Northrop Grumman delivered three 63-inch-diameter Graphite Epoxy Motors (GEM 63) for United Launch Alliance’s (ULA) Atlas V rocket being built as part of U.S. Air Force’s Evolved Expendable Launch Vehicle (EELV) program.
The three motors were shipped from the Northrop Grumman facility in Magna to Cape Canaveral Air Force Station in Florida, and will be used as strap-on boosters to augment thrust on Atlas V.
Atlas V is the fifth major version in the Atlas rocket family. It is an expendable launch system originally designed by Lockheed Martin, now being operated by ULA, a joint venture between Lockheed and Boeing.
The GEM 63 rocket motors were developed under a cooperative agreement with ULA for the Atlas V vehicle. Each motor contributes a maximum thrust of 373,000 pounds to the launch with up to five GEM 63 motors being able to support a single Atlas V launch.
A series of motor ground tests beginning in September 2018 satisfied requirements for certification by the U.S.A.F. and ULA. The first flight of Atlas V that will utilize three GEM 63 rocket motors is expected to launch later this year.
The GEM family of strap-on motors was developed starting in the early 1980s with the GEM 40, supporting 132 Delta II launches. The company also developed the GEM 46, which used 54 motors to support six successful missions of the Delta II Heavy. Northrop Grumman later developed the GEM 60, which retired with 100 percent success in August 2019 with 86 motors flown over 26 Delta IV launches.
The company is once again evolving the GEM family with the development of the GEM 63XL variation to support ULA’s Vulcan Centaur launch vehicle.