Atlas valve booster scrubs launch of ViaSat-3 F2 satellite

Atlas Valve Booster Scrubs Launch of ViaSat-3 F2 Satellite

United Launch Alliance (ULA) postponed the Atlas 5 rocket launch scheduled for Wednesday night due to a valve issue that could not be fixed within the launch window. The rocket was set to carry a communications satellite for the California-based company Viasat.

Launch Delay Details

According to ULA, "an issue encountered while cycling the booster liquid oxygen tank valve during final checkouts" forced the team to delay the launch and aim for the following day. Liftoff from Space Launch Complex 41 is now planned for 10:16 p.m. EST (0316 UTC), the start of a 44-minute launch window.

Mission Overview

The rocket will launch eastward from Florida's Space Coast.
The 6-metric-ton satellite will be placed into a geosynchronous transfer orbit.
Deployment is expected nearly 3.5 hours after liftoff from Cape Canaveral Space Force Station.

Weather Forecast

The 45th Weather Squadron predicted a 95% chance of favorable weather for the launch window, with only a slight risk of interference from cumulus clouds. Launch weather officers noted,

“High pressure will bring fair weather to the Space Coast on both the primary and backup days. For the primary window, a ridge axis over Central Florida will develop light, onshore winds and partly cloudy skies.”

Rocket Configuration

ULA is using an Atlas 5 rocket configured as 551 for this mission.

Spaceflight Now will provide live coverage starting about an hour before liftoff.

Summary: The Atlas 5 launch of ViaSat-3 F2 was postponed due to a valve issue, with a new launch planned the next day amid favorable weather conditions and thorough preparations.

Spaceflight Now — 2025-11-06