Halted rocket test could stall NASA moon shot, redo possible

  • Halted rocket test could stall NASA moon shot, redo possible

Halted rocket test could stall NASA moon shot, redo possible

The test plan called for the rocket's four RS-25 engines to fire for a little more than eight minutes - the same amount of time it will take to send the rocket to space following launch.

Retesting the engines could further delay the multi-billion dollar program that is already years behind schedule and by some measures, is about 30% over budget. It remains unclear how the shortened test will affect NASA's original plans to try to launch the SLS for the first time later this year.

The core stage of NASA's giant Space Launch System (SLS) moon rocket is in good shape despite its early shutdown during a crucial test this past weekend, agency officials said. If this same issue crops up during an actual flight, the SLS will be able to fly through it, they added.

In addition to analyzing the data, teams also will inspect the core stage and its four RS-25 engines before determining the next steps. For the test, the 212-foot core stage (considered the backbone of the SLS rocket) "generated 1.6 million pounds of thrust, while anchored in the B-2 Test Stand", NASA said.

In the private briefing, officials provided more detail, saying that the movement of the engines, known as "gimbaling", was "much more vigorous" than previous gimbal tests in which the engines were not ignited, according to the notes of the participant, who spoke on the condition of anonymity because the person was not authorized to speak publicly.

The agency found that the test, conducted at the Stennis Space Center in MS, was automatically switched off by an off-limits reading of the hydraulic pressure in the thrust vector control mechanism used to move or steer the engines.

John Honeycutt, SLS program manager at NASA, said at the post-test briefing that it would take between 21 and 30 days to prepare for a second hotfire test, assuming no major repairs of or other maintenance on the core stage was needed.

Much earlier in the test, different sensors checking a second engine indicated a "major component failure". "You want to launch with full redundancy". On Tuesday, the agency said that the "temperatures in the core stage engine section were normal" and that the thermal blankets used to protect the engines from the extreme heat "did their job and protected the rocket". Given the need to get more propellant at the test site, a minor revamp of the vehicle, and possibly an irregular sensor change in the Engine 4, the agency estimates it will require about three to four weeks before another test can be done. Outgoing NASA administrator Jim Bridenstine said of the test, "It's not everything we hoped it would be".

The Space Launch System rocket core stage comes alive during the Green Run hot fire test on January 16 at NASA's Stennis Space Center near Bay St. Louis, Mississippi. NASA and Boeing officials had noted that to indicate engineers were very familiar with the engines and were confident the systems would perform as expected.

The so-called hot fire test is the final milestone in SLS's green run campaign, a final check-out before shipping the rocket to Kennedy Space Center ahead of a planned 2021 launch.