On Dec.
5, NASA will air the lunar flyby of the Orion spacecraft on its return trek toward Earth.
Orion completed a burn Dec.
1 to exit a lunar orbit thousands of miles beyond the Moon, where engineers have been testing systems to improve understanding of the spacecraft before future missions with astronauts.
The return powered flyby burn, in which the spacecraft will harness the Moon’s gravity and accelerate back toward Earth, is expected at 11:43 a.m.
(1643 UTC) The spacecraft is expected to fly about 79 miles above the lunar surface at 11:42 a.m.
(16:42 UTC) just before the burn.