Officially known as the flight termination system, it’s a detonation system designed to destroy a rocket in case it starts to veer wildly off course and threaten anyone on the ground. In the dangerous world of rockets, it is a vital and ubiquitous safety component, operated by the military. But it also caused some trouble for NASA, as it struggled to launch an SLS rocket for the first time.
The Space Force requires that the batteries on SLS end systems be charged frequently to ensure they are in good working order. The problem NASA faces is that this can only be done in the rocket’s assembly building, which means they need to perform the laborious work of rolling the 322-foot-tall rocket from its current launch pad back to the building four miles away — one way The journey takes about eight hours.
That would further delay launches that were twice abandoned last week due to other technical issues, including a massive leak of liquid hydrogen that the rocket uses as fuel.
NASA has asked the Space Force to extend the flight-end battery requirement from 20 to 25 days so that it can attempt a launch late in the final launch period that ended Tuesday.
Now, NASA is discussing a waiver with the Space Force to allow another extension of the time frame. But this time around, the waiver must extend the initial 20-day requirement to more than about 40 days, because the earliest NASA can attempt to launch is a two-week period starting on September 19.
The launch will be the first in NASA’s Artemis campaign to eventually return astronauts to the lunar surface. The first mission will send the Orion spacecraft into lunar orbit without any astronauts. It will be followed by a crewed flight that will orbit the moon again, but possibly land on the moon in 2024 and land in 2025 or 2026.
After years of delays and setbacks, NASA officials are eager to complete the first mission. But they have been grappling with a series of problems. The first attempt was canceled due to incorrect engine sensor readings. Then, on Saturday, they were unable to contain a massive hydrogen leak and said the pressure on the fuel lines also suddenly increased, surprising officials.
Now, it’s battling restrictions that end the system, and it’s unclear whether the Space Force’s space launch Delta 45, which oversees the so-called Eastern Range, will approve an extension.
“The first thing is to protect the public, and Eastern Sierra takes the mission of protecting the public very seriously,” said Wayne Hale, a former NASA space shuttle flight director who now chairs NASA’s advisory committee. He said in an interview that the rocket was “actually a bomb, it’s a huge bomb” and that the wings did everything they could to make sure the terminal systems were working properly before they were allowed to launch.
“They were the perfect professionals,” said Wayne Monteith, a former commander of the 45th Space Wing. “If something goes wrong, they’re the team you want on the console.”
NASA said late Tuesday that engineers would replace a seal that failed during a hydrogen leak from the launch pad, rather than returning it to the assembly building. This will allow it to test the seal by running liquid hydrogen held at minus 423 degrees Fahrenheit.
“Doing this work on the mat also allowed the team to collect as much data as possible to understand the cause of the problem,” NASA said in a statement.
There’s a downside, though — the longer the rocket is outside, the longer it’s exposed to the changeable weather that’s common on the Florida coast this time of year.
“We noticed that when we were on the mat, we were outside,” Artemis mission manager Mike Sarafin told reporters after scrubbing on Saturday.
In parallel with the repair work, NASA said it will “place an enclosure around the work area to protect the hardware from weather and other environmental conditions, but enable engineers to test repairs in cryogenic or ultra-cold conditions.”
It noted that in order to “meet current requirements” for the Space Force’s end-of-flight battery, it “needs to roll the rocket and spacecraft back” to the assembly building to reset the battery.
If that’s the case, NASA may not try to launch again until its next opportunity, roughly two weeks from Oct. 4. The launch capability of the SLS depends on the position of the Earth and the Moon, as the Orion spacecraft cannot be in the dark for more than 90 minutes at a time. Its solar array needs to keep the lights on in order to power the spacecraft and ensure it maintains the correct temperature.