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BULGARIA - 10 Leva (ΛΕΒΑ) Silver (90% pure) (14.00 grams) 31mm
- Bulgaria & Soviet Russia Joint Space Flight Commemorative -
Obverse: ПЕРВИЙ СЪВМЕСТЕН ΠΟΛΕΤ Β ΚΟСМОСА around Soviet Russian & Bulgarian
space craft, CCCP (star) HPБ in exergue, border of stars.
Reverse: НАРОДНАЯ РЕПУБЛИКА around Bulgarian national symbol, БЪΛГΑΡΙΑ 1979 10
ΛΕΒΑ in exergue.
Side Lettering: ИHTEPΚΟСМОС 79 CCCP (star) HPБ
Bulgaria was also the 6th country in the world to have an
astronaut in space: major-general Georgi Ivanov on Soyuz 33 (1979), followed by
lieutenant-colonel Alexander Alexandrov on Soyuz TM-5 (1988).
You are bidding on the exact item pictured,
provided with a Certificate of Authenticity and Lifetime Guarantee of
Authenticity.
Soyuz 33 (Russian:
Союз 33, Union 33) was a 1979
Soviet manned space flight to the
Salyut 6
space
station. It was the ninth mission to the orbiting facility, but an engine
failure forced the mission to be aborted, and the crew had to return to earth
before docking with the station. It was the first-ever failure of a Soyuz engine
during orbital operations.
The two-man crew, commander
Nikolai Rukavishnikov and
Bulgarian
cosmonaut
Georgi Ivanov, suffered a steep
ballistic re-entry, but were safely recovered. The original intention of the
mission had been to visit the orbiting crew for about a week and leave a fresh
vehicle for the station crew to return to earth in. The mission failure meant
that the orbiting Salyut 6 crew lacked a reliable return vehicle as their Soyuz
had the same suspect engine as Soyuz 33. A subsequent manned flight was canceled
and a vacant craft with a redesigned engine was sent for the crew to use.
Crew
Number in parentheses indicates number of spaceflights
by each individual prior to and including this mission.
Backup
crew
Mission
parameters
-
Mass: 6,860 kg (15,100 lb)
-
Perigee: 198.6 km (123.4 mi)
-
Apogee: 279.2 km (173.5 mi)
-
Inclination: 51.63°
-
Period: 88.99 minutes
Mission
highlights
After a two-day delay caused by a windstorm at the launch
site, Soyuz 33 was launched 10 April 1979 with the fourth international crew in
the Soviet
Intercosmos program.
Bulgarian
cosmonaut
Georgi Ivanov joined commander
Nikolai Rukavishnikov as the craft proceeded normally towards the Salyut 6
space station.
Rukavishnikov was the first civilian to command a Soviet
spacecraft, and Ivanov the first Bulgarian in space.[1]
At 9 km distance from the station, the Igla automatic docking
system was activated. But, as the craft approached to 1,000 metres, the engine
failed and automatically shut down after three seconds of a planned six-second
burn. Rukavishnikov had to hold the instrument panel as the craft shook so
violently. After consulting with ground control, the docking system was
activated again, but the engine shut down again, and
Valery Ryumin, observing from the station, reported an abnormal lateral glow
from behind the Soyuz during the burn. Mission control accordingly aborted the
mission and told the crew to prepare to return to earth.[1]
It was the first in-orbit failure of the Soyuz propulsion system.[2]
The failure was determined to be a malfunction of the main
engine. A pressure sensor in the combustion chamber was shutting down the engine
when it seemed normal combustion pressure was not being reached. This shut-down
mechanism was designed to prevent propellants from being pumped into a damaged
engine thus risking damage and/or an explosion.[1]
The crew requested another attempt at an engine burn, but
were denied and told to sleep. A recovery attempt could not be made for another
day.[2]
Rukavishnikov couldn't sleep, however, and thought about the film
Marooned which featured an
American space crew stranded in orbit.[1]
It was only in 1983 that the Soviets revealed how serious the
situation was.[2]
The craft had a back-up engine but it was feared that it may have been damaged
by the main engine, potentially leaving the crew stranded with five days of
supplies while it would take ten days for the orbit to decay. One option to
return the crew if the backup engine was inoperable would have been to use
attitude control thrusters to slow the Soyuz below orbit velocity. But there may
have not been enough propellant to do this, and the landing point would have
been unpredictable if it worked.[1]
Another option was to move the station to the Soyuz. The station could have been
moved to within 1,000 m of the craft, at which point Soyuz 33 could be docked
using its thrusters. But the two crafts were drifting apart at 28 metres per
second, and time was needed to calculate the maneuvers. In any event, four crew
on the station with one malfunctioning Soyuz and a second Soyuz (the station
crew's Soyuz 32,
already docked at Salyut 6) with a now-questionable engine (it had the same type
as Soyuz 33) was not considered the best option.[1]
The main option was to fire the back-up engine, but this
option was not guaranteed to work, even if the engine fired. The nominal burn
time was 188 seconds, and as long as the burn lasted more than 90 seconds, the
crew could manually restart the engine to compensate. But this would mean an
inaccurate landing. If, however, the burn was less than 90 seconds, the crew
could be stranded in orbit. A burn longer than 188 seconds could result in
too-high loads on the crew during re-entry.[2]
In the end, the backup engine did fire, though for 213
seconds, 25 seconds too long, resulting in an unusually steep trajectory and
loads of 10 gravities to be endured by the crew. Rukavishnikov and Ivanov were
safely recovered.[1]
It was the second ballistic entry reported by the Soviets,
Soyuz 1 being
the first. Others noted that
Soyuz 18a
was a ballistic reentry, and
Soyuz 24
reportedly also was one.[1]
An investigation lasted a month and found that the part that
failed had been tested 8,000 times previously without failing, and the Soyuz
engine had fired some 2,000 times since 1967, also without a single failure. But
the engine was modified for the next flight, and a vacant Soyuz with the newly
modified engine,
Soyuz 34,
was sent to the orbiting Salyut for the crew there to return with.[1]
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