NASA's former chief of staff has pleaded guilty to conspiracy in a case stemming from a $600,000 contract for Mississippi State University, a client of his consulting firm.

Sheila Wilbanks, a U.S. Attorney's office spokeswoman, said Courtney Stadd pleaded guilty Wednesday in federal court in Gulfport, Miss.

Stadd faces up to five years in prison at sentencing on Nov. 18.

Prosecutors say Stadd conspired with Liam Sarsfield, NASA's former chief deputy engineer, to guide contracts. Sarsfield pleaded guilty in November to one count.

Stadd was NASA's chief of staff and White House liaison from 2001-2003. Stadd was convicted in 2009 and sentenced to probation in a different case for steering a $10 million contract to MSU.