NASA was forced to delay its first crewed mission around the Moon in more than 50 years due to unusually cold weather in Florida.

The US space agency explained that a “rare arctic outbreak” at the launch site forced the schedule of the Artemis II mission to be modified.

The launch of the first manned lunar voyage of the Artemis program is now scheduled for no earlier than February 8, two days later than initially planned.

NASA had planned to carry out a fueling test of the 98-meter-high Space Launch System (SLS) rocket on Saturday, but canceled the operation late on Thursday due to the forecast of sub-zero temperatures.

The dress rehearsal, a key pre-launch test, has been rescheduled for Monday, weather conditions permitting.

“Equipment and preparations on the launch pad remain ready for wet testing,” NASA said in a statement.

“However, adjusting the test schedule will allow NASA to ensure the success of the test, since the weather forecast for this weekend does not meet the conditions necessary for launch.”

NASA has only a few days a month to launch its first lunar crew, due to a narrow alignment window between the Earth and the Moon.

With the latest change to the schedule, the agency now has just three days in February to send four astronauts around the Moon and back before the window moves to March.

“Any additional delay would involve a day-to-day change,” NASA said in a statement issued Friday.

Officials said heating systems are keeping the Orion capsule at the top of the rocket warm and that the vehicle’s purge systems are also being adapted to the low temperatures.

The crew remains in quarantine in Houston and their arrival at the Kennedy Space Center in Florida remains uncertain.

The four astronauts — Reid Wiseman, Victor Glover and Christina Koch of NASA, and Jeremy Hansen of the Canadian Space Agency (CSA) — must spend approximately 14 days in quarantine to limit their exposure to diseases.

Crew will be able to stay in touch with friends, family and colleagues, but will avoid public places, wear masks and keep their distance from anyone they come into contact with.

The 10-day Artemis II mission will take humans further from Earth than any mission since Apollo 17 in 1972, which was also the last time an astronaut walked on the Moon.

A lunar landing is not planned for this mission: the objective is to test the systems and hardware necessary for the return of astronauts to the lunar surface in the future Artemis III mission, scheduled for 2027.