Tag Archives: Aerojet Rocketdyne

Rocket Engine Ban

According to DefenseNews, the Pentagon late last week refused to waive a law banning the use of Russian rocket engines for military satellite launches, rejecting a plea from United Launch Alliance (ULA). ULA, a joint venture of Lockheed Martin and Boeing that provides spacecraft launch services to the U.S. government, has threatened to skip an upcoming Air Force competition for satellite launches unless it gets some relief from the ban. ULA relies on the Russian RD-180 rocket engine to power its Atlas V rocket, although it also builds a Delta IV rocket powered by U.S. company Aerojet Rocketdyne’s RS-68 engine.

The ULA uses Russian RD-180 rocket engines to power its Atlas 5 rocket (Photo: ULA)
The ULA uses Russian RD-180 rocket engines to power its Atlas 5 rocket (Photo: ULA)

Elon Musk’s SpaceX is the other potential competitor for the Air Force’s GPS III Launch Services solicitation, part of the Evolved Expendable Launch Vehicle (EELV) program. SpaceX has invested heavily over the past few years to develop its own Merlin engine to power its Falcon 9 rocket. Proposals for GPS III Launch Services are due November 16.

In response to recent Russian aggression, particularly Moscow’s annexation of Crimea last year, lawmakers in the fiscal 2015 defense budget banned the use of Russian RD-180 rocket engines for military satellite launches after 2019.

The Pentagon remains committed to maintaining two sources of launch services to ensure access to space, according to Lieutenant Commander Courtney Hillson, spokeswoman for the deputy secretary of defense. Department of Defense (DoD) will continue to evaluate the need for a waiver and consider a range of options, including possible sole-source contracts, to keep both companies in business, she continued.

«We are not planning at this time to issue a waiver lifting the prohibition against award of an EELV space launch services contract to a contractor intending to use a Russian manufactured engine, although we will continue to evaluate the need for such waiver, if deemed necessary», Hillson said in a statement emailed to Defense News on October 13.

«We will continue to work with the Administration and Congress to maintain assured access to space, to achieve the mutual goal of a healthy and competitive industrial base, and to ensure a rapid transition away from the Russian RD-180 engine».


Full-Duration Test

Aerojet Rocketdyne announced on August 13 that it successfully completed a full duration (535 seconds) verification test of its RS-25 rocket engine that will power NASA’s Space Launch System (SLS), America’s next generation heavy-lift launch vehicle. A test, conducted at NASA’s Stennis Space Center, was the sixth test in a seven-test series that began in January 2015 to validate the engine for use on the SLS.

NASA conducted a developmental test firing of the RS-25 rocket engine, on August 13 at the agency’s Stennis Space Center in Mississippi
NASA conducted a developmental test firing of the RS-25 rocket engine, on August 13 at the agency’s Stennis Space Center in Mississippi

«It is great to see this revered engine back in action and progressing full steam ahead for launch aboard Exploration Mission-1 in 2018», said Julie Van Kleeck, vice president of Aerojet Rocketdyne’s Advanced Space & Launch Programs business unit. «The RS-25 is the world’s most reliable and thoroughly tested large liquid-fueled rocket engine ever built».

The RS-25, previously known as the Space Shuttle Main Engine (SSME), successfully powered the space shuttle during 30 years of operation. The RS-25 uses a staged-combustion engine cycle that burns liquid hydrogen and liquid oxygen propellants to achieve performance never previously attained in a production rocket engine. Interestingly, the only exhaust produced by the RS-25 is water vapor in the form of steam.

The RS-25 will continue to serve the nation’s human exploration propulsion needs as the core stage engines for SLS. The SLS program has 16 engines in inventory at Aerojet Rocketdyne’s facility within Stennis Space Center, with 14 of them previously flown aboard the space shuttle.

«The engine that was tested on August 13, development engine 0525, continues demonstration of the new controller’s functionality and the engine’s ability to perform to SLS requirements», said Jim Paulsen, vice president, Program Execution, Advanced Space & Launch Programs at Aerojet Rocketdyne. «We are conducting engine testing to ensure all 16 flight engines in our inventory meet flightworthiness requirements for SLS».

SLS will fly 4 RS-25 engines at the bottom of the core stage as opposed to three that flew on the space shuttle; the solid rocket boosters will be closer to the RS-25 engines than they were on the shuttle stack; and the taller SLS launch vehicle will result in higher propellant inlet pressure on the engine system. These changes, as well as operating them at 109% thrust means the engines will need to withstand more demanding conditions than when they were previously flown.

In addition to preparing for the new environmental conditions, the engines also are receiving a technology «refresh» of their controllers, which serve as the brains of the engines. The upgraded controller provides for communication between the vehicle and the engine, relaying commands to the engine and transmitting data back to the vehicle to regulate the thrust and fuel mixture ratio and monitor the engine’s health and status.

«The new controller provides modern electronics, architecture and software», said Paulsen. «It will improve reliability and safety for the SLS crew as well as the ability to readily procure electronics for decades to come».

The first flight test of the SLS will be configured for a 70-metric-ton lift capacity and carry an un-crewed Orion spacecraft. As SLS evolves, it will be the most powerful rocket ever built and provide an unprecedented lift capability of 130 metric tons.

«SLS is the vehicle that will take astronauts to Mars and pre-position cargo for their survival», said Van Kleeck. «It is great to see that the red planet is one step closer and know our Aerojet Rocketdyne team is helping make that dream a reality».