Ku-Band
The frequency band that brought satellite TV to small dishes on rooftops and revolutionized direct-to-home broadcasting
CGRO (21225)
COSPAR: 1991-027B | Alt Name: Compton Observatory
DECAYED
Image
Additional Sources
Launch Details
Launch Date
April 5, 1991
Launch Site
Launch Pad
LC39B
Launch Vehicle
Space Shuttle
Orbital Elements
NORAD ID
21225
International Designator
1991-027B
Decay Date
6/4/2000
Basic Satellite Info
Name
CGRO
Alternative Name
Compton Observatory
Type
Payload
Status
Decayed
Owner
GSFC
Country
United States
Constellation
N/A
Related Satellites
Major Events
N/A
Summary
The CGRO (Compton Gamma Ray Observatory), also known as Alt Name Compton Observatory, was launched on April 5, 1991, from Launch Pad LC39B at the AFETR site using a Space Shuttle launch vehicle. It is owned by GSFC and manufactured by TRW. The satellite has dimensions of 7.6 meters in length, 4.6 meters in diameter, and spans 21.3 meters with its deployable components. Its dry mass was 13891 kg and it weighed 15622 kg at launch. Equipped with OSSE, ICT, EGRET, and 8 BATSE detectors for astronomy and gamma-ray observations, the satellite was powered by two deployable solar arrays and batteries. The CGRO's mission lasted between 6 to 10 years.
Physical Characteristics
Length
7.6
Diameter
4.6
Span
21.3
Dry Mass
13891
Launch Mass
15622
Shape
Box + 2 Pan
Radar Cross Section
39.0437
Visual Magnitude
Unknown
Color
Unknown
Material Composition
Unknown
Technical Details
Payload
Gamma Ray Observatory
Purpose
Astronomy, Gamma rays
Mission
Astronomy, Gamma rays
Manufacturer
TRW
Life Expectancy
6-10 years
Bus
GRO
Configuration
Unknown
Motor
MRE-5 x8
Equipment
OSSE, ICT, EGRET, 8 BATSE detectors
Power System
2 deployable solar arrays, batteries
ADCS
Unknown
Transmitter Frequency
Unknown
Satellite Articles
View All Posts »Learn more about satellites and other related topics.
Geosynchronous Orbit (GEO)
Understanding the unique orbital sweet spot that keeps satellites perfectly positioned above Earth
Space Brief 17 Jun 2025
Today's space brief covers key developments in satellite monitoring, U.K. defense contracts, and critical licensing reforms supporting national security.
Space Force Adds Relativity, Impulse to NSSL Phase 3 | KeepTrack Space Brief
Space Force expands National Security Space Launch Phase 3 with Relativity Space and Impulse Space joining Lane 1 competition. New entrants gain pathway to military payload contracts.
Space Brief 3 Sep 2024
Today's brief covers China's Yaogan-43 satellite launch, delays in ESA's BepiColombo mission, regulatory approval for OHB's KKR deal, and an upcoming Sentinel-2C launch.
Space Brief 4 Sep 2024
Today's brief highlights SpaceX's Starlink launch, the sale of Telesat's remote communications services, advancements in hypersonic missile tracking, and more on satellite imagery from the NGA.
The NASA Budget Proposal That Nobody Asked For (Again)
The White House wants to cut NASA's science budget nearly in half for the second year running. Administrator Jared Isaacman says it's enough. Congress already rejected this exact idea once.
Space Brief 5 Feb 2025
Today's briefing covers strategic military developments including missile defense proposals and board realignments, intertwined with rising space defense exports and autonomous launcher progress.