ORION

In the early 1980s, a successor to the RHYOLITE/AQUACADE SIGINT (Signal Intelligence) satellites was developed by the CIA under the name MAGNUM, which was changed to ORION before the first launch. The satellites were built by TRW, and were significantly larger and heavier than their predecessors. Their original primary task was also FISINT (Foreign Instrumentation Signals Intelligence), and therefore the "Mission 7600" designation was taken over from AQUACADE. However, over the years COMINT (Communication Intelligence) became ever more important, and became the part of Mission 7600, which produced by far the most data.

The ORION satellites were built in several distinct batches. The first of these consisted of two satellites, USA-8 and USA-48, with an estimated mass of around 2200-2700 kg. They were carried into low-earth orbit by the Space Shuttle, and placed into their final near-geostationary 24h orbits by a Boeing IUS (Inertial Upper Stage). Both satellites had an operational lifetime of around 25 years. The second ORION batch also consisted of two satellites, USA-110 and USA-139. They had a still higher mass, reportedly around 4500-5200 kg. They are sometimes called "Advanced ORION" or "MENTOR", but leaked NRO documents prove that their code name is still ORION. They were launched into geostationary orbits by Titan IV-class rockets in May 1995 and May 1998, respectively.

Beginning with the 5th ORION satellite, launched on 3 September 2003 and named USA-171, ORION uses the designator "Mission 8300". It combines the various SIGINT tasks of Mission 7600 and the COMINT-oriented Mission 7500 (VORTEX/MERCURY) into a single system. USA-171 was launched by a Titan IV, and may therefore have been of similar design as the two preceding ORIONs. From USA-202 (ORION-6) onwards, the satellites were launched by the Delta 4 Heavy, indicating a still higher mass and/or larger size.

Image: NRO, published by The Intercept

ORION (USA-202)

Based on a leaked NRO graphic, the basic layout of the USA-202 satellite is known. It consists of an octagonal main body, to which solar panels and all sorts of receiver and transmitter antennas are attached. The most prominent one is a very large parabolic reflector dish. Although several sources report a diameter of up to 100 m (330 ft) for this dish, a detailed analysis of the leaked image in source [4] yields an estimate of only 21-29 m (69-95 ft). The satellite has a second receiver dish, smaller than the primary one, which is dedicated for ELINT, test-range surveillance and general signal search.

The minimal Mission 8300 constallation consists of three satellites in near-geosynchronous orbits. They cover the area of the former Soviet Union, China, South and East Asia, the Middle East, Eastern Europa and the Atlantic landmasses. The system is controlled by two Mission Ground Stations (MGS), one at RAF Menwith Hill in the UK, and one at the Joint Defense Facility Pine Gap in Australia. The MGS receive the data stream, and send command and control signals to the spacecraft. The Mission 8300 satellites are effectively all-purpose SIGINT assets, able to monitor a wide variety of frequencies and signal types - COMINT (incl. so-called PROFORMA, machine-to-machine communications), ELINT (incl. OPELINT, Operational ELINT) and FISINT. For high-accuracy OPELINT geolocation, Mission 8300 satellite cooperate with Mission 8200, a system which has not yet been identified.

The current prime contractor for ORION is most likely Northrop Grumman, which had acquired TRW in 2002. Until April 2024, eight Mission 8300 satellites have been launched (assuming that the association of all launches with ORION / Mission 8300 is correct). It is unknown, if or how the design was modified over time, and how many of the satellites are operationally active at the time of this writing.

ORION Launch List

• No.: Sequential flight number for the ORION program
• Name: Unclassified name of the satellite. Since June 1984, all U.S. military satellites get a sequential "USA" number. "NROL" stands for National Reconnaissance Office Launch, a number assigned by the NRO to its satellite launches since 1996.
• Mission: The first ORION missions had a unique serial number in the 76xx range, continuing the series of RHYOLITE/AQUACADE missions. This was replaced by a 83xx series for the upgraded satellites. The mission numbers are mostly inferred from the launch sequence and the general "Mission 7600" and "Mission 8300" categories.
• COSPAR ID: International designation of the satellite

ORION launches

Main Sources

[1] Desmond Ball, Bill Robinson and Richard Tanter: The SIGINT Satellites of Pine Gap: Conception, Development and in Orbit, Nautilus Institute for Security and Sustainability, October 2015
[2] The Intercept: Menwith satellite classification guide, uploaded 6 September 2016
[3] The Intercept: M7600 M8300 SIGINT Guide, uploaded 19 August 2017
[4] SatelliteObservation.net: A radiotelescope in the sky: the USA-202 ORION satellite, September 2017
[5] Gunter's Space Page (for launch lists)

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Last Updated: 30 June 2025