Wellor the past 23 days, the Space Launch System (SLS) lunar rocket has been more monument than machine, rising 32 stories on Launch Pad 39B at the Kennedy Space Center, the most prominent object for miles around as it towers over the landscape of Florida. On August 29 and again on September 3, the rocket was scheduled to take off on an uncrewed mission around the moon – launching NASA’s Artemis program, which aims to return Americans to the lunar surface by 2026. Both launches proved unsuccessful as serial technical problems kept the engines quiet and the hardware stationary. But engineers hardly give up.
Like NASA reports, work is being done on the site, which could see the SLS finally lift off in one of two upcoming launch windows: on September 23, during a two-hour stretch beginning at 6:47 a.m. ET; or on September 27 during a 70-minute period beginning at 11:37 a.m. ET. During these two time frames, the moon will be in a favorable position to make the planned mission possible. First, however, comes the turn of the repair.
The biggest challenge facing engineers is fixing leaks that have formed around two fuel lines that feed liquid hydrogen to the rocket. The first leak involves an 8-inch (20 cm) wide cable used to fill the SLS’s massive tanks. The second includes one of four 4-inch (10 cm) cables that cool the rocket’s main stage engines, conditioning them to the correct temperature so they can withstand the ignition head.
It’s good that the work can be done on the launch pad, as if the SLS had to do 4 mi. (6.4 km), 12-hour crawl back to the Vehicle Assembly Building (VAB) aboard its mobile launch platform, the September launch windows will likely be missed. However, the SLS may return to the hangar anyway. That’s because fuel lines aren’t the only problem facing the massive rocket. There’s also a problem with his self-destruct system.
The rocket is equipped with built-in batteries that would set off a controlled explosion over the Atlantic Ocean if the SLS goes awry during launch and threatens to drift back over land. The batteries are certified for 25 days – a period that ends this Sunday – and can only be serviced and charged at VAB. However, NASA is confident that the batteries will continue to function beyond the two upcoming launch windows. But it’s not up to NASA to give the go-ahead to extend the certification. That’s up to U.S. Space Force officials, who have not yet responded to the space agency’s request for an extension.
“We really provided them with our release package,” Jim Free, NASA’s director of exploration, said CBS News. “They were very kind and understanding of what we were trying to do. … It’s our job to accommodate their demands, so we will.”
For now, it’s a waiting game — both for the space agency and for lunar enthusiasts hoping the SLS candle will finally be lit. America’s era of manned lunar exploration will eventually resume. The question remains when.
This story originally appeared in TIME Space, our weekly newsletter covering all things space. You can register here.
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