Countdown Under Way as Crew Preps for Launch Today

Two American astronauts and a Russian cosmonaut are making final preparations for their journey to the International Space Station. At the Baikonur Cosmodrome in Kazakhstan, NASA astronauts Drew Feustel and Ricky Arnold and cosmonaut Oleg Artemyev of Roscosmos are set to launch in the Soyuz MS-08 spacecraft at 1:44 p.m. EDT (11:44 p.m. Kazakhstan time).

Live coverage will air on NASA Television and the agency’s website.

The three will join Expedition 55 commander Anton Shkaplerov of Roscosmos, Scott Tingle of NASA and Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA) to continue work on hundreds of experiments in biology, biotechnology, physical science and Earth science aboard humanity’s only permanently occupied microgravity laboratory.

Below is the crew’s launch timeline in EDT:

EDT L-Hr/M/Sec Event

10:39:25am 3:05 First and second stage oxygen fueling complete
10:44:25am 3:00 Crew walkout from 254 and board bus for the launch pad
10:49:25am 2:55 Crew departs for launch pad (Site 1)
11:09:25am 2:35 Crew arrives at launch pad (Site 1)
12:19:25pm 2:25 Crew boards Soyuz; strapped in to the Descent module
12:09:25pm 1:35 Descent module hardware tested
12:24:25pm 1:20 Hatch closed; leak checks begin
12:44:25pm 1:00 Launch vehicle control system prep; gyro activation
12:45:00pm :59:25 NASA TV LAUNCH COVERAGE BEGINS
12:59:25pm :45 Pad service structure components lowered
1:00:25pm :44 Clamshell gantry service towers retracted
1:05:00pm :39:25 NASA TV: Crew pre-launch activities played (B-roll)
1:07:25pm :37 Suit leak checks begin; descent module testing complete
1:10:25pm :34 Emergency escape system armed
1:29:25pm :15 Suit leak checks complete; escape system to auto
1:34:25pm :10 Gyros in flight readiness and recorders activated
1:37:25pm :07 Pre-launch operations complete
1:38:25pm :06 Launch countdown operations to auto; vehicle ready
1:39:25pm :05 Commander’s controls activated
1:40:25pm :04 Combustion chamber nitrogen purge
1:41:25pm :03 Propellant drainback
1:41:40pm :02:45 Booster propellant tank pressurization
1:42:55pm :01:30 Ground propellant feed terminated
1:43:25pm :01:00 Vehicle to internal power
1:43:50pm :00:35 First umbilical tower separates
Auto sequence start
1:43:55pm :00:30 Ground umbilical to third stage disconnected
1:44:10pm :00:15 Second umbilical tower separates
1:44:13pm :00:12 Launch command issued
Engine Start Sequence Begins
1:44:15pm :00:10 Engine turbopumps at flight speed
1:44:20pm :00:05 Engines at maximum thrust

1:44:25pm :00:00 LAUNCH OF SOYUZ MS-08 TO THE ISS
(At the time of launch, the space station will be over the south Atlantic, east of Argentina; altitude of about 257 statute miles)

1:53:10pm +8:45 THIRD STAGE SHUTDOWN; SOYUZ ORBITAL INSERTION

The next update will be after the crew safely reaches orbit.

After a two-day flight, the new crew members will dock to the station’s Poisk docking module at 3:41 p.m. Friday, March 25. About two hours later, hatches between the Soyuz and the station will open, and the new residents will begin their mission.

Learn more about station activities by following @space_station and @ISS_Research on Twitter as well as the ISS Facebook and ISS Instagram accounts.