{
  "id": "wsf-m",
  "name": "Weather System Follow-on – Microwave (WSF-M)",
  "aliases": [],
  "domain": "space",
  "country": "USA",
  "category": "Military weather satellites",
  "status": "in-service",
  "fielded": 2025,
  "operators": [
    "USA"
  ],
  "summary": "Microwave weather satellite replacing DMSP for ocean surface winds and other environmental data.",
  "specs": [
    {
      "k": "orbit_regime",
      "v": "LEO (sun-synchronous)",
      "src": [
        "asf-wsf-m"
      ],
      "conf": "medium"
    },
    {
      "k": "altitude_km",
      "v": 832,
      "src": [
        "asf-wsf-m"
      ],
      "conf": "medium",
      "note": "About 517 miles"
    },
    {
      "k": "sats_count",
      "v": 1,
      "src": [
        "asf-wsf-m"
      ],
      "conf": "medium",
      "note": "SV-1 launched 11 April 2024"
    },
    {
      "k": "first_launch",
      "v": 2024,
      "src": [
        "asf-wsf-m"
      ],
      "conf": "medium"
    },
    {
      "k": "mass_kg",
      "v": 1200,
      "src": [
        "asf-wsf-m"
      ],
      "conf": "medium",
      "note": "2,645 lb at launch"
    },
    {
      "k": "contractor",
      "v": "Ball Aerospace (now BAE Systems)",
      "src": [
        "asf-wsf-m"
      ],
      "conf": "medium"
    },
    {
      "k": "program",
      "v": "IOC 24 April 2025; SV-2 scheduled by end of 2026",
      "src": [
        "asf-wsf-m"
      ],
      "conf": "medium"
    },
    {
      "k": "on_orbit",
      "v": 1,
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Payloads with current element sets in the public catalog, active or not."
    },
    {
      "k": "active_sats",
      "v": 1,
      "src": [
        "celestrak-gp"
      ],
      "conf": "medium",
      "note": "Count in the CelesTrak active satellites list, which estimates operational status."
    },
    {
      "k": "perigee_km",
      "v": 820,
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "apogee_km",
      "v": 825,
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "period_min",
      "v": 101.4,
      "src": [
        "celestrak-gp"
      ],
      "conf": "high",
      "note": "Active satellites per CelesTrak, element epoch about 2026-11-08."
    },
    {
      "k": "inclination_deg",
      "v": 98.72,
      "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): 1 catalogued, 1 active."
    }
  ],
  "satellites": [
    {
      "name": "WSF-M",
      "norad": 59481,
      "cospar": "2024-070A",
      "perigee_km": 820,
      "apogee_km": 825,
      "inclination_deg": 98.72,
      "period_min": 101.4,
      "epoch": "2026-11-08",
      "active": true,
      "owner": "US",
      "launch": "2024-04-11"
    }
  ],
  "url": "https://www.defensepedia.com/systems/wsf-m.html",
  "sources": {
    "asf-wsf-m": {
      "title": "Weather System Follow-On-Microwave (weapons and platforms entry)",
      "publisher": "Air & Space Forces Magazine",
      "url": "https://www.airandspaceforces.com/weapons/wsf-m/",
      "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"
    }
  }
}