Commercial orbital complex developer Bigelow Aerospace is in the final stages of negotiating a deal with Lockheed Martin to provide a manned capsule and up to 50 Atlas V launches for crew and cargo by 2015.

The transportation deal will support Bigelow's planned orbital complex that is being marketed for use from 2012 to nations and private organisations.

Bigelow has already selected Lockheed's Atlas V 401 variant, with its 4m (13.1ft) fairing and a single engine-powered Centaur upper stage, for the 2010 and 2011 launches of its habitable Sundancer inflatable orbital spacecraft and its propulsion node module, respectively.

Bigelow's orbital complex concept calls for three inflatable modules and a propulsion node. Sundancer's ground test sister-module, Galaxy, is being built at the moment.

In late 2006 Bigelow announced it was in talks with Lockheed and the two are now in firm discussions for a contract for the 2010 and 2011 launches followed by six launches in 2012, 12 in both 2013 and 2014 and then 18 in 2015, in line with Bigelow's business plan.

"The capsule has to be determined at this time. Lockheed has a concept for a capsule. Our application is specifically for experienced astronauts and we will have our own training regime," says Bigelow.

This represents a change for Lockheed, which had said it would not involve itself in non-government work until it had delivered NASA's Orion crew exploration vehicle, for which it won the contract in 2006.

Lockheed is a member of the PlanetSpace-led team competing for NASA's Commercial Orbital Transportation Service demonstration programme's $175 million space act agreement. It is contributing technology to PlanetSpace's cargo and crew capsule.

Although NASA's Orbital Space Plane programme determined that the Atlas V could carry a manned capsule, with modifications, nothing has been done beyond that paper study.

Bigelow Aerospace has offered $760 million in funds for any company willing to develop a man-rated transportation system but the Lockheed talks do not include this. US space industry sources have informed Flight that Bigelow has circulated a request for proposals for its propulsion node. Bigelow declines to comment.