Alliant Techsystems [ATK] and NASA Feb. 25 successfully performed the final ground test of a reusable solid rocket motor (RSRM) for the Space Shuttle program at ATK’s Promontory, Utah facility.
The test marks the completion of a 30-year program that continuously improved the RSRM’s performance and safety features. With the completion of today’s test, ATK is ready to usher in the next generation of space exploration.
The space shuttle is scheduled to retire this year after completing four additional flights. The ground test program, with the philosophy of “test before flight,” was used from the inception of the shuttle program to qualify materials, improve motor performance and gain a complete understanding of its flight characteristics.
Since 1988, 210 RSRMs have flown on 105 shuttle missions. ATK has conducted 34 ground tests during that period that have enabled new materials, enhanced performance, and human rated safety margins to be adequately tested and verified before incorporating them into flight hardware.
Significant investments and technical upgrades made to the RSRMs as a result of the robust test program have produced a human-rated rocket motor that has achieved:
- 100% on-time delivery.
- 100% launch readiness, with zero scrubs or countdown issues.
- 3.2 million pounds of thrust delivered safely, every time, and
- a program that has never exceeded its budget
“Successfully conducting 52 ground tests and launching 210 operational motors using the current robust design is a testament to the dedication, work ethic, and unique skills of ATK’s workforce,” said Mike Kahn, executive vice president, ATK Space Systems. “I want to commend this team for a great accomplishment. We look forward to utilizing the skills of our workforce as we move toward the next generation of human space flight.”
The solid rocket motor tested today measures more than 126 feet in length and 12 feet in diameter. It generated the equivalent of 15 million horsepower throughout the duration of the test, which lasted approximately two minutes.
A total of 43 design objectives were measured through 258 instrument channels. Objectives included ensuring the final shuttle motors were built with the level of quality required to safely put astronauts into space, demonstrating performance of minor upgrades to materials, and testing acoustic measurements around the aft end of the motor that will provide valuable data for the Ares program.
“These solid rocket motors have proven themselves to be the safest and most reliable human-rated launch system,” said Charlie Precourt, vice president and general manager of Space Launch Systems and former four-time shuttle astronaut. “The investment made in this technology, infrastructure and skilled work force has created a national asset that is prepared to support a successful transition to the country’s next human-rated space system.”
The data from this ground test will also aid in continued development of the five-segment motor that is scheduled for its second ground test this fall. Last year ATK successfully conducted the first Ares five-segment ground test as well as the first flight test of the Ares I-X vehicle. Planned upgrades for the five-segment motor are expected to improve overall system reliability and reduce system costs going forward.