Crowds gather and watch the launch of NASA space shuttle Endeavour from Kennedy Space Center on the beach May 16, 2011 in Cocoa Beach, Florida. (Photo by Roberto Gonzalez/Getty Images)

In this handout image provided by NASA, the space shuttle Endeavour is seen on launch pad 39a as a storm passes by prior to the rollback of the Rotating Service Structure (RSS) April 28, 2011, at Kennedy Space Center in Cape Canaveral, Florida. During the 14-day mission, Endeavour and the STS-134 crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts, including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre. Launch is targeted for April 29 at 3:47 p.m. EDT.

A helicopter pours water over a wildfire with the Space Shuttle Endeavour seen through heavy smoke in the background April 27, 2011 in Cape Canaveral, Florida. (Photo by Roberto Gonzalez/Getty Images)

Axel, a research prototype rover for exploring the Moon, Mars and other planets, is remotely driven over rocks as engineers from Jet Propulsion (JPL) and grad students from Caltech (California Institute of Technology) demonstrate its mobile over the steep and rocky grounds of the JPL Mars Yard on January 14, 2009 in Pasadena, California. The rover is capable of descending cliffs or into craters and returning by a cable tethered to its starting point. Development of the Axel rover is a point effort funded by NASA Exploration Systems Mission Directorate (ESMD) and lead by Principal Investigator Issa Newnas and Co-Investigator and Caltech professor of mechanical engineering bio engineering Joel Burdick. (Photo by David McNew/Getty Images)

(L-R), Pilot Gregory H. Johnson, European Space Agency astronaut Roberto Vittori, Mission Specialist Greg Chamitoff, Commander Mark Kelly, Pilot Gregory H. Johnson, Mission Specialist Michael Fincke, and Mission Specialist Andrew Feustel, participate in a Terminal Countdown Demonstration Test (TCDT), at the Kennedy Space Center, on April 1, 2011 in Cape Canaveral, Florida. The TCDT will culminate in a full dress rehearsal for the planned April 19th launch of Space Shuttle Endeavour’s final scheduled flight to the International Space Station before being retired. (Photo by Mark Wilson/Getty Images)

Gliding past the planet Jupiter, the Cassini spacecraft captures this awe inspiring view of active Io, Jupiter's third largest satellite, with the largest gas giant as a backdrop, offering a stunning demonstration of the ruling planet's relative size, April 20, 2001. The Cassini spacecraft itself was about 10 million kilometers from Jupiter when recording the image data. (Photo courtesy of NASA/Newsmakers)

“The Lockheed Martin X-33 is an unmanned, sub-scale technology demonstrator suborbital spaceplane developed in the 1990s under the U.S. government-funded Space Launch Initiative program”. – Wikipedia

Photo: An Artist's Rendering Shows How Nasa's X-33 Technology Demonstrator, A Cost-Cutting Fully Reusable Single-Stage-To-Orbit Space Vehicle, Will Look Upon Completion. The 67 Foot-Long, 278,600 Pound, Twin Engine Space Vehicle, Capable Of Reaching Speeds In Excess Of Mach 15, Will Lead To The Construction Of A 127 Foot-Long, 2,186,000 Pound Version With Seven Engines And A 50,000 Pound Payload Capacity Called The “Venturestar”. (Photo By Nasa/Getty Images)

Space Shuttle Discovery is towed from the shuttle landing facility to the orbiter processing facility at Kennedy Space Center on April 20, 2010 in Cape Canaveral, Florida. Discovery's landing attempts at KSC were scrubbed yesterday due to unacceptable weather conditions. Discovery is returning from a successful mission to the International Space Station. (Photo by Matt Stroshane/Getty Images). CAPE CANAVERAL, FL – APRIL 20 2010