NASA’s Artemis 1 moon rocket on pad 39B. Credit: Spaceflight Now
Faced with stormy weather ahead of soon-to-be Hurricane Ian, NASA managers Saturday ruled out a third attempt to launch the Artemis 1 moon rocket Tuesday but held open the option of making a run at blastoff on October 2, the current backup date.
That would require leaving the $4.1 billion 330-foot-tall Space Launch System rocket exposed to the elements atop pad 39B, assuming assurances from forecasters winds would not exceed 74 knots, the certified safety limit.
NASA’s Artemis 1 management team deferred making a decision on whether to haul the rocket back to the protection of the Vehicle Assembly Building in hopes of more favorable forecasts overnight that might allow it to ride out the weather at the pad.
A decision is expected Sunday. If rollback is ordered, the 4.2-mile-trip from pad 39B to the Kennedy Space Center’s iconic Vehicle Assembly Building would begin late Sunday or early Monday.
That would allow the agency “to protect its employees by completing a safe roll in time for them to address the needs of their families while also protecting for the option to press ahead with another launch opportunity in the current window if weather predictions improve,” NASA said in a blog post.
The Space Launch System rocket is the most powerful ever built for NASA, a gargantuan booster that will generate 8.8 million pounds of thrust at liftoff, enough to propel Orion crew ships into lunar orbit.
The rocket’s upcoming maiden flight — the Artemis 1 mission — will be unpiloted. NASA hopes to launch four astronauts on an around-the-moon trip in 2024 followed by a landing near the south pole in the Artemis 3 mission, optimistically targeted for launch in the 2025-26 timeframe.
But first, the Artemis 1 mission must get off the ground, and the Orion capsule must successfully orbit the moon and safely complete a hellish high-speed re-entry at the end of the flight, proving the capsule’s head shield will protect astronauts returning from deep space.
The forecast track for Tropical Storm Ian as of 11 a.m. EDT (1500 GMT) on Saturday, Sept. 24. The official National Hurricane Center forecast predicts the storms will strengthen to a major hurricane in the Gulf of Mexico. Credit: National Hurricane Center
The SLS rocket can only head for the moon during launch periods allowing carefully mapped out trajectories that take into account a wide variety of factors, including the ever changing positions of the Earth and moon, the desired lunar orbit, proper lighting for Orion’s solar arrays and optimized communications.
After multiple fueling tests and work to address multiple problems, including repeated hydrogen leaks, NASA attempted to launch the Artemis 1 mission on August 29 only to be derailed by more trouble with liquid hydrogen plumbing at the pad. A second attempt September 3 also was called off by yet another hydrogen leak.
After work to replace a suspect seal in a quick-disconnect fitting, NASA carried out a fueling test and while the fitting leaked initially, engineers were able to adjust flow rates and pressures to successfully fill the rocket’s tanks, setting the stage for a third launch try Tuesday. Then Ian intervened.
The current lunar launch period closes October 4, seven days beyond Tuesday. But two of those days — October 29 and 30 — are not available because of trajectory constraints and three feature launch windows less than an hour long.
NASA earlier reserved October 2 as a backup launch date and that’s the target the agency is protecting by deferring a rollback decision to Sunday. If forecasters can give NASA managers confidence the rocket will not be buffeted by winds gusting above 74 knots, the SLS booster may be able to ride out the weather at the pad, preserving the October 2 option.
But if the rocket isn’t off the pad by October 4, the end of the currently launch period, it faces rollback to the VAB anyway to service batteries in its self-destruct system that cannot be accessed at the launch pad.
The Space Force Eastern Range, which oversees all military and civilian launches from Florida, earlier extended a battery servicing waiver to allow launches through the end of the current period, but it’s not known what options might be available after that.
The next launch period opens October 17 and runs through October 31.