Paul Allen’s six-engine Stratolaunch

[DeltaV]

And that's the downside of air launch. You drop the rocket, then light it off. If there's a problem with it, the computer can't just abort the launch and shut it down to be repaired ... gravity is in control and the bird with its payload become an expensive hole in the ocean. You have the choice of one big splash or a lot of little ones.

It's a downside for a wingless booster. For a winged, liquid-fueled booster, you could dump fuel, glide to a recovery point and try again later. A winged booster could explain the large size of the carrier aircraft.

[GIThruster]

Any liquid fueld, single stage carried by the plane would need a very big plane to launch decent payload. AirLaunch was pretty small and only lifted to 30k feet. I think this is supposed to lift to 50k and much more capacity.

When I first mentioned this to Gary Hudson he said "yup, Burt gets to build his really big plane." I guess its something he'd thought about for along time.

[DeltaV]

http://aviationweek.com/blog/inside-rocs-lair

[hanelyp]

One advantage of air launch if you want stage reuse, launch from the right point and the first rocket stage has free return to near the home airfield.

What's the point of that with a 3 stage solid? Even if the first stage (of 3!) could be recovered, solid rocket boosters are difficult to refill so it does not really safe any money to recover them. Recovering the shuttle SRBs pretty much saved nothing. The Europeans don't even bother with the Ariane V boosters.

If I were going for reusable stages I'd favor 2 stage liquid fuel more strongly than I usually do. Refurbishment of solid fuel stages is expensive. For that matter, fishing stages out of the ocean after a splashdown is also expensive, and makes refurbishment harder. And 3 rocket stages makes recovery of the second stage a problem.

[Skipjack]

One advantage of air launch if you want stage reuse, launch from the right point and the first rocket stage has free return to near the home airfield.

What's the point of that with a 3 stage solid? Even if the first stage (of 3!) could be recovered, solid rocket boosters are difficult to refill so it does not really safe any money to recover them. Recovering the shuttle SRBs pretty much saved nothing. The Europeans don't even bother with the Ariane V boosters.

If I were going for reusable stages I'd favor 2 stage liquid fuel more strongly than I usually do. Refurbishment of solid fuel stages is expensive. For that matter, fishing stages out of the ocean after a splashdown is also expensive, and makes refurbishment harder. And 3 rocket stages makes recovery of the second stage a problem.

Well, yes. That is what I said. They originally wanted to have a two stage liquid fueled rocket built by SpaceX, but after SpaceX stepped out of the project, they have now settled for a 3 stage solid built by OSC. So there is no chance of reuse and even if they refurbished the first stage, I can not see how that can be cost competitive with SpaceX. Pegasus ended up being one of the most expensive launchers ever and this looks pretty much like a big Pegasus to me.

[JonP]

And that's the downside of air launch. You drop the rocket, then light it off. If there's a problem with it, the computer can't just abort the launch and shut it down to be repaired ... gravity is in control and the bird with its payload become an expensive hole in the ocean. You have the choice of one big splash or a lot of little ones.

True, but perhaps there's the possibility of an escape system. Would be extra stuff/weight that would be contrary to the cheaper flight cost philosophy, but you probably have enough time falling from 50K' to pull off the payload before you blow up your booster or it plunks in the drink, if you wanted to build such. Of course you have to land it safely in the ocean too... so parachutes, framework to support payload under rocket escape as well as ocean drop recovery, flotation, etc...

Hmm... comparing this to the thin but sturdy composite clamshell fairings and a bare satellite... its probably a LOT more weight and cost than I was thinking...

Now I'm thinking of how hard a thump the average payload can deal with, as well as how recoverable is it after a dunk in salt water... wrapping to protect it creates more problems including how to safely free it when you have a successful boost...

All kinds of negative things with my idea... maybe I've discovered why it's not done this way!!

[Skipjack]

There was a discussion about a LAS like system for satellite and cargo transport on NSF a while back. It was quite interesting.

[KitemanSA]

I wonder if this can be augmented with a kite-launch stage?

Cool idea...

Check out http://en.wikipedia.org/wiki/Non-rocket ... ic_tethers .

[swamijake]

The concept is neat, but I look at this as a new heavy cargo hauler. They can put any cargo pod in the middle. How about a tube full of tanks? Or just getting more sushi fish to New York.

As a way to make space travel cheaper, not so sure. In any event it's going to be a hell of a plane to see take off and land. The whole thing is going to flex like heck and look just wrong before lift off.