NASA's space shuttles are icons of American spaceflight, but the storied space planes retired for good after one final mission in July 2011.
<p>The shuttle Atlantis is launched <a href="http://www.space.com/12046-nasa-space-shuttle-final-flight-atlantis-sts135.html">NASA's final shuttle mission</a>, called STS-135, on July 8 at 11:26 a.m. EDT (1526 GMT) from the agency's Kennedy Space Center spaceport in Florida. Atlantis flew a 12-day mission to the International Space Station to deliver spare parts and supplies. It was the 135th and last mission for the shuttle fleet since flights began in 1981.
<p>Here's a look at five of the most patriotic shuttle missions ever flown:
The first space shuttle mission, STS-1 (Columbia), launched on April 12, 1981, kicking off three decades of the shuttle program. The mission came twenty years after the (former) Soviet Union won the first leg the space race by putting the first person in space, Yuri Gagarin. STS-1 was 54 hours long, during which the shuttle orbited Earth 37 times. [<a href="http://www.space.com/11345-photos-nasa-space-shuttle-1st-flight-sts1.html">Photos: NASA's First Shuttle Launch, STS-1</a>]
<p>As the most complex spacecraft ever, it's surprising to note that it was also the first U.S. manned space vehicle launched without an unmanned powered test flight. Because of this, NASA described the mission as "The boldest test flight in history."
During the Cold War, the United States kept fighting for new bragging rights in space adventures. A big step for the U.S. came in 1984, when Bruce McCandless II became the first human to make a free, <a href="http://www.space.com/12156-7-notable-space-shuttle-astronauts-countdown.html">untethered spacewalk</a> (using the Manned Maneuvering Unit) during STS-41B, and thus becoming the first true "human satellite."
In 1990, STS-31 set off with the sole mission of deploying the <a href="http://www.space.com/17-amazing-hubble-discoveries.html">Hubble Space Telescope</a> — the only telescope in orbit that is also designed to be serviced and repaired in space. Hubble is one of NASA's most successful and long-lasting science missions, and many Hubble observations have led to breakthroughs in astrophysics and have provided some of the most stunning photos of deep space, among those the iconic photos of the "Pillars of Creation" in the Eagle Nebula.
<p>Every 97 minutes, Hubble completes its orbit around Earth, moving at the speed of about 5 miles per second (8 km) — fast enough to travel across the United States in about ten minutes.
STS-114 was the first <a href="http://www.space.com/1346-nasa-returns-flight-discovery-reaches-orbit.html">Return to Flight mission</a> since the tragic loss of the space shuttle Columbia and its crew on Feb. 1, 2003. Two-and–a-half years were spent researching and implementing safety improvements for the orbiters and external tanks. Both the Discovery and Expedition 11 crews paid tribute to the Columbia crew and other <a href="http://www.lifeslittlemysteries.com/the-fallen-heroes-of-human-spaceflight-1535/">astronauts and cosmonauts who have lost their lives</a> in the human exploration of space.
<p>First scheduled for July 1, 2006, weather conditions postponed the <a href="http://www.space.com/2582-shuttle-discovery-reaches-orbit.html">STS-121 launch</a> to July 2. In a patriotic turn of events, that launch was also postponed, and the space shuttle ended up blasting off two days later, on Independence Day, giving a whole new meaning to patriotic firework celebrations.
<p>NASA retired its space shuttle fleet in 2011 after 30 years of service to make way for a new program aimed at deep space exploration.