NROL-66, carrying advanced dosimeters, during ground processing
Mission typeTechnology
COSPAR ID2011-006A Edit this at Wikidata
SATCAT no.37364
Spacecraft properties
Launch mass350 kilograms (770 lb)[1]
Start of mission
Launch date6 February 2011, 12:26 (2011-02-06UTC12:26Z) UTC[2]
RocketMinotaur I SLV-10
Launch siteVandenberg SLC-8
ContractorOrbital Sciences
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude1,202 kilometers (747 mi)
Apogee altitude1,230 kilometers (760 mi)
Inclination90 degrees
Period109.76 minutes
Epoch6 February 2011[3]

USA-225, also known as the Rapid Pathfinder Prototype (RPP) and NRO Launch 66 (NROL-66), is an American satellite which was launched in 2011. The satellite is being used to perform technology demonstration and development experiments, including advanced dosimeters to characterize the space environment from a 1,200 kilometer low Earth orbit.[4] It is operated by the United States National Reconnaissance Office.[5]

Rapid Pathfinder was developed for less than US$20 million over a period of less than two years. Its dimensions are 0.5 m times 0.5 m times 0.5 m, and its mass including payload is 235 kg.[4]

A Minotaur I carrier rocket was used to launch USA-225, flying from Space Launch Complex 8 of the Vandenberg Air Force Base. The launch of was originally scheduled for March 2011; however, it was subsequently moved forwards to 5 February.[6] During the attempt to launch on 5 February 2011, a transmitter malfunctioned, and the launch attempt was scrubbed. Another attempt was scheduled for the next day. At 12:26 on 6 February 2011, the Minotaur lifted off, carrying USA-225 into orbit.[7] The launch was conducted by Orbital Sciences Corporation.

For launch, the RPP satellite was given the designation NRO Launch 66, or NROL-66. Upon reaching orbit it was named USA-225 in accordance with the usual naming system for American military spacecraft. The satellite received the International Designator 2011-006A, and the Satellite Catalog Number 37364.[8]

See also


  1. ^ "UCS Satellite Database". Union of Concerned Scientists. Archived from the original on 4 January 2014. Retrieved 30 November 2013.
  2. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 30 November 2013.
  3. ^ McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 30 November 2013.
  4. ^ a b Carlson, Bruce (8 August 2011). "NRO's Historical, Current, and Potential Use of Small Satellites" (PDF). NRO. Retrieved 26 August 2011.
  5. ^ Krebs, Gunter. "RPP". Gunter's Space Page. Retrieved 9 February 2011.
  6. ^ "Launch Log". Tracking Station. Spaceflight Now. Retrieved 9 February 2011.
  7. ^ Clark, Stephen (6 February 2011). "Classified satellite climbs to space on Minotaur rocket". Spaceflight Now. Retrieved 9 February 2011.
  8. ^ "USA 225 Satellite details 2011-006A NORAD 37364". N2YO. Retrieved 9 February 2011.