Thread by @WeAreSpaceScout

Good morning. We're currently at T- 50:00 to the 15th launch of Northrop Grumman's Cygnus resupply vehicle, destined for a two-day ISS rendezvous. #NG15

Listen in to Mission Control: video.ibm.com/channel/nasa-t…
Watch live on NASA TV, starting at 12 p.m. EST:

(Tweet reposted due to a typo.)

T- 45 minutes now to launch of #NG15.

Today's #NG15 mission includes a variety of payloads, on both Cygnus and Antares - including eye cell regeneration experiments, space sleep monitors, and 30 student-built picosatellites. Read more about the payloads flying on Cygnus itself today:
nasa.gov/mission_pages/…

T- 30 minutes. FTS is powered on after a go/no-go poll. #NG15

T- 20 minutes now. All systems are nominal. #NG15

Today's launch timeline:
Liftoff: +3.7 sec
MECO: +3:18
S1 sep and coast: +3:24
Fairing sep: +3:54
Interstage sep: +3:59
S2 Ignition: +4:07
S2 Burnout: +6:52
Payload sep: +8:52.

Remember - the coast phase is over 40 seconds. This is normal. #NG15

(image credit: Northrop Grumman)

ISS layout once #NG15 docks. Cygnus will be berthed to the Unity nadir port.

T- 13 minutes. Cygnus in launch mode and nominal. #NG15

T- 10 minutes. Go-no go poll complete. And a couple memorials. #NG15

T- 8 minutes. #NG15

T- 6 minutes. All systems nominal at this time. #NG15

T- 5 minutes. Engines are primed, avionics are transferred to internal power. #NG15

T- 4 minutes. The range is green. #NG15

Now in terminal count.

T- 1 minute. #NG15

LIFTOFF of #NG15, carrying the Cygnus S.S. Katherine Johnson and over 30 secondary payloads, at 12:36:51 p.m. EST.

#NG15 continues to fly smoothly on a very nominal ascent, now passing Max Q.

One minute now to engine burnout. T+ 2 minutes.

Main engine cutoff! #NG15 will now enter a 40 second COAST period as the second stage calculates a trajectory for its solid rocket motor.

Stage 2 ignition! Can't see much now. 2 minutes left in the burn. #NG15

One minute to S2 burnout.

Stage 2 cutoff. Antares has successfully placed the S.S. Katherine Johnson in orbit! 2 minutes to payload separation now. #NG15

Altitude 185 km, velocity 7.5 km/s. #NG15

Payload separation confirmed! This concludes the #NG15 launch. Cygnus will be berthed to the Unity nadir port with coverage starting at 6 a.m. EST, Monday, Feb 22.