6 Earth-Shattering Space Published 2 weeks ago Headlines From 2011

There may not have been any human exploration of Mars this year, but there certainly were plenty of galactic milestones in the last 12 months from NASA and international space programs. From the end of the space shuttle program that once had kids dreaming of becoming astronauts to the launch of a space robot to a possible planet twin, which of these 2011 headlines was your highlight of the year's space exploration?

• End of Shuttle Era — Over the Summer, NASA marked its 135th and final space shuttle mission. After a 30-year long program, the shuttle Atlantis was the last manned American spaceship of its kind to leave Earth. NASA is turning future missions to the exploration of other planets and deep space.

• Curiosity Mars Rover Takes Off — In hopes of learning more about the Red Planet, NASA launched the Mars Science Laboratory, with a rover named Curiosity on board in November. It will take about nine months before the Rover descends on our neighbor planet, where its high-tech components will analyze the Martian terrain.

• Earth-Like Planet Confirmed in the Habitable Zone — The team of NASA scientists working with the Kepler satellite confirmed the sighting of a planet in the habitable zone of a distant star. Kepler-22b, is 600 light years away from Earth, is larger in size than our planet, and orbits its sun-like star in just 290 days.

• Voyager Enters Interstellar Space — After 30 years of travel, the Voyager 1 spacecraft passed the boundaries of our solar system, inching closer to interstellar space. Launched from the US in 1977, Voyager 1 is now about 11 billion miles away from the sun.

Reminisce back to two more 2011 space events after the break.

• Researchers exit Mars simulation after 520 days — With dreams of humans one day landing on Mars at the top of scientists' wish lists, in November, a group of six men exited a container in Russia where they stayed in close quarters for 18 months to simulate the possible conditions of Mars exploration.

• Robonaut 2 — Robonaut 2 was launched aboard the space shuttle Discovery in February for transport to the International Space Station. Robonaut is used as the crew's right-hand droid performing tasks that might be too monotonous or dangerous for humans. Plus, it even tweets!