Hubble Telescope

Hubble Telescope

The Hubble telescope was named after Edwin P. Hubble, an American astronomer. Hubble is almost the size of a large school bus, but it can fit inside a space shuttle cargo bay. It has a length of 43.5 feet, a weight of 24,500 pounds, and a maximum diameter of 14 feet, but with a top speed of 17,500 miles per hour (5 miles per second), it only takes 97 minutes to complete one complete orbit around Earth.

The Hubble launched April 25, 1990 from the space shuttle Discovery. Its first image was taken May 20, 1990 of a start cluster. It has a mission duration of up to 20 years and has had servicing missions in December 1993, February 1997, December 1999, and February 2002. The Hubble can’t observe the Sun or Mercury because it’s too close to the Sun. The Hubble is sensitive to ultraviolet light. The most frequently observed celestial object is our planet, the Earth because scientists use the observations to make calibrations. The Hubble transmits about 120 gigabytes of science data every week. That's equal to about 3,600 feet of books on a shelf. The growing collection of pictures and data is stored on magneto-optical disks. The Sun is Hubble’s main energy source. It uses 2 twenty-five foot solar panels to use the Sun’s energy. In an average orbit, the Hubble’s power usage is 2,800 watts, which is equivalent to 28 one-hundred watt light bulbs. The Hubble has 6 nickel-hydrogen batteries with a storage capacity equal to 20 car batteries. In order to take images of distant, faint objects, the Hubble must be extremely steady and accurate. The telescope is able to lock onto a target without deviating more than 7/1000th of an arcsecond, or about the width of a human hair seen at a distance of 1 mile. This is possible because of Hubble’s 2 mirrors. The primary mirror has a diameter of 94.5 inches and a weight of 1,825 pounds, while the secondary mirror has a diameter of 12 inches and a weight of 27.4 pounds. The two mirrors are so perfect that the curve of the mirrors don’t vary more than 1/800,000ths of an inch. If Hubble’s primary mirror were scaled up to the diameter of the Earth, the biggest bump would be only six inches tall.

The Hubble telescope is an important scientific tool that will lead to important discoveries.