Space Launch Initiative
The Space Launch Initiative (SLI) was a NASA and U.S. Department of Defense joint research and technology project to determine the requirements to meet all the nation’s hypersonics, space launch and space technology needs. The program began with the award of reusable launch vehicle study contracts in 2000. In November 2002 it was evolved into the Orbital Space Plane Program and the Next Generation Launch Technology Program.
The primary goal of this research was to increase safety and reliability and to reduce overall costs associated with building, flying and maintaining the nation’s next generation of space launch vehicles. NASA anticipated that these advances would revitalize the nation’s space transportation capabilities, and dramatically improve NASA’s ability to conduct science and exploration missions in space.|This program was ended with the cancellation of the X-33 and X-34 and the conclusion of the X-43 programs. NASA changed its focus to Constellation Program.
The Space Launch Initiative Propulsion Office, managed by NASA’s Marshall Space Flight Center in Huntsville, Ala., sought to advance technologies and explore new avenues of space propulsion to develop safer, more reliable and affordable propulsion solutions. Four main engine candidates for a second generation reusable launch vehicle emerged, including two hydrogen-fueled (COBRA, RS-83, TR-106) and two kerosene-fueled (RS-84, TR-107) staged combustion engines.
California Poly Pomona's Professor Steven Dobbs was the Lead Systems Engineer on the project, making significant use of the program as an example for failed systems engineering.
Propulsion system proposed by Pratt & Whitney-Aerojet Propulsion Associates to cover a wide range of thrust. This LH2/LOX reusable rocket engine was designed in 2003 to produce 4,500 kN thrust. Proposed as a long-life, moderate-to high-thrust, reusable booster engine that incorporated a safe, low-cost, low-risk, LH2/LOX single burner, using a fuel-rich, staged combustion cycle.
The RS-83 was a rocket engine design for a reusable LH2/LOX rocket larger and more powerful than any other. The RS-83 was developed by Rocketdyne Propulsion and Power, located in Canoga Park, California to power the launch vehicle as part of the Space Launch Initiative program. This engine was designed to produce a thrust of 664,000 lbf (2,950 kN) at sea level and 750,000 lbf (3,300 kN) in a vacuum with an Isp of 395 and 446 seconds (3.87 and 4.37 kN·s/kg), respectively. The RS-83 is loosely based on the RS-68 that powers the Delta IV expendable launch vehicle. The RS-83 design is more efficient, lighter, slightly stronger, and yet reusable. The RS-83 was designed to last 100 missions, and was intended for use on the first stage of a two-stage-to-orbit reusable launch vehicle.
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