AT&T, Verizon, T-Mobile Unite vs Starlink D2D, X Report 18 May 2026
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SL-4 R/B (21612)
COSPAR: 1991-052B | Alt Name: Soyuz-U 12-152 Blok-I
DECAYED
Image
Additional Sources
Launch Details
Launch Date
July 23, 1991
Launch Site
PLMSC
Launch Pad
LC43/3
Launch Vehicle
Soyuz-U
Orbital Elements
NORAD ID
21612
International Designator
1991-052B
Decay Date
7/25/1991
Basic Satellite Info
Name
SL-4 R/B
Alternative Name
Soyuz-U 12-152 Blok-I
Type
Rocket Body
Status
Space Junk
Owner
RVSN
Country
USSR
Constellation
N/A
Related Satellites
Major Events
N/A
Summary
A rocket body, also commonly referred to as an upper stage or spent rocket stage, is the structural shell left behind after a rocket has delivered its payload to orbit. These large and often heavy pieces of space hardware can remain in orbit for years, posing significant collision hazards as part of the growing space debris problem. If left uncontrolled, rocket bodies have the potential to reenter Earth's atmosphere unpredictably, which can lead to falling debris in populated areas. Additionally, they risk colliding with operational satellites or the International Space Station, creating more debris and putting human life at risk.
Physical Characteristics
Length
6.7
Diameter
2.7
Span
6.7
Dry Mass
2350
Launch Mass
2350
Shape
Cyl
Radar Cross Section
10.38
Visual Magnitude
Unknown
Color
Unknown
Material Composition
Unknown
Technical Details
Payload
11S510
Purpose
Unknown
Mission
Unknown
Manufacturer
PROG
Life Expectancy
Unknown
Bus
Blok-I
Configuration
Unknown
Motor
Unknown
Equipment
Unknown
Power System
Unknown
ADCS
Unknown
Transmitter Frequency
Unknown
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