Space shuttle Discovery reached orbit 200 miles above earth tonight at 7:51 local time, after taking off from Kennedy Space Center in Cape Canaveral, Florida at 7:43:44.

The shuttle will drop off the final pieces of the International Space Station's (ISS) solar arrays, and parts for its urine recycling system that would expand the ISS’s capacity from three to six crew members.

The launch was pushed back twice, first on February 4 when NASA said it needed more time to make sure that the valves controlling the flow of hydrogen gas into the external fuel tank do not pose a hazard. Engineers discovered that one of those valves had been damaged when another shuttle, Endeavour, lifted off in November.

A scheduled March 12 launch was delayed until tonight after engineers discovered a leak in the gaseous hydrogen venting system outside of the external fuel tank. That system carries excess hydrogen away from the launch pad, and an accumulation of gas could have caused an explosion at launch.

The issues were unrelated, NASA spokesperson William Johnson told Bloomberg News last week.

The successful launch was good news for NASA and the seven-man crew, which includes Koichi Wakata, a Japanese astronaut who will remain behind on the ISS, taking NASA astronaut Sandra Magnus' place.

It may not have been as good news for a fruit bat that the agency found clinging to an external fuel tank earlier in the day, as The Orlando Sentinel's Robyn Shelton reported. A NASA spokesperson told her the bat was expected to fly away from the tank unharmed; follow us on Twitter for news on that front and others.

Space shuttle Discovery's patch, featuring solar panels, courtesy NASA