Science —

NASA wraps up Space Launch System engine test, Buzz Aldrin points way to Mars

RS-25 rockets from Aerojet Rocketdyne completed seven “hot fire” tests.

"The RS-25 engine fires up for a 535-second test August 27, 2015 at NASA's Stennis Space Center near Bay St. Louis, Mississippi. This is the final in a series of seven tests for the development engine, which will provide NASA engineers critical data on the engine controller unit and inlet pressure conditions," NASA writes.
"The RS-25 engine fires up for a 535-second test August 27, 2015 at NASA's Stennis Space Center near Bay St. Louis, Mississippi. This is the final in a series of seven tests for the development engine, which will provide NASA engineers critical data on the engine controller unit and inlet pressure conditions," NASA writes.

On Thursday, NASA completed an initial developmental test series using an RS-25 engine of the sort that will drive NASA's next-generation launch vehicle, the Space Launch System (SLS).

NASA's SLS is a successor to the Space Shuttle program and the shuttered Constellation Project. In development since 2011, the SLS is slated to make its first flight in 2018 and will carry astronauts and cargo on missions from Low-Earth Orbit jaunts to deeper space exploration, including Mars missions.

NASA engineers at the Stennis Space Center in Bay St. Louis, Mississippi, fired up a developmental, Aerojet Rocketdyne-designed RS-25 engine for 535 seconds total earlier this August. When it's ignited, the RS-25 can consume more than 300 gallons of liquid hydrogen and oxygen per second, which burns hotter than 3,300 degrees Celsius.

The launch vehicle is designed to reuse components from other NASA programs, and the RS-25 is one notable part of that—it's probably best known for its role as the Space Shuttle main engine.

Although it's a tried-and-true engine, NASA has been testing the top-shelf RS-25 to gather data about how well it will work within an SLS design. Specifically, NASA is building a new engine controller for the SLS (the part of the vehicle that monitors engine status and performance), which will affect the RS-25's operation. The engine will also have to operate at higher thrust settings than it did on the Space Shuttle, NASA said.

Steve Wofford, an engines manager at NASA’s Marshall Space Flight Center in Huntsville, Alabama, said in a statement that the RS-25 engine “is one of the most experienced large rocket engines in the world, with more than a million seconds of ground test and flight operations time.” He also noted that “the completion of this test series is an important step in getting SLS ready for the journey to Mars.”

The Mars journey won't be for a while, though. The current SLS design will employ four RS-25 rockets in the core launch stage, capable of lifting a 70-metric-ton load into space. But it won't be until the next SLS iteration, which will be able launch a 130-metric-ton load, that a Mars mission might be feasible.

According to CBS News, NASA has 16 RS-25 shuttle engines left over that it is upgrading for use on the SLS. “The agency is in negotiations with Aerojet Rocketdyne to purchase another four-engine flight set and two spares,” CBS reports.

More testing will continue this fall and lead up to an eventual uncrewed mission by the SLS.

Keeping an eye on the prize (Mars)

While a Mars mission may be relatively distant, space flight icon and Apollo 11 astronaut Buzz Aldrin announced this week that he would be working with the Florida Institute of Technology (FIT) to create the Buzz Aldrin Space Institute. One of the main goals of the institute would be to develop a plan for putting an outpost on Mars.

Aldrin, 85, will serve as a research professor of aeronautics and a senior faculty adviser at FIT. A press release from the Institute notes that Aldrin has been working on drawing up a plan to get humans to Mars since 1985.

His original plan was called the “Aldrin Mars Cycler” and proposed “a spacecraft system with perpetual cycling orbits between Earth and Mars.” In such a theoretical system, spacecraft rely on the orbits of Mars and Earth around the Sun to complete the journey between two planets, using taxi spacecraft to get crew and cargo onboard and offboard the Cycler.

In 2015, that plan has become what FIT called “Cycling Pathways to Occupy Mars,” which “establishes pathways of progressive missions to cis-lunar space, asteroids, Phobos, and eventually to the surface of Mars.” The Institute will work on fostering commercial and international support for a Mars mission within that framework.

“I’m thrilled to be partnering with FIT in my new home state of Florida,” said Dr. Aldrin in a statement. “I am proud of my time at NASA with the Gemini 12 and Apollo 11 programs, but I hope to be remembered more for my contributions to the future. FIT will play a key role in my ongoing legacy and Cycling Pathways to Occupy Mars. You ain’t seen nothing yet!”

Correction: Ars originally wrote that the RS-25 test was run for 535 minutes, when the test really ran for 535 seconds. 

Channel Ars Technica