NASA landed on Mars, photographed distant worlds, added to the International Space Station, took part in a lunar science mission with India and made major progress toward returning astronauts to the moon as the agency celebrated its 50th birthday in 2008. Here on Earth, NASA researchers recorded the continued decline of Arctic sea ice, won awards for aviation breakthroughs, discovered the cause of storms that brighten the Northern Lights and helped create state-of-the-art swimsuits worn by Olympic gold medalists. Ten of the top accomplishments of America's space agency in its golden anniversary year are listed below:

INTERNATIONAL SPACE STATION NEARS COMPLETION ON 10TH ANNIVERSARY

NASA completed four space shuttle missions in 2008 to deliver modules and hardware to the International Space Station, allowing it to grow in size, volume and science capability. The flights also prepared the station to house six crew members for long-duration missions and to expand scientific exploration. The activation in 2008 of the European Space Agency's Columbus module and Jules Verne Automated Transfer Vehicle, as well as the Japan Aerospace Exploration Agency's Kibo laboratory, marked the beginning of new human spaceflight control centers in Germany, France and Japan that are working with existing control centers in the U.S., Russia and Canada. Nov. 20 was the 10th anniversary of the launch of Zarya, a Russian control module that was the station's first component. In the decade since Zarya arrived in orbit, the station has grown to become the largest spacecraft ever built. Its mass has expanded to more than 313 tons, and its interior volume is more than 25,000 cubic feet, comparable to the size of a five-bedroom house. The station now hosts 19 research facilities, including nine sponsored by NASA, eight by European Space Agency and two by Japan Aerospace Exploration Agency. http://www.nasa.gov/mission_pages/station/main/10th_main.html

PHOENIX WRAPS UP SUCCESSFUL MISSION TO MARS

NASA's Phoenix Mars Lander ceased communications Nov. 2 after successfully returning unprecedented science data to Earth. Launched Aug. 4, 2007, Phoenix safely touched down on Mars on May 25, 2008, at a site farther north than where any previous spacecraft had landed. Phoenix's soft landing on Mars was the first in 32 years and only the third in history. Cameras on Phoenix sent more than 25,000 images back to Earth. Preliminary science data shed light on whether the Martian arctic environment ever has been favorable for microbes; documented a mildly alkaline soil environment unlike any found by earlier missions; discovered small concentrations of salts that could be nutrients for life; located calcium carbonate; and detected perchlorate salt. The findings also advanced the goal of documenting the history of water on Mars. Phoenix exceeded its planned operational life of three to five months. Analysis of data from its instruments continues. http://www.nasa.gov/phoenix

ARES I ROCKET PASSES IMPORTANT DESIGN MILESTONE

NASA successfully completed the preliminary design review for the new Ares I rocket in 2008. Starting in 2015, the rocket will launch the Orion crew exploration vehicle, its crew of four to six astronauts, and small payloads to the International Space Station. The rocket also will be used as part of missions to explore the moon and beyond in coming decades. The preliminary design review is the first such milestone in more than 35 years for a U.S. rocket that will carry astronauts into space. The review examined the design of Ares I to confirm the planned technical approach will meet NASA's requirements for the fully integrated vehicle and ensure all of the rocket's components and supporting systems are designed to work together. NASA is preparing for the rocket's first test flight in 2009. Hardware for the test flight, including the forward skirt and the upper stage simulator, began arriving at NASA's Kennedy Space Center in Florida this fall. http://www.nasa.gov/ares

ARCTIC SEA ICE DECLINE CONTINUES

In September, Arctic sea ice coverage reached the second-lowest level recorded since the dawn of the satellite era, according to observations from the NASA-supported National Snow and Ice Data Center at the University of Colorado. While slightly above the record-low set in September 2007, this season further reinforces the strong negative trend in summer sea ice coverage observed during the past 30 years. In March, when the Arctic reached its annual maximum sea ice coverage during the winter, scientists from NASA and the data center reported that thick, older sea ice was continuing to decline. NASA developed the capability to observe the extent and concentration of sea ice from space using passive microwave sensors. http://www.nasa.gov/home/hqnews/2008/sep/HQ_08234_Artic_Sea_Ice.html

LIGHTING UP THE NIGHT

Researchers using a fleet of five NASA satellites discovered in 2008 that explosions of magnetic energy occurring a third of the way to the moon power substorms that cause sudden brightenings and rapid movements of the aurora borealis, or Northern Lights. The cause is magnetic reconnection, a common process that occurs throughout the universe when stressed magnetic field lines suddenly snap to a new shape, like a rubber band that has been stretched too far. These substorms often accompany intense space storms that can cause power outages and disrupt radio communications and global positioning system signals. Scientists are studying the beginning of substorms using a network of 20 ground observatories located throughout Canada and Alaska and five THEMIS, or Time History of Events and Macroscale Interactions during Substorms, satellites. http://www.nasa.gov/mission_pages/themis/auroras/themis_power.html

