https://www.flightglobal.com/news/ar...ssions-210697/
During the tests, which involved the USAF Test Pilot School and Air Force Institute of Technology (AFIT) together with NASA's Dryden Flight Research Center, a heavily instrumented Let L-23 Super Blanik sailplane was flown at high speeds and low altitudes in boundary-layer windshears over the dry lake bed at Edwards AFB, California.
Google search - [Let L-23 Super Blanik dynamic soaring]
returns a lot of hits about the program.