C3PO - NASA's Commercial Crew/Cargo Program Office

COMSTAC - Federal Aviation Administration's Commercial Space Transportation Advisory Committee

COTS - Commercial Orbital Transportation Services is a NASA initiative to provide commercial services to the ISS.

EELV - Evolved Expendable Launch Vehicle

ELV - Expendable Launch Vehicle

FAA AST - Federal Aviation Administration's Office of Commercial Space Transportation

GEO - Geostationary Earth Orbit

GTO - Geostationary Transfer Orbit

ISS - International Space Station

LEO - Low Earth Orbit

VSE - Vision for Space Exploration — The policy announced by President Bush on January 14, 2004 that set NASA's long term goals as a return of humans to the Moon and a mission to Mars.