t/Space Demonstrates New Air-Launch Method

FleaPlus writes "Last month t/Space, an organization with plans for constructing a simple, low-cost successor to the Space Shuttle, was mentioned on Slashdot. Recently t/Space used a portion of the concept study funds it had been awarded by NASA to also build and test actual hardware. They performed three weeks of drop tests of a 23%-scale model from a Scaled Composites Proteus carrier aircraft to demonstrate the feasibility of a new air launch method they had devised, dubbed 'Trapeze-Lanyard Air Drop.' The new method eliminates the need for wings on air-launched rockets, potentially leading to improved safety and cost-effectiveness. Last month at a space conference they also displayed a full-scale model of their vehicle. Unfortunately, with the recent selection of Boeing/Northrop-Grumman and Lockheed-Martin as the two competing teams for the contract to build the Shuttle's successor, t/Space's future path is somewhat uncertain."

Comments

Oops wrong link.. check this...

[mister_llah]

Damn it, Beautrice... that's something different :)

http://www.eng.titech.ac.jp/jyosei/t_yabe.pdf

That is more along the lines of what I meant!

Re:'Trapeze-Lanyard Air Drop.'

[Rei]

And the abort mode for a stuck cable or bad chute is....? :)

Not that it's not an interesting deployment concept, mind you. There are lots of interesting airbreathing assisted methods, although none of them scale up to very large orbital craft. In addition to this and standard belly-dropped rockets, there's also wing-dropped (doesn't usually need a custom aircraft, but is geometrically constrained and offbalances the craft), roof-launched (the whole "tail" thing tends to get in the way unless you have a custom craft, but you can handle almost any geometry), tow-launch (you pay a penalty in carrying heavy landing gear, but the modifications to the towing craft are minimal), unfuelled tow launch (you fuel midair from lines attached to the craft at liftoff), docking and fuelling (taking off with just enough fuel to get to altitude - allows for multiple reentries and possibly powered landing), and carrying the craft inside the carrier, launching with a drogue chute (very geometrically constraining, but almost no modifications to the carrier needed).

The problem with scaling up is that airplanes get tougher to scale up beyond a point. It's really only realistic for small satellites and humans to LEO.

Re:What you saw was a weather balloon!

[FleaPlus]

Whatever happened to launching from lighter-than-air platforms? With conventional rockets, so much weight goes into fuel to move the fuel you'll burn later to move the fuel that comes even later. Surely someone's doing something with a straightforward idea like this?

That's pretty much what JP Aerospace is doing, "airship to orbit." RLV News has some additional info and news items on them.

Takes much less energy

[Anonymous Coward]

Both of which would require the same amount of energy as just burning the fossile fuels to begin with. From where would you get that energy? A power plant that burns fossil fuels?

The overwhelming majority of fuel used to launch spacecraft is spent accelerating the rest of the fuel. If you don't carry the fuel with you, it will take much less energy to reach orbit. Consider the European Union's Hopper which will accelerate spacecraft on magnetic rails. They already have a prototype.

Re:'Trapeze-Lanyard Air Drop.'

[MichaelSmith]

tow-launch (you pay a penalty in carrying heavy landing gear, but the modifications to the towing craft are minimal)

The spacecraft does need some kind of landing gear, unless a disposable sled is used for takeoff. Consider a cart strapped to the vehicle and dropped at liftoff

But the real problem is that the spacecraft has to fly from the word go, and (unless we assume your next option) needs to do so fully fuled.

This works surprisingly well for sailplanes but spacraft have the opposite problem. They are much heavier than the carrier vehicle.

How about a "sandwich" design: Towed spacecraft with disposable launch cart and wings. At altitude the system splits into three parts with the wings being (possibly) recovered by parachute.

Other Uses for Air Launch

[roughapprox]

"Unfortunately, with the recent selection of Boeing/Northrop-Grumman and Lockheed-Martin as the two competing teams for the contract to build the Shuttle's successor, t/Space's future path is somewhat uncertain."

That's baloney. The US military loves the air launch thing. Back in the '70s there was a pathfinder-type mission that air launched a Minuteman. And the MDA is heavily invested in air launched targets for the various interceptor programs. There was the LRALT program and a newer target launched by Orbital Sciences. And, of course, there's also Orbital's Pegasus space launch vehicle.

The benefit of the type of air launch method that t/Space is showing is that the LRALT and MRT programs require the extremely heavy sleds that they sit on and that they are limited by the cargo capacity of a C-17. And Pegasus has to carry that enormous wing and tail structure (not to mention its failures, such as the first X-43A flight).

I think if t/Space can show superiority over the existing air launch methods (which doesn't seem to be difficult), they will definitely fill a demand in both the small space launch and targets markets.

Re:Missiles

[EvilTwinSkippy]

Er, no.

Yes, there are ballistics involved, but Missile technology is a helluva a lot more complicated because you are accellerating a mass that is constantly shrinking through an atmosphere that is constantly thinning to a speed that is so fast that the "bullet" enters a state of perpetually falling.

New branches of mathematics and numerical analysis have been fleshed out just to describe the problem properly. You know all those Differential equations you High School math teacher told you were impossible to solve. Well, that's not true. And while I'm at it, electrical engineers regularly work with sqrt(-1).

Saying a missile is just a guided long range bullet is like saying biology is just chemistry on a nanotech level.

Re:What you saw was a weather balloon!

[radtea]

It turns out that it only takes about 5% of the fuel (or less) to get to the altitude that a typical airship flies - and that a reasonable size payload requires an airship twice the size of the Hindenburg to carry it.

But reducing fuel mass by 5% allows you to increase your payload mass by at least a factor of two for many launch vehicles. I'm not sure balloon-launch is the way to go, because as you say speed is the issue, but rockets are so enormously inefficient that relatively small percentage savings in fuel mass translates into very substantial increases in payload mass.