Rotor Recovery?

[tomnackid]

I have been trying to find info on spacecraft recovery systems based on helicopter style rotors. I know the Soviets did some experiments with model Soyuz capsules and it was proposed as an alternative for parachutes in the early days of Apollo. Gary Hudson has seem to taken this idea the furthest with his Roton, proposing a rotor to decelerate and land an entire SSTO spacecraft! But that's about all I can find.<br /><br />I figure if rotors can be designed to work with and SSTO it could be far easier to do with just a capsule. Rotors seem to have many advantages. They have greater lift to weight than wings. They are more controllable than parachutes. They can decelerate a capsule passively through autogyration then be spun up for the last few hundred feet for a true soft landing. Depending on the disc loading they can potentially safely land a capsule with no power. A rotor in autogyration can't stall like a lifting body does. You can still have a reserve chute for emergencies.<br /><br />What are the downsides to rotors? Is it just too weird to contemplate a "space helicopter".<br />

 

[barrykirk]

Roton if I recall had Burt Rutan involved in it.<br /><br />The idea was actually not primarily for landing.<br /><br />The idea was based on the following.<br /><br />There are two general types of liquid rocket engines.<br /><br />1) Pressure Fed.<br />2) Turbine Fed.<br /><br />Pressure fed has the disadvantage that chamber pressure and therefore thrust is lower and the fuel tank is heavy to handle the pressure.<br /><br />Turbine fed has the disadvantage that turbines are expensive and heavy.<br /><br /><br />Roton is described on the scaled composites website. It uses a centrifugal fuel pump with a rotary wing used as the pump. The rockets are on the wingtips. At low altitutudes and velocities. It works like a helicopter with a rocket propelled rotary wing which is much more efficient than a conventional rocket.<br /><br />At higher altitudes and velocities the blades face almost straight down and act like a conventional rocket but with centrifugal fuel pump.<br /><br />I don't know whatever happened with the concept.

 

[tomnackid]

Hudson ran Rotary Rocket. He contracted with Rutan to build the shell of the test vehicle.<br /><br />I know Hudson abandoned the whole centrifugally pumped engine/rotor early on and just kept he rotor for landing purposes.

 

[barrykirk]

OK

 

[nexium]

A returning space craft typically enters the outer atmosphere at about 18,000 miles per hour, which would burn up the rotor unless it was protected somehow. I don't think the rotor is useful until the craft is slowed to about 5000 miles per hour. A rotor may be useful for sub orbital flights. Neil

 

[bobvanx]

The engineers of Rotary Rocket calculated that the rotors, allowed to flex into the slipstream, would experience heating that was within tolerances of existing materials. While that seems unlikely to me, I have to say I'm in no way qualified to hazard an opinion.<br /><br />What I do know is that any sort of transitional environment for wing loading is typically far more difficult than originally anticipated. I'm thinking of the Osprey, for example, which operates in a vertical lift mode and then transitions to a horizontal lift mode.<br /><br />Rotors as a recovery system would have to transition from a non-lifting, drag (streamer, shuttle-****) stabilizing element through the supersonic zone, to a rotating, lifting controlled flight element in the subsonic zone. It <i>feels</i> possible, but I don't know what's actually been accomplished.<br /><br />It would be an ideal recovery system for a reusable craft, if it could be engineered.