NASA and Orbital ATK [OA] conducted the first qualification ground test of a five-segmented rocket motor planned to be used for NASA’s Space Launch System (SLS), the company said on March 11.
This first pre-flight test, performed at Promontory, Utah, was called Qualification Motor 1 (QM-1). It is a milestone in validating the rocket motor’s use for SLS and deep space missions, the company said.
Initial data indicates the motor performed as designed and delivered the anticipated performance. It produced about 3.6 million pounds of thrust (22 million horsepower equivalent) while firing for over 2 minutes.
Additional data will become available after post-test analysis is finished. Over 531 instrumentation channels on the booster were measured to assess 102 design objectives.
“Today’s qualification test included newly-designed avionics hardware and equipment to control the motor and provide improved test monitoring capability,” Orbital ATK said.
Further test improvements included a new main pivot flexure design in the forward thrust block to transfer the test forces into the load cells for thrust monitoring and a mid-span support to assist in adjusting the motor centerline to make the test consistent with flight conditions.
“The data from today and from our three development motor tests, along with information we have collected on hundreds of predecessor motors over the past three decades, confirms this is the most capable and powerful solid rocket motor ever designed,” Charlie Precourt, Vice President and General Manager of Orbital ATK’s Propulsion Systems Division, and four-time space shuttle astronaut, said in a statement.
The motor is 12 feet in diameter and 154 feet in length. This makes it the largest human-rated solid rocket motor built today, the company said. Once fully assembled as a booster it is set to be 177 feet tall (about 17 stories).
When completed, two five-segmented boosters are planned to work with four RS-25 main engines to power the SLS for deep space missions. The boosters operate in parallel with the main engines for the first two minutes of flight and provide over 75 percent of the thrust needed to escape Earth’s gravity, NASA said.
The motor produces 20 percent more power than a previously used four-segment motor. New materials in construction produce cost and weight savings, Orbital ATK said.
“Deep space missions require a heavy-lift vehicle to ensure success, and SLS and Orion can accomplish a deep space mission in fewer launches than current or planned vehicles,” Blake Larson, Orbital ATK’s Chief Operating Officer, said in a press statement.
The next SLS milestones are the core stage welding at the Boeing [BA] Vertical Assembly Center, further testing of the RS-25 Aerojet Rocketdyne engine at the NASA Stennis Space Center, avionics and controls testing at the Marshall Space Flight Center, and Orbital ATK’s QM-2 static firing in 2016.