Northrop Grumman’s Pegasus XL rocket, set to deploy the TacRL-2 mission in orbit, has been mentioned several times in previous editions of This Week in Rocket Launches but still hasn’t launched.

A Pegasus XL vehicle can lift 443 kilograms into low Earth orbit for $13.5 million. Launching a heavy satellite will require more lift. An Ariane 5G rocket can launch an 18,000-kilogram satellite ...