Engineers at Scaled Composites have been wrestling with issues of airflow over tail control surfaces of their SpaceShipOne suborbital vehicle. A fourth high-altitude drop test of the craft on October 17 has assessed several modifications to the tail section.

Aerodynamic troubles with the tail cropped up in a previous drop test in September. SpaceShipOne encountered an unwanted nose rise, but was safely maneuvered to runway touchdown by the craft's pilot, Mike Melvill.

Putting high-tech computational fluid dynamics (CFD) analysis of their design aside, SpaceShipOne handlers decided to "road test" the craft's boom-tail.

Several days of ground testing validated aerodynamic fixes meant to solve the tail stall problem. The fixes were first flown on the October 17 drop test of SpaceShipOne. After release from the White Knight carrier plane at 46,200 feet, pilot Mike Melvill checked out the vehicle's handling qualities.

The Scaled Composite team reported "considerable improvement" of SpaceShipOne's flying attributes, with no vehicle pitch up noted. Real time video from the craft to mission control was used to study aerodynamic improvements to the craft's tail section.