Collaborating with astrophysicists, aerospace engineers and an international community of astronauts, the Swiss watch company FORTIS chose a self-winding movement for its reliance on kinetic energy. To insure that seIf-winding movement would maintain accurate time in space, scientists tested the Cosmonauts Chronograph within the Gagarin Centre’s massive high velocity TsF-18 centrifuge. The FORTIS models withstood an overload of 12 G. (12 times the Earth gravitational pulI) from three different angles with no negative effects. By comparison, most combat aviation equipment is engineered to withstand am maximum of 9 G.
The watches were also tested aboard a 1L-76 MDK, a four-engine jet which flies in a parabolic pattern of steep climbs and dives simulating zero gravity conditions. Even under weightless conditions, the watches demonstrated optimal performance. Finally, officials at the Gagarin Centre exposed the watches to extreme vacuum conditions within a pressure chamber. They tested it for 10-minute intervals at 40 mm Hg with no impact on the movement. By comparison, normal air pressure on Earth is 760 mm Hg. After passing all trials at the Gagarin Space Centre, the FORTIS Official Cosmonauts Chronographs made their maiden voyage with the Soyuz TM - 19 mission becoming the first automatic chronographs ever in open space. Crew members wore their Cosmonauts Chronographs in open space during the EVA for a total of more than 11 hours while preparing to dock with the Space Shuttle Atlantis. The Chronographs had to withstood temperature fluctuations between -170 degrees centigrade in Earth shade and a maximum of +130° centigrade when exposed to direct sunlight, at an orbital velocity of approximately 12,500 miles per hour. Since 1994 the FORTIS Official Cosmonauts Chronograph became the official standard equipment of the Russian space flight program.
