WASHINGTON — Aerojet Rocketdyne will build landing system thrusters for NASA’s Mars 2020 rover and install the craft’s nuclear power source under separate sole-source contracts from the space agency and U.S. Department of Energy (DoE) worth roughly $14.5 million combined.
The hardware Aerojet Rocketdyne will provide is substantially the same as what it contributed to the $2.5 billion Mars Science Laboratory’s Curiosity rover, which landed on the red planet in 2012 and was cleared this year to continue traversing the martian surface through 2016. Mars 2020 will be based on Curiosity’s design, but modified to cache Mars surface samples.
Like Curiosity, Mars 2020 will use the skycrane system to land on the martian surface. The system lowers the rover by cable to the martian surface from a mothership that hovers above using thrusters.
Sacramento, California-based Aerojet Rocketdyne will again provide the skycrane’s thrusters, this time under a contract worth roughly $7 million, NASA spokesman Guy Webster wrote in an Oct. 21 email. The company is slated to deliver the hardware by Aug. 1, 2015, to NASA’s Jet Propulsion Laboratory in Pasadena, California, which is leading the mission, Webster wrote.
Aerojet Rocketdyne will provide eight hydrazine-fueled MR-80B thrusters, which can be throttled from 7 to 700 pounds of thrust, and eight MR-107U 68-pound-thrust motors. Some of these thrusters will also help steer Mars 2020 during its roughly seven-month interplanetary cruise to Mars.
Meanwhile, the company is also being paid to install Mars 2020’s power source, a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), under a DoE contract worth roughly $7.5 million, a department official wrote in an Oct. 23 email. The MMRTG is one of three such units built under a DoE contract awarded in 2003 to Boeing, which at the time owned the Rocketdyne propulsion and energy business.
One of those MMRTGs is powering Curiosity on Mars now. Mars 2020 will use one of the other two, which are mostly complete and currently in storage in an undisclosed DoE facility. Besides installation, Aerojet Rocketdyne’s contract also calls for the company to complete some final manufacturing tasks on the hardware, including “completing installation of the cooling tubes and emissive coating on the second and third units,” DoE said in an emailed statement.
An MMRTG converts heat generated by the decay of radioactive plutonium-238 into electricity. Heat not converted to electricity is used to keep the rover’s instruments warm in the frigid martian environment.
Plutonium-238, which must be artificially refined, is in short supply in the United States. The material is kept in iridium-coated capsules known as clads, of which DoE currently has 24 set aside for NASA missions. The department plans to start production of another eight clads in the U.S. government’s 2015 fiscal year, which ends Sept. 30. That will give DoE enough to fully fuel the Mars 2020 MMRTG, plus a few spares. The plutonium-238 will be produced at DoE’s Los Alamos National Laboratory in Los Alamos, New Mexico. NASA is paying for the plutonium refinement.
The MMRTG will be one of the last critical subsystems integrated with the rover before launch, according to the Draft Environmental Impact Statement for the Mars 2020 Mission released in June by NASA’s Science Mission Directorate.
According to that document, Mars 2020 will be built at the Jet Propulsion Lab and then shipped to NASA’s Kennedy Space Center in Florida, where the MMRTG will be installed before the spacecraft is placed atop a United Launch Alliance Atlas 5 rocket — the only U.S. launcher certified to carry nuclear material. Mars 2020 will launch from Space Launch Complex 41 at Cape Canaveral Air Force Station, next-door to Kennedy.