The countdown to start the NASA’s Space Launch System (SLS) the moon rocket officially launched just over 48 hours before the 32-story rocket’s six massive engines finally fired at 1:47 a.m. ET this morning, pushing the 2.6 million kg (5.75 million pound) machine off the launch pad 39B at the Kennedy Space Center in Florida and launched it toward the moon. With the successful launch, NASA’s Artemis program, which aims to return Americans to the Moon as early as late 2025, has finally begun.
In some ways, however, the real countdown to this morning’s launch began on January 15, 2004, when then This was announced by President George Bush that the US would return astronauts to the moon and called for the construction of a new heavy-lift rocket to make the journey possible.
“The desire to explore and understand is part of our character,” Bush said in a White House speech at the time. “We don’t know where this journey will end, but we do know this: human beings are headed for space.” Exactly 18 years, 10 months and one day later, that journey – so far without humans on board – has finally begun.
SLS will now make a 25-day trip, during which the Orion spacecraft will complete two circular orbits around the Moon before returning to Earth for a Dec. 11 landing. This morning’s liftoff was plagued by last-minute problems, including a hydrogen leak at the base of the rocket’s main stage and a faulty Ethernet switch in the range’s safety mechanism, which would have been used to trigger a self-destruct system if the rocket went awry during of the launch. The repair of both causes 44-min. delaying the originally scheduled launch at 1:04 a.m. ET. Once takeoff occurred, the flight went exactly according to the bosses’ plans.
The SLS is a six-engine rocket: its main stage is powered by four liquid-propellant RS-25 engines—the same engines that powered the Space Shuttle. On the side of the main stage are a pair of solid-propellant rocket engines – also legacy shuttle hardware. Together, the half-dozen engines deliver 4 million kg (8.8 million lbs) of thrust, or 15% more than the 3.4 million kg (7.5 million lb.) produced by the Apollo-era Saturn 5, once the most powerful rocket that has ever flown — until the SLS liftoff this morning.
The solid rocket boosters, which produce 75 percent of the rocket’s power, didn’t last long, burning out just two minutes and 12 seconds after ignition. After the SLS reached an altitude of 48 km (29 mi), the boosters disengaged, separated, and fell. After that point, the main stage engines run for another six minutes and eight seconds before shutting down at a low-Earth orbital altitude of 161 km (100 mi) and a speed of just under 28,300 km/h (17,500 mph). The Orion spacecraft and its own smaller second stage then separate from the main stage and within 90 minutes complete a complete orbit around Earth before the second stage engine fires, accelerating the spacecraft to just under 25,000 mph (40,200 km/h). (25,000 miles per hour). — enough to break away from Earth’s orbit and head for the Moon. About 30 minutes after that — or two hours after liftoff — the second stage also dropped, leaving the Orion spacecraft to make the lunar journey alone.
It will take five days for Orion to reach the Moon, where its own on-board engine will fire, establishing the spacecraft in a lunar orbit that will see it circle the Moon at altitudes ranging from 96 km (60 miles) from the lunar surface up to 61,000 km (38,000 mi). After two weeks of orbiting the moon, Orion will re-ignite its engine and head home. If all goes well, the mission, known as Artemis 1will be followed in 2024 by Artemis 2, which will see astronauts make a similar circumnavigation – marking the first time humans have been near the Moon since Apollo 17 in 1972. Then will follow Artemis 3, a crew lander on the moon .
“After 50 years, we’re going back to the moon, but this time to stay,” said NASA Administrator Bill Nelson. “We will learn to work, to improve, to innovate, to create so that we can go to Mars later.”
Adds Chris Cianciola, deputy manager of the SLS program: “This is a huge step for both us at the agency and for humanity. This is the signal that we are returning to space, deep space, not low Earth orbit. This mission will kick off many of our flight test goals before we get humans on board.”
Test flight with experiments on board
Although the Artemis 1 mission was largely an engineering exercise — designed to prove the flightworthiness of SLS and Orion — there was also some solid scientific research involved. Hitchhiking aboard the rocket were 10 CubeSats — or minisatellites, each about the size of a shoebox — that were launched into space when the second stage separated. They will conduct a number of experiments.
