The Space Launch System is the next step in the space exploration agenda envisioned by NASA. It is the successor of the Space Shuttle program following the retirement of the last 3 operational NASA Orbital Vehicles , Discovery, Atlantis and Endeavour.
The Space Launch System is a heavy expendable launch spacecraft, capable of carrying in space large payloads of equipment as well as astronauts.
The SLS program is expected to cost $18 billion when it is finished and launched, presumably in November 2018.
As it is an entirely new design, every SLS component needs to be thoroughly tested and this week NASA is doing that for the hydrogen burn-off igniters.
These components do not generate any thrust and have the purpose of generating sparks like fireworks .
The SLS spacecraft will be using, aside from the solid rocket boosters, engines powered by liquid oxygen and hydrogen and those burn-off igniters have the task of igniting the hydrogen and oxygen gases that form just before of the launch of the spacecraft.
While on a launch pad, the spacecraft is in an upright position and hydrogen and oxygen gases form in the lower part of the vehicle. If a large enough quantity of gases accumulates, then the shock wave generated by their ignition when the engines start is so great that it could damage the spacecraft.
The scientists are taking into consideration the larger size of the space craft, the different layout of the launch pad and water suppression system design when testing these new burn-off igniters. At the same time they have to closely follow the scatter pattern of the sparks, the distance reached by the plume, which has to be at least 15 feet, and the influence of cross winds on the dispersion of the sparks.
There are 9 tests planned for the burn-off igniters and they are taking place at the Redstone Technical Test Center in Huntsville, Alabama. The tests began on May 5th and are expected to last almost two weeks, during which the results will be recorded with high speed cameras and analyzed.
The location was chosen because Redstone Test Center is certified for pyrotechnics trials, testing of small rockets and missiles and static trial running of liquid rocket engines.
NASA has been hard at work this past half year, as it has been developing different components for the SLS. On February 9th 2015, NASA has completed the 120 hours anti-geyser testing on the full-scale replica of the SLS liquid oxygen tank and on March 11th , the rocket booster prototype was tested in Utah. All this testing is going on as the SLS program has just entered its critical design review, on 11th of May, which will take place until the end of July 2015 and will decide on the future course of the SLS spacecraft development.
Image Source: NASA