SL-4 R/B (15907)

COSPAR: 1985-060B | Alt Name: Soyuz-U 21-325 Blok-I

DECAYED

Image

Additional Sources

Launch Details

Launch Date

July 15, 1985

Launch Site

Tyuratam Missile and Space Complex

Launch Pad

LC31

Launch Vehicle

Soyuz-U

Orbital Elements

NORAD ID

15907

International Designator

1985-060B

Decay Date

7/24/1985

Basic Satellite Info

Name

SL-4 R/B

Alternative Name

Soyuz-U 21-325 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

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.

Besxar Semiconductor Pods Launch on Starlink 10-50 | KeepTrack Space Brief

SpaceX Falcon 9 launches Starlink 10-50 with two Besxar semiconductor manufacturing test pods. In-space fabrication experiment explores cost reduction for commercial payloads.

Space Brief 25 Apr 2025

Today's briefing covers the largest-ever spectrum sharing demo planned by the Pentagon, innovative strategies for drone deployment in the Air Force, and significant military procurement developments.

Space Brief 28 Apr 2025

Today's highlights include SpaceX's 250th Starlink mission, a key Senate vote for NASA's next administrator, and insights into satellite missions and movements.

Space Force Awards Counter-Surveillance Payload Contracts | KeepTrack Space Brief

Space Force RCO awarded SBIR contracts for radar-detection payloads to counter adversary surveillance of U.S. satellites. Follow-on miniaturization effort already planned.

The Day Humanity Gained New Eyes on the Sun

Fifteen years ago, NASA launched its most advanced solar observatory, revolutionizing our understanding of our star and transforming space weather prediction

X Report 18 Dec 2024

SpaceX achieves significant milestones with Starship and multiple launch missions, while Starlink connectivity expands through T-Mobile's beta program.

SpaceX Resumes Falcon 9 Launches After Investigating Upper Stage Anomaly

SpaceX successfully returns to flight with a Starlink mission, detailing the cause of the July 11 anomaly and implementing fixes to prevent future incidents.

Pentagon Pulls the Plug on GPS OCX | The $8 Billion Ground System That Never Worked

On April 17, 2026, the U.S. Space Force officially cancelled the Next Generation Operational Control System after sixteen years of development, cost overruns, and testing failures. The $8 billion program was supposed to unlock the military's encrypted GPS signal. Instead, the satellites are flying with capabilities the ground can't command.