Rocket Rumbles in the Utah Desert

The 5-segment SRB ignites. NASA TV.

Another step has been taken in the development of the NASA SLS rocket system. On March 11, Orbital ATK successfully tested the new version of the 5-segment Solid Rocket Booster which will be part of NASA's new giant rocket. For two minutes, the booster shot superheated gas and exhaust out over the desert while officials and visitors some distance away shook from the shockwaves.

The enormous plume of fire gives an idea of the power of just one booster.

Originally Thiokol, then ATK, the company that built the SRBs for the space shuttle has been working to include the system in the future of American spaceflight. Planned for the Ares-1 rocket system, the new 5-segment booster (the shuttle used two 4-segment SRBs) would have been designated the first stage of the Ares-1. A successful test of the Ares-1 occurred in 2009. However, with rising costs, the Obama Administration cancelled the program. Too bad, because according to the proposed schedule the Ares-1 would be flying by next year. The new SLS rocket is not planned to lift astronauts until after 2020.

Planned development of the Ares-1.

When NASA began working with the Commercial Development of manned rockets, ATK joined with Astrium to develop the Liberty rocket to compete with submitted plans by Boeing, SpaceX, and several other companies. Liberty would have been similar to the Ares-1 and also would use the 5-segment motor. Unfortunately for ATK, NASA selected Boeing and SpaceX for further development, even though ATK had already done initial testing with the Ares rocket. Again, too bad, as the plan would have had the system flying by now.

ATK illustration of Liberty launch.

Fortunately for the company the new NASA design for the giant SLS rocket included two SRBs for the first stage launch. The 5-segment motor would therefor be used in missions designed to lift heavy items into orbit and for missions that would eventually go to Mars. Recently, the company has completed a merger with Orbital Sciences, maker of the Antares rocket, the Pegasus sub-rbital rocket, and the Cygnus cargo spacecraft. Now named Orbital-ATK, the company needs to complete one more test firing of the booster before it is ready to begin shipping to the Kennedy Space Center for the first launch tests.

Planned development of the SLS rocket family.

During the test firing, the booster produced 3.6 million pounds of thrust. 102 design objectives were met by the success of the test. Temperatures inside the booster reached 5,600 degrees. Now THAT is a great piece of engineering.

All done! Water is sprayed into the motor to cool it down for post-test analysis.