When is a space flight not a space flight?

Over a decade later, a third suborbital trajectory was inadvertently flown during an aborted Soyuz launch in April 1975. In this case, a spent stage of the R-7 launch vehicle failed to separate cleanly and caused the remaining launch vehicle to veer off course, triggering an abort just a few minutes into the mission before completing an emergency parachute recovery just over 21 minutes after launch. As a result of the failure, the Soviets did not assign an official Soyuz designation to the flight (it should have become Soyuz 18). Instead, they termed the event “the April 5 anomaly”. In the West, this “mission” is often referred to as Soyuz 18-1, to distinguish it from the successful replacement Soyuz 18 mission flown with a

different crew a few weeks later. As the aborted flight attained a peak altitude of 119 miles (192 km) it was officially credited as a space flight in progress, becoming the highest altitude suborbital trajectory to date.

In September 1983, a second Soyuz launch was aborted seconds before release from the pad when the carrier rocket suddenly exploded. The emergency escape rocket fired and propelled the crew to a safe, if rapid recovery five minutes later. As the maximum altitude attained was just a few thousand feet and the “launch” had not taken place, this did not become an accredited space flight or official “mission”. It was an unwelcome and surprising experience. In July 1985, Shuttle mission 51F suffered a main engine failure which threatened its ascent to orbit. Fortunately, sufficient velocity and altitude had been attained at the time of the failure and the loss of the engine could be compensated by those remaining. Abort-To-Orbit (ATO) mode was followed, resulting in a lower-than-planned Earth orbit which was modified over the next few days.

The question of when a space flight is not credited as a flight into space, but is instead deemed a mission in progress, was demonstrated tragically in January 1986 with the STS-51L mission and the tragic loss of the Space Shuttle Challenger and its crew of seven. The vehicle exploded just 73 seconds after leaving the pad at an altitude of 14,020 m (45,997 ft.), far below the recognized altitude to be termed a true space flight. However, in respect to the lost crew, NASA credited them post­humously with a mission duration of 1 minute 13 seconds to the point of the disaster and officially termed the ill-fated flight a “space mission in progress”.

This same classification was attributed to the STS-107 mission in February 2003, when that vehicle and its crew of seven were lost during a high-altitude breakup just 16 minutes from the planned landing in Florida. Again as a mark of respect to the crew, they were credited a mission duration to the point of loss of signal. Unlike STS-51L, they had completed a 16-day flight and were coming home from orbit when disaster struck. In most records of space flight missions, the flights of Soyuz 18-1 and STS-51L tend to be listed as attempted orbital mis­sions which fell short of that goal during flight. Had all gone well, they would have both attained sufficient velocity to have been accredited as true orbital space flights.