Since its launch from the Kennedy Space Center aboard Space Shuttle Columbia (STS-93) on July 23, 1999, NASA’s Chandra X-ray Observatory has continued to change our view of the Universe—allowing us to see star clusters, black holes, supernovas, and stellar nurseries in exquisite detail. With Chandra, we continue to see what would otherwise be invisible to the human eye, as its delicate sensors scan the cosmos absorbing the X-ray emissions of immensely distant objects and phenomena.

NASA's premier X-ray observatory was named Chandra in honor of the late Indian-American Nobel laureate Subrahmanyan Chandrasekhar. He was known as Chandra—"moon" or "luminous" in Sanskrit—and was one of the foremost astrophysicists of the 20th century. He developed a new understanding of the life-cycle of massive stars, from formation to their endings as neutron stars or black holes. Chandrasekhar spent much of his career at the University of Chicago.

On July 23, 1999 at 12:31 a.m. EDT, under the command of Col. Eileen Collins, Space Shuttle Columbia lifted off Kennedy Space Center’s Launch Pad 39-B at Cape Canaveral, FL. Its mission: to carry NASA's Chandra X-ray Observatory into space. Chandra was the heaviest payload ever carried by the Shuttle and posed challenges and dangers to the astronauts in charge of getting the telescope safely into orbit. STS-93, as the mission is officially known, was the first commanded by a female astronaut.

At 45-feet long—about the size of a school bus—Chandra is the largest satellite the Space Shuttle ever launched. This made the take-off and landing scenarios more complex than usual, particularly as contingencies had to be planned to land with Chandra still on board. Astronauts Eileen Collins, Jeff Ashby, Cady Coleman, Steve Hawley, and Michel Tognini spent 5 days and 1.8 million miles orbiting the Earth to deliver Chandra to space, and safely touched-down late on the night of July 27, 1999.

When Eileen Collins (b.1956) joined the Air Force ROTC, women weren’t allowed to be pilots. That changed in 1976 while Collins was studying math and economics for her undergraduate degree. In 1990 she was selected to the astronaut corps. She trained at the Johnson Space Center in Houston, TX, and became the first woman to command a NASA space shuttle mission in 1999, when STS-93 brought Chandra to orbit.

Air Force Colonel, chemist, and astronaut Cady Coleman (b. 1960) helped deploy the Chandra X-ray Observatory into space in 1999, and then went on to spend over 180 days on the International Space Station in later missions. She is a renowned flautist and played multiple flutes in space. It was during Coleman’s undergraduate years at the Massachusetts Institute of Technology (MIT), when astronaut Sally Ride shook her hand after a lecture, that Cady first envisioned joining NASA’s astronaut corps.

Once deployed, Chandra went to work. Observational tasks are relayed to Chandra daily from the Operations Control Center (OCC) through NASA's Deep Space Network (DSN). After observing, Chandra transmits data on cosmic objects, plus information about the spacecraft, back to the OCC via the DSN about every eight hours. Engineers analyze spacecraft data for information on Chandra’s health, such as temperature and power. The cosmic observations are then transmitted to scientists around the world.

Earth’s atmosphere absorbs X-rays, the specific wavelengths of light that reveal the mysteries Chandra was designed to unlock. So Chandra and its ultra-precise mirrors and detectors–plus the electronics–had to be designed to survive a rocket launch and thrive in the hostile environment of space. NASA's Marshall Space Flight Center in Huntsville, AL tested Chandra’s unusual, sturdy, barrel-shaped mirrors, and continues to manage the successful Chandra program to this day.

Chandra's resolving power is like being able to read a stop sign from twelve miles away. Northrop Grumman was the primary development contractor that assembled and tested the Chandra X-ray Observatory for NASA. Here you can see the immense size of the instrument; a true challenge to pack into and deploy from the Space Shuttle.

The mirrors on Chandra are incredibly smooth. To picture the surface uniformity, imagine the topology of the state of Colorado, which varies from 0 feet to over 14,000 feet high at Pikes Peak. Now imagine scaling Chandra’s ultra-smooth mirrors up to match the size of Colorado. Even when scaled to this enormous size, the tallest peak on Chandra’s incredibly smooth mirror would STILL only reach 1 inch high. The Chandra telescope’s mirrors were ground and polished by BF Goodrich Optical.