Fact Sheet: August 29, 1997

Overall Specifications

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Size	45.3 feet long x 64.0 feet wingspan (fully deployed)
Weight	10,160 pounds
Orbital Data	Inclination: 28.5 degrees Perigee altitude: 10,000 kilometers ApogeApogee altitude: 140,000 kilometers Ascending node: 200 degrees Argument of perigee: 270 degrees
On-orbit life	> 5 years

Spacecraft System

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Electrical Power	Two 3-panel, silicon solar arrays provide 2350 watts of power (End of Life) Three 40 ampere-hour nickel hydrogen batteries supply power in eclipse
Antennas	Two low-gain, conical log sprial antennas provide spherical coverage
Frequencies	Transmit 2250 megahertz (MHz) Receive 2071.8 MHz
Command Link	2 kilobits persecond (kbps)
Data Recording	Solid-state recorder; 1.8 gigabits (16.8 hours) of recording capacity
Downlink Options	Selectable rates from 32 to 1024 kbps Downlink data includes pre-recorded engineering and science instrument data interleaved with real-time data
Downlink Operations	Data downloaded to Earth typically every 8 hours
Contingency Mode	32kbps
Safing	Autonomous operation No ground intervention required to safe against any single fault

Telescope System

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High Resolution Mirror Assembly	4 sets of nested, grazing incidence parabaloid/hyperboloid mirror pairs Mirrors are each 83.3 cm long, constructed of zerodur material, polished to better than 7 angstroms root-mean-square (RMS) micro rougness, covered with 600 angstrom iridium coating Set of mirrors weighs 2104 pounds Focal Length: 10 meters Outer diameter: 1.2 meters Field of view: 1.0 degree diameter Unobscured clear aperture > 1136 sq. cm
Altitude Control	6 reaction wheel control 2 inertial reference units, each with two (2) two-degrees of freedom dry-tuned gyros updated autonomously with aspect camera data
Aspect Camera	1.40o x 1.40o field of view
Pointing Stability	0.25 arcsec (RMS) radius over 95% of all 10 second periods
Pointing Accuracy	30 arcsec 99% of viewing time

Science Instruments

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Advanced Charged Coupled Imaging Spectrometer (ACIS)	Provides simultaneous time-resolved imaging and spectroscopy Uses two CCD arrays, one for imaging, one for spectroscopy Imaging resolution is 0.5 arcsec over spectral range of 0.2 to 10 keV
High Resolution Camera (HRC)	Uses large field-of-view imaging micro-channel plates to detect X-ray photons Provides highest spatial resolution of any instruments on Chandra satellite Angular resolution <0.5 arcsec over the field of view 31 x 31 arcmin over the spectral range of 0.1 to 10 keV
High Energy Transmission Grating	Designed to be inserted into focused X-ray beam Contains 336 diffraction gratings Provides spectral resolution (E/E) of 60-1000 over the energy range 0.4 to 10 keV
Low Energy Transmission Grating	Designed to be inserted into focused X-ray beam Provides spectral resolution (E/E) of 40-2000 over the energy range 0.09 to 3 keV

Science Instrument Module

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Structural support for Advanced Charged Coupled Imaging Spectrometer and High Resolution Camera (HRC) Thermal Environment for ACIS and HRC Positions either ACIS or HRC into focal plane Provides focus adust for ACIS and HRC

Information provided by NGST, the prime contractor for Chandra

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