An engine problem forced NASA on Monday to postpone for at least four days the launch of its colossal next-generation rocketship on a long-awaited debut test flight around the moon and back 50 years after Apollo’s last lunar mission.
The countdown was halted about 40 minutes before launch time as the 32-story-tall, two-stage Space Launch System (SLS) rocket and its Orion crew capsule awaited liftoff from the Kennedy Space Center in Cape Canaveral, Florida.
The U.S. space agency cited a problem on one of the rocket’s main engines, after launch teams had begun filling its core fuel tanks with super-cooled liquid oxygen and hydrogen propellants. Mission engineers struggled to properly condition that engine to the right temperature for launch, the agency said.
NASA did not give a new launch date but said its first available backup launch opportunity was set for Friday, Sept. 2.
Whether the agency sticks with that date depends on how quickly engineers can resolve the engine issue. The subsequent launch opportunity is Monday, Sept. 5.
The maiden journey of the SLS-Orion marks the kickoff of NASA’s highly vaunted moon-to-Mars Artemis program, the successor to the Apollo lunar missions of the 1960s and ’70s.
The voyage is intended to put the 5.75-million-pound vehicle through its paces in a rigorous demonstration flight, pushing its design limits, before NASA deems it reliable enough to carry astronauts in a subsequent flight targeted for 2024.
Billed as the most powerful, complex rocket in the world, the SLS represents the biggest new vertical launch system the U.S. space agency has built since the Saturn V rocket flown during Apollo, which grew out of the U.S.-Soviet space race of the Cold War era.
If the first two Artemis missions succeed, NASA is aiming to land astronauts back on the moon, including the first woman to set foot on the lunar surface, as early as 2025, though many experts believe that time frame is likely to slip by a few years.
The last humans to walk on the moon were the two-man descent team of Apollo 17 in 1972, following in the footsteps of 10 other astronauts during five earlier missions beginning with Apollo 11 in 1969.
The Artemis program seeks to eventually establish a long-term lunar base as a stepping stone to even more ambitious astronaut voyages to Mars, a goal that NASA officials have said will probably take until at least the late 2030s to achieve.
The program was named for the goddess who was Apollo’s twin sister in ancient Greek mythology.
SLS has been under development for more than a decade, with years of delays and cost overruns. But the Artemis program also has generated tens of thousands of jobs and billions of dollars in commerce under the primary contractors Boeing Co for SLS and Lockheed Martin Corp for Orion.
One issue cited by NASA officials last week as a potential show stopper for Monday’s launch was any sign during rocket fueling that a newly repaired hydrogen line fitting had failed to hold. NASA officials said on Sunday they were also eyeing a potential, but minor, helium leak in launch pad equipment.
Although no humans will be aboard, Orion will be carrying a simulated crew of three – one male and two female mannequins – fitted with sensors to measure radiation levels and other stresses that real-life astronauts would experience.
