NROL-21

Launch data:

Mission details:

• The NRO's experimental USA 193 surveillance satellite, which was reported to be crippled soon after its launch on a Delta II in Dec 2006 into a 351 x 365 km x 58 deg orbit, is approaching reentry. Orbital data from independent observers show that the satellite's trajectory has slowly decayed since launch due to friction with the atmosphere; by Jan 22 it was in a 275 x 279 km x 58 deg orbit dropping about 1 km a day, and the decrease in height will soon accelerate catastrophically. The satellite is thought to have been intended to test prototype instruments for future spy satellites, possibly including a radar sensor; it was reportedly developed by Lockheed Martin (LM-Sunnyvale has experience in recon satellites, but LM-Denver is involved in the Space Radar area; both groups could be involved).
• Reports of 'dangerous material' on board the satellite refer to hydrazine orbit adjust propellant; mass of the spacecraft is probably around 2000 to 4000 kg. It's fairly rare for satellite payloads of this mass to have an uncontrolled reentry - only one or two a year - but empty rocket stages as heavy as this come down about once every three weeks. The spacecraft carries about 1000 kg of hydrazine, which has frozen; about 500 kg is expected to survive reentry as a slushy lump giving off toxic fumes. The US government has announced plans to launch Aegis SM-3 ballistic missile interceptors to destroy the satellite, in the first US antisatellite test since 1986. The US Department of Defense states that the danger of the falling hydrazine is the motivation for this test. However, some observers suggest that the danger is not large enough to justify such extreme measures.
• On Feb 21, 2008 the National Reconnaissance Office's crippled USA 193 satellite was in a 242 x 257 km x 58.5 deg orbit. At 0326 UTC a three stage Aegis SM-3 missile was fired from the USS Lake Erie in the Pacific Ocean west of Hawai'i to intercept the satellite. The US Dept. of Defense reports that the missile successfully hit USA 193; visual reports from British Columbia of high altitude debris trails at 0343 UTC, and lack of later observations of the satellite in orbit, suggest that the satellite has indeed been destroyed. This can be considered to be the first “operational” – rather than “experimental” destruction of a satellite in orbit by a weapon, even though the SM-3 missile is not normally considered to be an ASAT weapon.
• On Feb 26-Mar 8, 2008 the DoD cataloged 153 debris objects in orbits with perigees in the 170-250 km range and apogees of up to 2700 km; 36 of these debris pieces had already reentered by Mar 9, and the apogee of the highest-apogee piece was decreasing by 35 km per day, supporting assertions that the debris will not remain in orbit for long.
• On Jul 2009, all the debris had reentered.
  However during a routine update of debris found in orbit, a new piece of the satellite has been found in a 234 x 934 km x 56.1 deg orbit and catalogued as 2006-057GH.