NASA Nears Choice on Private Space Taxis for Astronauts
The Dream Chaser space plane designed by Sierra Nevada Space Systems is one of several private space taxis NASA is considering to launch American astronauts on round trips to the International Space Station. A decision is expected in late August or early September, NASA officials say.
Credit: NASA

The world could know by the end of the week which private spaceship is going to fly NASA astronauts to and from the International Space Station.

The space agency is about to give out its Commercial Crew Transportation Capability contract, or CCtCap, the last in a series of awards and agreements NASA began putting in place in 2010 to encourage the development of private space taxis for American astronauts.

While one winner is widely expected, it's possible that NASA will tap multiple companies, agency officials said. [SpaceX's Manned Dragon V2 Spaceship in Photos]

SpaceX CEO Elon Musk stands near the company's Dragon V2 manned space capsule during its public unveiling on May 29, 2014. The seven-person Dragon V2 space capsule is SpaceX's entry to fly NASA astronauts to the International Space Station.
SpaceX CEO Elon Musk stands near the company's Dragon V2 manned space capsule during its public unveiling on May 29, 2014. The seven-person Dragon V2 space capsule is SpaceX's entry to fly NASA astronauts to the International Space Station.
Credit: SpaceX

"NASA has not specified a set number of awards under CCtCap," NASA officials wrote in a blog post last week. "In late August or September, the agency will select the company or companies that will build an operational space transportation system."

Four companies remain in the running for the final contract — Blue Origin, Boeing, SpaceX and Sierra Nevada. Two of them are led by billionaires; Amazon.com founder Jeff Bezos heads Blue Origin, while SpaceX's CEO is entrepreneur Elon Musk.

Boeing's Crew Space Transport 100 (CST-100) capsule is shown atop an Atlas 5 rocket in this artist's illustration of the company's entry for NASA's commercial crew program. The CST-100 capsule is designed to ferry seven astronauts to and from low-Earth orbit.
Boeing's Crew Space Transport 100 (CST-100) capsule is shown atop an Atlas 5 rocket in this artist's illustration of the company's entry for NASA's commercial crew program. The CST-100 capsule is designed to ferry seven astronauts to and from low-Earth orbit.
Credit: Boeing

Blue Origin is developing a conical craft called the Space Vehicle, while Boeing and SpaceX are building capsules called the CST-100 and Dragon, respectively. Sierra Nevada's entry is a space plane named Dream Chaser.

NASA wants at least one of these vehicles to be up and running by 2017. The agency has relied on Russia to provide manned flights to and from low-Earth orbit since the retirement of the space shuttle fleet in 2011. NASA is currently paying about $70 million per seat to fly its astronauts aboard Russia's Soyuz capsule.

An artist's depiction of the secretive company Blue Origin's Space Vehicle, an orbital spacecraft for commercial manned spaceflights.
An artist's depiction of the secretive company Blue Origin's Space Vehicle, an orbital spacecraft for commercial manned spaceflights.
Credit: Blue Origin

NASA views its commercial crew program as a way to free up some of the agency's limited resources for other, more ambitious projects.

"By encouraging private companies to provide human transportation services to and from low-Earth orbit — a region NASA's been visiting since 1962 — the nation's space agency can focus on getting the most research and experience out of America's investment in the International Space Station," officials wrote in last week's blog post. "NASA also can focus on building spacecraft and rockets for deep-space missions, including flights to Mars in the 2030s."

The space agency also looks to the private sector to provide cargo services to the orbiting lab. NASA signed billion-dollar deals with Orbital Sciences and SpaceX to make unmanned supply runs to the space station, and both companies already have successful cargo missions under their belts. SpaceX uses a robotic version of Dragon for this purpose.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.