Webb, which is touted as the US space agency's next great space observatory, was first targeted to launch in March this year. It was later pushed back to October due to impacts from the ongoing Covid-19 pandemic, as well as technical challenges.
The agency set the new target launch date in coordination with Arianespace after Webb recently and successfully completed its rigorous testing regimen -- a major turning point for the mission, NASA said in a statement on Wednesday.
The new date also follows French company Arianespace successfully launching an Ariane 5 rocket in late July and scheduling a launch that will precede Webb. The July launch was the first for an Ariane 5 since August 2020.
Webb, an international programme led by NASA with its partners ESA (European Space Agency) and the Canadian Space Agency, will launch on an Ariane 5 from Europe's Spaceport in French Guiana on the northeastern coast of South America. ESA is providing the Ariane 5, NASA said.
The highly complex space telescope is currently resting in its final stow configuration at Northrop Grumman's facilities in Redondo Beach, California.
"Webb is an exemplary mission that signifies the epitome of perseverance," said Gregory L. Robinson, Webb's programme director at NASA Headquarters in Washington.
"We've overcome technical obstacles along the way as well as challenges during the coronavirus pandemic. Now that we have an observatory and a rocket ready for launch, I am looking forward to the big day and the amazing science to come," he added.
The Webb team is preparing for shipment operations, during which the observatory will undergo final closeout procedures and packing for its journey to the launch site. The major elements of the Ariane 5 rocket that will carry Webb into space have safely arrived in Kourou, French Guiana, from Europe, NASA said.
The telescope is designed to help in solving the mysteries of our solar system, looking beyond distant worlds around other stars, and probing the mystifying structures and origins of our universe.