Shuttle Mission Number - STS-nn

thecommander

Was looking back over the older shuttle missions and saw that some of the earlier missions where suffixed by a letter (STS-61A, STS-61B, STS-61C) and also there is a jump from STS9 to STS-41B.

Anyone shed any light on why they didn't just use a regular numbering system like they've done in later missions.

Beeker

thecommander wrote: »

Was looking back over the older shuttle missions and saw that some of the earlier missions where suffixed by a letter (STS-61A, STS-61B, STS-61C) and also there is a jump from STS9 to STS-41B.

Anyone shed any light on why they didn't just use a regular numbering system like they've done in later missions.

Its a good question my friend. Following STS-9 in 1983 NASA decided to change the numbering system, the 10th flight in Feb 1984 was called STS-41B. This pratice continued until the Challenger accident STS-51L {flight 25} in Jan 1986. The numbering system was dropped after that and flight 26 was called STS-26.
The logic was to avoid confussion:) When a flight was planned it received its STS designation but sometimes the flight slipped and ended up launching out of sequence as often happens STS-126 launched before STS-119 and STS-125. To avoid this they brought in the new system after STS-9. The first number indicated the financial year the flight was to launch. The second number was the launch site 1 for Kennedy Space Center and 2 for Vandenburg {California}. The letter was the sequence the flight was originaly due to fly in. So STS-41B {Feb 1984} was part of NASA's 1984 year from KSC and was the second schedules flight. Challengers STS-51L was from NASA's 1985 financial year {but was delayed to 1986} from KSC and was the 12 scheduled flight. No flights were ever launched from Vandenberg so we never had a STS-62A. The system was far more complicated then the old system so was dropped. What they would have done when we reached the 90's and financial year 1994 etc I have no idea:)
Hope that explains it.

thecommander

Beeker wrote: »

Its a good question my friend. Following STS-9 in 1983 NASA decided to change the numbering system, the 10th flight in Feb 1984 was called STS-41B. This pratice continued until the Challenger accident STS-51L {flight 25} in Jan 1986. The numbering system was dropped after that and flight 26 was called STS-26.
The logic was to avoid confussion:) When a flight was planned it received its STS designation but sometimes the flight slipped and ended up launching out of sequence as often happens STS-126 launched before STS-119 and STS-125. To avoid this the brought in the system after STS-9. The first number indicated the financial year the flight was to launch. The second number was the launch site 1 for Kennedy Space Center and 2 for Vandenburg {California}. The letter was the sequence the flight was originaly due to fly in. So STS-41B {Feb 1894} was part of NASA's 1984 year from KSC and was the second schedules flight. Challengers STS-51L was from NASA's 1985 financial year {but was delayed to 1986} from KSC and was the 12 scheduled flight. No flights were ever launched from Vandenberg so we never had a STS-62A. The system was far more complicated then the old system so was dropped. What they would have done when we reached the 90's and financial year 1994 etc I have no idea:)
Hope that explains it.

Perfect answer. 10/10

BULLER

thecommander wrote: »

Perfect answer. 10/10

Haha, not quite!

STS-41B in Feb 1894? NASA really screwed up the numbering there, that was way before even STS-1!

A- Beeker

Beeker

BULLER wrote: »

Haha, not quite!

STS-41B in Feb 1894? NASA really screwed up the numbering there, that was way before even STS-1!

A- Beeker

:oooops:D