This year was a big one for spaceflight, with governmental agencies and the private sector alike marking many key milestones.
During this watershed year, for example, NASA changed course to pursue new goals, the first private space capsule was launched into orbit and the International Space Station reached the 10-year mark of continuous human habitation.
Here's a brief rundown of the top six spaceflight
stories of 2010:
6. Space Station Celebrates 10 years of Continuous Occupation
The first live-in crew arrived at the International Space Station on Nov. 2, 2000. Since then, individuals have come and gone, but NASA and its international partners have been occupying the station uninterrupted. This year, they reached the 10-year anniversary of continous human presence on the orbital laboratory.
The fact that humanity has an established, decade-long presence on a space outpost 220 miles (354 kilometers) above Earth's surface is a big deal, NASA officials have said. It highlights the progress we've made in becoming a true spacefaring civilization, and it hints at bigger achievements to come.
Assembly of the station began in 1998 and is almost complete. The station, now nearly as long as a football field, has hosted more than 600 science and technology experiments over its lifetime, NASA officials have said. That number should rise substantially as the station transitions fully from its assembly phase to a fully-functioning research laboratory.
NASA plans to operate the space station until at least 2020.
5. First Successful Solar Sail Mission
For years, engineers have dreamed about powering a craft through space using nothing but the constant stream of photons from the sun. That dream finally became a reality this year with the launch of Japan's Ikaros spacecraft.
Ikaros lifted off on May 20 along with Japan's troubled Akatsuki Venus probe. In June, Ikaros successfully deployed its solar sail, which catches photons the way a ship's sail catches wind. The probe is now riding that photon wind, speeding toward the far side of the sun.
Ikaros is demonstrating the viability of solar sail technology, showing that probes can travel through space without relying on costly (and heavy) chemical propellant. Its success could lead to the development and launch of many more solar sail craft.
Japan's space agency, for example, is planning to launch a
solar sail mission to Jupiter around 2019 or 2020, officials have said.
4. Space Shuttle Program Winds Down
Three of the last-ever space shuttle missions lifted off this year, as NASA prepares to shut down the shuttle program in 2011.
All of the 2010 shuttle missions delivered key parts and supplies to the International Space Station, helping put the finishing touches on the orbiting outpost. On Feb. 8, the shuttle Endeavour blasted off on mission STS-130, ferrying a cupola with seven windows and a robotic control station.
The STS-131 mission of the shuttle Discovery launched April 5, bringing up racks for scientific experiments, as well as new sleeping quarters for the station's crew. Then Atlantis launched May 14 on the STS-132 mission to deliver the Russian-built module known as Rassvet. Rassvet provides additional storage space and serves as a new docking port for Russia's Soyuz and Progress spacecraft.
Discovery was supposed to make another trip to the station this year. Its STS-133 mission — which will deliver a storage room and a humanoid robot called Robonaut 2 — was slated to launch in November, but the discovery of cracks in the shuttle's external fuel tank pushed the mission back to February 2011.
3. SpaceShipTwo's First Flights
Space tourism made some big strides in 2010, as Virgin Galactic's suborbital space plane SpaceShipTwo took to the skies for the first time.
SpaceShipTwo will eventually ferry customers on joyrides to suborbital space, at $200,000 a pop. The space plane is designed to ride a mothership known as WhiteKnightTwo up to about 50,000 feet (15,240 meters); at that altitude, it will drop off, fire its own rocket engines and cruise up to the edge of space.
Virgin Galactic founder Richard Branson publicly unveiled SpaceShipTwo in December 2009. In March 2010, it made its first flight, staying firmly anchored to WhiteKnightTwo the entire time. Then, on October 10, the space plane flew free for the first time, detaching from WhiteKnightTwo and gliding back down to Earth.
Next up is a powered test flight, giving SpaceShipTwo the chance to fire its rocket motors. That could take place in early 2011. If all goes well, tourists could be flying to the edge of space by late 2011 or 2012, Virgin Galactic officials have said.
2. SpaceX Launches, Returns Dragon Capsule
NASA will need help getting cargo to the space station after the space shuttle fleet retires in 2011, and late this year a private company served notice that it's just about ready to step up.
On Dec. 8, Space Exploration Technologies (SpaceX) became the first commercial outfit to launch and re-enter a spacecraft from low-Earth orbit — something only six nations or governmental agencies had ever done before.
The California-based company lifted its Dragon capsule into space aboard its Falcon 9 rocket. Dragon orbited Earth twice, then splashed down in the Pacific Ocean off the coast of Mexico, where SpaceX crews retrieved it.
The mission was the first test flight under NASA's Commercial Orbital Transportation Services (COTS) program, which is designed to foster the development of private vehicles capable of carrying cargo and crew to the International Space Station. SpaceX holds a $1.6 billion NASA contract to make 12 supply flights to the station with Dragon through 2016.
Dragon's next test flight could take it directly to the space station, SpaceX officials have said. The capsule could begin making bona fide supply runs as early as next year.
1. NASA's New Space Plan
President Barack Obama's new plan for NASA, announced as part of his administration's 2011 budget request, calls for the space agency to shift gears, goals and priorities.
Gone, for example, is the Constellation program, which aimed to take astronauts back to the moon using Ares I and Ares V rockets, along with a spacecraft called Orion. Instead of Constellation, President Obama proposed that NASA work to get humans to an asteroid by 2025 and then to Mars by the mid-2030s.
NASA's new direction isn't responsible for mothballing the shuttle fleet in 2011; that plan has been in place since 2004. But the new plan looks outside of the space agency to fill the looming hole in low-Earth orbit transportation capability that the shuttle retirement will create.
In the short term, Russian Soyuz spacecraft will ferry cargo and crew to and from the International Space Station. But NASA's new plan aims to spur the development of American commercial space capabilities, with private companies — such as SpaceX and the Virginia-based outfit Orbital Sciences — soon shouldering much of the load.
NASA would then be free to concentrate on more ambitious projects to explore deeper space — the asteroid and Mars missions, for example.
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