Space Brief 1 Mar 2025
Today's Space Brief covers reentries, the impact of NOAA dismissals on space weather tracking, a strategic academic partnership probing cosmic mysteries, and a newly unveiled space motto.
SL-4 R/B (21144)
COSPAR: 1991-016B | Alt Name: Soyuz-U-PVB 23-819 Blok-I
DECAYED
Image
Additional Sources
Launch Details
Launch Date
March 6, 1991
Launch Site
PLMSC
Launch Pad
LC16/2
Launch Vehicle
Soyuz-U-PVB
Orbital Elements
NORAD ID
21144
International Designator
1991-016B
Decay Date
3/17/1991
Basic Satellite Info
Name
SL-4 R/B
Alternative Name
Soyuz-U-PVB 23-819 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.
Mega-Constellations Are Set to Flood Earth's Orbit
We forecast how many satellites could be in orbit by 2030 and what capabilities we can expect.
The Day a Rocket Changed Space Policy Forever
Thirty years ago, a Chinese rocket veered off course two seconds after liftoff, destroyed a village, and triggered a political scandal that reshaped how the United States controls space technology to this day
The Day America Reached Orbit
Sixty-three years ago, John Glenn became the first American to orbit Earth, piloting Friendship 7 through three historic orbits that transformed the Space Race
Crew-11 Completes First-Ever ISS Medical Evacuation, SpaceX Sets Pad Record | KeepTrack X Report
Crew-11 astronauts splashdown off California in first-ever ISS medical evacuation. SpaceX sets pad turnaround record at Cape Canaveral with Starlink 6-98 deploying 29 satellites.
NASA Postpones Spacewalk Over Medical Concern, Sierra Space Delivers SDA Satellites Early | KeepTrack Space Brief
NASA delays first 2026 spacewalk due to ISS crew medical issue. Sierra Space completes SDA Tranche 2 satellite structures ahead of schedule. Space Force advances Handle 2.0 standardization.
SpaceX Preps Starlink 6-96 Launch, Starship TPS Testing Continues at Starbase | KeepTrack X Report
SpaceX readies Starlink 6-96 launch of 29 satellites from Cape Canaveral. Thermal Protection System evaluations underway at Starbase for next Starship prototypes. SpaceX IPO expected to reshape market.
China's Rocket Factory Finds a Second Gear
In 2024, China launched 68 orbital missions. In 2025, the number jumped to 97. In 2026, state media and Western analysts agree the target is 140 or more. Most of that growth is being driven by two state-backed mega-constellations, a half-dozen private launch companies hitting stride, and a deliberate national pivot toward commercial space. Beijing is no longer trying to catch SpaceX. It is trying to build an industrial base that outlasts one.