After months of testing, troubleshooting and repairs, the engineers began refueling thebefore blastoff Monday on a much-anticipated test flight to send an unmanned Orion capsule on a 42-day journey around the moon.
Lightning showers moved within five nautical miles of launch pad 39B just after midnight, forcing launch director Charlie Blackwell-Thompson to delay the start of propellant charging by 55 minutes. But the six-hour procedure finally began at 1:13 a.m. EDT.
The only other topic up for discussion as the countdown ticked to its final hours was troubleshooting to find the cause of a temporary communications failure in one of the channels carrying commands and telemetry to and from the Orion spacecraft.
It was not immediately clear what impact the delay in refueling and troubleshooting could have on the scheduled start time of 8.33am. But engineers were optimistic about getting NASA’s most powerful on its much-anticipated maiden flight at some point during a two-hour launch window.
The carefully scripted fuel procedure is required to load 196,000 gallons of liquid oxygen and 537,000 gallons of hydrogen into the rocket’s massive nuclear stage. An additional 22,000 gallons of oxygen and hydrogen are required for the upper stage, for a total of 750,000 gallons of propellant.
The SLS’s four shuttle-era engines and two attachable extended solid fuel boosters will generate a staggering 8.8 million pounds of thrust to propel the 5.7 million pound rocket away from pad 39B at Kennedy Space Center. .
The rocket is part of theThe mission lasts just one hour and 36 minutes, blasting the Orion capsule and the service module supplied by the European Space Agency into space, out of orbit and onto a trajectory to the moon.
After a short flight at an altitude of just 60 miles, Orion will fly back into distant orbit around the moon for two weeks of testing and checking out. If all goes well, the capsule will fall back to the moon on October 3 for another close-up that will set up a rapid descent to a landing in the Pacific Ocean on October 10.
NASA plans to follow the Artemis 1 mission by launching four astronauts on a round-the-moon flight in 2024, setting the stage for the first astronaut landing in nearly 50 years when the first woman and the next man step on the surface in the 2025-26 time frame.
But first, NASA needs to prove that the rocket and capsule will work as planned, starting with Monday’s Artemis 1 launch.
Starting approximately 6.6 seconds before launch, the four RS-25 engines at the base of the core stage will ignite and accelerate to full thrust, generating a combined thrust of two million pounds.
When the countdown reaches zero, after a lightning round of computer checks to verify engine performance, commands are sent to ignite both solid rocket boosters. At the same time, signals will detonate four explosive bolts at the base of each booster, freeing the SLS from its launch pad.
The solid rocket boosters provide the lion’s share of the power needed to lift the SLS out of the dense lower atmosphere, firing for two minutes and 10 seconds before dropping off at an altitude of 27 miles.
The RS-25 core stage engines will continue the ascent on their own, firing for another six minutes to propel the rocket to an altitude of 137 miles.
The core stage’s RS-25 engines will fire for eight minutes, propelling the ship to an altitude of 87 miles before shutting down.
According to the flight plan, the rocket’s upper stage, containing the unpiloted Orion capsule and the European Space Agency-supplied service module, was to be separated from the now-empty core stage and continue flying to an altitude of about 1,100 miles, the highest. point, or apogee, of its original orbit.
The engine that powers the Interim Cryogenic Propulsion Stage, or ICPS, would fire 51 minutes after launch to raise the orbit’s nadir, or perigee, from 20 miles to about 115.
Forty-five minutes later it bottomed out – an hour and 36 minutes after launch – the ICPS programmed to fire its RL10B engine for 18 minutes, increasing the vehicle’s speed to about 22,600 mph, more than 10 times faster than a rifle bullet.
That’s what it takes to break free from Earth’s gravity and raise its zenith to a point in space where the moon will be in five days.
After spreading its four solar wings and separating from the ICPS, the Orion capsule will make a 60-mile flight from the moon on Sept. 3, then in “distant retrograde orbit” transport the spacecraft farther from Earth — 280,000 miles — than any previously human-assessed spacecraft.
The flight is the first in a series of missions designed to establish a lasting presence on and around the moon with a lunar space station called Gateway and periodicallywhere ice deposits are accessible in cold, permanently shaded craters.
Future astronauts may be able to “mine” that ice if it’s present and accessible, turning it into air, water and even rocket fuel to vastly lower the cost of deep space exploration.
More generally, Artemis astronauts will conduct extensive explorations and research to learn more about the origin and evolution of the moon and test the hardware and procedures needed before sending astronauts to Mars.
The aim 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 October 10 and diving at 25,000 mph. back into the atmosphere that’s protective heat shield to a hellish 5,000 degrees.
Testing the heat shield and confirming that it can protect astronauts returning from deep space is the No. 1 priority of the Artemis 1 mission, a goal for which the SLS rocket must first send the capsule to the moon.
If all goes well with the Artemis 1 mission, NASA plans to launch a second SLS rocket in late 2024 to boost four astronauts on a loop-free reentry orbit around the moon before the first woman and the next man on the lunar surface enter the moon. land near the moon. south pole in the Artemis 3 mission.
That flight, intended for launch in the 2025-26 time frame, will depend on the readiness of new spacesuits 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 builder will actually be ready for the Artemis 3 moon landing mission.
But if the Artemis 1 test flight is successful, NASA could figure out whether a super-heavy rocket is needed to get the first missions off the ground. With a thrust of 8.8 million pounds — 15 percent more than the Saturn 5 — the SLS rocket is the most powerful ever built by NASA.
Congress instructed NASA to build the rocket in the wake of the space shuttle’s retirement in 2011, committing the agency to use leftover shuttle components and existing technology whenever possible to keep costs down.
But management errors and technical issues led to delays and billions in cost overruns. According to NASA’s inspector general, the US space agency is “expected to spend $93 billion on the Artemis (lunar program) through FY 2025.”
“We also project the current production and operating costs of a single SLS/Orion system at $4.1 billion per launch for Artemis 1 through 4, although the Agency’s ongoing initiatives aimed at increasing affordability are trying to cut costs.”
Among the causes cited as contributing to the SLS’s astronomical price tag: the use of cost-plus contracts with a single source “and the fact that, except for the Orion capsule, its subsystems, and launch support facilities, all components be expendable and ‘single-source’ as opposed to emerging commercial spaceflight systems.”
In stark contrast to SpaceX’s commitment to fully reusable rockets, all but the Orion crew pod is discarded after a single use. As SpaceX founder Musk likes to point out, that’s like flying a 747 jumbo jet from New York to Los Angeles and then throwing the plane away.
“That’s a concern,” Paul Martin, NASA’s inspector general, said in an interview with CBS News. “This is a single use replaceable system, unlike some of the launch systems out there in the commercial side of the house where there are multiple uses. This is a single use system. And so the $4.1 billion per flight … worries us so much that we said in our reports that we consider that untenable.”