Thr X-38 vehicle is released from NASA's B-52 and completes a 10 1/2-minute flight test. Photos: NASA TV/Spaceflight Now

The path a future space "lifeboat" would take returning from orbit was successfully navigated Thursday as NASA's X-38 prototype crew return vehicle completed its fifth atmospheric test flight at the Dryden Flight Research Center in Edwards, Calif.

"We traveled a road for the first time today that we will soon follow all the way home from space," said John Muratore, X-38 Crew Return Vehicle Program Manager. "By intercepting the spaceflight return profile, we verified the X-38's operation in a phase of flight it will encounter as a station lifeboat. As our tests continue over the next couple of years, they will replicate those conditions more and more, culminating in a complete return from orbit."

In the highest, fastest and longest test of the X-38 to date, the vehicle was released from Dryden's NB-52 airplane at an altitude of 39,000 feet and flew free for 44 seconds, reaching a speed of over 500 miles per hour before it began to deploy its parachutes. Opening at the same speed and altitude as it will during a return from space, a 60-foot diameter drogue parachute first slowed the X-38 to about 70 miles per hour.

Then, a 5,500-square foot parafoil began a phased opening, successfully demonstrating a new, more stable parafoil design recently developed by the X-38 team. The revised parafoil proved successful in ensuring a smooth ride for the craft during its 11 1/2-minute descent. The X-38 touched down smoothly on target, even though one of three landing skids did not deploy.

"This is not art; it is now a science." said Bob Baron, Dryden's X-38 project manager. "We understand the dynamics of parafoil deployment and some of the separation operations of the vehicle, which will play into the development of the X-38 space test vehicle and Crew Return Vehicles."

The test also was the first use of automatic flight control software aboard the X-38. The new software, developed in a fraction of the time and cost of past spacecraft software, performed flawlessly. The X-38 is a prototype "lifeboat" for the International Space Station, designed to carry up to seven passengers home from orbit in an emergency. The project combines proven technologies -- a shape borrowed in part from a 1970s Air Force project -- with some of the most cutting-edge aerospace technology available today, such as the most powerful electric motors ever used to control a spacecraft.

The innovative approach is enabling the X-38 to be developed at a tenth of the cost of past estimates for such a project. Although the United States leads the development of the X-38, international space agencies also are participating. Contributing nations include Germany, Belgium, Italy, Netherlands, France, Spain, Sweden and Switzerland.

Throughout the rest of this year and 2001, increasingly complex, uncrewed X-38 atmospheric flight tests will continue at Dryden. A space test of an uncrewed X-38 is planned for 2002, when a vehicle already under construction at the Johnson Space Center, Houston, will be released from a Space Shuttle to fly back to Earth.