Video: Time lapse of ATV’s final departure from ISS

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.

The European Space Agency’s $1.7 billion robotic Jupiter Icy Moons Explorer mission is ready for liftoff Thursday from French Guiana, beginning an eight-year cruise to the solar system’s largest planet before becoming the first-ever spacecraft to orbit one of Jupiter’s moons in the 2030s.

Sierra Nevada Corp. has business activity across a spectrum of programs, from Orbcomm communications satellites to parts on the New Horizons mission to Pluto, but all eyes are now on the company’s Dream Chaser spacecraft. Sierra Nevada’s Mark Sirangelo met with reporters at the 2015 International Symposium for Personal and Commercial Spaceflight.