The tip of the Boeing Delta II rocket with its MESSENGER spacecraft on top breaks through the billows of smoke below as it lifts off on Aug. 3, 2004 from Launch Pad 17-B at Cape Canaveral Air Force Station. MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) is on a seven-year journey to the planet Mercury. The spacecraft will fly by Earth, Venus, and Mercury several times to burn off energy before making its final approach to the inner planet on March 18, 2011. NASA
This artist's concept depicts a distant hypothetical solar system, similar to one discovered with the Spitzer Space Telescope. In this artist's rendering, a narrow asteroid belt filled with rocks and dusty debris, orbits a star similar to our own Sun when it was approximately 30 million years old (about the time Earth formed). Within the belt a hypothetical planet also circles the star. NASA/JPL-Caltech/T. Pyle (SSC)
Infant stars are glowing gloriously in this infrared image of the Serpens star-forming region, captured by NASA's Spitzer Space Telescope. The reddish-pink dots are baby stars deeply embedded in the cosmic cloud of gas and dust that collapsed to create it. A dusty disk of cosmic debris, or "protoplanetary disk," that may eventually form planets, surrounds the infant stars. NASA/JPL-Caltech/L. Cieza (UT Austin)
This infrared composite image from NASA's Spitzer Space Telescope shows the Andromeda galaxy, a neighbor to our Milky Way galaxy. Spiral galaxies tend to form new stars in their dusty, clumpy arms, while their cores are populated by older stars. This view also shows Andromeda's dust lanes twisting all the way into the center of the galaxy, a region that is crammed full of stars. NASA/JPL-Caltech/P. Barmby (Harvard-Smithsonian CfA)
Saturn's rings cast a dramatic shadow separating the blues and greens of the planet's northern hemisphere from the creamy pastels coloring the southern hemisphere. This mosaic combines 6 images – 2 each of red, green and blue spectral filters – to create this natural color view. The images were obtained with the Cassini spacecraft wide-angle camera on Dec. 30, 2008 at a distance of approximately 750,000 miles from Saturn. NASA/JPL/Space Science Institute
Astronaut James F. Reilly, STS-104 mission specialist, joins fellow astronaut and mission specialist Michael L. Gernhardt (not pictured) in using the new Quest Airlock for the first ever space walk to exit the International Space Station in 2001. The major objective of the mission was to install and activate the airlock, which completed the second phase of construction on the ISS. NASA
The afternoon sun casts shadows on space shuttle Endeavour's external fuel tank as workers remove the seal from the Ground Umbilical Carrier Plate, or GUCP, on the tank. Jack Pfaller/NASA
John Glenn, Jr. enters into the spacecraft Friendship 7 prior to MA-6 launch operations at Launch Complex 14 in 1962. Astronaut Glenn is entering his spacecraft to begin the first American-manned orbit around the Earth. NASA
Astronaut Edgar D. Mitchell, Apollo 14 Lunar Module pilot, moves across the lunar surface as he looks over a traverse map during extravehicular activity. Lunar dust can be seen clinging to the boots and legs of the space suit. NASA
This McDonnell-Douglas concept drawing depicts a robotic arm controlled by an astronaut. The arm is being used to maneuver a new addition to the space station into place. The robotic arm was to have been essential to building the space station in orbit. NASA
While Ukraine is not a NATO member, alliance members in Eastern and Central Europe fear they could be Russia's next targets, prompting the 28-nation bloc to seek a robust response.
ByJulie Pace, AP White House Correspondent
Confronted by a Kremlin-backed military offensive in Ukraine, President Barack Obama and Western allies will approve plans this week to position at least 4,000 troops and military equipment in Eastern Europe, bolstering NATO's security commitments to nervous member states near the Russian border.