Alliant Techsystems (ATK) announced today that it has reached an agreement with Rocketplane Kistler (RpK) to work together on the development of the K-1. ATK will become the lead contractor for the K-1 development effort, with responsibility for “Launch vehicle development, assembly, integration and test of the launch system, and will conduct launch and landing site development and launch vehicle preparation for the K-1,” according to the press release; ATK will also provide “critical” composite structures for the K-1 payload modules.

The role ATK is taking is largely one vacated by Orbital Sciences Corporation back in September, when Orbital backed out of a teaming and investment agreement with RpK that was made before the COTS awards were made. RpK signed Andrews Space a few days later to partially fill the role (including making an estimated $10-million investment that Orbital was to have provided), but at the COMSTAC meeting at FAA Headquarters last month RpK’s Will Trafton said that Andrews Space was not a “one-for-one” replacement for Orbital, and that ongoing negotiations (presumably, it now seems, with ATK) prevented him from discussing the issue in more detail.