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Paul Allen's new rocket-launching plane

arstechnica.com

61–70 of 170 posts

Re: Paul Allen's new rocket-launching plane

#61
This is a very good idea. In rocketry, air is your enemy. At the speeds rockets move it causes enormous heat/mechanical stress on the rocket, drag energy losses, and it messes with the flow of matter out the back of the engine that provides your thrust.

With a jet engine, air is your friend, because it is the matter you spit out the back of the engine. And at the much smaller speeds of an airplane, mechanical and thermal stresses are much smaller.

Re: Paul Allen's new rocket-launching plane

#62
post #27

IANARS 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.

Could always dump fuel on the way back.

Re: Paul Allen's new rocket-launching plane

#63
post #55

Earlier quoted context omitted.

Is 4. really doable? Would have thought landing while carrying a fully fueled rocket might be pretty high risk.

I haven't actually seen anyone mention it, but it shouldn't be much more risky than taking off fully-fueled. That said, landing with the rocket still on board might break some fuel-balancing assumptions.

Landing weights are usually a bit lower than take off weights due to the extra shock on landing.

for example the a340-600 has a MTOW of 380 tons but a Max landing weight of 265 tons. Just a bit of a difference.

Re: Paul Allen's new rocket-launching plane

#64
post #50
post #27

IANARS 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…

Looks more like the Pineering Spirit, a ship made from 2 hulls side by side:

https://en.wikipedia.org/wiki/Pioneering_Spirit_(ship)

There are videos of this thing lifting an entire oil platform at once.

Re: Paul Allen's new rocket-launching plane

#65
post #46

Since the Orbital ATK Pegasus already exists and already has a customised plane it launches from, can we assume launching Pegasus is just phase 1 for this plane? If that's all it's going to do there would be no point. So presumably this has capabilities the current Pegasus launch plane doesn't have, and eventually we'll see it launching something like a Pegasus XL Plus? Do we have any indication how big a rocket this…

Originally it was going to use a Falcon 5 Air, and later a Pegasus II. Both projects were cancelled.

Re: Paul Allen's new rocket-launching plane

#66
I feel overcome by the Dianne Kruger effect, to an extent I don't remember feeling any time recently. I'm becoming more and more interested in news about rocketry (due to SpaceX of course) but I'm still a full on space-pleb. I see something like this and my intuition screams "Woah! Of course! Why don't other rocket companies do this? What's wrong with them?!"

But the rational part of my brain kicks in and slaps me down for being so arrogant. It feels humbling to be reminded how stupid one can be.

Re: Paul Allen's new rocket-launching plane

#67

I feel overcome by the Dianne Kruger effect, to an extent I don't remember feeling any time recently. I'm becoming more and more interested in news about rocketry (due to SpaceX of course) but I'm still a full on space-pleb. I see something like this and my intuition screams "Woah! Of course! Why don't other rocket companies do this? What's wrong with them?!" But the rational part of my brain kicks in and slaps me do…

Dianne Kruger......?????

Re: Paul Allen's new rocket-launching plane

#68

I feel overcome by the Dianne Kruger effect, to an extent I don't remember feeling any time recently. I'm becoming more and more interested in news about rocketry (due to SpaceX of course) but I'm still a full on space-pleb. I see something like this and my intuition screams "Woah! Of course! Why don't other rocket companies do this? What's wrong with them?!" But the rational part of my brain kicks in and slaps me do…

Do you mean Dunning-Kruger effect?

Re: Paul Allen's new rocket-launching plane

#69

I feel overcome by the Dianne Kruger effect, to an extent I don't remember feeling any time recently. I'm becoming more and more interested in news about rocketry (due to SpaceX of course) but I'm still a full on space-pleb. I see something like this and my intuition screams "Woah! Of course! Why don't other rocket companies do this? What's wrong with them?!" But the rational part of my brain kicks in and slaps me do…

Dianne Kruger......?????

Haha! *Dunning–Kruger :P

Re: Paul Allen's new rocket-launching plane

#70

I feel overcome by the Dianne Kruger effect, to an extent I don't remember feeling any time recently. I'm becoming more and more interested in news about rocketry (due to SpaceX of course) but I'm still a full on space-pleb. I see something like this and my intuition screams "Woah! Of course! Why don't other rocket companies do this? What's wrong with them?!" But the rational part of my brain kicks in and slaps me do…

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

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