SpaceX's manned rocket launch this evening will be visible over Ireland
Elon Musk's SpaceX is due to reattempt its first launch of passengers into orbit on Saturday.
It had been scheduled to take place on Wednesday but poor weather scuppered the launch from Florida's Kennedy Space Center.
The launch is all part of NASA's Commercial Crew Programme which has tasked private companies with creating new spacecraft for NASA that are capable of transporting astronauts to and from the International Space Station.
It will be the first time that NASA astronauts have been launched from US soil since the Space Shuttle programme ended in 2011 and also the first time that the space agency has used a private company to transport one of its crews to orbit.
While the launch is still scheduled to go ahead on Saturday, forecasters have once again said the weather puts their chances of launch around 50/50.
Providing the weather doesn't cause disruption and no other problems occur, the Falcon 9 rocket is due to lift off at 8.22pm this evening Irish time with astronauts Doug Hurley and Bob Behnken making the trip to the International Space Station.
Similar to Wednesday's planned launch, the flight will pass over Ireland around 15 minutes after launching and will pass over for a second time around 10.15pm.
The two astronauts will be carried inside the Crew Dragon capsule, which will be making its first flight into orbit with humans on board.
The capsule was successfully launched and attached to the ISS last year with no crew on board.
SpaceX, is run by the tech billionaire Elon Musk, and has $2.6bn contract with NASA to provide six crew flights to the ISS with one of these scheduled for August this year.
Boeing has a similar contract with NASA but is thought to be behind SpaceX in its development.
Both President Donald Trump and Vice-President Mike Pence were in attendance on Wednesday for the cancelled launch and Trump is expected at Saturday's launch as well.