One of the CubeSats will make seven orbits of the moon, scanning its surface for water ice in the lunar regolith, or soil, that future lunar astronauts could collect and use. Another will search for hydrogen – which astronauts could also use for rocket fuel – at the moon’s permanently shadowed poles. Another, provided by JAXA, the Japanese space agency, will use a rocket engine and cushioning air cushion to make a landing on the moon, where it will measure radiation on the lunar surface.
On board Orion there will also be samples of plants, algae, fungi and yeasts that will be recovered and studied when Orion returns to Earth to measure the effect that ionizing radiation from deep space has on their genetic make-up , which has implications for astronauts venturing into the same radiation field.
“We absolutely want to make the most of this opportunity,” says Cianciola. “There are some really unique payloads here, and I’m excited about them.”
NASA’s Long Struggle to Launch
However, these scientific discoveries are for later. Today, NASA is celebrating the liftoff as a triumph not only of design and execution but also of institutional tenacity—the culmination of what was close to a generation of setbacks, course changes, and near-death experiences for SLS.
Under the Bush administration, the Moon Return Initiative was named Constellation program, and the new heavy-lift rocket was known as Ares V. NASA engineers and mission planners spent four years working on Constellation, designing and beginning construction of both Ares V and Orion. By the time the Bush administration left town and Barack Obama’s presidency began, however, Constellation was way over budget and behind schedule. President Obama, who never mentioned space as a campaign priority, pulled the plug on the program in 2010diverting Orion money to other NASA projects, including the continued construction and maintenance of the International Space Station.
Congress, however, had something to say about it — especially the delegations from space-centric Texas, Alabama, and Florida — and forced to refinance for both Orion and Ares V, not to mention the tasks they represented. Obama relented, but only partially. Constellation was still banned and the moon was no longer on the route. Instead, the White House proposed the mind-boggling idea of sending an unmanned spacecraft to find a small asteroid, tow it to the vicinity of the moon, and have astronauts land there and explore it instead. The new rocket that will send the crews of the so-called asteroid redirection mission (ARM) would no longer be known as Ares V. As a signal of the new seriousness and frugality of the space program, NASA and the White House settled on the more prosaic-sounding Space Launch System.
More changes are coming under President Donald Trump’s administration, which in 2017 canceled the ARM and restored the moon as the first destination of SLS and Orion, with possible manned missions to Mars also on the agenda for some time in the 2030s. The New Moon-Mars program will be known as Artemis – named after Apollo’s sister.
Read more: NASA’s Mega-Moon Rocket Survives Hurricane
It took until June 2021 before the last SLS rocket was finally fully built, its components stacked together in the Kennedy Space Center’s Vehicle Assembly Building (VAB). It then went through a series of preparations and tests. SLS made multiple trips to and from the VAB to Pad 39B for simulated countdowns—known as wetsuit rehearsals—during which the rocket was loaded with more than 2.6 million liters (700,000 gal) of fuel and the countdown lasted only for seconds before what the ignition would have been before the clock stopped and the fuel was drained. A rehearsal attempt in April failed due to a fuel leak and a defect in the vent valve and was not until June this year that NASA successfully finished the wet dress and declared the rocket ready for launch.
Multiple attempts to lift Artemis 1 from the pad were made in August and September, with an initial liftoff, scheduled for Aug 29 due to a fuel leak and a faulty temperature sensor on one of the main engines. New attempt on 3 Sept was also canceled due to a hydrogen fuel leak. Launch attempt on September 27 it was then cancelled and the SLS had to return it to the VAB as Hurricane Ian approached Florida.
This morning’s launch was too postponed by two days from the original target date of November 14, due to weather, this time in the face of Hurricane Nicole, although forecast winds and rain were within parameters to allow the rocket to remain on the launch pad without seeking cover.
As of this morning, Nicole has passed away and the SLS – 18 years in the making – has flown. That space travel that Bush had been calling for for so long has finally begun.
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