A passenger spaceship that lost a bid for additional NASA funding may have new life ferrying passengers for Paul Allen's space startup, Stratolaunch Systems, company officials said on Wednesday.

Privately owned Sierra Nevada Corp is challenging NASA's September 16 decision to award contracts worth $6.8 billion for space taxi development and flights to competitors Boeing and Space Exploration Technologies, which is owned and operated by technology entrepreneur Elon Musk.

The U.S. General Accountability Office is expected to issue its ruling on the challenge, which was filed on Friday, by January 5, 2015.

Whatever the outcome, Colorado-based Sierra Nevada intends to continue developing its Dream Chaser space plane, a winged seven-person ship that resembles a miniature space shuttle.

On Wednesday, Stratolaunch Systems, a startup owned by Microsoft co-founder Paul Allen, said it is considering buying a three-person version of the Dream Chaser for its orbital space transportation system, currently under development in Mojave, California.

Stratolaunch is building a gigantic airplane that will serve as an airborne launch pad for putting satellites - and eventually people - into orbit.

The aircraft, which has a wingspan of 385 feet (117 meters) and will be powered by six 747-class engines, is about halfway finished, Stratolaunch Executive Director Charles Beames said at the International Astronomical Congress in Toronto.

Initially, the system is intended to deliver satellites weighing up to about 13,500 pounds (6,124 kg) into orbits between 112 miles and 1,243 miles (180 km and 2000 km) above Earth. A debut test flight is expected in 2018.

Instead of a satellite, the Stratolaunch airplane also could launch a Dream Chaser spaceship, which would be outfitted with an as-yet-unspecified upper-stage rocket motor.

"Dream Chaser seemed to be the logical way to go," Beames told reporters in Toronto. "We feel pretty good that we have enough analysis there. Paul just hasn't made a decision yet."

He said Allen is expected to make a decision on the project before the end of the year.