{
  "id": "milstar",
  "name": "Milstar",
  "aliases": [],
  "domain": "space",
  "country": "USA",
  "category": "Protected military communications constellation",
  "status": "in-service",
  "fielded": 1997,
  "operators": [
    "USA"
  ],
  "summary": "First-generation protected EHF satellite communications system, now operated together with AEHF.",
  "specs": [
    {
      "k": "orbit_regime",
      "v": "GEO",
      "src": [
        "asf-milstar-satellite-communications-system"
      ],
      "conf": "high"
    },
    {
      "k": "sats_count",
      "v": 5,
      "src": [
        "asf-milstar-satellite-communications-system"
      ],
      "conf": "medium",
      "note": "Two Milstar I and three Milstar II (page also mentions six launched through 2003)"
    },
    {
      "k": "first_launch",
      "v": 1994,
      "src": [
        "asf-milstar-satellite-communications-system"
      ],
      "conf": "medium"
    },
    {
      "k": "design_life_yr",
      "v": 10,
      "src": [
        "asf-milstar-satellite-communications-system"
      ],
      "conf": "medium"
    },
    {
      "k": "mass_kg",
      "v": 4536,
      "src": [
        "asf-milstar-satellite-communications-system"
      ],
      "conf": "medium",
      "note": "About 10,000 lb"
    },
    {
      "k": "power_w",
      "v": 8000,
      "src": [
        "asf-milstar-satellite-communications-system"
      ],
      "conf": "medium"
    },
    {
      "k": "mission",
      "v": "Milstar I: 75 bps–2.5 kbps over 192 EHF channels; Milstar II adds medium data rate up to 1.5 Mbps over 32 channels",
      "src": [
        "asf-milstar-satellite-communications-system"
      ],
      "conf": "medium"
    },
    {
      "k": "program",
      "v": "Passed 30 years of operations on 7 February 2024",
      "src": [
        "asf-milstar-satellite-communications-system"
      ],
      "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": 4,
      "src": [
        "celestrak-gp"
      ],
      "conf": "medium",
      "note": "Count in the CelesTrak active satellites list, which estimates operational status."
    },
    {
      "k": "perigee_km",
      "v": [
        35373,
        35768
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "apogee_km",
      "v": [
        35806,
        36202
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "period_min",
      "v": [
        1436,
        1436.1
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "inclination_deg",
      "v": [
        11.35,
        14.12
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    }
  ],
  "payloads": [],
  "variants": [],
  "art": "satellite",
  "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, 4 active."
    }
  ],
  "satellites": [
    {
      "name": "USA 99 (MILSTAR-1 1)",
      "norad": 22988,
      "cospar": "1994-009A",
      "perigee_km": 36210,
      "apogee_km": 36243,
      "inclination_deg": 17.84,
      "period_min": 1458.6,
      "epoch": "2026-11-08",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 115 (MILSTAR-1 2)",
      "norad": 23712,
      "cospar": "1995-060A",
      "perigee_km": 35768,
      "apogee_km": 35806,
      "inclination_deg": 14.12,
      "period_min": 1436.1,
      "epoch": "2026-11-08",
      "active": true,
      "owner": "US",
      "launch": "1995-11-06"
    },
    {
      "name": "USA 143 (MILSTAR-2 1)",
      "norad": 25724,
      "cospar": "1999-023A",
      "perigee_km": 1099,
      "apogee_km": 5146,
      "inclination_deg": 28.23,
      "period_min": 153.6,
      "epoch": "2026-11-08",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 157 (MILSTAR-2 2)",
      "norad": 26715,
      "cospar": "2001-009A",
      "perigee_km": 35606,
      "apogee_km": 35964,
      "inclination_deg": 11.7,
      "period_min": 1436,
      "epoch": "2026-11-08",
      "active": true,
      "owner": "US",
      "launch": "2001-02-27"
    },
    {
      "name": "USA 164 (MILSTAR-2 3)",
      "norad": 27168,
      "cospar": "2002-001A",
      "perigee_km": 35373,
      "apogee_km": 36202,
      "inclination_deg": 11.35,
      "period_min": 1436.1,
      "epoch": "2026-11-07",
      "active": true,
      "owner": "US",
      "launch": "2002-01-16"
    },
    {
      "name": "USA 169 (MILSTAR-2 4)",
      "norad": 27711,
      "cospar": "2003-012A",
      "perigee_km": 35386,
      "apogee_km": 36187,
      "inclination_deg": 12.55,
      "period_min": 1436.1,
      "epoch": "2026-11-08",
      "active": true,
      "owner": "US",
      "launch": "2003-04-08"
    }
  ],
  "url": "https://www.defensepedia.com/systems/milstar.html",
  "sources": {
    "asf-milstar-satellite-communications-system": {
      "title": "Milstar Satellite Communications System (weapons and platforms entry)",
      "publisher": "Air & Space Forces Magazine",
      "url": "https://www.airandspaceforces.com/weapons/milstar-satellite-communications-system/",
      "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"
    }
  }
}