X Report 3 Dec 2025
SpaceX completes multiple successful launches, enhancing its Starlink constellation with new satellites while resolving personnel issues related to Crew 12.
SL-4 R/B (12403)
COSPAR: 1981-036B | Alt Name: Soyuz-U 53-479 Blok-I
DECAYED
Image
Additional Sources
Launch Details
Launch Date
April 16, 1981
Launch Site
PLMSC
Launch Pad
LC41/1
Launch Vehicle
Soyuz-U
Orbital Elements
NORAD ID
12403
International Designator
1981-036B
Decay Date
4/19/1981
Basic Satellite Info
Name
SL-4 R/B
Alternative Name
Soyuz-U 53-479 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.
X Report 18 Nov 2024
SpaceX launches multiple satellites, prepares for Starship Flight 6, and exciting collaborations with AST SpaceMobile.
Space Brief 24 May 2025
Today's key space events include a milestone Falcon booster landing, advances in US military satellite operations, and a new missile defense initiative.
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.
Space Brief 30 Nov 2024
Today's highlights include SpaceX's dual satellite launches, a new Space Force contract with Raytheon, and Astroscale's upcoming OneWeb mission.
X Report 11 Apr 2025
SpaceX postpones a Starlink launch, Bell Canada targets Starlink subsidies, and questions around Elon Musk's involvement in a NASA appointment arise.
X Report 25 Jun 2025
SpaceX successfully launched the historic Axiom-4 mission to the ISS, marking a significant milestone in private space travel, while also expanding Starlink's reach into Vietnam's healthcare sector.
X Report 16 Sep 2025
SpaceX continues to make headlines with successful launches and advancements in satellite technology. Notably, a Falcon 9 rocket delivered an upgraded Cygnus spacecraft to the ISS amid a busy launch schedule this week.