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
SL-4 R/B (19939)
COSPAR: 1989-031B | Alt Name: Soyuz-U 59-391 Blok-I
DECAYED
Image
Additional Sources
Launch Details
Launch Date
April 20, 1989
Launch Site
PLMSC
Launch Pad
LC43/3
Launch Vehicle
Soyuz-U
Orbital Elements
NORAD ID
19939
International Designator
1989-031B
Decay Date
4/24/1989
Basic Satellite Info
Name
SL-4 R/B
Alternative Name
Soyuz-U 59-391 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
46.69
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 25 May 2025
Today's brief covers crucial developments in satellite technology and operations, including new Starlink launches, groundbreaking satellite data on flood waves, and pivotal changes in South African telecom policy driven by Starlink.
SpaceX Starfall Reentry Capsule Debuts, X Report 23 Jun 2026
SpaceX Starfall reentry capsule debuted June 23: the 2,100 kg disk launched on a Falcon 9 from Cape Canaveral to demo cargo return from orbit.
X Report 28 Nov 2025
Today marks a significant milestone as SpaceX successfully launches another batch of Starlink satellites, boosting global connectivity efforts.
The Dog They Never Planned to Bring Home
On April 14, 1958, Sputnik 2 burned up over the North Atlantic, carrying the remains of a stray dog from Moscow who had been dead for five months. The Soviet Union told the world she survived for days. It took forty-five years for the truth to come out.
Space Brief 26 Oct 2025
Today's brief covers a new Space Force contract for advanced tracking systems, innovative debris removal strategies, pivotal new satellite launches, and significant updates in air quality tracking from orbit.
Space Brief 3 Mar 2025
Historic moon landing by Firefly Aerospace, Spanish Air and Space Force advances with new simulator, and spotlight on OneWeb's communication satellite.
Space Brief 16 Sep 2024
Highlights of the day include the Polaris Dawn mission's splashdown, advances in space traffic management, and intriguing astronomy insights from the cloud's edge.