Tundra (EKS / Kupol)

Missile early warning satellite constellationIn servicePending verification

Also known as: EKS, Kupol, 14F142

SpaceRUS

Identification silhouette. Not drawn to scale between entries.

Fact cardConfidence · Source

System

TypeMissile early warning satellite constellation

Alternative designationsEKS, Kupol, 14F142

ProliferationOrigin country only

Satellites6Kosmos 2510 (2015) to Kosmos 2563 (2022)Med^[1]

First launch2015Med^[1]

Orbit

Orbit regimeHEO (Molniya)Med^[1]

Orbit1,626 km × 38,552 km, 63.4° (first satellite)Med^[1]

Design life7.5 yearsMed^[1]

Catalogued on orbit6Payloads with current element sets in the public catalog, active or not.High^[2]

Active (CelesTrak)6Count in the CelesTrak active satellites list, which estimates operational status.Med^[2]

Perigee1,110–3,211 kmActive satellites per CelesTrak, element epoch about 2026-11-08.High^[2]

Apogee37,155–39,259 kmActive satellites per CelesTrak, element epoch about 2026-11-08.High^[2]

Orbital period717.3–718.1 minActive satellites per CelesTrak, element epoch about 2026-11-08.High^[2]

Inclination62.71–63.42 °Active satellites per CelesTrak, element epoch about 2026-11-08.High^[2]

Catalogued satellites · 6^[2]

Name	NORAD	COSPAR	Perigee km	Apogee km	Incl. °	Period min	Status
COSMOS 2510 (EKS 1)	41032	2015-066A	1,110	39,259	63.42	718.1	Active
COSMOS 2518 (EKS 2)	42719	2017-027A	1,860	38,469	63.02	717.3	Active
COSMOS 2541 (EKS 3)	44552	2019-065A	2,864	37,499	62.71	717.9	Active
COSMOS 2546 (EKS 4)	45608	2020-031A	1,205	39,146	63.17	717.7	Active
COSMOS 2552 (EKS 5)	49503	2021-113A	3,211	37,155	62.82	718	Active
COSMOS 2563 (EKS 6)	54223	2022-145A	1,646	38,716	63.13	717.9	Active

Mean elements at epoch 2026-11-07 or later. Perigee and apogee are computed from mean motion and eccentricity and are approximate. Status follows the CelesTrak active list.

Summary

Russia's space-based missile early warning system, replacing Oko; reportedly also carries an emergency communications payload.

Draft entry. Values come from the cited public sources and are awaiting editor verification.

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Operators

Russia

Sources

Tundra (Kupol, EKS, 14F142), Gunter's Space Page
Tier 3 · checked 2026-11-08
NORAD GP element sets (current data), CelesTrak (data from the U.S. Space Force 18th/19th Space Defense Squadron catalog)
Published/updated 2026-11-08 · Tier 1 · checked 2026-11-08

Change log

2026-11-08 Entry created from cited open sources
2026-11-08 Orbital elements from CelesTrak GP data (epoch about 2026-11-08): 6 catalogued, 6 active.