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Rutans' X-prize Entry Tested In Re-Entry Configuration

Posted by timothy on from the one-among-many dept.

evenprime writes "Burt Rutan's X-Prize entry has completed another drop test. This is the second drop over-all, and the first with its wings locked into their re-entry position. The flight results are here."

3 of 27 comments (clear)

  1. Pictures! by elvesRgay · · Score: 5, Informative
    This article really needs a link to some cool pictures. So here they are.

    Scoll down to the bottom to get to the newest pictures. Hope the server doesn't get hammered.

    1. Re:Pictures! by bananahammock · · Score: 3, Informative

      Perhaps like others (and maybe this point has been raised previously), I was curious why this "spaceship" has umpteen windows. Searching the Scaled website, this is addressed under FAQs. For those interested:

      "The windows must be small to keep the weight of the vehicle down and they must be round to minimize the structural loads. This configuration is also the least expensive to manufacture. Each portal consists of two windows to provide redundancy for the integrity of the pressure vessel should one window crack or fail. The number and location of the windows were selected to provide the pilot a view of the horizon throughout SpaceShipOne's mission profile."

  2. I wouldn't bet on success by Anemomenous+Cowherd · · Score: 2, Informative

    These early flights are all well and good, but:

    1) They are low altitude flights

    2) They are low airspeed flights

    This is the easy corner of the flight envelope. The spacecraft will eventually have to go Mach 2+ and handle re-entry conditions. That will be the real test. The reasons I don't have a high degree of confidence they'll pull it off are:

    1) Only CFD was used for design and analysis, no wind tunnel testing. This is a cardinal sin. Orbital Sciences has been burned twice for doing this, once on the first flight of the Pegasus XL, and recently on the first flight of the X-43A.

    2) The thermal protection system consists of an ablative paint over the composite structure. Such a system has never been used on a re-entry vehicle. I do not believe it will provide sufficient protection.

    3) The high-drag re-entry configuration, with a potentially inaccurate aerodynamics model, could put the vehicle in a vastly different re-entry trajectory than planned. The vehicle could be subjected to thermal and aerodynamic loads far greater than anticipated.

    4) There are areas of the high speed/high altitude flight envelope that you can't just bite off one piece at a time. There can be uncontrollable speed/altitude regions in the flight envelope that require careful trajectory planning to avoid. Chuck Yeager found one of these regions in the NF-104A, that lead to a near fatal loss of control.

    Yes, I know what I'm talking about. I'm an aerospace engineer.