New Flow-Through Wind-Tunnel Balance for Retropropulsion Testing

Supersonic retropropulsion, or the use of retrorockets starting at supersonic conditions, is an enabling technology for large-scale human Mars lander vehicle concepts. A new flow-through balance was designed and fabricated to support an upcoming retropropulsion test campaign at the NASA Langley Research Center Unitary Plan Wind Tunnel. The balance employs membranes in place of bellows, which have historically been used, and passes the flow-through load-bearing parts of the balance. Flow through the balance is optimized via the addition of flow guides, which are manufactured as separate parts, and attached to the balance. Calibration of this new flow-through balance demonstrates that it can suitably characterize the load and pressure ranges it was designed for, which provides aerodynamicists a new tool to directly measure supersonic retropropulsion performance of powered descent vehicles.