{
  "id": "tundra-eks",
  "name": "Tundra (EKS / Kupol)",
  "aliases": [
    "EKS",
    "Kupol",
    "14F142"
  ],
  "domain": "space",
  "country": "RUS",
  "category": "Missile early warning satellite constellation",
  "status": "in-service",
  "fielded": null,
  "operators": [
    "RUS"
  ],
  "summary": "Russia's space-based missile early warning system, replacing Oko; reportedly also carries an emergency communications payload.",
  "specs": [
    {
      "k": "orbit_regime",
      "v": "HEO (Molniya)",
      "src": [
        "gsp-tundra"
      ],
      "conf": "medium"
    },
    {
      "k": "orbit_text",
      "v": "1,626 km × 38,552 km, 63.4° (first satellite)",
      "src": [
        "gsp-tundra"
      ],
      "conf": "medium"
    },
    {
      "k": "sats_count",
      "v": 6,
      "src": [
        "gsp-tundra"
      ],
      "conf": "medium",
      "note": "Kosmos 2510 (2015) to Kosmos 2563 (2022)"
    },
    {
      "k": "first_launch",
      "v": 2015,
      "src": [
        "gsp-tundra"
      ],
      "conf": "medium"
    },
    {
      "k": "design_life_yr",
      "v": 7.5,
      "src": [
        "gsp-tundra"
      ],
      "conf": "medium"
    },
    {
      "k": "on_orbit",
      "v": 6,
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Payloads with current element sets in the public catalog, active or not."
    },
    {
      "k": "active_sats",
      "v": 6,
      "src": [
        "celestrak-gp"
      ],
      "conf": "medium",
      "note": "Count in the CelesTrak active satellites list, which estimates operational status."
    },
    {
      "k": "perigee_km",
      "v": [
        1110,
        3211
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "apogee_km",
      "v": [
        37155,
        39259
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "period_min",
      "v": [
        717.3,
        718.1
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "inclination_deg",
      "v": [
        62.71,
        63.42
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    }
  ],
  "payloads": [],
  "variants": [],
  "art": "satellite",
  "image": null,
  "verified": null,
  "changelog": [
    {
      "date": "2026-11-08",
      "change": "Entry created from cited open sources"
    },
    {
      "date": "2026-11-08",
      "change": "Orbital elements from CelesTrak GP data (epoch about 2026-11-08): 6 catalogued, 6 active."
    }
  ],
  "satellites": [
    {
      "name": "COSMOS 2510 (EKS 1)",
      "norad": 41032,
      "cospar": "2015-066A",
      "perigee_km": 1110,
      "apogee_km": 39259,
      "inclination_deg": 63.42,
      "period_min": 718.1,
      "epoch": "2026-11-07",
      "active": true,
      "owner": "CIS",
      "launch": "2015-11-17"
    },
    {
      "name": "COSMOS 2518 (EKS 2)",
      "norad": 42719,
      "cospar": "2017-027A",
      "perigee_km": 1860,
      "apogee_km": 38469,
      "inclination_deg": 63.02,
      "period_min": 717.3,
      "epoch": "2026-11-06",
      "active": true,
      "owner": "CIS",
      "launch": "2017-05-25"
    },
    {
      "name": "COSMOS 2541 (EKS 3)",
      "norad": 44552,
      "cospar": "2019-065A",
      "perigee_km": 2864,
      "apogee_km": 37499,
      "inclination_deg": 62.71,
      "period_min": 717.9,
      "epoch": "2026-11-07",
      "active": true,
      "owner": "CIS",
      "launch": "2019-09-26"
    },
    {
      "name": "COSMOS 2546 (EKS 4)",
      "norad": 45608,
      "cospar": "2020-031A",
      "perigee_km": 1205,
      "apogee_km": 39146,
      "inclination_deg": 63.17,
      "period_min": 717.7,
      "epoch": "2026-11-07",
      "active": true,
      "owner": "CIS",
      "launch": "2020-05-22"
    },
    {
      "name": "COSMOS 2552 (EKS 5)",
      "norad": 49503,
      "cospar": "2021-113A",
      "perigee_km": 3211,
      "apogee_km": 37155,
      "inclination_deg": 62.82,
      "period_min": 718,
      "epoch": "2026-11-08",
      "active": true,
      "owner": "CIS",
      "launch": "2021-11-25"
    },
    {
      "name": "COSMOS 2563 (EKS 6)",
      "norad": 54223,
      "cospar": "2022-145A",
      "perigee_km": 1646,
      "apogee_km": 38716,
      "inclination_deg": 63.13,
      "period_min": 717.9,
      "epoch": "2026-10-21",
      "active": true,
      "owner": "CIS",
      "launch": "2022-11-02"
    }
  ],
  "url": "https://www.defensepedia.com/systems/tundra-eks.html",
  "sources": {
    "gsp-tundra": {
      "title": "Tundra (Kupol, EKS, 14F142)",
      "publisher": "Gunter's Space Page",
      "url": "https://space.skyrocket.de/doc_sdat/tundra.htm",
      "published": null,
      "tier": 3,
      "checked": "2026-11-08"
    },
    "celestrak-gp": {
      "title": "NORAD GP element sets (current data)",
      "publisher": "CelesTrak (data from the U.S. Space Force 18th/19th Space Defense Squadron catalog)",
      "url": "https://celestrak.org/NORAD/elements/",
      "published": "2026-11-08",
      "tier": 1,
      "checked": "2026-11-08"
    }
  }
}