- Jonathan Amos
- BBC science correspondent
8 hours ago
The US space agency, NASA, was forced to postpone the launch of its new rocket in the Artemis imoon program for the second time in a week.
Controllers have been unable to stop the hydrogen leak on the vehicle, almost since the countdown began on Saturday.
NASA now has another chance to launch the rocket on Monday or Tuesday.
After that, the vehicle will have to return to its assembly building for inspection and maintenance, which means further delays.
The SLS is the most powerful rocket ever developed by NASA, and is designed to bring astronauts and their equipment back to the lunar surface following a 50-year absence.
Much of the SLS’ massive thrust comes from burning nearly three million liters of super-cooled liquid hydrogen and oxygen – in four large engines on the underside of the vehicle.
But when the controllers sent the command early in the morning to fill the rocket’s hydrogen tank, an alarm went off indicating a leak.
The problem was traced back to the connection as hydrogen was pumped into the craft.
Controllers have tried a number of fixes, including allowing devices to heat up for short periods, in the hope that this will lead to a reset. But without success.
The Artemis Eye mission is an unmanned display, but NASA Administrator Bill Nelson said the rocket’s future role in human spaceflight means extreme caution is still required in its operation.
It is possible that NASA will try once more in the next few days. But there are battery systems on this missile that will soon need to be examined. And if the craft has to be returned to the engineering building for further work, we may wait until mid-October before we see it once more on the launch pad.
NASA astronaut Zena Cardman said she understands everyone’s frustration, but they must recognize the challenge of using ultra-cold propellants.
She told the BBC: “Liquid hydrogen is a volatile substance; it is difficult to deal with. But the fact that we are able to get this large amount of data is really useful. I think we will be able to solve this problem in the future. Every time we have a problem, it makes us wiser in Next time”.
The goal of the 100-meter-high craft is to push a test capsule, called Orion, toward the moon, something that hasn’t happened since the Apollo project ended in 1972.
NASA attempted a launch for the first time on Monday, but that offer was eventually canceled because controllers weren’t sure the four large motors on the rocket’s primary stage were set up properly for flight.
When the SLS gets away, it’s sure to be a great sight.
“It’s going to be a shuttle on steroids,” said Doug Hurley, who was a pilot on the last shuttle mission in 2011.
The former astronaut now works for Northrop Grumman, which makes the large white solid boosters on the sides of the SLS.
