Rain, winds scrub launch of ULA Atlas V with OA-4 Cygnus
CAPE CANAVERAL, Fla. — Weather conditions at Cape Canaveral Air Force Station’s Space Launch Complex 41 in Florida plummeted from providing a 60 percent chance of launch to just 10. This caused the flight of a United Launch Alliance Atlas V 401 rocket with Orbital ATK’s Cygnus spacecraft to be scrubbed.
The primary constraints involved with this decision were thick clouds with freezing temperatures and precipitation that violated the weather rules for launching.
The launch team tried repeatedly to get the Atlas off the pad repeatedly throughout the course of the 30-minute launch window – but the weather would not relent. The launch team officially concluded their efforts at 6:11 p.m. EST (23:11 GMT).
The writing had been on the wall as soon as the weather briefing had been conducted, however, with the weather officer stating that even the prediction of weather conditions providing only a 10 percent chance of favorable conditions for launch as being “optimistic”.
With that decision made, NASA, ULA, and Orbital ATK opted to try again 24 hours later with the window opening at 5:33 p.m. EST (22:33 GMT).
Conditions tomorrow are only predicted to be slightly better than they were this evening – with just a 30 percent chance of favorable conditions to support the launch.

Jason Rhian
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.