The US Missile Defense Agency has developed a classified draft request for proposals as it tries to rapidly restart a stalled ballistic missile interceptor program designed to knock down North Korean missiles in space, Breaking Defense reported.

Dubbed the Next Generation Interceptor, the program will replace the US$1 billion Redesigned Kill Vehicle which was cancelled last month after Pentagon leadership came to the conclusion that the multi-billion dollar program just wouldn’t work.

The draft RFP was handed out to defense industry reps — on CDs — at an industry day on August 29, about two weeks after the RKV was terminated by Mike Griffin, the Pentagon’s research and engineering chief, the report said.

The RKV program was part of an ambitious technology effort helmed by Boeing — though Raytheon was building the Kill Vehicles — to replace the current Exo-Atmospheric Kill Vehicle.

Both are ground-based interceptors designed to defend the US mainland against long-range ballistic missile attacks.

The cancellation came as North Korea is in the midst of a series of short-range ballistic missile tests, which experts have said is likely assisting the country in its quest to build new, more reliable longer range missiles.

While the cancellation of the RKV was a surprise, issues had been mounting for the program for years.

The Missile Defense Agency said back in 2016 it expected the first RKV flight test by 2019, with fielding in 2020. The latest estimate, released earlier this year with the fiscal 2020 budget request, pushed the fielding date back to 2025.

But the program, Griffin insisted earlier this week at the annual Defense News conference, still provided the Pentagon with a return on its investment, which had already spent just under $1.2 billion in developmental costs, according to sources.

“The money, which was spent, did not go toward hardware which will be mothballed somewhere. It went towards the acquisition of knowledge, which will inform our future,” he said.

Boeing and Raytheon also won’t have to pay back any of the billion-plus dollars the government awarded them to do the work — money down the tubes, essentially.

“We terminated for convenience, not default,” Griffin added.

“There are no paybacks due, and we learned quite a lot that we’ll carry forward into the next-generation interceptor.”