EUTELSAT 172B
Europe's first high-power all-electric telecom satellite doesn't just sit above the Pacific - it got there on robotic arms and plasma thrusters, broke records doing it, and now keeps your airplane Wi-Fi running between LA and Tokyo.
SL-4 R/B (26750)
COSPAR: 2001-017B | Alt Name: Soyuz-U No. 674 Blok-I
DECAYED
Image
Additional Sources
Launch Details
Launch Date
April 28, 2001
Launch Site
Launch Pad
LC1
Launch Vehicle
Soyuz-U-PVB
Orbital Elements
NORAD ID
26750
International Designator
2001-017B
Decay Date
4/29/2001
Basic Satellite Info
Name
SL-4 R/B
Alternative Name
Soyuz-U No. 674 Blok-I
Type
Rocket Body
Status
Space Junk
Owner
RVSNR
Country
Russia
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
PROGT
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 23 Oct 2025
SpaceX continues to break records with its Falcon 9 missions while facing public scrutiny from Elon Musk regarding NASA's leadership. Meanwhile, satellite spectrum battles heat up as Lynk Global and Omnispace prepare to merge.
Starship V3 Targets May 19 Debut; FCC OKs $2.4B Spectrum Deal | KeepTrack X Report
SpaceX targets May 19 for Starship V3's first flight from Pad 2 as the FCC approves a $2.4B EchoStar spectrum deal for Starlink D2D.
Vulcan Grounding Could Last Months, Space Force Weighs Alternatives | KeepTrack Space Brief
ULA's Vulcan Centaur faces potential months-long stand-down. Space Force actively exploring payload reassignment and satellite operational life extensions to cover critical national security missions.
China's 75 Unusual GEO Maneuvers Flagged by CSIS | KeepTrack Space Brief
CSIS analysis identifies 75 unusual orbital maneuvers by Chinese GEO satellites over 10 years, consistent with military reconnaissance. Track GEO objects via KeepTrack.
Space Brief 25 Jun 2025
Today's highlights include the launch of a U.S. military satellite via SpaceX, a new French defense agreement for satellite services, and the Missile Defense Agency's successful ICBM target tracking with long-range radar.
Starship All 6 Engines Fire for 60 Seconds Before Flight 13 | KeepTrack X Report
SpaceX ignited all 6 Starship engines for a full minute at Starbase, while a Falcon 9 added 24 more Starlinks from Vandenberg on July 1.
The Day Humanity Gained New Eyes on the Universe
Forty-seven years ago, a revolutionary space telescope changed our view of the cosmos, pioneering international cooperation in space-based astronomy