A new generation of American private spaceships is on the horizon, with their sights set on both orbital and suborbital space. Here's a look at 10 of the most promising crew-carrying commercial craft in development today.
FIRST STOP: XCOR's Lynx Space Plane
XCOR has already signed a deal with the Southwest Research Institute, a nonprofit organization based in Boulder, Colo., to fly some of its scientists and experiments to suborbital space.
The Lynx could be in flight-test operations by the end of 2012, accoring to XCOR officials. The company plans to charge $95,000 per seat when the space plane is up and running.
NEXT STOP: Virgin Galactic's SpaceShipTwo
SpaceShipTwo will be carried to an altitude of about 50,000 feet (15,000 meters) by a mothership known as WhiteKnightTwo. At that point, the spacecraft's rocket will kick on, boosting SpaceShipTwo up to 62 miles (100 kilometers) or so above Earth's surface.
Virgin Galactic has already collected deposits from more than 500 customers willing to pay $200,000 for a seat aboard SpaceShipTwo. Virgin officials say they hope to begin rocket-powered flight tests of SpaceShipTwo later this year, with commercial operations perhaps starting in 2013 or 2014.
NEXT STOP: Armadillo Aerospace's Vertical Lander
Armadillo's spacecraft will have room for two passengers. The space tourism firm Space Adventures is booking seats on the craft for $110,000 each. An Arizona man recently won a free flight on the vehicle in a contest sponsored by Space Adventures and Seattle's Space Needle, though the date of his trip has yet to be set.
NEXT STOP: Bigelow Aerospace's Private Space Labs
Bigelow has already launched two prototype test habitats into orbit, one in 2006 and one in 2007. The company's current module, the six-person BA 330, provides about 11,650 cubic feet (330 cubic meters) of usable volume. Bigelow envisions joining at least two BA 330s together in space.
The company has separate partnerships with Boeing and SpaceX, whose craft would ferry passengers to and from Bigelow's huge space hotels. Potential clients include space agencies, government departments and research groups.
Stratolaunch aims to send cargo and satellites into space initially, but it hopes to launch astronauts eventually as well. The firm is aiming for an initial test flight in 2015, with a first operational launch coming in 2016.
NEXT STOP: Liberty Rocket and Capsule
The company is teaming up with Lockheed Martin and European aerospace firm Astrium on the venture, which would use the 300-foot-tall (91-meter) Liberty rocket to blast a seven-passenger capsule into orbit.
ATK is aiming to begin test flights of the Liberty system in 2014, with the first manned mission expected to occur in late 2015, officials said. If all goes well, Liberty could be available to NASA and other potential customers by 2016.
NEXT STOP: Blue Origin's Secret Spaceship
The Space Vehicle is a biconic craft designed to carry seven passengers, or a mix of cargo and crew. Blue Origin is developing a reusable first-stage booster to help get the Space Vehicle to orbit relatively cheaply.
Company officials have said the Space Vehicle should be ready to begin commercial operations between 2016 and 2018. Blue Origin is also working on a suborbital spacecraft called New Shepard, which would be launched by a reusable propulsion module.
The company has received more than $25 million over the last two years from NASA's Commercial Crew Development (CCDev) program to help its efforts along.
NEXT STOP: Dream Chaser Space Plane
NASA's CCDev program granted Sierra Nevada more than $100 million in the past two years to aid in the Dream Chaser's development. Company officials say the space plane should be ready to begin operations by 2016.
NEXT STOP: Boeing's CST-100 Capsule
NASA's CCDev program has invested roughly $120 million in the CST-100, which is designed to seat up to seven passengers. The capsule, which measures 14.8 feet (4.5 meters) across at its widest point, utilizes proven technology from NASA's Apollo and space shuttle programs, Boeing officials have said.
The CST-100 is expected to make ground landings, though it will also be capable of splashdowns in emergency situations. Each capsule is designed to make 10 spaceflights, and the CST-100 could be operational by 2016.
NEXT STOP: SpaceX's Manned Space Dragon
The company is planning to launch an unmanned version of Dragon to the International Space Station this Saturday (May 19). The flight is a demonstration mission to see if Dragon and SpaceX's Falcon 9 rocket are ready to begin a series of 12 contracted robotic cargo runs to the station for NASA.
SpaceX is also working on a crewed version of Dragon, which would carry up to seven astronauts to the orbiting lab or deep space destinations such as Mars. SpaceX CEO Elon Musk has said he founded the company with the primary goal of helping make humanity a multiplanet species.
Last year, NASA's CCDev program gave SpaceX $75 million to help the company upgrade Dragon to carry crew.