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Artemis launch plan: Here are NASA’s next steps

Artemis launch plan: Here are NASA's next steps
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Kennedy Space Center

Photo: NASA/Cory Huston

Early Saturday morning, NASA abandoned its second attempt to launch the Artemis 1 mission into lunar orbit after engineers were unable to plug a hydrogen leak that occurred while refueling the rocket’s main stage fuel tanks. After the second launch attempt failed, NASA is unlikely to launch a third attempt in September.

NASA said the hydrogen leak occurred “at an interface between liquid hydrogen.” fuel supply line and the Space Launch System (SLS) rocket”. The SLS is capable of carrying the Orion spacecraft, astronauts and supplies to the Moon in a single mission.

The second launch of the Artemis 1 mission, an unmanned test, is scheduled for Saturday at 2:17 p.m. ET (11:17 a.m. PT) at the Kennedy Space Center in Florida.

The SLS main stage, manufactured by Boeing, is 212 feet (64.6 meters) tall and 27.6 feet (8.4 meters) in diameter. It houses cryogenic liquid hydrogen and liquid oxygen, as well as systems to feed the stage’s four R2-25 engines.

SEE: What is Artemis? Everything you need to know about NASA’s new moon mission

Artemis is a multi-phase project that plans to send astronauts to the Moon and beyond. The Artemis mission will also see the first woman and person of color land on the moon.

NASA’s Artemis mission was canceled earlier launch attempt on August 29 when the engineers failed to cool all four RS-25 engines minus 420 degrees Fahrenheit (-250C)—a necessary step to ensure the core stage is not damaged during the eight-minute journey into low Earth orbit. After reaching low Earth orbit, the main stage separates from the upper stage and the Orion spacecraft.

According to NASA, during the second launch attempt, one of the four engines showed higher temperatures than the others. This so-called “bleed test” takes place before the super-cold liquid hydrogen flows into the rocket’s core stage.

Engineers also discovered during the first launch attempt hydrogen leak in the “cleaning box”. but at this stage the fuel flow can be controlled by manually adjusting the rates.

After a failed bid to launch the Artemis 1 mission on Saturday, NASA announced it had tried three times to fix the leak.

“Engineers found a leak in the gap between the ground side and the rocket’s side plates, which surrounds the 8-inch line used to fill and unload liquid hydrogen from the SLS rocket. Three attempts to reposition the seal failed,” NASA said in an update. Saturday evening.

NASA is investigating whether an “erroneous command” sent early in hydrogen loading may have temporarily increased pressure in the system and caused a leaky seal.

“During the initial phase of hydrogen loading operations, called chilldown, when launch controllers cooled the lines and propulsion system before super-cold liquid hydrogen flowed into the rocket’s tank at minus 423 degrees F, a command was accidentally sent that temporarily increased the pressure. The rocket remained safe and the shock in pressure caused a leaking seal.” “It’s too early to say, engineers are investigating,” NASA said.

SEE: NASA’s new small, high-powered laser has been able to find water on the Moon

At about 11:17 a.m. ET, about three hours before Saturday’s opening window, Artemis launch director Charlie Blackwell-Thompson decided to scrap the second attempt.

According to Reuters, NASA has tentatively set launch times for Monday or Tuesday this week, but concluded it will take longer to fix the new hydrogen leak. NASA Assistant Administrator Jim Free said at a media briefing that the next available window is September 19 to 30, or another window in October.

Mike Sarafin, NASA’s Artemis mission manager, said it would take “several weeks of work” to resolve the current technical issues. If that involves rolling the SLS back into the assembly building, any launch could be pushed back to mid-October.

According to NASA Artemis mission availability web page, there are 11 launch opportunities between October 17th and October 31st. The rocket cannot be launched on any day – there are four main criteria that must be met.

  • The launch day must take into account the Moon’s position in the lunar cycle so that the SLS rocket’s upper stage can time the lunar trans-lunar injection burn to cut off the “ramp” for the far retrograde orbit of the Moon.
  • The resulting trajectory should keep Orion in darkness for no more than 90 minutes at a time so that the solar array wings can capture sunlight and convert it into electricity.
  • It should support Orion’s planned return-to-Earth trajectory, which would see the spacecraft descend into the upper part of Earth’s atmosphere, allowing for a planned “skip-entry” technique to slow down and re-enter after bouncing back through the atmosphere. final landing and splash.
  • The launch date should mean daylight savings for Orion to facilitate the spacecraft’s removal from the Pacific Ocean.

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