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SpaceUnited States

UHF Follow-On (UFO)

Narrowband military communications constellationIn serviceFielded 1993Pending verification
SpaceUSA
Identification silhouette. Not drawn to scale between entries.
Fact cardConfidence · Source
System
TypeNarrowband military communications constellation
Date of introduction1993
ProliferationOrigin country only
Satellites4UFO 8, 9, 10 (Block 3) and UFO 11 (Block 4) remain active of 11 launchedMed[1]
First launch1993Med[1]
ContractorsHughes (Blocks 1–3), Boeing (Block 4)Med[1]
Dimensions and weight
Mass3,206 kg7,068 lb7,068 lb (Block 3)Med[1]
Power3,800 WBlock 3Med[1]
Orbit
Orbit regimeGEOHigh[1]
Catalogued on orbit11Payloads with current element sets in the public catalog, active or not.High[2]
Active (CelesTrak)4Count in the CelesTrak active satellites list, which estimates operational status.Med[2]
Perigee35,761–35,773 kmActive satellites per CelesTrak, element epoch about 2026-11-08.High[2]
Apogee35,802–35,811 kmActive satellites per CelesTrak, element epoch about 2026-11-08.High[2]
Orbital period1,436.1 minActive satellites per CelesTrak, element epoch about 2026-11-08.High[2]
Inclination9.08–11.95 °Active satellites per CelesTrak, element epoch about 2026-11-08.High[2]
Catalogued satellites · 11[2]
NameNORADCOSPARPerigee kmApogee kmIncl. °Period minStatus
UFO 1 (USA 98)225631993-015A36,05836,09126.151450.8Inactive
UFO 2 (USA 95)227871993-056A35,76435,80811.951436.1Active
UFO 3 (USA 104)231321994-035A35,76035,81312.431436.1Inactive
UFO 4 (USA 108)234671995-003A35,77335,8029.741436.1Active
UFO 5 (USA 111)235891995-027A36,20336,23312.111458.2Inactive
UFO 6 (USA 114)236961995-057A36,18436,24611.681458Inactive
UFO 7 (USA 127)239671996-042A35,79635,83811.261437.6Inactive
UFO 8 (USA 138)252581998-016A35,76935,82111.311436.5Inactive
UFO 9 (USA 140)255011998-058A36,34236,42811.481466.8Inactive
UFO 10 (USA 146)259671999-063A35,76135,8119.931436.1Active
UFO 11 (USA 174)281172003-057A35,76835,8059.081436.1Active

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

Legacy UHF satellites that replaced FLTSATCOM and Leasat; being superseded by MUOS.

Draft entry. Values come from the cited public sources and are awaiting editor verification.
CompareJSON
Operators
United States
Sources
  1. Ultra-High Frequency Follow-On (weapons and platforms entry), Air & Space Forces Magazine
    Tier 3 · checked 2026-11-08
  2. 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): 11 catalogued, 4 active.