Today in history: April 12 a big day in space

It's Cosmonautics Day in the former Soviet Union, and also a day of note here in the United States.

Forty-six years ago today -- on April 12, 1961 -- a Russian Air Force pilot named Yuri Alekseyevich Gagarin blasted off from Baikonur Cosmodrome in the former Soviet republic of Kazakhstan, becoming "the Columbus of the Cosmos."

Riding aboard Vostok 1 with the call sign Cedar, Gagarin became the first human to travel into space and the first to orbit Earth. U.S. astronaut Alan Shepard would fly a suborbital jaunt 23 days later, but it wasn't until Feb. 20, 1962, when John Glenn flew aboard Friendship 7, that an American astronaut orbited Earth.

At liftoff, Gagarin shouted: "Poyekhali! (Off we go!)"

Born in a region west of Moscow to parents who worked on a collective farm, Gagarin whistled the tune "The Motherland Hears, The Motherland Knows" during his single circumnavigation of the planet.

For the curious, an MP3 of the song is here: sovietsong.mp3

Gagarin died when his MiG 15 crashed during a routine training flight in 1968.

Twenty years after Gagarin's groundbreaking flight -- on April 12, 1981 -- NASA's shuttle Columbia blasted off, marking the opening of a new era of spaceflight after a six-year gap in U.S. human expeditions beyond the grasp of Earth's gravity.

Legendary U.S. astronaut John Young, who flew during the Gemini program and also walked on the moon, commanded the 54-hour flight. His right-seater Robert Crippen piloted the mission. Crippen went on to fly three other shuttle missions and also served as KSC director during the 1990s.

NASA's Space Transportation System became the first to fly a reusable spacecraft -- the delta-winged shuttle orbiter. The most versatile space vehicle ever designed, the orbiter is capable of flying crews of seven astronauts as well as payloads weighing around 50,000 pounds.

You can read a NASA interview with Young and Crippen here: STS-1 Interview. Both now are retired.

NASA to date has launched 117 shuttle missions; another 13 to 16 are planned before the orbiter fleet is retired around Sept. 30, 2010.

In the history of human spaceflight, 456 people from 34 nations have flown into space, and 12 U.S. astronauts walked on the moon.

A moment of silence for those who have lost their lives in flight:

Russian cosmonaut Vladamir Komarov was killed on April 24, 1967, when the parachute on his Soyuz 1 spacecrafte failed.

Three cosmonauts -- Georgy Dobrovolsky, Victor Patsayev and Vladislav Volkov -- died June 29, 1971, when their Soyuz 11 spacecraft depressurized during atmospheric reentry.

Seven U.S. astronauts died when shuttle Challenger exploded 73.6 seconds after liftoff on Jan. 28, 1986. They included Francis "Dick" Scobee, Michael Smith, Eillison Onizuka, Robert McNair, Judith Resnik, Gregory Jarvis and Teacher-In-Space Christa McAuliffe.

Seven U.S. astronauts also were killed when the orbiter Columbia was destroyed during atmospheric reentry on Feb. 1, 2003. They included Rick Husband, William McCool, David Brown, Kalpana Chawla, Michael Anderson, Laurel Clark and Ilan Ramon.

Rest in peace.