Regular maintenance visits to the telescope keep the steady stream of pictures rolling off the Hubble assembly line. In fact, NASA designed the telescope for servicing in space. Earthbound telescopes receive routine checkups to ensure they're functioning properly; they also receive regular upgrades when new advances in technology come around. Hubble is no different. That's why astronauts visit the telescope every few years, replacing older equipment and adding state-of-the-art science instruments. Future servicing missions are planned for 2001 and 2003. In 2001 astronauts will install the Advanced Camera for Surveys, which will capture an even wider swath of the sky and will yield even sharper pictures than Hubble's current wide-field camera.

IN THE BEGINNING

Orbiting space observatories like Hubble can trace their roots to the 1920s. While most scientists considered a space telescope as pure science fiction, some were seriously exploring the idea. Rocket pioneer Hermann Oberth, for example, speculated about orbiting telescopes in his writings, and scientist Robert Goddard began testing his newly invented liquid-fuel rockets. As these men were pushing the technological envelope, Edwin Hubble was unveiling new heavenly horizons. Before Hubble came along, astronomers had a restricted view of the universe, believing that the only galaxy in the heavens was our Milky Way. But Hubble used the latest technology, a powerful 100-inch telescope, and made some startling discoveries that changed our concept of the cosmos.

First, he observed that galaxies exist beyond the Milky Way. Then he found that those galaxies are flying away from each other, an observation that helped him determine that the universe is expanding.

< BACK | NEXT >