Northrop Grumman Antares

Antares, known during early development as Taurus II, is an American expendable medium-lift launch vehicle developed by Orbital Sciences Corporation with financial support from NASA under the Commercial Orbital Transportation Services program, and manufactured by Northrop Grumman since 2018. Its first stage burns RP-1 kerosene and liquid oxygen, and its second stage is a solid-fuel motor from the Castor 30 family derived from the Peacekeeper missile. The 100 and 200 series first stages were built by the Ukrainian companies Pivdenne and Pivdenmash, with refurbished NK-33 engines on the 100 series and Russian RD-181 engines on the 200 series. After Russia invaded Ukraine in 2022, Northrop Grumman contracted Firefly Aerospace to build the first stage of the 300 series. Antares first flew on April 21, 2013, from the Mid-Atlantic Regional Spaceport, and it has flown only NASA cargo missions with the Cygnus spacecraft as its sole payload.