SL-4 R/B (10784)

COSPAR: 1978-036B | Alt Name: Soyuz-U No. 123 Blok-I
DECAYED

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

Launch Date

April 4, 1978

Launch Pad

LC1

Launch Vehicle

Soyuz-U

Orbital Elements

NORAD ID

10784

International Designator

1978-036B

Decay Date

4/6/1978

Basic Satellite Info

Name

SL-4 R/B

Alternative Name

Soyuz-U No. 123 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.

X Report 5 Dec 2025

X Report 5 Dec 2025

SpaceX made significant strides with the launch of 28 Starlink satellites while navigating regulatory challenges regarding rural broadband funding. Additionally, developments on the Crew Dragon mission continue to evolve with a change in cosmonaut assignment.

SpaceX S-1 Sinks Tesla 5%, Merger Talk Grows, X Report 2 Jun 2026

SpaceX S-1 Sinks Tesla 5%, Merger Talk Grows, X Report 2 Jun 2026

SpaceX IPO paperwork stokes Tesla merger predictions: the amended S-1 sank Tesla stock 5% in a day. Starlink stands at 10,492 working satellites.

Space Brief 25 Oct 2025

Space Brief 25 Oct 2025

Today's brief covers significant growth forecasts for global defense satellite communications, the integration of hypersonic missiles, cyber authority expansion in the Army, and more pivotal military developments.

Space Brief 13 Nov 2025

Space Brief 13 Nov 2025

Delve into the latest on military AI leadership debates, Wedgetail funding increases, and the Army's Short Range Reconnaissance Program advancements. Explore how these developments influence satellite tracking and defense initiatives.

York Space Goes Public at $629M, Cold War JUMPSEAT Spy Satellites Declassified | KeepTrack Space Brief

York Space Goes Public at $629M, Cold War JUMPSEAT Spy Satellites Declassified | KeepTrack Space Brief

York Space raises $629M in IPO to expand satellite manufacturing. NRO declassifies Cold War-era JUMPSEAT spy satellites. Lockheed to boost THAAD interceptor production from 96 to 400 per year.

X Report 21 Jun 2025

X Report 21 Jun 2025

Today's report highlights the causes behind a recent Starship explosion, a significant delay in Axiom-4's launch, and the ongoing tension surrounding SpaceX's market dominance.

Space Brief 19 Nov 2025

Space Brief 19 Nov 2025

Today's Space Brief covers the latest developments in space debris detection, Ursa Major's defense push, and SpaceX's Starlink launch. Additionally, insights into microreactors for military bases, US Cyber Command updates, and gravitational wave discoveries are highlighted.

Space Brief 22 Oct 2024

Space Brief 22 Oct 2024

Today's Space Brief highlights SpaceX's 99th operational launch, China's calibration satellite launch, and Space Force's role in a commercial space age. Special spotlight on the satellite YAOGAN 1!