The recent hotfire test of NASA’s next-gen megarocket should go eight minutes, but it lasted only 67 seconds. The space agency has an explanation for the premature shutdown by saying everything is fine, but a second test remains a clear possibility.
The Space Launch System (SLS) first hotfire test, conducted on Saturday, Jan. 16 came to a stop at NASA’s Stennis Space Center in Mississippi at just above one-minute mark when an important parameter entered the territory out of range, explained NASA in a statement. The parameter in question has to do with the hydraulics required for gimbal, or the turning of each rocket motor.
For the test – the eighth and (perhaps) final of the Green Run test regime – NASA planned to fire all four of the rocket’s RS-25 engines for up to eight minutes. With the 212-foot-long (65-meters) rocket stage anchored to the B-2 test rig, and with the nuclear stage filled with over 700,000 liters of propellant, the engines kicked into action at 5:27 PM EST, spewing out a giant cloud of exhaust fumes. This took exactly 67.2 seconds until computers turned off the whole thing.
NASA reviewed the data and performed preliminary inspections of the system, determining that the rocket’s hardware is in “excellent working order” and that the shutdown “was caused by test parameters that were deliberately conservative to ensure the safety of the nuclear phase during the test. to ensure. “
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Built by Boeing, SLS NASA’s most powerful missile and an important part of the upcoming Artemis missions to the moon. It consists of a core stage with four RS-25 engines, along with two smaller solid rocket boosters attached to each side, à la the Space Shuttle program. Once operational, SLS will used to send American astronauts to the moon sometime in the 2020s. A first launch could take place later this year.
In conversation with SpaceFlightNow, outgoing NASA chief Jim Bridenstine said NASA “could take the missile to Kennedy [Space Center in Florida] and get it ready for launch ”, adding that this“ decision has not been made ”as the situation remains uncertain.
Indeed, NASA is still trying to determine if a second is hotfire test is required. Given the results of the first test, the team was able to adjust the thrust vector control parameters to avoid a similar closuredown, according to NASA.
The pre-programmed parameters for the hotfire test are specific to ground testing and they are designed so that the core stage thrust vector control system can safely adjust the orientation of the RS-25 engines. In addition to the thrust vector control system, a range of actuators provide the forces required to gimbal each motor and are powered by multiple Core Stage Auxiliary Power Units (CAPU). The gimbalThe engines worked as planned, but the associated hydraulic system “ exceeded the preset test limits that were set, ” resulting indown, according to NASA.
NASA says this isn’t a problem, and if SLS had been in the air, the missile would have continued its journey using the remaining CAPUs. And in fact, NASA said the abbreviated test actually showed this in action.
What’s more, the gimbalOne test that the CAPU halted was “a deliberately stressful business for the system intended to exercise the capabilities of the system,” NASA said. “The data will be reviewed as part of the process of completing the preset test limits prior to the next use of the core stage.”
In terms of positives, it was the second successful wet test (i.e. the rocket was fully loaded with propellant), the team was able to pressurize the propellant tanks and they completed a countdown that led to the ignition of the engines. At full throttle, the engines reached their maximum capacity with 1.6 million pounds of thrust.
The team will continue to investigate the apparent flashes around the bikes. Thermal blankets used to protect the engine from the intense heat showed signs of scorching, which is not surprising given their proximity to the engines and CAPU exhaust. Still, NASA wants to make sure this was normal behavior.
As noted, a second hotfire test is not out of the question. As reported in SpaceFlightNow, John Shannon, SLS program manager at Boeing, said the team wanted to collect and evaluate at least 250 seconds of data during the test before moving on to the next stage. Ocheerful, a full eight-minute test would be even better, as that’s the total time it takes for the SLS rocket to reach space.
Yes, this would cause a possible delay, but there may be no more rush. It’s not clear if the Biden administration will demand that NASA reach the lunar surface by 2024, speed upa timeline pushed by the Trump administration.