NASA today released a status report on six firms' progress developing rockets and spacecraft that could launch astronauts to the International Space Station by 2016.
Read the report here.
The report says the companies have completed 21 of the 57 planned milestones under the second round of NASA's Commercial Crew Development program, which awarded four companies $270 million and includes unfunded agreements with two others.
"It's exciting to see these spaceflight concepts move forward," Phil McAlister, NASA's director of commercial spaceflight development, said in a statement.
The program's progress will be the subject of a U.S. House Committee on Science hearing scheduled at 10 a.m. Wednesday. Watch a live Webcast here.