ULA says it has all its ducts in a row for today’s Atlas V launch

An Atlas V 531 rocket with the NROL-101 payload on the launch pad is seen Monday before returning to the Vertical Integration Facility for additional payload environmental control system repairs/checkouts.
Super-telephoto view of the upper ECS (environmental control system) duct after repair on November 4, 2020.

Trevor Mahlmann for Ars
Close-up of the NROL-101 fairing artwork. The Elvish script translates to “Goodness Persists.”

Trevor Mahlmann for Ars
This is the first flight of Atlas V with the GEM-63 solid rocket booster. ULA aims to build flight experience before the GEM-63XL fly on Vulcan as early as next year.

Trevor Mahlmann for Ars

United Launch Alliance returns to one of its two main pads at Cape Canaveral Air Force Station Wednesday to try to break a string of recent launch scrubs due to various issues, mostly related to ground systems.

The company’s Atlas V rocket is scheduled to liftoff from Space Launch Complex-41 at 5:54pm EST (22:54 UTC), carrying a satellite for the National Reconnaissance Office. The mission is named NROL-101, and its final orbit is classified. There is a 70-percent chance of favorable conditions.

The venerable Atlas V rocket, which has flown 85 missions since its debut in 2002, will be testing new hardware with this flight. For the first time, the Atlas V will use solid-rocket boosters built by Northrop Grumman rather than Aerojet Rocketdyne. These GEM-63 boosters cost less than the booster previously used. United Launch Alliance plans to use an extended version of this booster, the GEM-63L, on its Vulcan rocket, which could make its first flight in a year or so.

Perhaps the biggest question heading into today’s launch attempt is whether the Atlas V rocket will get off the ground. This mission was originally scheduled to launch on Tuesday, but after a rollout on Monday, the company discovered a problem with an environmental control…