After the Shuttle:SpaceX Prepares For ISS Demonstration Mission

Good progress is being made in the successor to the space shuttle program,even as the shuttles are being retired to museums.On May 7,NASA contractor SpaceX is set to launch its unmanned Dragon spacecraft on its Falcon 9 rocket toward the International Space Station.According to NASA,this date now appears unlikely,however,because of a software problem.A firm date will be announced when the issue is resolved.The spacecraft and rocket were successfully sent into low earth orbit in 2010-the first time a commercial entity had achieved low earth orbit,or LEO.
On this mission,the goal is to rendezvous with the ISS.At that point,the ISS will grapple the Dragon,which is a capsule atop a module,draw it close with its robot arm and dock with it.The ISS astronauts will enter the Dragon,retrieve 1200 pounds of cargo,and insert a return load into the Dragon.
The Dragon spacecraft will undock,reenter earth's atmosphere and splash down.The spacecraft and its return cargo are then to be retrieved.Should this mission succeed,SpaceX will begin regular resupply missions to the ISS under its 12 mission contract with NASA that has a renewal option.
SpaceX was founded in 2002 by South African native Elon Musk,a noted engineer and billionaire entrepreneur,who cofounded PayPal.
Another NASA contractor,Orbital Sciences,is to conduct an unmanned demonstration mission with its Cygnus spacecraft later this year.Once the cargo missions are underway and further testing is completed,manned low earth missions with NASA astronauts in commercial spacecraft are slated to begin.SpaceX and Boeing are vying for the manned LEO mission contract.
The low earth orbit contractors allow NASA to husband its resources for deep space exploration with the new Space Launch System and Orion Multi-Purpose Crew Vehicle,which are to be capable of taking astronauts to the asteroids and Mars,as well as the Webb Space Telescope,successor to the Hubble.Initial testing of the SLS and MPCV have been going well.The first launch of the SLS is planned for 2017.
Orbital Sciences(ORB),Boeing(BA)