Mercury, also known as Advanced Vortex, was a series of three United States

spy satellites A reconnaissance satellite or intelligence satellite (commonly, although unofficially, referred to as a spy satellite) is an Earth observation satellite or communications satellite deployed for military or intelligence applications. Th ...

launched in the 1990s. These satellites were launched and operated by the

National Reconnaissance Office The National Reconnaissance Office (NRO) is a member of the United States Intelligence Community and an agency of the United States Department of Defense which designs, builds, launches, and operates the reconnaissance satellites of the U.S. fe ...

with the participation of the

United States Air Force The United States Air Force (USAF) is the Aerial warfare, air military branch, service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part ...

. Two of the three launches from Cape Canaveral were successful, with the third failing to achieve orbit. The satellites collect

SIGINT Signals intelligence (SIGINT) is intelligence-gathering by interception of '' signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication ...

from near- geosynchronous orbits. Their precise mission and capabilities are highly classified, but they are widely believed to be successors to the Vortex/Chalet satellites. The last launch attempt, on 12 August 1998 failed, with the USD $700–800 million satellite and the $344 million Titan IV(401)A launch vehicle exploding over the Atlantic Ocean. The failure was caused by a

short circuit A short circuit (sometimes abbreviated to short or s/c) is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circui ...

in the guidance system, which lost power and reset, causing the vehicle to pitch over. This in turn led to premature separation of one of the SRBs, which automatically self-destructed. The resulting explosion also destroyed the core vehicle, and the second SRB then initiated its own self-destruction. Roughly 4 seconds later the

Range Safety Officer In the field of rocketry, range safety may be assured by a system which is intended to protect people and assets on both the rocket range and downrange in cases when a launch vehicle might endanger them. For a rocket deemed to be ''off course' ...

also issued a self-destruct signal to the rocket. Observers estimate each spacecraft has a mass of 4,000–5,000 kg.

Launches

References

External links

Mercury ELINT
at

Encyclopedia Astronautica The ''Encyclopedia Astronautica'' is a reference web site on space travel. A comprehensive catalog of vehicles, technology, astronauts, and flights, it includes information from most countries that have had an active rocket research program, f ...

Mercury/Advanced VORTEX
from Federation of American Scientists
Video of the launch and destruction
{{US-spacecraft-stub Reconnaissance satellites of the United States Signals intelligence satellites Military equipment introduced in the 1990s