After completing a dress rehearsal for launch day over the weekend, the four astronauts gearing up for liftoff Thursday on a SpaceX Falcon 9 rocket are in good spirits and spending time with their families in Florida before leaving the planet for a six-month expedition on the International Space Station. Forecasters with the U.S. Space Force’s 45th Weather Squadron predict an 80% chance of acceptable weather for launch early Thursday.

Watch the launch of a commercial Falcon 9 rocket carrying a Dragon cargo ship bound for the International Space Station, as seen live on NASA Television.

Orbital ATK’s proposed rocket to answer the U.S. Air Force’s desire for two families of satellite launchers with U.S.-made propulsion systems will be named OmegA, and the company has selected the cryogenic Aerojet Rocketdyne RL10 engine to power the vehicle’s upper stage, officials announced this week.