Scaled Composites has carried out the third drop test of SpaceShipOne and moves ever closer to the first private manned suborbital flight. The test objectives were:
Aft CG flying qualities and performance evaluation of the space ship in both the glide and re-entry or “feather” mode. Glide envelope expansion to 95% airspeed, 100% alpha and beta and 70% loadfactor. More aggressive post stall maneuvering and spin control as a glider and while feathered. Nitrous temperature control during climb to altitude and performance of upgraded landing gear extension mechanism and space-worthy gear doors.
These were mostly met, but the flight uncovered some minor control problems:
Launch conditions were 46,800 feet and 115 knots and produced a clean separation. First stall entry maneuver resulted in an un-commanded nose rise before reaching the wing stall angle of attack. Lateral/directional controls were used in conjunction with forward stick to effect recovery. This aft-cg stall characteristic was worse than predicted and will likely require aero modifications to fix. The feather entry was not explored and the rest of the glide flight used to assess the handling qualities of the vehicle leading to an uneventful landing. The White Knight’s heating system was able to keep the Spaceship’s nitrous oxidizer conditioned during climb, such that the maximum N2O pressure variation was less than 6 psi.
This is not unusual for a test flight. After all, that is why they are called test flights! One of the beauties of composite airframes is that even major changes can be made relatively easily. When I visited the Rutan facility it was pointed out to me how Rutan and his merry band had modified the tail of one aircraft with a chainsaw. After cutting out the bits they didn’t like, they laid up a replacement structure.
Since the main engine has been undergoing tests and SpaceShipOne seems well along on glide trials, it really may come down to whether the government approvals come through in time for the Wright Anniversary date.
Credit for my tour goes to Jeff Greason. This was long before the blog, back when he and Rand Simberg worked for Gary Hudsen’s Rotary Rocket and I showed up at the Mojave Civilian Test Flight Facility and bothered them for a day. Perhaps someday I’ll find an excuse to do a pictorial on the place as I’ve several rolls of film from the visit.
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