NR-1: The Space Shuttle Challenger, Egypt Air 990, but not Air France 447

NR-1 operated under a longstanding veil of secrecy, conducting Cold War reconnaissance missions that are still classified.

In the 1980s NR-1 became widespread public knowledge when used for search and recovery of space shuttle Challenger's wreckage, as well as that of Egypt Air 990.

NR-1 was deactivated several months ago, so it will be no use in the forensic investigation of Air France's flight 447, the least of which would be recovery of the aircraft's flight data and cabin voice recorders. The Airbus 330 with 228 souls aboard disappeared from radar in flight from Rio de Janeiro to Paris. the least of which would be recovery of the aircraft's black boxes.

The unavailability of NR-1 certainly does not mean equally effective submersibles are not available. Wreckage located by the Brazilian Air Force about 400 miles northeast of Fernando do Noronha island, where the missing plane disappeared from radar screens.

France is also sending a research ship equipped with two mini-submarines to the search area. The mini-subs on the Pourquoi Pas can work at depths of up to 6,000m and the area where the plane disappeared has maximum depths of 4,700m (19,700 ft), French naval experts told AFP news agency.

Submarines are always silent and strange.