The funny story of NASA's numbering
Introduction
To understand the numbering system of NASA, we must plunge into the glorious and euphoric years of the first missions of the U.S. Space Shuttle. On April 12, 1981 Shuttle Columbia made its maiden flight in order to certify the Shuttle as machine operational. The missions follow and nothing seems to stop this mad frenzy. Launch after launch, the shuttle impressed by its reliability and its modernism.
NASA and the USAF main "customers" of the shuttle are not always in agreement. The USAF wants to have its own shuttle (Atlantis) and his own base (Vandenberg) as originally scheduled by the program. NASA must imagine a new numbering system.
To do this, NASA will take into account the fiscal year, the number of the launch site, and the chronological order set out the mission during its design. It may seem attractive, but in fact, this terminology will become a real headache!
The implementation
With the certification of acquired after the Shuttle STS-4, USAF completes preparations for its base in Northern California at Vandenberg (They will use the Shuttle Enterprise for its testing of assemblies on the shooting pad SLC-6 "pronounced Slick Six ", as the Shuttle" military "Atlantis is still under construction). NASA early in 1984 introduced a new numbering system, after STS-9 (should have called STS-41-A is the first of the fiscal year 1984 (30 September 83 October 1, 84).
Thus, the 10th shuttle flight was called STS-41-B instead of STS-10. The number 4 shows the fiscal year (1984) and the number 1, the launch pad at the Kennedy Space Center in Florida (2 being that of Vandenberg in California). The letter B is the second launch scheduled in the fiscal year.
Please note that the NASA's fiscal year begins October 1 to September 31 which will not simplify things.
In a perfect world, this system was relatively simple, but the problem is that it is difficult to make a shuttle take off on schedule (but is still in the phase "Nasa Euphoric" that sees think big ... )
So why the 21th Space Shuttle mission which took off October 3, 1985 was called STS-51-J? Because, as mentioned above, the fiscal year of 85 NASA ends September 30! She should have called STS-61A! Or why do we find in the list of missions an STS-51-L (ie the 12th mission of the year) while in the same year there are only nine missions?
Welcome to the crazy story of NASA's numbering! To understand what real quack, we must understand that the missions are decided long before launch and that these launches themselves suffer delays often very long because of the state of the fleet of shuttles and even cancellations as was the case with the STS-51-E (combined with STS-51-D). Some commercial missions are simply canceled while the numbering of the following tasks are already allocated ... What to do when a Mission is canceled? Change and rename all following missions in order not to leave a "gap"? What to do when a Mission can not be achieved because no Shuttle is available or that the payload is not ready?
Take for example the fiscal year 84 of the 10 scheduled flights, only five were able to achieve. Indeed, the shuttles Columbia and Atlantis will be available in late 85) and was only two Nasa Shuttles for that year. Difficult to launch 10 missions in these conditions. Note that NASA had to repeatedly postpone the first flight of the Shuttle Discovery due to technical problems.
As the years pass more such anomalies are shown in Table hunting of the U.S. space agency.
The back
On January 28, 1986, NASA will experience a serious setback that will require to reassess its ambitions. 73 seconds after the launch of the Shuttle Challenger for mission STS-51-L, the Shuttle disintegrates killing seven crew members. NASA will be blamed and budget revised down. The Shuttle is no longer American dream and they see it as a lethal weapon ... Shaken by the tragedy, the authorities of NASA will have to make significant changes to use the shuttles again one day.
Changes in the launch pad from Vandenberg SLC-6 is still under way (The choice of this site was chosen to perform missions with polar orbits), and expenses incurred in the redevelopment had been problematic and costly.
Vandenberg Air Force Base should have been commissioned for mission STS-62-A October 15, 1986 but the explosion of Challenger Shuttle nailed the ground for more than two years.
On December 26, 1986, the site of Vandenberg as a base for launching shuttles was officially canceled. Without two launch bases, the value of using such a naming system has no purpose and NASA returned to the previous numbering system. And the first flight which followed that of the STS-51-L was the STS-26.
Xavier Jehl
