The nine Merlin 1D engines have done their part for this mission and are shut down. The first stage separated from the rocket as planned and the second stage has picked up the load. Its single Merlin 1D engine is firing and the Dragon is on course for its rendezvous with the International Space Station.
The rocket just passed through the region of maximum dynamic pressure where the air build-up in front of the rocket is at its strongest.
The Falcon 9 and Dragon have left the launch pad and are climbing skyward!
T-2 minutes . . . The SpaceX launch director gave his final clearance for tonight’s liftoff.
The support structure called a strongback has moved away from the Falcon 9 into its launch position.
The Falcon 9’s two stages have moved to internal power, meaning they are running on their batteries through launch and ascent.
T-6 minutes and counting . . . The nine engines of the first stage are being conditioned to the frigid conditions they will encounter when super-cold liquid oxygen begins running through them at launch.
This fourth cargo mission by SpaceX will carry the first living creatures: a cadre of mice that will be used in microgravity research on bone density. The mice, part of a collaborative experiment including NASA and the Center for the Advancement of Science in Space (CASIS), will fly to space in their own habitat that will be transferred to the inside of the space station. A company called TechShot developed a Bone Densitometer that will be used to X-ray the mice. The official name of the payload is Rodent Research-1 and you can read more about it here.
The countdown is in its last, or terminal, phase and the launch team is moving through its steps methodically. Less than 10 minutes until liftoff at 1:52 a.m. EDT.
The final readiness poll has been conducted and the SpaceX CRS-4 mission is go. Controllers can still hold the count at any point before liftoff should an issue pop up.