The reigning title holder for world’s most powerful rocket saw action on both its center core and its two solid rocket boosters this month, with pieces for the Artemis II launch coming together as NASA aims to send humans on a trip around the moon next year.
Arriving by train to Florida on Monday were all 10 segments for the two side boosters of the Space Launch System rocket that will launch the Orion spacecraft with four humans on board from Kennedy Space Center as early as November 2024. The core stage of that booster remains in New Orleans, but teams last week installed the last of four converted space shuttle engines to the base of the stage.
The core stage’s primary contractor Boeing still has more work to do before it can be shipped by barge from NASA’s Michoud Assembly Facility to KSC, currently on track for a November arrival, but the tail end finally got the last of its four R2-25 engines stuck in place. Aerojet Rocketdyne, which was recently acquired by Melbourne-based L3Harris, manufactured all four engines that were originally designed for the Space Shuttle Program, but have since been converted for use on the SLS.
Two of the engines have been to space for a combined 20 missions already, including both Space Shuttle Endeavour’s last flight on STS-134 and Space Shuttle Atlantis’ last flight and final mission of the shuttle program, STS-135, in 2011. The other two engines are making their first trip to space, but the parts were mostly manufactured for the shuttles. All four have at least one component that flew on Space Shuttle Columbia on STS-1 in 1981.
RS-25s have been to space a combined 409 times, and former shuttle program engines will be used through Artemis IV, with brand new RS-25s used for Artemis V and beyond.
The mission marks the second launch of the SLS rocket, which became the most powerful to make orbit when Artemis I lifted off on its uncrewed flight to the moon in late 2022. It broke a record held by the Saturn V rockets of the Apollo era.
That’s a title that would get pushed to No. 2 if SpaceX’s in-development Starship and Super Heavy rocket manages to make orbit with its more than 17 million pounds of thrust. Its second attempt to orbit is on hold awaiting approval to fly from the Federal Aviation Administration in the wake of its first attempt ending with the rocket self-destructing over the Gulf of Mexico back in April.
For NASA, it’s going to need both powerhouse rockets to continue its plans to return humans to the moon’s surface on the Artemis III mission as a version of Starship is contracted to be the astronauts’ Human Landing System.
Plans are for Starship to dock with the Orion spacecraft while it orbits the moon and then take two of that mission’s four-person crew, including the first woman, down for about a weeklong mission to explore the lunar south pole.
While that mission is still on NASA’s roadmap for as early as December 2025, delays to Starship could push that mission deeper into the decade. That potential delay is among sources for rising costs to the Artemis program.