Space Brief 4 Apr 2025
Today's highlights include the release of a mystery object by Russian military satellites, SpaceX Fram2 mission insights, Amazon's upcoming satellite launch, and more.
SL-4 R/B (20074)
COSPAR: 1989-047B | Alt Name: Soyuz-U 59-398 Blok-I
DECAYED
Image
Additional Sources
Launch Details
Launch Date
June 16, 1989
Launch Site
Launch Pad
LC1
Launch Vehicle
Soyuz-U
Orbital Elements
NORAD ID
20074
International Designator
1989-047B
Decay Date
6/21/1989
Basic Satellite Info
Name
SL-4 R/B
Alternative Name
Soyuz-U 59-398 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
10.06
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.
Voyager 1
In November 2023, Earth's most distant spacecraft started speaking gibberish. Five months, one dead memory chip, and 30 billion miles of round-trip troubleshooting later, engineers got it talking again - using code written before most of them were born.
NRO Adds 3 New Partners to Commercial Imaging Program | KeepTrack Space Brief
NRO expands commercial imaging with HEO, SatVu, and Sierra Nevada. ChatGPT rolls out to 3 million military users via GenAI.mil. C-130J deliveries paused.
Space Brief 28 Sep 2025
Today's highlights include China's latest satellite launches, Blue Origin's expansion plans, and Purdue University's groundbreaking suborbital mission with Virgin Galactic.
The Evolution of Space Stations
A brief journey through the evolution of space stations, delving into Russia's Mir, the International Space Station, China's Tiangong, and envisioning the future of orbital habitats.
X Report 17 Feb 2025
Key insights on Starship development challenges and latest Starlink satellite status.
Block 3 Starship Prep Accelerates at Starbase | KeepTrack X Report
SpaceX accelerates Block 3 Starship pad work at Starbase as Russia preps Soyuz-5 debut alongside Falcon 9 internet satellite launches.
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.