NASA develops new design process for future spacecraft

An efficient, timely, revolutionary process, developed by NASA, may help design the next generation of space vehicles.

Engineers at NASA Ames Research Center in California’s Silicon Valley, in collaboration with astronauts from NASA Johnson Space Center, Houston, are using the Virtual Flight Rapid Integration Test Environment (VF-RITE) to develop and evaluate vehicle designs that may eventually ferry astronauts to and from the International Space Station. The new process quickly and efficiently incorporates virtual test-flight data into the design process, creating a continuous dialog between test pilots and vehicle designers.

“The objective of the VF-RITE project is to produce systems and infrastructure to facilitate the use of aerodynamic data from CFD (computational fluid dynamics) technology in real-time, piloted flight simulation,” said Julie Mikula, Vertical Motion Simulator (VMS) lead. CFD uses high-speed computers to solve basic equations to predict complex fluid flow patterns across the surface of an object. “The flight simulation data and input from the astronaut test pilots allow the design team to apply ‘return knowledge’ to improve vehicle performance,” she said.

The VF-RITE process begins with the development of a mathematical model of the concept vehicle using the latest in wind tunnel and CFD technologies. The mathematical model is programmed into the extensive VMS vehicle database. The VMS is one of NASA’s most capable vehicle simulators with 60 feet of vertical and 40 feet of horizontal travel, giving pilots a realistic sensation of gravity forces. Once the vehicle is in the database, the design can be modified, based on input from astronaut test pilots, engineers and designers.

“You literally can come up with any geometric change, press a button and you are flying another version of the vehicle. Press another button and you are flying the space shuttle or any vehicle in the VMS database,” said Mikula. In the latest round of testing, a tailless design was tested in efforts to decrease weight and drag.

With VF-RITE, radically new designs, using the latest materials, can be evaluated and refined. One design using Ultra-High Temperature Ceramics (UHTCs) departs from the traditional lifting body design of the space shuttle. Developed at Ames, UHTCs are thinner, lighter and more durable than current space shuttle heat-resistant exterior tiles. This new material can be used at the vehicle’s leading edges, allowing for more aerodynamic and maneuverable designs.

For off-site researchers and managers, the VMS has a virtual counterpart called the Virtual Laboratory (VLAB). The virtual environment allows off-site participants access to all displays in the VMS control room, and the ability to interact with the VMS crew and the test pilots in real time. In addition to VMS displays, high-speed data links allow viewing of the pilot’s actions and out-of-the-window displays, as well as participation in videoconferences.

The VF-RITE is the fourth generation in the development of the RITE process. Since 1999, nearly a dozen astronauts have participated in the design process and have been impressed
with the capabilities of the VMS and the VF-RITE software.

“It is great to see the process they have instituted here, to be able to change a vehicle’s specifications, quickly turn it around and test the modifications,” said astronaut Barry ‘Butch’ Wilmore. “To involve the astronaut office early in the design process is terrific. We are grateful we have the time and opportunity to come here, make our inputs early and be a part of the process,” he added.