A month late and after five very frustrating delays because of bad weather and lightning storms, the shuttle Endeavor finally blasted towards the International Space Station late on Wednesday, Space.com informs. The launch took place at 6:03 p.m. EDT (2203 GMT), from Launch Pad 39A at the Kennedy Space Center, with Endeavor meant to deliver vital equipment for the Station.

Initially, Endeavor was scheduled for lift-off in mid June, but the launch had to be pushed back two consecutive times when the crew noticed a hydrogen gas leak on the external fuel tank. The leak was repaired at a later hour. Three other attempts were foiled over the weekend by thunderstorms and lightning, much to the frustration of the entire crew, who was already running a month late.

“Running a month late, Endeavour roared into the Florida evening sky at 6:03 p.m. EDT (2203 GMT) from Launch Pad 39A here at the seaside Kennedy Space Center. The orbiter is ferrying seven astronauts, vital spare equipment and a Japanese-built experiment porch to the orbital outpost.” Space.com writes about the sixth successful attempt. NASA Launch Director Pete Nickolenko was almost convinced the sixth time would be a success, telling Endeavor’s seven astronauts, “Persistence pays off, good luck and Godspeed,” just before the takeoff.

Bad weather was not the only thing that might have prevented the sixth attempt, either. “Mission managers cleared Endeavour to fly today after fears surfaced that one of the shuttle’s power-generating fuel cells was malfunctioning. A faulty cell is not a risk for launch, but could shorten the planned 16-day mission if it cannot provide power for as long as planned. After subsequent checks suggested the fuel cell was functioning within normal limits, NASA decided to go ahead with launch.” the aforementioned publication further says.

Before the launch, mission specialist Dave Wolf talked about the mission the astronauts on Endeavor had before them. According to him, it includes five spacewalks and robotic arm maneuvers meant to install new hardware equipment on the International Space Station. Endeavor is scheduled to reach the Station at 1:55 p.m. EDT (1755 GMT) on Friday.