NAS Researcher Wins NASA Space Flight Awareness Award
Derek J. Dalle, a fluid mechanics researcher at the NASA Advanced Supercomputing (NAS) Division, was the recipient of the agency’s Silver Snoopy Award for outstanding performance and contribution to space flight safety and mission success. The Silver Snoopy is one of NASA’s most coveted honors, with fewer than one percent of the aerospace workforce receiving it annually. Astronaut Megan McArthur Behnken, who served on space shuttle mission STS-125, presented the award to Dalle on April 29, 2019, along with an actual silver lapel pin featuring Charles Schulz’s iconic Snoopy character in a space suit.
Dalle was the primary engineer involved in running more than 25,000 cases of simulations using the Cart3D flow solver to develop the aerodynamic database for the Space Launch System’s (SLS) Block 1 booster separation during the Artemis 1 (previously known as EM-1) mission, an unmanned SLS flight set for 2020. He followed up this database with continued work on modeling and understanding the complex booster separation event, leading to the development of a new process using the FUN3D Navier-Stokes computational fluid dynamics (CFD) solver, developed at NASA’s Langley Research Center.
Dalle's efforts led to increased trust in the aerodynamic results and improved flight safety. Prior to his work, obtaining more than ten thousand full viscous CFD simulations of the SLS and booster configuration with 22 rockets firing was considered impractical or even impossible with available computing assets. Dalle’s dedication to solving the problem led to technological improvements in flow solver technology, meshing, computing capability, and software development tools, in addition to developing a new process for acquiring an unprecedented amount of aerodynamic simulation data.
In order to provide this analysis under tight time constraints and support the SLS Critical Design Review, Dalle maintained a special queue on NAS’s Pleiades supercomputer around the clock for months, often sleeping only four hours at a time to ensure compute cycles were not wasted. The resulting knowledge provided by the complex aerodynamic database led to small design changes for the second flight of the SLS, which will improve the safety for the first crewed mission, Artemis 2 (EM-2), in 2023.
As a leader in SLS aerodynamics, Derek Dalle’s work has greatly reduced the turnaround time to provide new aerodynamic databases and improved reproducibility for future spaceflight missions and programs, in addition to increasing the safety and reliability of human spaceflight for NASA’s goal to reach the Moon, Mars, and beyond.
