SL-4 R/B (20351)

COSPAR: 1989-095B | Alt Name: Soyuz-U 39-971 Blok-I
DECAYED

Image
SL-4 R/B Satellite Image
Additional Sources
Launch Details

Launch Date

November 30, 1989

Launch Site

PLMSC

Launch Pad

LC16/2

Launch Vehicle

Soyuz-U

Orbital Elements

NORAD ID

20351

International Designator

1989-095B

Decay Date

12/3/1989

Basic Satellite Info

Name

SL-4 R/B

Alternative Name

Soyuz-U 39-971 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

10.47

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.

SpaceX Logs Record 165 Launches in 2025, X Report 1 Jan 2026

SpaceX Logs Record 165 Launches in 2025, X Report 1 Jan 2026

SpaceX number of launches in 2025: a record 165 orbital flights. Starlink added 4.6M customers across 35 new markets; new Vandenberg pad offered.

Space Brief 16 Sep 2025

Space Brief 16 Sep 2025

Today's brief highlights the impact of military spending and technology competition on the space economy, new satellite connectivity partnerships, and defense spending pledges in Europe.

X Report 25 Oct 2025

X Report 25 Oct 2025

SpaceX prepares for a record-setting launch of Starlink satellites, while Iridium faces challenges against SpaceX's expanding services.

Space Brief 23 Feb 2025

Space Brief 23 Feb 2025

SpaceX launches Starlink satellites from both coasts, while first 3D atmospheric map of an exoplanet reveals extreme weather patterns, and Starlink missions push total count over 8,000 satellites.

Space Brief 1 Dec 2025

Space Brief 1 Dec 2025

Today's brief covers China's latest classified satellite launch, breakups in orbital refueling experiments, exciting advancements in microsatellites, and SpaceX's remarkable strides in spaceflight.

Space Brief 3 Dec 2024

Space Brief 3 Dec 2024

Today's Space Brief highlights the U.S. Air Force's $48 million investment in testing reentry capsules, a Pentagon-backed GPS alternative, and the Space Force's quest for funding autonomy.

Artemis II Crew Sets Human Distance Record at Moon | KeepTrack Space Brief

Artemis II Crew Sets Human Distance Record at Moon | KeepTrack Space Brief

Artemis II crew surpassed Apollo 13's distance record during April 6 lunar flyby. Orion carried 4 astronauts—including Canadian Jeremy Hansen—farther from Earth than any humans.

Starlink 17-40 Adds 24 Sats from Vandenberg | KeepTrack X Report

Starlink 17-40 Adds 24 Sats from Vandenberg | KeepTrack X Report

SpaceX's Starlink 17-40 mission launches 24 satellites from Vandenberg SFB at 7:36 a.m. PDT, expanding the 10,705-satellite constellation.