Space Brief 30 Oct 2025
Today's brief explores rising investments in space with defense ties, potential Space Force-NRO coordination, and more, offering insight into current military and defense satellite dynamics.
SL-4 R/B (12584)
COSPAR: 1981-064B | Alt Name: Soyuz-U 53-477 Blok-I
DECAYED
Image
Additional Sources
Launch Details
Launch Date
July 7, 1981
Launch Site
PLMSC
Launch Pad
LC43/3
Launch Vehicle
Soyuz-U
Orbital Elements
NORAD ID
12584
International Designator
1981-064B
Decay Date
7/17/1981
Basic Satellite Info
Name
SL-4 R/B
Alternative Name
Soyuz-U 53-477 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
Unknown
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
Satellite Articles
View All Posts »Learn more about satellites and other related topics.
Starlink Mobile US Plan, Ship 40 Static Fire, X Report 27 Jun 2026
Starlink mobile service is planned for the US as SpaceX fires Ship 40's single Raptor in a prelaunch test, with 10,689 Starlink satellites working.
Space Brief 22 Nov 2024
Today's key topics include delays in Vulcan's national security launches, a significant network upgrade contract for the Space Force, and military interest in SpaceX's Starship.
SpaceX Lands $2.29B Space Force Contract, X Report 27 May 2026
SpaceX wins a $2.29 billion US Space Force contract for a military space data network, NASA adds 6 crew missions, and Starship V3 makes its first flight.
DAF Space Restructure Announced Within Days, PAE Leaders Named | KeepTrack Space Brief
Department of Air Force announces finalized Program Acquisition Executive structure within days, reshaping oversight of GPS, SBIRS, and Protected Tactical Satcom systems.
Space Brief 9 Apr 2025
Today's brief covers Blue Origin’s new defense launch contracts, the ISS launch of a Navy SEAL astronaut, Sierra Space’s GPS security advancements for the U.S. Space Force, and the Space Force's 'Orbital Watch' initiative.
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.
Starship V3 Targets May 19 Debut; FCC OKs $2.4B Spectrum Deal | KeepTrack X Report
SpaceX targets May 19 for Starship V3's first flight from Pad 2 as the FCC approves a $2.4B EchoStar spectrum deal for Starlink D2D.