SL-4 R/B
SL-4 R/B is a spent rocket body rather than an active satellite. SL-4 is associated with Soyuz-family rocket bodies, descendants of the R-7 architecture that has launched spacecraft for decades. What remains in orbit is a physical record of the launch itself - an object that once supplied the final energy needed to place a payload on its trajectory.
Object identity
- NORAD ID
- 39679
- COSPAR ID
- 2014-021B
- Operator
- Not listed
- Country
- Not listed
- Launch date
- Not listed
Immediate discovery
Why this satellite matters
A rocket stage becomes an orbiting object if it is released with enough horizontal velocity. Its later path can be modeled with the same two-body orbital equations used for an active spacecraft, while atmospheric drag gradually changes lower orbits.
Understanding the mission
Science and engineering ideas
A rocket stage becomes an orbiting object if it is released with enough horizontal velocity. Its later path can be modeled with the same two-body orbital equations used for an active spacecraft, while atmospheric drag gradually changes lower orbits.
Mission
Mission and purpose
The current public orbital catalog identifies this object, but verified mission-specific information may be limited. TransitSatellite will expand this page when authoritative information is available.
- A rocket stage becomes an orbiting object if it is released with enough horizontal velocity. Its later path can be modeled with the same two-body orbital equations used for an active spacecraft, while atmospheric drag gradually changes lower orbits.
Design
Engineering
A rocket stage becomes an orbiting object if it is released with enough horizontal velocity. Its later path can be modeled with the same two-body orbital equations used for an active spacecraft, while atmospheric drag gradually changes lower orbits.
Real orbital values
The mathematics
The current two-line element set reports approximately 15.4386 revolutions per day. Dividing 1,440 minutes by that value gives an estimated orbital period of 93.3 minutes.
Period
93.3 min
Representative speed
27,536 km/h
Representative altitude
442 km
Inclination
51.6°
Launch record
Launch and deployment
The orbital catalog lists the launch designator as 2014-021B. A fully sourced launch story, launch vehicle, deployment sequence, historical weather, and documented delays have not yet been added to this page.
Orbit
LEO orbit explained
Low Earth orbit is the region closest to Earth used by most crewed spacecraft, many science missions, Earth-observation satellites, and large constellations. Objects move quickly and commonly complete an orbit in roughly 90 to 130 minutes.
LEO can provide detailed Earth views, lower communications delay, and easier access than higher orbits, but it covers less area per spacecraft and is more affected by atmospheric drag.
Live TransitSatellite experience
See SL-4 R/B moving now
Open the live tracker to view its current calculated position, trajectory, orbital information, visibility tools, and Save and Share controls.
Learning
Questions to explore
- What can an orbit tell us before the mission is fully identified?
- Why are stable catalog identifiers important?
Evidence
Sources and data notes
Current identity and orbital elements come from CelesTrak’s public GP data. Calculated orbit values are derived from the current TLE and may change after catalog updates. Mission-history claims are added separately and require authoritative sources.
Catalog updated
Sep 17, 2026, 1:04 AM UTC
Story review
1970-01-01T00:00:00.000Z