SLS: Test of NASA's "megarocket" engine ends early

 

Fundamental examination of NASA's new "Megarocket" engine ended early, but the company denied that this had previously been a malfunction.

The four main engines were fired in unison for the first time

Shortly before 22:30 GMT (17:30 EST) on Saturday, the four engines were on fire, and burned for more than a minute before the event was foiled.

The primary stage of the Space Launch System (SLS) was evaluated at the Stennis Space Center, in Mississippi.

The engines were to fire for eight minutes to simulate the rocket's ascent into orbit.

SLS is part of NASA's Artemis Program, which aims to take Americans back to the bottom of the Moon in the 1920s.

When it makes its maiden flight - possibly later this year - the SLS will become the most powerful rocket ever launched into space.

The teams at Stennis are still examining the data to see what happened. There was "a lot of dynamics going on" when the engine was turned off, said John Honeycutt, SLS program manager at NASA's Marshall Space Flight Center in Alabama.

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The engines' power levels have been lowered down and up again; They were also ready to rotate or pivot. This movement allows the missile to be steered in flight.

"We noticed a little flash coming from around the floor between the thermal safety blanket of the 4th engine at the time we started the axle," Honeycutt told reporters at a post-test news conference in the Stennis.

The yet unknown issue caused what NASA calls a failure identification (Fid), followed by a major component failure (MCF). As a result of the error, the on-board computer known as the engine control unit sent a message to another computer called the primary stage control unit, which made the decision to shut down the vehicle.

John Honeycutt stated: "Any parameter that deviates in the engine must transmit an error identifier."

It was the first time that the four RS-25 engines had been fired together, in a test known as a "hot fire".

The missile's base stage was installed on a massive steel chassis called the B-2 test platform on the grounds of the Stennis facility.

To prepare the base stage, engineers filled its tanks with more than 700,000 gallons (2.6 million liters) of supercooled hydrogen and liquid oxygen.

It was the eighth and final test of the Green Run program, an evaluation program conducted by engineers from NASA and Boeing - the main contractor for the missile.

Although the test was supposed to last for eight minutes, the engineers received all the data required to certify the missile for flight after 250 seconds.

They wanted to settle any problems before using the base stage to launch the first SLS, as it would send NASA's next-generation Orion spacecraft in a loop around the moon.

Outgoing NASA Administrator Jim Bridenstein refused to describe Saturday's event as a failure, saying, "This is why we are testing," adding, "Before we put American astronauts on American missiles, then we need them to be perfect."

Officials have to find out if they have to re-fire or proceed with moving the base stage to the Kennedy Space Center (KSC) in Florida for assembly in the missile's first unmanned flight, a mission referred to as Artemis-1.

"It depends on what the anomaly is and how difficult it is to recover," Bridenstein said.

Asked if a launch this year was still possible, he added, "I think it's too early to tell. As we discover what went wrong, we'll know what the future holds."

However, if one or more engines need to be replaced, there are spare parts waiting to be used at Stennis Space Center.

The Artemis-1 mission will assess the performance of both the SLS and the Orion capsule before NASA replicates this lunar loop with astronauts in 2023.

This will be followed by the first human landing on the moon since the Apollo 17 mission in 1972.

The SLS consisted of a 65 m (212 ft) base stage with two smaller solid rocket boosters (SRBs) attached to the sides. Engineers at KSC began stacking individual Artemis-1 SRB clips.

"This powerful missile will put us in a position that must be assembled to assist the company and the kingdom in deep zone missions to the moon and beyond," John Honeycutt stated at one point in a media briefing on Tuesday.