In the 1960s NASA for some time been wanting to use for braking and landing, the lander capsules manned spacecraft no parachute and jet look like a helicopter, but in fact working like autogyro. The advantages of this method are obvious: air flow not only will rotate the screw, slowing down the system, but also creates a lifting force, will allow capsule, down the autorotation, effectively manage trajectory. But weighty and cons of the parachute easier and cheaper. However, despite the era of severe financial constraints, when the share of funding for NASA in the GDP of the USA has fallen to historic lows, the office comes back again to the old idea. Strange, because the way and the good times was considered expensive...

New materials allow to make sturdy folding propellers much easier, and the main thing - they will keep the capsule into the ocean, but rather precisely to the ground where it should, minimizing the costs of search and transportation. Of course, theoretically, to avoid these problems, you can integrate descent vehicle what is used in capsule brake motors, as in "Soyuz TM". But this option is heavier and more expensive screws with less manageable actually in flight. In addition, the same scheme in the long term plan to apply for salvation and subsequent reuse fuel tanks SLS - new media being developed right now NASA.

But while all looks modest: the system descent on autorotation was tested on models, dropped from 165 m in the vertical Assembly building" (our MICK, just standing on end). Tested different angles of the screws in order to select those that provide the maximum lifting force.

On assurances of developers, what they do, not just a more efficient replacement of a parachute. According to their calculations, the planting of such capsules will be possible not only to any predefined runway, but even on the roof of a detached job. Accuracy, first unattainable for devices of this kind, including designed in the USSR. In General orientation toward increasing freedom of movement of descent module in the atmosphere is similar to the traditional U.S. approach is most fully expressed in the concept of the Space Shuttle.

Nevertheless, we can already say, that on this path of Americans waiting for some fundamental difficulty is perhaps insurmountable. Yes, the screws will be produced and only rotate (after aerodynamic braking) at subsonic speeds. And still the speed at which they will have to start, will be significantly higher than that of autogyros, helicopters. That is, modes of screws, as well as the probability of failure of a stream with them, will be fundamentally different than existing devices that use autorotation. If the screws will be quite small, the rate of decrease will remain too high; if the scale is a helicopter, you will have to suffer with entanglement. In other words, designers awaits truly pioneering work.

Prepared according to NASA.