This November 16 will remain etched in the history of the American agency: after more than a decade of development and several postponements, the Space Launch System (SLS) successfully completed its first takeoff. The mission Artemis I is in transit for the Moon and signs in the first hours a decisive success for NASA.
The teams are finally rewarded for their efforts.
A long night of preparation…
The saga of the first takeoff of the Space Launch System (SLS) ended on November 16 at precisely 7:47 a.m. (Paris time) and 1:47 a.m. in Florida. After 7 years of development, 2 of production and assembly, almost a year of testing before arriving on the Space Coast, then several months of take-off attempts, the relief of all the teams was palpable when the center of control announced the last minutes of the countdown.
The last night itself was not the calmest. On the evening of November 15, the control center authorized the filling of the tanks, a special step, because during previous attempts, the ground teams had detected several leaks. There were some in particular on the hydrogen supply lines (the 4 RS-25 main engines are supplied with liquid oxygen and hydrogen). This time, the filling took place, but it took several interventions.
… and a few scares before take-off
In particular, NASA authorized the “red team”, a specialized team, to intervene on the launch structure to check and manually tighten a valve after detecting a new small leak. A dangerous maneuver, but successful! Later, NASA also suffered an Ethernet connection problem which was rectified, then necessary checks on the rocket’s backup system, which allows it to be destroyed remotely if it ever deviates from its trajectory.
But, at approximately 6:45 a.m. (Paris time), after the return of the “red team” and the end of the filling of the tanks, the teams no longer publicly raised any problem. However, there was still enough work to shift the shot, and the final countdown was only able to restart at T-10 minutes at 7:37 a.m. The largely automated sequence was able to come to an end. And, in a moment of disbelief, shared excitement and tremendous spectacle, the Space Launch System ignited its 4 central engines. Four seconds later, the two auxiliary solid boosters ignited, and Artemis I sped through the clear Florida sky.
Maximum power !
SLS is one of the most powerful launch vehicles to ever fly into orbit. However, its ratio between mass and thrust is much greater than that of the iconic Saturn V which started from the same site. So SLS tore the sky much faster, in the intense crackle of its boosters. The mild weather even allowed the very large public on site (several tens of thousands of spectators) to observe in detail the ejection of these boosters after 2 minutes and 12 seconds of flight.
This veritable pyrotechnic show ended up masking the image of the central stage, which for its part headed towards orbit to finally go out after 8 minutes and 20 seconds. The ejection of the upper stage therefore took place in quasi-orbit (apogee at 1,800 km), which gave the Orion capsule, still attached to the thruster, time to extend its four solar panels. This delicate deployment was observed with excitement by the teams from ESA and Airbus Defense & Space in particular, since it was one of the first tasks devolved to the service module delivered by the Europeans on this American mission.
Objective moon !
It then took almost 2 hours of patience to observe the action of the upper stage ICPS (Interim Cryogenic Propulsion Stage), which ignited its engine for the first time to adjust the low orbit of the mission, then accelerated the whole for its translunar injection, at T+1 hour and 26 minutes. And it was not just a few seconds of action, but 18 minutes of thrust to drive the Orion capsule and its service module in transit to the Moon.
The teams that have worked so many years on SLS can be proud, because not only was the trajectory good, but the ejection from Orion was able to take place as planned 2 hours and 5 minutes after takeoff. In the next 90 minutes, 10 small CubeSats (6U) format satellites will be ejected in turn, before a final maneuver by the ICPS, which has already succeeded in its main mission. Orion, on the other hand, is on its way to the Moon, and it will approach it until November 21, the day of its injection maneuver into a highly elliptical distant retrograde orbit (DRO). The entire mission will last 26 days and will test all critical elements for the return of astronauts around the Moon.
50 years after the Apollo 17 mission, Orion is the first habitable (but unmanned) vehicle to go around the Moon. Its start to the mission is a highly anticipated success for NASA.
Source (direct): NASA
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