

In one of the most detailed astronomical images ever produced, NASA's Hubble Space Telescope captured an unprecedented look at the Orion Nebula. This turbulent star formation region is one of astronomy's most dramatic and photogenic celestial objects. More than 3,000 stars of various sizes appear in this image.
An eruption of Sicily's Mt. Etna is seen in this satellite photo. A sulfur dioxide plume (in purple) originates form the summit, drifting over the city of Catania, and continuing over the Ionian Sea.
A new chapter in space flight began in July 1950 with the launch of the first rocket from Cape Canaveral, Florida: the Bumper 2. Shown above, Bumper 2 was an ambitious two-stage rocket program that topped a V-2 missile base with a WAC Corporal rocket. The upper stage was able to reach then-record altitudes of almost 250 miles, higher than even modern Space Shuttles fly today.
Astronaut Jeffrey N. Williams, Expedition 13 NASA space station science officer and flight engineer, is photographed during a productive 5 hour, 54 minute excursion that he shared with European Space Agency astronaut Thomas A. Reiter in 2008.
In this ASTER image, the features that look like folded material are carbonate sand dunes in the shallow waters of Tarpum Bay, southwest of Eleuthera Island in the Bahamas. The sand making up the dunes comes from the erosion of limestone coral reefs, and has been shaped into dunes by ocean currents. This image was acquired on May 12, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite.
A nuclear thermal rocket fires upon arrival in the vicinity of Mars to insert the transfer vehicle into orbit in this artist's concept. Nuclear propulsion can shorten interplanetary trip times and can reduce the mass launched from Earth. As the primary transfer propulsion system, the spaecraft's reactor would remain inactive until departure from Earth orbit. This artwork was done for NASA by Pat Rawlings, of SAIC.
Astronaut David R. Scott holds maneuvering unit while suspended in a weightless state during extravehicular activity (EVA) training in a C-135 Air Force plane.
Astronaut James B. Irwin, lunar module pilot, uses a scoop in making a trench in the lunar soil during Apollo 15 extravehicular activity. Mount Hadley rises approximately 14,765 feet above the plain in the background.
The first ground experimental nuclear rocket engine (XE) assembly, (l.), is shown here in 'cold flow' configuration, as it makes a late evening arrival at Engine Test Stand No. 1 at the Nuclear Rocket Development Station, in Jackass Flats, Nevada in 1967. Cutbacks were made in response to a lack of public interest in human spaceflight in the early 1970s, after the end of the space race and the Apollo Moon landing. Eventually NERVA lost its funding, and the project ended in 1973.
The Global Hawk is a robotic plane that can fly autonomously to altitudes above 60,000 feet -- twice as high as a commercial airliner -- and as far as 11,000 nautical miles -- half the circumference of Earth. Operators pre-program a flight path, and then the plane flies itself for as long as 30 hours, staying in contact through satellite and line-of-sight communications to the ground control station at NASA's Dryden Flight Research Center in California's Mojave Desert.