With FUD:

Unlike Vulcan, which is still a paper rocket, and Falcon 9, which has yet to fly defense missions, Atlas V has 53 successful missions under its belt. This long history of reliability will be an attractive selling point for the government customer, which is intolerant of launch risk, especially when lofting payloads sometimes costing as much as $1 billion.

Furthermore, Atlas V has earned a reputation of being on time, a key requirement for some missions with very tight launch windows. Some government officials are concerned SpaceX has not consistently performed in optimal launch windows.

“Compared to starting with a clean-sheet launch system, upgraded launch pad and clean sheet engine, we believe that re-engining the Atlas V is the lowest cost, risk and schedule solution to getting the U.S. off of dependence on Russian engines,” King tells Aviation Week in an email. He notes that the company has been under contract to NASA for the past two and a half years developing and demonstrating kerosene-powered booster stages and engines. This work will provide lessons on the Atlas V re-engining project.

Here’s their problem, though:

Aerojet Rocketdyne officials have been openly frustrated by slow progress by the Air Force in crafting a strategy for a propulsion program. A traditional Pentagon contractor with less access to private funding, Aerojet Rocketdyne has been lobbying hard for government money to augment its work on the engine while propulsion for Falcon variants and the Vulcan are privately funded.

This means the Aerojet/Dynetics/Schafer team will likely rely on a more traditional government funding model to bring their design to fruition while ULA and SpaceX tap private cash at a time when defense spending is under pressure.

Led by the old guard of Griffin and King, it’s a thrashing dinosaur.

Here’s more at Reuters.