Hello, Goodbye.

Goodbye to Themis Computer of Fremont, California. The privately held manufacturer of ruggedized military computers was snapped up for a reported $ 180 million by Mercury Systems Inc.

And farewell to CSRA, a provider of IT services to federal, state and local governments. CSRA--created in 2015 after a merger of two other IT firms--was a mere three years old when General Dynamics bought the Falls Church, Virginia-based company in February for $9.6 billion.

Aerojet Rocketdyne announced that Greg Jones joined the company as senior vice president, strategy and business development. Jones will report directly to CEO and President Eileen Drake and will serve as one of the officers of parent company Aerojet Rocketdyne Holdings Inc. Jones has 30 years of experience at Orbital ATK, The Boeing Co. and McDonnell...