"The follow-on contract to produce 18 engines is valued at $1.79 billion. This includes labor to build and test the engines, produce tooling, and support SLS flights powered by the engines. This modifies the initial contract awarded in November 2015 to recertify and produce six new RS-25 engines and brings the total contract value to almost $3.5 billion with a period of performance through Sept. 30, 2029, and a total of 24 engines to support as many as six additional SLS flights", the release said.
Each SLS rocket uses four RS-25 engines, providing a total of 2 million pounds of thrust to send vehicles to space. NASA has an additional 16 RS-25 engines left over from the Space Shuttle program, which have been upgraded with new controllers and tested to fly at higher performance levels needed to power the SLS rocket, the release added.
Once completed, the SLS will be the most powerful rocket ever made. Designed to carry heavy payloads into the far reaches of outer space, the rocket’s maiden flight scheduled for late 2021 will place an uncrewed Orion Spacecraft into orbit around the moon, according to NASA.
The SLS rocket was designed for travel deep into the solar system, with heavy payloads needed to support astronauts on extended missions.