena I. (Two good liquid stages can reach a Mars trajectory
without help.) Even John Hunter's gas guns would have needed major rocket
boost at apogee, typically two stages of it, and unsurprisingly this was a
major cost driver; the more detailed and realistic his designs got, the
less appealing they were.
Rocket without propellant has been ignored for too long...
For good reason. Gun launch makes sense only if the gun can do the
*whole* job, which it can't for orbit or deep space.
"The gun will not rise again. The future of space exploitation belongs
strictly to the rocket. It is quite adequate for the job." -- Max Hunter,
Thrust Into Space, 1966.
Henry
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