Specs
Launch date: July 23, 1999
Launch vehicle: space shuttle Columbia
Time to orbit Earth: 64 hours
Altitude: from 9,660 km (6,000 miles) to 139,000 km (86,500 miles)
Length (sun shade open): 45.3 feet
Width (solar arrays open): 64 feet
Satellite builder: TRW
Fast Fact: Chandra was deployed on the first shuttle mission commanded by a woman, Col. Eileen Collins.

These are two images of the crab nebula. The one on the left is an X-ray image taken by the Chandra; the one on the right is from an optical telescope. The X-ray image is only 40% of the size of the optical image, but as you can see, the two images show very different phenomena. Photo credits: X-ray - NASA/CXC/SAO; optical - Palomar Observatory.

The Chandra X-ray Observatory is currently in orbit around Earth, peering out into the universe in search of extremely high-temperature events in space. These events give off X-rays, which are a highly energized form of light that cannot be seen by human eyes. X-rays can't make it through the Earth's atmosphere, so for astronomers to study them, X-ray telescopes like the Chandra must be based in space. The Chandra collects X-rays, some from as far as ten billion light years away, and uses a high resolution camera (HRC) to interpret them into images. The Chandra also contains scientific instruments that can measure the strength and temperature of X-rays.

Because X-rays would be absorbed right into the dish-shaped mirrors typically used in telescopes that measure visible light, the Chandra contains barrel-shaped mirrors with reflecting surfaces that run almost parallel to the X-rays. The X-rays barely bounce off the mirrors and are focused onto a point about half the width of a human hair, where they are recorded and measured.

X-ray telescopes are important because they allow us to see events in space that would normally be invisible to us. High-energy events such as huge explosions, black holes and neutron stars can be seen in much greater detail with an X-ray telescope, and X-ray telescope images can add an extra dimension to objects in space that also give off visible light.

The Chandra, which is named after Nobel prize winner Subrahmanyan Chandrasekhar, orbits up to 200 times higher above Earth than the Hubble—about a third of the distance to the moon! Chandra is the third in NASA's series of four great observatories designed to explore the universe from Earth's orbit.

Chandra Links
Chandra X-Ray Observatory Center
This site, designed by the by the Smithsonian Astrophysical Observatory for NASA, features all the background information you could need on Chandra, as well as an online album of all Chandra images that have been released to the public. You'll also find some fun online games and ecards to send to friends and family. Visit the Chandra Chronicles pages for the latest Chandra news, online polls and a Chandra locator.

Chandra X-Ray Observatory News
The best feature on this site from NASA's Marshall Space Flight Center is the collection of video and audio footage available online. Watch interviews with Chandra scientists, video of Chandra being assembled and even animations of Chandra in action. The site also offers up-to-date news on Chandra's discoveries.

NASA's Great Observatories
To find out more about the Chandra, as well as about NASA's other three Great Observatories, check out this site from NASA's Space Infrared Telescope Facility, makers of the final great observatory, which will be launched in January 2003.