HUBBLE FINDS PLANET CIRCLING A DISTANT STAR

Astronomers announced in 2008 that NASA's Hubble Space Telescope has taken the first visible-light snapshot of a planet circling another star. Observations taken 21 months apart by the coronagraph on Hubble's Advanced Camera for Surveys showed the object orbiting around a star named Fomalhaut. The planet, called Fomalhaut b, is approximately 10 times the distance of Saturn from our sun. Estimated to be as much as three times Jupiter's mass, Fomalhaut b is located 25 light-years away in the constellation Piscis Australis, or the "Southern Fish." Fomalhaut has been a candidate for planet hunting since an excess of dust was discovered around the star in the early 1980s by NASA's Infrared Astronomy Satellite. The planet is brighter than expected for an object of three Jupiter masses. One possibility is that it has a Saturn-like ring of ice and dust reflecting starlight. Scientists theorize that the ring might eventually coalesce to form moons. http://www.nasa.gov/mission_pages/hubble/science/fomalhaut.html

NASA COMPLETES FIRST TESTS ON NEXT-GENERATION ROCKET ENGINE

NASA engineers successfully completed in 2008 the first series of tests in the early development of the J-2X engine that will power the upper stages of the Ares I and Ares V rockets. Ares I will launch the Orion spacecraft that will take astronauts to the International Space Station and on to the moon by 2020. Ares V will carry cargo and components into orbit for trips to the moon and later to Mars. NASA conducted nine tests of heritage J-2 engine components from December to May as part of a series designed to verify J-2 performance data and explore performance boundaries. Engineers at NASA's Stennis Space Center near Bay St. Louis, Miss., conducted the tests on a heritage J-2 "powerpack," which, in a fully assembled engine, pumps liquid hydrogen and liquid oxygen into the engine's main combustion chamber to produce thrust. The test hardware consisted of J-2 components used from the Apollo program in the 1960s through the X-33 program in the 1990s. http://www.nasa.gov/home/hqnews/2008/may/HQ_08116_power_pack_tests.html

NASA TEAM A RECIPIENT OF CELEBRATED COLLIER TROPHY

NASA was part of a team that received one of the most prestigious awards in aviation in June. Judges for the Robert J. Collier Trophy, awarded by the National Aeronautic Association, chose the Automatic Dependent Surveillance-Broadcast, or ADS-B, team of public and private groups to receive the 2007 honor. According to the selection committee, "ADS-B is a ground-breaking effort for next-generation airborne surveillance and cockpit avionics. Its implementation will have a broad impact on the safety, capacity and efficiency of the national airspace system." Researchers at NASA's Ames Research Center in Moffett Field, Calif., and NASA's Langley Research Center in Hampton, Va., were part of the extensive team that developed and tested ADS-B. http://www.nasa.gov/home/hqnews/2008/jun/HQ_08148_Collier_Trophy.html

NASA RETURNS TO THE MOON WITH INSTRUMENTS ON INDIAN SPACECRAFT

NASA has partnered with India to fly two science instruments aboard the country's first lunar explorer, Chandrayaan-1. The Indian Space Research Organization launched Chandrayaan-1 on Oct. 22 from Sriharikota, India. It entered lunar orbit on Nov. 8. NASA's Moon Mineralogy Mapper is surveying mineral resources of the moon, and the Miniature Synthetic Aperture Radar is mapping the moon's polar regions and looking for ice deposits in the permanently shadowed craters. Data from the two instruments is contributing to NASA's increased understanding of the lunar environment as the agency implements the nation's space exploration policy, which calls for robotic and human missions to the moon. http://moonmineralogymapper.jpl.nasa.gov/ and http://www.nasa.gov/mission_pages/Mini-RF/main/index.html

NASA TESTS HELP RECORD-BREAKING OLYMPIANS ROCKET THROUGH WATER

NASA know-how helped swimsuit designers create a body suit worn by an assortment of gold medalists and world record holders at the 2008 Summer Olympics in Beijing. Among the medalists wearing Speedo's LZR Racer were Americans Michael Phelps -- winner of more Olympic gold medals than any athlete in the modern era -- and Natalie Coughlin. Aerospace engineer Steve Wilkinson at NASA's Langley Research Center in Hampton, Va., played a role in developing the swimsuit by testing dozens of fabrics in Langley's 7-by-11-inch low speed wind tunnel. Warnaco Inc., the U.S. licensee of the Speedo swimwear brand, approached Langley to test fabric samples because the NASA center has researched drag reduction for aircraft and boats for decades. Just as reducing drag helps planes fly more efficiently, reducing drag helps swimmers go faster. Studies indicate viscous drag or skin friction is almost a third of the total restraining force on a swimmer. Wind tunnel tests measured the drag on the surface of the fabrics. Speedo's research and development team, Aqualab, took the results and used them to help create advanced "space-age" swimsuit designs. http://www.nasa.gov/topics/technology/features/2008-0813-swimsuit.html

NASA Television's Video File newsfeed will include items featuring these top stories beginning at 12 p.m. EST today, Dec. 15. For NASA TV streaming video, schedules, and downlink information, visit: http://www.nasa.gov/ntv

Visitors to NASA's Web site can vote on the top NASA story of the year at: http://www.nasa.gov/news/08_YIR_poll.html