SpaceX's Falcon 9 rocket and Dragon space capsule are seen atop a launch pad, fully fueled, at Cape Canaveral Air Force Station just after aborting an attempted launch on May 19, 2012 at 5 a.m. ET.
A SpaceX Falcon 9 rocket stands topped with an unmanned Dragon space capsule - the first commercial spacecraft ever to launch to the International Space Station - on May 17, 2012. The rocket and Dragon are due to launch on May 19, 2012 from Cape Canaveral Air Force Station, Florida.
Clara Moskowitz, SPACE.com Assistant Managing Editor, stands in front of SpaceX's Falcon 9 rocket. It is set to launch the Dragon cargo capsule to the International Space Station on Sunday, May 20, 2012.
SpaceX's Falcon 9 rocket carrying the Dragon cargo capsule stands on the launch pad at Cape Canaveral. Image taken May 18, 2012.
SpaceX's first Falcon 9 rocket to launch an unmanned Dragon capsule to the International Space Station stands atop its launch pad at Cape Canaveral Air Force Station, Fla., one day before its May 19, 2012 launch.
Falcon 9 Rocket and Dragon Spacecraft rolls to launch pad in May 2012.
Falcon 9 Rocket and Dragon Spacecraft rolls to the launch pad in May 2012.
COTS 2 mission patch.
SpaceX's Falcon 9 rocket carrying the Dragon cargo capsule stands on the launch pad at Cape Canaveral. Image taken May 18, 2012.
SpaceX's Falcon 9 rocket carrying the Dragon cargo capsule stands on the launch pad at Cape Canaveral. Image taken May 18, 2012.
SpaceX's Dragon capsule is loaded with cargo to bring to the International Space Station. Launch is planned for March 20, 2012.
This still image from an animated video shows SpaceX's Dragon capsule close to berthing at the International Space Station.
A still from an animated video shows an artist's impression of SpaceX's Dragon capsule at the International Space Station.
This still image from an animated video shows SpaceX's Dragon capsule in orbit.
This week the Dragon spacecraft was mated to the Falcon 9 rocket in SpaceX’s hangar in Cape Canaveral, FL.
The Dragon spacecraft being rotated before it is mated to the Falcon 9 rocket in SpaceX’s hangar in Cape Canaveral, FL.
SpaceX engineers prepare for the launch at SpaceX’s launch control center in Cape Canaveral, FL.
SpaceX tweeted on April 21, 2012: "Earlier this month we worked with @NASA to load cargo into Dragon in advance of our upcoming demo flight."
A photo of SpaceX's Falcon 9 rocket during a March 1 launch readiness test at its Cape Canaveral launch pad.
A photo of SpaceX's Falcon 9 rocket during a March 1 launch readiness test at its Cape Canaveral launch pad.
This NASA illustration shows the Dragon spacecraft approaching the ISS. The mission is scheduled for May 2012.
SpaceX's first Falcon 9 rocket launching toward the International Space Station ignites its nine main engines briefly in this NASA photo shortly before aborting the launch try on May 19, 2012 due to an unexpected engine sensor reading. The Falcon 9 rocket will now launch the Dragon cargo capsule to the space station on May 22.
