{
  "id": "dsp",
  "name": "Defense Support Program (DSP)",
  "aliases": [],
  "domain": "space",
  "country": "USA",
  "category": "Missile warning satellite constellation",
  "status": "retired",
  "fielded": 1972,
  "operators": [
    "USA"
  ],
  "summary": "The first U.S. space-based missile launch detection system, operated from 1970; Air & Space Forces reported its sunset in October 2026.",
  "specs": [
    {
      "k": "orbit_regime",
      "v": "GEO",
      "src": [
        "asf-defense-support-program"
      ],
      "conf": "medium"
    },
    {
      "k": "sats_count",
      "v": 23,
      "src": [
        "asf-defense-support-program"
      ],
      "conf": "medium",
      "note": "23 deployed; five listed operational (DSP-18 to DSP-22) before sunset"
    },
    {
      "k": "first_launch",
      "v": 1970,
      "src": [
        "asf-defense-support-program"
      ],
      "conf": "medium"
    },
    {
      "k": "mass_kg",
      "v": 2359,
      "src": [
        "asf-defense-support-program"
      ],
      "conf": "medium",
      "note": "About 5,200 lb"
    },
    {
      "k": "contractor",
      "v": "Northrop Grumman (formerly TRW), Aerojet",
      "src": [
        "asf-defense-support-program"
      ],
      "conf": "medium"
    },
    {
      "k": "program",
      "v": "Detected Iranian missiles at Al Asad (January 2020) and strikes on Israel (April and October 2024) with SBIRS; sunset reported 1 October 2026",
      "src": [
        "asf-defense-support-program"
      ],
      "conf": "medium"
    },
    {
      "k": "on_orbit",
      "v": 11,
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Payloads with current element sets in the public catalog, active or not."
    },
    {
      "k": "active_sats",
      "v": 2,
      "src": [
        "celestrak-gp"
      ],
      "conf": "medium",
      "note": "Count in the CelesTrak active satellites list, which estimates operational status."
    },
    {
      "k": "perigee_km",
      "v": [
        36126,
        36127
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "apogee_km",
      "v": [
        36137,
        36167
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "period_min",
      "v": [
        1453.8,
        1454.6
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "inclination_deg",
      "v": [
        12.25,
        13.31
      ],
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    }
  ],
  "payloads": [],
  "variants": [],
  "art": "satellite",
  "image": {
    "file": "dsp.jpg",
    "thumb": "dsp-thumb.jpg",
    "credit": "Ken LaRock, U.S. Air Force / DVIDS",
    "license": "Public domain",
    "url": "https://www.dvidshub.net/image/5774065",
    "title": "Northrop Grumman Defense Support Program Satellite(DSP)",
    "source": "DVIDS",
    "dvids_id": 5774065,
    "unit": "National Museum of the U.S. Air Force"
  },
  "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): 11 catalogued, 2 active."
    }
  ],
  "satellites": [
    {
      "name": "USA 7 (DSP 12)",
      "norad": 15453,
      "cospar": "1984-129A",
      "perigee_km": 36168,
      "apogee_km": 36206,
      "inclination_deg": 11.26,
      "period_min": 1456.6,
      "epoch": "2026-11-08",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 28 (DSP 13)",
      "norad": 18583,
      "cospar": "1987-097A",
      "perigee_km": 36202,
      "apogee_km": 36446,
      "inclination_deg": 11.93,
      "period_min": 1463.6,
      "epoch": "2026-11-08",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 39 (DSP 14)",
      "norad": 20066,
      "cospar": "1989-046A",
      "perigee_km": 36180,
      "apogee_km": 36216,
      "inclination_deg": 12.8,
      "period_min": 1457.2,
      "epoch": "2026-11-08",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 65 (DSP 15)",
      "norad": 20929,
      "cospar": "1990-095A",
      "perigee_km": 36312,
      "apogee_km": 36330,
      "inclination_deg": 13.92,
      "period_min": 1463.5,
      "epoch": "2026-11-08",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 75 (DSP 16)",
      "norad": 21805,
      "cospar": "1991-080B",
      "perigee_km": 36086,
      "apogee_km": 36099,
      "inclination_deg": 13.93,
      "period_min": 1451.7,
      "epoch": "2026-11-07",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 107 (DSP 17)",
      "norad": 23435,
      "cospar": "1994-084A",
      "perigee_km": 36084,
      "apogee_km": 36164,
      "inclination_deg": 14.49,
      "period_min": 1453.3,
      "epoch": "2026-11-08",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 130 (DSP 18)",
      "norad": 24737,
      "cospar": "1997-008A",
      "perigee_km": 36088,
      "apogee_km": 36189,
      "inclination_deg": 14.49,
      "period_min": 1454.1,
      "epoch": "2026-11-08",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 142 (DSP 19)",
      "norad": 25669,
      "cospar": "1999-017A",
      "perigee_km": 581,
      "apogee_km": 34723,
      "inclination_deg": 29.46,
      "period_min": 617.9,
      "epoch": "2026-11-08",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 149 (DSP 20)",
      "norad": 26356,
      "cospar": "2000-024A",
      "perigee_km": 36126,
      "apogee_km": 36137,
      "inclination_deg": 13.31,
      "period_min": 1453.8,
      "epoch": "2026-11-08",
      "active": true,
      "owner": "US",
      "launch": "2000-05-08"
    },
    {
      "name": "USA 159 (DSP 21)",
      "norad": 26880,
      "cospar": "2001-033A",
      "perigee_km": 36081,
      "apogee_km": 36100,
      "inclination_deg": 12.92,
      "period_min": 1451.7,
      "epoch": "2026-11-07",
      "active": false,
      "owner": null,
      "launch": null
    },
    {
      "name": "USA 176 (DSP 22)",
      "norad": 28158,
      "cospar": "2004-004A",
      "perigee_km": 36127,
      "apogee_km": 36167,
      "inclination_deg": 12.25,
      "period_min": 1454.6,
      "epoch": "2026-11-07",
      "active": true,
      "owner": "US",
      "launch": "2004-02-14"
    }
  ],
  "url": "https://www.defensepedia.com/systems/dsp.html",
  "sources": {
    "asf-defense-support-program": {
      "title": "Defense Support Program (weapons and platforms entry)",
      "publisher": "Air & Space Forces Magazine",
      "url": "https://www.airandspaceforces.com/weapons/defense-support-program/",
      "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"
    }
  }
}