Last Friday NASA announced that the space agency and ATK would announce an agreement this Tuesday “that could accelerate the availability of U.S. commercial crew transportation capabilities”. (The announcement was originally going to be only available to media calling into a telecon line, but NASA said Monday the announcement will be on NASA TV at 3 pm EDT.) The announcement has generated various degrees of glee or despair, depending on one’s opinions about ATK’s work on solid rocket motors it has proposed for its Liberty rocket and is seeking to have incorporated into NASA’s Space Launch System (SLS) heavy-lift rocket.

What seems likely to be announced tomorrow, though, is some kind of unfunded Space Act Agreement that is part of NASA’s second-round Commercial Crew Development (CCDev) program. NASA already has one such unfunded CCDev-2 agreement, with United Launch Alliance (ULA); when that agreement was announced in July, NASA administrator Charles Bolden said that it “may speed the development of a commercial crew transportation system for the International Space Station”, language similar to the announcement last week. Given that the funded CCDev-2 awards focused on spacecraft development, unfunded agreements allow companies like ULA and ATK to keep their launch vehicle efforts on track, although they get no funding from NASA.

The announcement comes just after ATK performed the third successful test-firing of its five-segment solid rocket motor, originally intended for the Ares 1 and Ares 5 but now proposed for Liberty and SLS. An unfunded CCDev-2 award would help ATK keep the Liberty vehicle on track. There’s one problem, though: right now there’s no obvious commercial crew customer for Liberty. Of the four funded CCDev-2 vehicle developers, three (Blue Origin, Sierra Nevada, and, most recently, Boeing) have selected ULA’s Atlas 5, while SpaceX, not surprisingly, is sticking with its own Falcon 9 rocket. Unless another company enters the commercial crew competition down the road, or one of ULA’s customers have second thoughts, Liberty may remain on the outside looking in.