Deep Space Exploration

The idea of space travel in science fiction is hundreds of years old. Cyrano de Bergerac wrote about taking trips to the Moon and the sun in a space rocket in his story, "Voyages to the Moon and the Sun," published in 1662 - more than four centuries ago.

After the moon came exploration of the planets within our solar system, as in Garret Serviss's A Columbus of Space (1909). Edgar Rice Burroughs used psychic powers to send John Carter to Mars in "Under the Moon of Mars" (1912), but used a spaceship in his 1930s Venus novels.

E.E. Doc Smith's Skylark of Space (1928) was the first SF story to move into interstellar space exploration, along with Edmond Hamilton's "Clashing Suns" (1928) about an Interstellar Patrol. Others include L. Ron Hubbard's Return to Tomorrow (1950), Poul Anderson's Tau Zero (1967), and Robert A. Heinlein's Have Spacesuit-Will Travel (1958).

Reality has a long way to go before it catches up with science fiction, at least when it comes to space travel. We have sent unmanned spacecraft to Jupiter and beyond. But a manned space travel has not gone beyond the quarter of a million miles from here to the Moon.

Launched by NASA in 1977, two Voyager space left our solar system in 1989, and are now headed toward the boundary zone, known as the heliopause, where the Sun's influence ends and interstellar space begins. A signal sent from Earth to the Voyagers traveling at light speed takes 12 hours to reach the space craft.

What about visiting destinations beyond our own solar system? Even if we stay within our galaxy, the nearest star is about 10,000 times as far away as Pluto. To travel to such a destination within a human lifetime requires a spaceship that cruises at more than 10,000 miles a second - around 5 percent the speed of light - and can accelerate to this speed within 10 years.

Robert Heinlein's "Universe" (1941) was the classic early statement of the generation space ship. The concept was more firmly established in Murray Leinster's "Proxima Centauri" (1935) and A.E. van Vogt's "Far Centaurus" (1944). In George Zebrowski's Macrolife (1979), humankind travels through space in habitats made from hollowed out asteroids.