NASA successfully tests Space Launch System main engine

 The pieces are coming together for NASA’s next-generation manned launch vehicle, the Space Launch System (SLS). The Orioncapsule is coming along swimmingly, and the solid rocket booster was successfully tested last year. Now, NASA has test-fired the updated RS-25 main engine for the first time. It went off without a hitch, burning at 109% thrust for 500 seconds.

NASA has been relying upon Russian Soyuz capsules to reach low-Earth orbit since the Space Shuttle was retired a few years back. It’s on target to begin sending astronauts to orbit on commercial vehicles in the next few years, but NASA’s sights are set on much more distant targets like Mars and asteroids. Those are the destinations the Space Launch System is intended to reach.

https://youtu.be/njb9Z2jX2fA

To get there, the SLS will need slip the bonds of gravity using a pair of solid rocket boosters larger than any previously made, as well as four updated RS-25 liquid fuel engines. The RS-25 engine that was just tested is the first of a new breed, re-purposed from the Shuttle program. The RS-25 is the same basic engine that flew on the Shuttle, but contractor Aerojet Rocketdyne took the 16 leftover Shuttle engines and refitted them for use on the SLS. Prior to the modifications, the engines would peak at 104% thrust.

A trio of RS-25 engines flew on each Shuttle mission, and with 135 successful uses under its belt, Aerojet Rocketdyne is fond of saying they are the most reliable rocket engines ever produced. With the Shuttle, the engines were returned to Earth with the orbiter to be refurbished and used again. That won’t be the case with the SLS. The first stage where the engines are will not be reusable, so the 16 remaining engines will be enough for four launches. NASA has awarded a $1.16 billion contract to Aerojet Rocketdyne to restart construction of new RS-25 engines. That gets NASA up to five SLS flights in the current configuration.

The successful test at NASA’s Stennis Space Center facility is an important step. A 500-second burn is what it will take to get the SLS second stage into space. The next time the engine burns for that long, it will be sending humans into space. Of course, other RS-25 units will be tested at Stennis in the meantime. The first official launch of the SLS is currently scheduled for 2018 when the four RS-25s and two SRBs will carry an unmanned Orion capsule into orbit along with 13 cubesats. If all goes as planned, the first crewed mission will take place in 2023.