SpaceX’s fired the engines of its Falcon Heavy rocket at launch pad 39A at 12:30 p.m. EST (1730 GMT) on Wednesday. The crucial pre-launch engine test has been repeatedly delayed since the rocket returned to the launch pad earlier this month.

Now in the home stretch of a complex, multi-year upgrade, two space station astronauts floated outside the lab complex Thursday and pressed ahead with the third of four spacewalks the current crew is carrying out to complete the replacement of aging batteries in the station’s solar power system.

Three days after high winds scrubbed a launch attempt Friday, Rocket Lab launched an Electron rocket with four satellites from New Zealand at 1212 GMT (8:12 a.m. EDT) Monday.