Tuesday, August 23, 2011

Orbit War One: Mercury, Vostok, and the triumph of cumulative risk.

The First Orbital war (1958),  while politically indecisive, was mainly a proof of concept for orbital conflict.  Both sides relied on single seat earth launch interceptors (Hermes/Mercury and Vostok series orbital craft); The initial USAF Hermes Orbit Interceptor relied on rail boost whereas the Vostok used direct rocket launch systems.   The USAF Mercury Interceptor, deployed mid war, was an uparmed Hermes designed for rocket boost, which had proven a more rapid, (if less reliable) deployment system for intercept missions responding to Soviet launches.

Both the Vostok and the Hermes/Mercury had minimal weapon capacity ,  limited maneuverability, endurance and apogee.  As a result mission duration was limited, as was actual engagement time and maneuverability. Craft in this period had much more capacity for evasion than controlled interception, but for both sides, actual maneuvering fuel and endurance was sharply limited, resulting in indecisive missions against manned targets.    The usual goal of an offensive mission was to knock out a particular unmanned and non-maneuvering satellites; typically, if such an attack was detected at launch, an interceptor was launched to engage the attacker.  The usual result of an engagement was for both craft being forced to maneuver to avoid attack, expending all discresionary maneuver fuel, and having to abort, leaving the target unharmed.  In several cases, either or both of the craft lost sufficient maneuver ability to successfully reenter, and if a rescue mission was impossible, were lost attempting to return, or became derelict.

While the popular press played up the image of raging space dogfights, only three actual combat kills occurred; most intercepts were resolved by one of the combatants aborting, or surrendering when unable to further maneuver without losing return capability.  This was known as a “gentleman’s kill”, and allowed the loser to return to earth after acknowledging defeat; while this procedure was officially discouraged, and then  banned by the command of both sides, it was almost universally accepted by both sides.

Despite the actions in orbit, most of the losses in both forces were the result of launch or reentry failures.  In particular the rate of launch failures increased dramatically in intercept missions due to the unwillingness to reschedule or abort a launch.

Wartime mission failures invariably resulted in a dead pilot , and ran  about 6% per launch/recovery cycle for both sides;  while this seems small, the cumulative  result was an ~50% death rate across 10 missions; the existing astro/cosmonaut corps could not sustain these losses, especially as the rate of mission launches increased in the final months to an average three day turnaround per pilot. As a result, unlike typical air combat, where loss rates are typically asymmetric, both sides faced an almost total loss of skilled pilots, and after approximately 11 months, decided on a cease fire.

The lesson learned for both sides was that ground based interceptor forces could not be relied on for long term conflict.  Accordingly, when the second orbit war broke out in 1961, both sides had larger and truly maneuverable craft (Gemini/Voskhod) operating from either long orbit missions (stretch Gemini,dual Voskhod fighter/tender) , space stations (the Soviet Almaz, USAF MOS), and the first larger fighter conveyors (The USAF Agena I and II FiCons,and the Soviet TKS tender).

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