This flight is a milestone for NASA and for SpaceX. NASA has been without a domestic carrier for their astronauts since the end of the space shuttle program in 2011. The space agency has relied on Russian Soyuz capsules for access to ISS ever since. SpaceX and Boeing are both in the final stages of testing the multi-billion dollar capsules NASA contracted them to build under its Commercial Crew program. And NASA hopes to certify the companies to fly crewed missions before the end of the year. That certification relies on tomorrow’s Demo-1 mission succeeding, as well as SpaceX’s crewed Demo-2 flight, scheduled for July. Boeing has similar uncrewed and crewed test flights planned for April and August, respectively.
SpaceX has flown 16 missions to ISS using their Dragon cargo capsule, but this is their first full flight of the redesigned Dragon 2 crew capsule, with seats on the inside for six crewmembers, life support systems, controls, and additional safety precautions should anything go wrong during launch or landing. Those precautions include additional thrusters in case they need to abort after launch but before reaching orbit, and an extra parachute (four instead of the usual three) for landing.
This will also be the first time the Dragon capsule has docked, instead of merely berthed, with ISS. This means Dragon will connect to the ISS under its own guidance and propulsion. Previously, it has merely flown close before being grabbed by a robotic arm under the control of ISS crewmembers. The three members currently aboard ISS will also get the chance to enter Dragon in space to remove the cargo.
NASA and SpaceX will be carefully monitoring the capsule throughout its mission, and the dummy – named Ripley, in a reference to the Alien movie franchise – will track how the flight feels from inside the capsule.
Weather reports are positive for tonight, so the flight is likely to proceed. NASA and SpaceX will be livestreaming the event starting at 1 a.m. CST for a 1:48 a.m. launch time.