Mid-Air Launch

[Unstung]

I've never heard of this idea:
[ame="http://www.youtube.com/watch?v=1GsG-y7dFVE"]YouTube- t/Space Full Concept of Operations Video[/ame]
It seems buyable, but how would the concept compare to a reusable ground-launch vehicle?
http://en.wikipedia.org/wiki/T/Space

 

[Bloodworth]

It's an interesting idea in that it's cheap...more or less. The problem comes in that it still requires not 1 but 2 disposable stages. If space flight is to ever truly become affordable, or even sustainable, we need to start developing nothing but reusable SSTO vessels or completely reusable TSTO vessels such as the Virgin Galactic white knight - space ship # design for manned space flight. We may never be able to get an SSTO version of an HLV, all research for manned vehicles needs to be directed towards creating completely reusable launch vehicles.

 

[garyw]

Air launched rockets already exist:

 

[Star Voyager]

I don't think I like that re-entry. Wouldn't the heat protection on the nose make that capsule top-heavy when launched (maybe I should read the Wiki article?)?

 

[tori]

Kinda looks like ballistic reentry too. G-heavy.

Aside from that - I love the concept. Really easy on ground infrastructure, and that's where a huge part of launch costs is buried.

 

[Alexw95]

i think nasa should focus on this concept as aircraft travel is fairly cheep and would be easy to haul a rocket like that on a 747 or so but how about insted of a rocket a shuttle style ctv that has wings ?

 

[garyw]

i think nasa should focus on this concept as aircraft travel is fairly cheep and would be easy to haul a rocket like that on a 747 or so but how about insted of a rocket a shuttle style ctv that has wings ?

Too heavy to put into orbit. The only reason for air launch is to remove all that annoying ground infrastrucutre like flame trenches. The Pegasus video I linked uses solids so there is no cyro boil off.

Anything that uses liquid fuels has a multitude of issues when air launched which adds complexity and so costs.

Aircraft for launching space rockets is fine for small probes but not for anything bigger than that.

Anyway, t/space are bidding for part of the COTS contract so if they have way's of making the concept work they now have the backing to do it.

 

[Bloodworth]

I don't think I like that re-entry. Wouldn't the heat protection on the nose make that capsule top-heavy when launched (maybe I should read the Wiki article?)?

yes, it would a little, but as the article stated, the rocket is spin stabilized as it is dropped from the aircraft and it is dropped in such a way that it is assured to drop tail first. Even still, the weight of the first stage engine is likely to be more than that of the heat shielding. So now that i mention it, I guess that wouldn't make it top heavy.

 

[tori]

but as the article stated, the rocket is spin stabilized as it is dropped from the aircraft

sounds like a helluva ride :lol: I missed that, where does it say anything about spin stabilization?

 

[Bloodworth]

Aircraft for launching space rockets is fine for small probes but not for anything bigger than that.

I think the Burt Rutan and friends would beg to differ with you. With only a little tweaking, white knight 2 and spaceship 2 could be modified to be able to make it clear to the ISS. That's quite a bit bigger than a small probe...

 

[T.Neo]

I think the Burt Rutan and friends would beg to differ with you. With only a little tweaking, white knight 2 and spaceship 2 could be modified to be able to make it clear to the ISS. That's quite a bit bigger than a small probe...

There is a big difference between ~110 km suborbital and ISS orbit. Unless you mean a "little tweaking" as in "upgrading the lifting capacity of White Knight and installing a new propulsion system on SpaceShipTwo".

Not to mention the fact that SpaceShipTwo wouldn't be able to reenter from orbit. :suicide:

 

[garyw]

I think the Burt Rutan and friends would beg to differ with you. With only a little tweaking, white knight 2 and spaceship 2 could be modified to be able to make it clear to the ISS. That's quite a bit bigger than a small probe...

Sorry that's wrong. SS1 and 2 are solids, again no cryo boil off and at flight apogee are doing about Mach 3-Mach 5. The energy required to get into a proper orbit and get to the ISS is over 100 times more than they have. That's NOT a little tweaking. If it was why haven't they done it?

 

[T.Neo]

SS1 and 2 are solids, again no cryo boil off

Slight correction: they are hybrid rockets, with HTBP rubber fuel and pressurised N2O oxidiser. They do not, as you said, suffer from boiloff problems.

 

[Bloodworth]

Sorry that's wrong. SS1 and 2 are solids, again no cryo boil off and at flight apogee are doing about Mach 3-Mach 5. The energy required to get into a proper orbit and get to the ISS is over 100 times more than they have. That's NOT a little tweaking. If it was why haven't they done it?

Probably because SS2 hasn't even FLOWN yet. The vehicle was just recently rolled out and to my knowledge hasn't even had a test flight yet. White Knight 2 just recently had its first successful test flight.

 

[garyw]

Doesn't matter. This is from the wiki article:

"SpaceShipTwo will reach 4,200 km/h (2,600 mph), using a single [ame="http://en.wikipedia.org/wiki/Hybrid_rocket"]hybrid rocket[/ame] motor"

2,600 MPH is just a little bit slower than the 17,500MPH needed for orbit but the amount of energy needed to push the vessel to orbit speed is much, much, much greater, then you need to add heat protection and so on.

 

[T.Neo]

2,600 MPH is just a little bit slower than the 17,500MPH needed for orbit but the amount of energy needed to push the vessel to orbit speed is much, much, much greater, then you need to add heat protection and so on.

And the more massive the vehicle becomes, the more mass the carrier will have to be able to lift. Neither SS2 or WK2 would be suitable at all for this task.

But I think a feasible reusable spaceplane concept could come from Scaled given the right interest. It'd undoubtedly be a revolutionary design.

 

[Unstung]

Would a plane be able to carry a fueled rocket that can lift four people into orbit?

 

[Andy44]

Early in the shuttle program, it was assumed that the space shuttle would be a 2-stage reusable vehicle. The first stage would be a manned flyback booster, and the orbiter would be the second stage with internal propellants.

There were two problems with this.

One was that the orbiter would have to be very large, since it was carrying all its own propellant. The eventual solution was to put all the propellants in an external drop tank, our beloved ET.

The other problem was that the flyback booster would be the largest aircraft ever built, much bigger than a 747, with the ability to reach hypersonic speeds and altitudes near the edge of space, and it had to do this with the orbiter on its back.

The solution to that problem was, again, to reduce the size of the orbiter using an ET, and to ditch the manned liquid booster and substitute a pair a SRBs. The SRBs could always be upgraded to liquid flyback rocket boosters (LRBs) if the money ever became available.

Here's a picture of the early shuttle concept I just described. Note the enormous size of the booster plane:
http://astronautix.com/graphics/s/shutbnar.jpg (The hotlink is blocked by astronautix; paste it into your browser window to see it)

---------- Post added at 12:02 AM ---------- Previous post was at 12:01 AM ----------

BTW, the answer to the above question is "maybe, but it would be a technical challenge".