[image-36]

[image-96]

[image-51]

[image-80]

By Sasha Congiu,

NASA's Langley Research Center, Va.

With meticulous effort and attention to detail, NASA technician Ricky Hall hand-glued 250 grains of sand across a 22-inch long model of Sierra Nevada Corporation’s (SNC) Dream Chaser spacecraft. Each individually placed grain of sand creates turbulent flow along the vehicle, simulating what the actual spacecraft will experience during flight.

After more than four hours of prep work, the model was ready for testing in the Unitary Plan Wind Tunnel at NASA's Langley Research Center in Hampton, Virginia.

As part of Space Act Agreement with the agency for use of the wind tunnel as part of a milestone during the Commercial Crew Integrated Capability initiative under NASA's Commercial Crew Program, SNC spent six weeks observing how turbulent flow affects the Dream Chaser model at different angles and positions. The use of Langley’s facilities as well as the center’s experienced engineering team has been integral to SNC’s progress with the Dream Chaser so far.

"The NASA-SNC effort makes for a solid, complementary relationship," said Andrew Roberts, SNC aerodynamics test lead. "It is a natural fit. NASA facilities and the extensive work they’ve done with the Dream Chaser predecessor, HL-20, combined with SNC’s engineering, is synergistic and provides great results."

Based on Langley’s HL-20 lifting-body design, the Dream Chaser spacecraft combines years of NASA analysis and wind tunnel research with SNC engineering, developing a reusable spacecraft that can ferry crew and critical cargo to and from low-Earth orbit.

During testing, teams of Langley and SNC engineers worked around the clock to quickly gather the required data.

According to NASA test engineer Bryan Falman, all the data acquired will be used to validate computer models and populate the Dream Chaser spacecraft performance database.

Engineers compared the data taken from the tests at the Unitary Plan Wind Tunnel to existing computer models to determine if adjustments were needed or if their predictions were accurate.

The data did, in fact, turn out to be accurate. So, the late nights were worth it for the continued development and performance advancement of the Dream Chaser spacecraft.

