AEHF-6 – Atlas V 551 (AV-086) – Canaveral SLC-41 – 26.03.2020 20:18 UTC

[tnt22]

Mar 26 21:43

Upper level winds have been verified acceptable for launch at 2:57 p.m. EDT (1857 UTC).

[tnt22]

Chris B - NSF @NASASpaceflight 9:52 PM - Mar 26, 2020

Polling to proceed out of the Built In Hold.

All GO!

(1:00)

[tnt22]

[tnt22]

[tnt22]

Hold, Hold, Hold!

Chris B - NSF @NASASpaceflight 9:58 PM - Mar 26, 2020

HOLD HOLD HOLD.

LC Switch Not Ready.

Back to T-4 mins. Two hour window.

(0:21)

[tnt22]

Mar 26 21:56
Hold

HOLD.

[tnt22]

Mar 26 21:58

Launch Conductor Scott Barney is guiding the launch team through steps to safe the rocket and pad systems following the unplanned hold called at T-minus 46 seconds. Meanwhile, engineers are examining the cause of the countdown stoppage.

[tnt22]

[tnt22]

Mar 26 22:03

Activities to safe the launch vehicle and ground support equipment are putting the Atlas V and Space Launch Complex-41 back into the same configuration as they were at the T-minus 4 minute hold point.

Today's available launch window extends to 4:57 p.m. EDT (2057 UTC) for liftoff to occur.

[tnt22]

Mar 26 22:08

The launch team has completed the countdown recycle of all systems. Engineers are troubleshooting what caused the countdown to be stopped and how to resolve the issue.

[tnt22]

Mar 26 22:11

Once the issue is resolved, mission management will establish a liftoff time. We do not have new time yet.

[tnt22]

Tory Bruno ✔@torybruno 10:11 PM - Mar 26, 2020

Ground hydraulics accumulator fault. Working it

[tnt22]

03/26/2020 22:41 Stephen Clark

While the Atlas 5 remains in an extended hold, launch crews are re-chilling the liquid oxygen transfer lines at the launch pad.

[tnt22]

Tory Bruno ✔@torybruno 10:32 PM - Mar 26, 2020

Cause understood. Working on a solution. Stand by.

[tnt22]

Tory Bruno ✔@torybruno 10:46 PM - Mar 26, 2020

Bad amplifier card on a ground system hydraulic pump controller.  Working on a solution

[tnt22]

03/26/2020 22:51 Stephen Clark

The launch team is uploading a new trajectory profile into the Atlas 5 rocket to take into account the latest upper level wind conditions over Cape Canaveral.

[tnt22]

Mar 26 23:02

After the hold, the launch team completed procedures to back out of the partially-completed terminal count. We are awaiting resolution of the issue before a new target launch time can be selected and the readiness polls reconducted at L-7 minutes.

[tnt22]

Обнадёживает...

Tory Bruno ✔@torybruno 11:04 PM - Mar 26, 2020

Looks like we might have a solution. Stand by

[tnt22]

Mar 26 23:06

The engineering team developed a troubleshooting test that proved successful in resolving the ground hydraulics issue. We are standing by to establish a new launch time today.

The available launch window remains open through 4:57 p.m. EDT (2057 UTC).

[tnt22]

Mar 26 23:08

NEW LAUNCH TIME has seen set for 4:18 p.m. EDT (2018 UTC).