NASA - National Aeronautics and Space Administration

Fact sheet number: FS-1999-09-111-MSFC
Release date: 08/99


NASAs newest space telescope, the Chandra X-ray Observatory, will allow scientists from around the world to obtain unprecedented X-ray images and spectra of violent, high-temperature events and objects to help us better understand the structure and evolution of our universe.

It will also serve as a unique tool to study detailed physics in a unique laboratory -- the universe itself one that cannot be replicated here on Earth.

Managed by NASAs Marshall Space Flight Center in Huntsville, Ala., Chandra is a sophisticated, state-of-the-art instrument that represents a tremendous technological advance in X-ray astronomy.

Did You Know?

• The Chandra X-ray Observatory is the worlds most powerful X-ray telescope. It has eight-times greater resolution and will be able to detect sources more than 20-times fainter than any previous X-ray telescope.

• The Chandra X-ray Observatory, with its Inertial Upper Stage and support equipment, is the largest and heaviest payload ever launched by the Space Shuttle.

• The Chandra X-ray Observatorys operating orbit takes it 200-times higher than the Hubble Space Telescope. During each orbit of the Earth, Chandra travels one-third of the way to the Moon.

• The Chandra X-ray Observatorys resolving power is 0.5 arc-seconds -- equal to the ability to read the letters of a stop sign at a distance of 12 miles. Put another way, Chandras resolving power is equivalent to the ability to read a 1-centimeter newspaper headline at the distance of a half-mile.

• If the State of Colorado were as smooth as the surface of the Chandra X-ray Observatory mirrors, Pikes Peak would be less than an inch tall.

• Another of NASAs incredible time machines, the Chandra X-ray Observatory will be able to study some quasars as they were 10 billion years ago.

• The Chandra X-ray Observatory will observe X-rays from clouds of gas so vast that it takes light more than five-million years to go from one side to the other.

• Although nothing can escape the incredible gravity of a black hole, not even light, the Chandra X-ray Observatory will be able to study particles up to the last millisecond before they are sucked inside.

• It took almost four centuries to advance from Galileos first telescope to NASAs Hubble Space Telescope an increase in observing power of about a half-billion times. NASAs Chandra X-ray Observatory is about one-billion times more powerful than the first X-ray telescope, and we have made that leap in slightly more than three decades.

Chandra Mission at a Glance: Chandra X-ray Observatory Mission Duration

General:

Chandra science mission: Approx. 5 yrs
Orbital Activation & Checkout period: Approx. 2 mos

Orbital Data:

Inclination: 28.5 degrees
Altitude at apogee: 86,487 sm
Altitude at perigee: 5,999 sm
Orbital period: 64 hrs
Observing time per orbital period: Up to 55 hrs

Dimensions:

Length (Sun shade open): 45.3
Length (Sun shade closed): 38.7
Width (Solar arrays deployed): 64.0'
Width (Solar arrays stowed): 14.0

Weights:

Dry: 10,560 lbs
Propellant: 2,153 lbs
Pressurant: 10 lbs
Total at launch: 12,930 lbs

Integral Propulsion System:

Liquid Apogee Engines: 4 engines (Only 2 used at a time)
Fuel: Hydrazine
Oxidizer: Nitrogen tetroxide
Thrust per engine: 105 lbs

Electrical Power:

Solar Arrays: 2 arrays, 3 panels each
Power generated: 2,350 watts
Electrical power storage: 3 batteries, 40-amp-hour, nickel hydrogen

Communications:

Antennas: 2 low-gain antennas
Communication links: Shuttle Payload Interrogator, Deep Space Network
Command link: 2 kbs per second
Data downlink: 32 kbs to 1024 kbs

On-board Data Capture:

Method: Solid-state recorder
Capacity: 1.8 gbs, 16.8 hrs

High Resolution Mirror Assembly:

Configuration: 4 sets of nested, grazing incidence paraboloid/hyperboloid mirror pairs
Mirror Weight: 2,093 lbs
Focal length: 33 ft
Outer diameter: 4 ft
Length: 33.5 in
Material: Zerodur
Coating: 600 angstroms of iridium

Attitude Control & Pointing:

Reaction wheels: 6
Inertial reference units: 2
Aspect camera: 1.40 deg x 1.40 deg fov

Science Instruments:

Charged Coupled Imaging Spectrometer (ACIS)
High Resolution Camera (HRC)
High Energy Transmission Grating (HETG)
Low Energy Transmission Grating (LETG)

Chandra Mission at a Glance: The Inertial Upper Stage

Dimensions:

Length: 17.0
Diameter: 9.25

Weights:

Stage 1 Dry: 2,566 lbs
Stage 1 Propellant: 19,621 lbs
Stage 1 - Total: 22,187 lbs
Stage 2 Dry: 2,379 lbs
Stage 2 Propellant: 6,016 lbs
Stage 2 - Total: 8,395 lbs
Total Inertial Upper Stage At launch: 30,582 lbs

Performance:

Thrust Stage 1: 46,198 lbs, average
Burn Duration Stage 1: 125 seconds
Thrust Stage 2: 16,350 lbs, average
Burn Duration Stage 2: 117 seconds

Chandra Mission at a Glance: Support Equipment

Weights:

Airborne Support Equipment: 5,365 lbs
Other: 1,285 lbs
Total Support Equipment: 6,650 lbs

Chandra Mission at a Glance: Total Payload

Weight:

Total Chandra/IUS/Support equipment at liftoff: 50,162 lbs

Length:

Total IUS/Chandra: 57.0

More Information

Links to the Chandra X-ray Observatory can be found at the following website:

http://chandra.nasa.gov/