RS-25 (LH2/LOX) reusable main engine for the retired Space Shuttle. Remaining engines are scheduled for consumption on Space Launch System first stage launches after which an expendable version, RS-25E will be developed for follow-on SLS launches.
Baby Bantam (kerosene/LOX)—In June 2014, Aerojet Rocketdyne announced that they had "manufactured and successfully tested an engine which had been entirely 3D printed." The engine is a 22 kN (5,000 lbf) thrust engine.
The AR-1 is a proposed 2,200-kilonewton-class (500,000 lbf) thrust kerosene/LOX rocket engine that Aerojet Rocketdyne proposed in 2014 to "lobby the government to fund an all-new, U.S.-sourced rocket propulsion system." As of June 2014[update] Aerojet's early projection was that the cost would be under US$25 million per pair of engines, not including the up to US$1 billion estimated development cost to be funded by the government.
^Butler, Amy (2014-06-03). "Aerojet Rocketdyne Targets $25 Million Per Pair For AR-1 Engines". Aviation Week. Retrieved 2014-06-16. "Aerojet Rocketdyne is targeting a cost of $20–25 million for each pair of new AR-1 engines as the company continues to lobby the government to fund an all-new, U.S.-sourced rocket propulsion system ... The effort to build a new, 500,000-lb. thrust liquid oxygen/kerosene propulsion system would take about four years from contract award and cost roughly $800 million to $1 billion. Such an engine is eyed for United Launch Alliance’s (ULA) Atlas V rocket as well as Orbital’s Antares"