WASHINGTON — NASA is moving forward with its next Artemis 1 launch attempt on Nov. 16 after finding no major repairs to the Space Launch System and Orion from Hurricane Nicole.
On a Nov. 11 call with reporters, Jim Free, NASA’s associate administrator for exploration systems development, said technicians were working on minor issues caused by the storm’s passage a day earlier, but nothing that couldn’t be fixed in time. for the current projected launch date of Nov. 16 during a two-hour window that opens at 1:04 A.M. east.
“Right now, there’s nothing stopping us from getting to 16,” he said. “We have some work to do.”
That work, he said, involves removing some loose caulks, known as RTVs, in the Orion launch abort system that are not needed for flight. A rain cover on one SLS engine was torn and is being repaired, while water that collected on the crew access arm was removed. An umbilical driver from the Orion launch tower was ejected from a disk and replaced.
He added that a tail service mast unit that feeds liquid hydrogen to the SLS had an electrical umbilical that had “some erratic signals,” which was being checked. This wiring harness could be replaced if required.
Free spent much of the call explaining and defending the agency’s decision to leave the SLS on the pad. He said there was a long discussion about the forecast before he decided to hit the pad on November 4. “There were people who thought very hard about it” to circulate, he recalls. “In the end, everyone agreed that we should release.”
By the time forecasts indicated that the storm had strengthened, it was too late to return to the Vehicle Assembly Building (VAB). At the Nov. 6 hearings, he said, the earliest he could turn the vehicle around was late Nov. 8. “Wind speeds at the time were predicted to be 35 knots [65 km/h] sustained burst up to 40 [74 km/h],” he said, raising concerns about the loads on the vehicle as it returned to the VAB. “At the risk of moving with the strong winds, we decided to stay on the pad.”
Winds ultimately remained just below certification limits for the SLS. At the 18-meter level, NASA reported a peak of just 82 miles per hour, just under the nominal limit of 84 miles per hour.
Free said NASA also measured winds at other levels of the pad, including the top of the 140-meter-tall lightning towers. “During the hurricane, all readings taken showed no breach of these limits,” he said.
Free declined to give windage limits on other levels of the vehicle, citing concerns related to International Traffic in Arms Regulations (ITAR), a category of export controls. “That’s how we do the calculations and the design of the vehicle,” he argued. “You can put some of these together and draw some conclusions that would violate it.”
However, NASA has previously published wind limits for the SLS, notably in an October 2021 document available on a NASA website with a notice that it has been “approved for public circulation. The distribution is unlimited.” This shows that wind thresholds increase with height on the cushion, reaching the 150-meter level at 172 kilometers per hour. The top wind gust reported during the storm was about 160 kilometers per hour at altitude 142 meters
Wind limits, he added, were conservative. “It’s 75% of what we can get, which means we have an extra 25% margin before we even get to the safety factor of 1.4,” he said. “From our perspective, we stayed with our certification on the wind that we saw during the hurricane.”
He acknowledged that NASA likely would have kept SLS in the VAB if it had known before the Nov. 4 launch how Hurricane Nicole would play out. “If we had known the night before we started that it was going to be a hurricane, we probably would have stayed in the VAB.”
However, keeping the vehicle on the pad maintains the November 16th launch attempt as well as a November 19th backup date. Free said NASA had also secured an additional launch date of Nov. 25, the latest available in the current launch window, from the Federal Aviation Administration.
He said he wasn’t nervous about having the SLS on the pad during the storm, at least no more than he generally is about the vehicle before its first launch. “I’m worried about this rocket if it’s been bright and sunny all the time because it’s our first and our flight mission has absolutely critical goals that will be difficult to achieve,” he said. “Well, I’ll worry about that missile until we see that [Orion] capsule safely back to the well deck of the Navy ship.”