With about an hour and 15 minutes remaining until today’s 4:33 p.m. EDT launch time, the countdown is proceeding according to schedule. NASA’s SpaceX Demo-2 crew members, Robert Behnken and Douglas Hurley, are buckled into their seats inside the SpaceX Crew Dragon spacecraft, and its side hatch has been closed and checked for leaks. Teams continue to monitor weather conditions.
Here’s a look at some of the major milestones still to come. (Times are shown in “L-time” – minutes and seconds prior to launch time.)
-45:00 SpaceX Launch Director verifies “go” for propellant load
-42:00 Crew access arm retracts
-37:00 Dragon launch escape system is armed
-35:00 RP-1 (rocket grade kerosene) loading begins
-35:00 1st stage LOX (liquid oxygen) loading begins
-16:00 2nd stage LOX loading begins
-07:00 Falcon 9 begins engine chill prior to launch
-05:00 Dragon transitions to internal power
-01:00 Command flight computer to begin final prelaunch checks
-01:00 Propellant tank pressurization to flight pressure begins
-00:45 SpaceX Launch Director verifies “go” for launch
-00:03 Engine controller commands engine ignition sequence to start
-00:00 Falcon 9 liftoff
The Demo-2 mission will serve as an end-to-end flight test to validate the SpaceX crew transportation system, from launch to docking to splashdown. It is the final flight test for the system to be certified for regular crew flights to the station as part of NASA’s Commercial Crew Program.