Has anybody tried launching a rocket from an airship/dirigible?
Paul Allen's new rocket-launching plane
71–80 of 170 posts
Re: Paul Allen's new rocket-launching plane
#72Earlier quoted context omitted.
It is a pretty big difference. In vacuum you want a huge nozzle to extract as much energy as possible from the engine's exhaust. In atmosphere, there's a limit to how large the nozzle can be before the exhaust flow separates from the sides and you get asymmetric thrust or worse. Since the nozzle can only be optimized for one particular altitude, that means that rockets which launch from sea level spend a good portion…
Cool, I was totally unaware of this "prior art". Thanks!
Here's a remarkable official USAF film from 1974 about the air-launched Minuteman. Really amazing. https://www.youtube.com/watch?v=8b8LLcdBaQc
Re: Paul Allen's new rocket-launching plane
#73IANARS but this plane should give the remaining stage(s) four advantages: 1. +230m/s orbital velocity [1] 2. +9km launch altitude [1] 3. can launch in more weather conditions 4. 1st stage can abort mid-launch without loss of payload. Of these, the most important is the increase in launch altitude, because that means stage 2 launches in air of greatly decreased density, leading to the following efficiencies: A. a vacu…
Is 4. really doable? Would have thought landing while carrying a fully fueled rocket might be pretty high risk.
Can the payload be dropped with a parachute? Is 200m/s safe for parachute deployment?
Re: Paul Allen's new rocket-launching plane
#74IANARS but this plane should give the remaining stage(s) four advantages: 1. +230m/s orbital velocity [1] 2. +9km launch altitude [1] 3. can launch in more weather conditions 4. 1st stage can abort mid-launch without loss of payload. Of these, the most important is the increase in launch altitude, because that means stage 2 launches in air of greatly decreased density, leading to the following efficiencies: A. a vacu…
The primary advantage of airplane launch is that you can fly to into a launch window for an orbital rendezvous. Otherwise you'd have to wait for the target's orbit to be just right w/respect to the launch site, or do a long orbit matching process. This is very useful if say you want to very quickly and quietly launch something towards another satellite. People are making comparisons with the Spruce Goose, but the Glo…
The largest downside is the rocket needs to be strong in more than one direction which adds a lot of weight. Sub Mach 1 first stage will save a little net weight but significantly less than you might diets assume.
Re: Paul Allen's new rocket-launching plane
#75Earlier quoted context omitted.
Dianne Kruger......?????
The Dunning-Kruger effect: The idea that people of low skill or knowledge about something don't know how much they don't know and thus think they're much better at it then they actually are. https://en.m.wikipedia.org/wiki/Dunning–Kruger_effect
was dianne his wife?
Re: Paul Allen's new rocket-launching plane
#76IANARS but this plane should give the remaining stage(s) four advantages: 1. +230m/s orbital velocity [1] 2. +9km launch altitude [1] 3. can launch in more weather conditions 4. 1st stage can abort mid-launch without loss of payload. Of these, the most important is the increase in launch altitude, because that means stage 2 launches in air of greatly decreased density, leading to the following efficiencies: A. a vacu…
The primary advantage of airplane launch is that you can fly to into a launch window for an orbital rendezvous. Otherwise you'd have to wait for the target's orbit to be just right w/respect to the launch site, or do a long orbit matching process. This is very useful if say you want to very quickly and quietly launch something towards another satellite. People are making comparisons with the Spruce Goose, but the Glo…
The spruce Goose analogy comes from wingspan, which is directly from the article
Re: Paul Allen's new rocket-launching plane
#77OK
Re: Paul Allen's new rocket-launching plane
#78Does anyone have any insight into how the dual flight decks are utilized?
There's only one flight deck and it in the right-hand fuselage. I was at a recent friends and family day at Scaled Composites and was able to see and touch this amazing plane.
Re: Paul Allen's new rocket-launching plane
#79This is awesome but a little bit scary. Interesting that they didn't physically connect the tail wings at all, I wonder what stresses and torques the main wing will endure under maneuvering or turbulence. I assume all the control surfaces are computer controlled to synchronize and minimize that, but from the perspective of an ignorant observer, looks a little fragile.
it's a proven design. scaled composites, which built this also built the GlobalFlyer with similar configuration. https://en.wikipedia.org/wiki/Virgin_Atlantic_GlobalFlyer
Well, proven at small scale. I'm sure the new bigger one will work fine too under most anticipated conditions, but I wonder what its structural safety factor is.
Re: Paul Allen's new rocket-launching plane
#80Earlier quoted context omitted.
The primary advantage of airplane launch is that you can fly to into a launch window for an orbital rendezvous. Otherwise you'd have to wait for the target's orbit to be just right w/respect to the launch site, or do a long orbit matching process. This is very useful if say you want to very quickly and quietly launch something towards another satellite. People are making comparisons with the Spruce Goose, but the Glo…
The spruce Goose analogy comes from wingspan, which is directly from the article
He's hinting that this is a black program with a fake public cover story.