A large crowd gathered in Utah’s west desert to not only see but to also feel the power of a major rocket test Tuesday. They included curious onlookers as well as officials from the National Aeronautic Space Administration and Orbital ATK.
“We had a delay, we had some electronic equipment that didn’t want to play this morning,” said Charlie Brown, program manager for the Space Launch System booster program for Orbital ATK. “We worked through that so the test happened an hour later than scheduled. Once we worked through the repair everything worked fine.”
The Space Launch System, or SLS, will accompany the most powerful rocket in the world and is built for deep space travel, specifically for a future trip to Mars.
Tuesday’s test accomplished several things, most importantly how the solid rocket fuel would perform after being cooled to 40 degrees Fahrenheit.
“Our flight specification with the government,” Brown explained, “(is that) we are required to fly between 40 and 90 degree average propellant temperature. The 90 was the one we did a year ago in March. This one was the 40.
“In Florida, we’ve never had the mass of propellant that cold. While we test at 40 we’ve never seen the propellant temperature below the mid-50s. But it’s an over test to make sure that we’re ready to support.”
The SLS rocket motor is 154 feet in length, 12 feet in diameter, and has five segments, one more than booster rockets of the Space Shuttle era. Brown said the extra segment provides approximately 20% more thrust for the rocket, helping to propel the entire Orion space craft deeper into space.
Over 500 channels of data were recorded during the two minute test. Analysts will review that data over the next couple of days and the rocket will be disassembled and dissected over the next couple of months.
Now that the ground tests are complete, and once the data is analyzed, NASA will shift its focus to a launch of the Orion spacecraft in late 2018. That test will not have a live crew on board, however.
“It’s going to do sort of a moon fly by,” Brown explained. “It will travel to the moon and a certain distance beyond, then turn around and come back to Earth. All of the systems on Orion will be live and they will monitor all of the guidance and other systems throughout the flight. I believe the flight will be in the neighborhood of about three weeks long.”
The Orion will come back to Earth the same way the old Apollo missions used to. The capsule will enter the Earth’s atmosphere, take a lot of heat on its heat shield, deploy a parachute then splash down in the ocean. NASA officials want to ensure this new system of space travel will work before putting people on board.
The SLS test produced approximately 3.6 million pounds of thrust, more than that produced by 14 Boeing 747-400s at full takeoff power. Keeping the rocket in place during its test Tuesday is quite an engineering fete on its own.
“At the head end of the motor is a thrust adapter, it looks kind of like a large Christmas tree made of big, thick, steel pipes,” Brown explained. “That thrust adapter hooks to the forward end of the rocket motor and directs all the thrust to an extremely large concrete and steel block.
“That concrete block, part of it is above ground which you can see…but the majority of that concrete extends into the ground. It’s like the iceberg effect, you can only see a small part of it.”
The SLS test and the progress of the Orion spacecraft is the next stage of space exploration and surpasses the abilities of the now-retired Space Shuttle.
“This vehicle gives us options,” explained Brown. “Obviously the moon is an option, ultimately on to Mars or one of the moons of Mars.”
The project is also breathing new life into the Orbital ATK facility in Promontory. After the shuttle was retired, there were questions about the facility’s future. Orbital ATK (in cooperation with NASA) enhanced what was done with the Space Shuttle boosters and created the SLS rocket motor.
<ul><li>The rocket motor for Tuesday’s test spent two months cooling down to an average temperature of 40 degrees.</li><li>The flame exits the motor at Mach 3 and burns for 126 seconds</li><li>Gas in the exit cone reaches 3,700 degrees.</li><li>Temperatures inside the booster reached nearly 6,000 degrees.</li><li>On average, 5.5 tons of propellant are burned each second of motor operation.</li><li>The SLS booster is the largest solid rocket booster ever guilt for flight.</li><li>The test stand forward thrust block is made up of more than 13 million pounds of concrete, most of which is underground.</li></ul>