Jernigan left NASA in 2001, and is Deputy Principal Associate Director in the Weapons and Complex Integration (WCI) organization at Lawrence Livermore National Laboratory.

Her research focused on the modeling of high-velocity outflows in regions of star formation, gamma-ray bursters, and the study of radiation produced by interstellar shock waves.

[2] Jernigan began working for NASA in June 1981 at the Ames Research Center while earning her degrees at Stanford and Berkeley.

She worked in the Theoretical Studies Branch as a research scientist until June 1985 when she was among the 13 people selected as astronaut candidates.

[2] Jernigan retired from NASA in 2001 and currently serves as Deputy Principal Associate Director in the Weapons and Complex Integration (WCI) organization at Lawrence Livermore National Laboratory.