- Most powerful rocket ever to leave Earth to blast off shortly
- No humans aboard capsule for critical test flight
- Nasa to launch first crew-rated rocket to moon since 1972
Launch control says Nasa’s missions engineers are forming a “troubleshooting plan” to address a problem with one of the four R-25 engines on the SLS rocket’s core stage. The engine is not responding correctly to efforts to condition it with cryogenic propellant in order to raise its temperature for launch.
A decision could come in the next 10 minutes whether a fix can be found in time to still launch during today’s two-hour window, which closes at 10.33am local time (3.33pm BST) or if the launch must be delayed to another day.
