After repeated fuel leaks, two hurricanes and a few launch delays, engineers refueled NASA’s $4.1 billion Space Launch System rocket for aearly Wednesday. The launch would kick off a much-anticipated maiden flight to send an unmanned Orion capsule to the moon. NASA set the launch time at 1:47:44 a.m. EST after a few delays.
Using a slower, so-called “kindler, gentler” refueling procedure to minimize pressure spikes that have contributed toAt 3:55 p.m. EST, the launch team began loading 730,000 gallons of ultra-cold liquid oxygen and hydrogen fuel for the SLS core stage.
Engineers were optimistic that the new procedures would provide a smooth transition from slow to “fast fill,” the point during previous refueling attempts when a sharp rise in pressure caused leakage in quick-disconnect umbilical seals at the base of the missile’s core stage .
“We are more confident than ever in our loading procedures and how we can do this in a way that puts the least amount of stress on the seals,” said Jeremy Parsons, deputy manager of Exploration Ground Systems at the Kennedy Space Center. . .
This time, the missile’s tanks were filled without incident. But late in the countdown, a valve used to refill hydrogen into the core stage developed an intermittent leak. A three-man “red crew” was sent to the pad to tighten the bolts around the valve in an effort to minimize the leak and keep the countdown on track.
Another problem that came up late: problems relaying data from a Space Force Eastern Range tracking radar. Engineers scrambled to replace an Ethernet switch before the opening of the SLS rocket’s two-hour launch window, which closes at 3:04 a.m. EST. Both issues were resolved, but mission managers had to order postponements while the team made up for lost time.
The last 10 minutes of the countdown were expected to culminate in the firing of four hydrogen-powered main engines, followed seconds later by the firing of two upgraded shuttle heritage solid-fuel boosters.
At that point, computer commands will be sent to detonate four massive explosive bolts at the base of each booster, freeing the 5.7 million pound SLS to climb away on top of 8.8 million pounds of thrust, briefly bringing the night into day changes as it roars to the sky on a slightly northeasterly trajectory.
The SLS accelerates rapidly as it consumes propellant and loses weight, and the SLS was expected to move faster than sound less than a minute after launch. A minute after that, the two strap-on boosters were expected to burn out and fall away, leaving the four engines to power the core stage to continue its ascent to space.
Eight minutes after launch, the flight plan called for the SLS second stage and attached Orion capsule to separate from the core stage in an initial elliptical orbit tilted 34 degrees toward the equator. The core stage, meanwhile, will be left to fall back into the atmosphere to break up over an uninhabited stretch of the Indian Ocean.
It took two critical “burns” from the single engine powering the Interim Cryogenic Propulsions Stage, or ICPS: one to elevate the nadir of its original orbit, and a second to propel Orion out of Earth’s gravitational coupling and toward the moon . The 18-minute translunar injection, or TLI, burn was expected about 90 minutes after launch.
The Orion capsule was expected to detach from the ICPS about two hours after launch and travel to the moon on Monday for a 60-mile high flight, using the moon’s gravity to hurl it into a distant orbit which will take him farther from the earth than any other. human-rated spacecraft.
The Artemis 1 mission is the first in a series of SLS/Orion flights intended to establish a sustainable presence on and around the Moon with a lunar space station called Gateway and periodic landings near the South Pole where ice deposits could be permanently accessible in cold conditions. shady craters.
Future astronauts may be able to “mine” that ice if it’s present and accessible, converting it into air, water and even rocket fuel to vastly reduce the cost of deep space exploration.
More generally, Artemis astronauts will conduct extensive explorations and research to learn more about the Moon’s origins and evolution and to test the hardware and procedures needed before sending astronauts to Mars.
The goal of the Artemis 1 mission is to put the Orion spacecraft to the test, testing its solar power, propulsion, navigation and life support systems before returning to Earth on December 11 and making a 25,000 mph nosedive into the atmosphere extending its protective heat shield to an infernal 5,000 degrees.
Testing the heat shield and confirming that it can protect astronauts returning from deep space is the #1 priority of the Artemis 1 mission.
If all goes well with Artemis 1, NASA plans to launch a second SLS rocket in late 2024 to boost four astronauts on a looped free-return orbit around the moon before the first woman and next man on the lunar surface near the land in the South Pole in the Artemis 3 mission.
That flight, scheduled to launch in the 2025-26 timeframe, depends on the readiness of new space suits for NASA’s moonwalkers and a lander being built by SpaceX that is based on the design of the company’s reusable Starship rocket.
SpaceX is working on the lander under a $2.9 billion contract with NASA, but the company has provided few details or updates, and it’s not yet known when NASA and the California rocket maker will actually be ready for the Artemis 3 lunar landing mission.
But if Artemis 1’s test flight is successful, NASA could tick off the requirement for a superheavy rocket to get the first missions off the ground and to the moon.