Every detail that goes into space exploration matters. While habitat design or making sure a rocket is powerful enough to launch supplies are obviously important, what may be less apparent are the smaller things, including the solvents used in manufacturing materials for spaceflight.
On Aug. 6, a 22-second hot fire test in the East Test Area at NASA’s Marshall Space Flight Center in Huntsville, Alabama, helped NASA and Northrop Grumman Corporation in Promontory, Utah – the solid rocket booster prime contractor – evaluate a new nozzle material for the Space Launch System (SLS) solid rocket boosters. These boosters produce more than 75 percent of the power to launch the rocket.
The nozzle construction enables the boosters to provide consistent performance while withstanding the 5,000 degree Fahrenheit flame produced as the solid fuel is burned to launch the rocket. Such material changes are checked out in phases from sub-scale to full-scale tests and this 24-inch motor was a significant step in that process. Using a 24-inch-diameter, 20-foot-long sub-scale test motor that burned nearly 1,800 pounds of propellant and produced 23,000 pounds of thrust, the team collected data to help verify use of the solvent on future SLS flights beyond Artemis III.
“This 24-inch motor test is to evaluate the material in a solid rocket motor environment and make sure that we don’t get any unexpected changes in how it performs,” said Tim Lawrence, manager for motor and booster separation motor systems at Marshall.
While the solid rocket boosters that will be used on NASA’s Space Launch System – which this test supports – are 177 feet tall and 12 feet in diameter, the motor used in the test is still large enough to produce valuable data.
“This booster is only 24-inches but the ability to fire it in a test stand helps us get the data we need to confirm that we want to test it in a larger, full-scale test,” Dennis Strickland, the test conductor said.
In addition to data about the solvent’s effects on the material during motor operation, engineers also collected information about its behavior during booster assembly.
“The 24-inch motor is large enough that we were able to use the same processes to manufacture the nozzle as are used on the full-scale motor and that gives us confidence it will provide a good indication of full-scale performance,” Lawrence explained.
While the verification test was to primarily support the SLS rocket, the test data may also be used by other government agencies to help advance their solid rocket propulsion technology as NASA and the agencies routinely share data with other government agencies and industry. Data sharing enhances capabilities and maximizes the return on investment for the taxpayer.
NASA’s SLS booster is based on three decades of knowledge and experience gained with the space shuttle boosters and has been updated with the latest technology. The agency is working to design, develop, and test next-generation boosters that will power SLS flights after all available shuttle-era hardware is expended. NASA has cast segments for the Artemis I and Artemis II lunar missions, the first two SLS flights, and has begun casting the Artemis III mission. Northrop Grumman delivered the segments for Artemis I to NASA’s Kennedy Space Center in Florida on June 15.
SLS and the Orion spacecraft, along with the Gateway in orbit around the Moon, are NASA’s backbone for deep space exploration and the Artemis program, which will send the first woman and next man to the lunar surface by 2024. SLS is the only rocket that can send Orion, astronauts, and supplies to the Moon on a single mission.