X Report 30 Dec 2024
SpaceX wraps up the year with significant launches, including a record-setting Astranis deployment and Starlink missions signaling the year's end.
SL-4 R/B (15841)
COSPAR: 1985-052B | Alt Name: Soyuz-U 21-155 Blok-I
DECAYED
Image
Additional Sources
Launch Details
Launch Date
June 21, 1985
Launch Site
PLMSC
Launch Pad
LC41/1
Launch Vehicle
Soyuz-U
Orbital Elements
NORAD ID
15841
International Designator
1985-052B
Decay Date
6/30/1985
Basic Satellite Info
Name
SL-4 R/B
Alternative Name
Soyuz-U 21-155 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
43.68
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.
Space Brief 9 Jul 2025
Today's brief covers the U.S. Space Force's new international strategy, Northrop Grumman's Golden Dome project, and ULA's Vulcan launches, alongside military budget priorities.
X Report 14 Jul 2025
SpaceX successfully launched the Dror 1 satellite for Israel Aerospace Industries, marking another step forward in their launch capabilities.
X Report 9 Jan 2025
Exciting advancements from SpaceX as Starshield satellites prepare for launch, Starship Flight 7 faces a short delay, and new Starlink satellites enter orbit.
Space Brief 25 Sep 2025
Discover the latest developments in space defense, innovative satellite technologies, nuclear advancements in space travel, and strategic military updates.
X Report 7 Nov 2025
SpaceX successfully launched 28 Starlink satellites while EchoStar enhances its stake in the company through a $2.6 billion spectrum deal, amid growing demands for space domain awareness.
The Day Humanity Gained New Eyes on the Universe
Forty-seven years ago, a revolutionary space telescope changed our view of the cosmos, pioneering international cooperation in space-based astronomy
Space Brief 12 Jun 2025
Today's Space Brief covers major developments including the public debut of Voyager Technologies, advancements in defense by Sierra Space, and Pentagon's mega-constellation challenges. Also featured are new software selections by the Space Force and legislative actions on acquisition pilots.