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Author
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Topic: Launch and scrub statistics
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mjanovec
Member Posts: 2611
From: Midwest, USA
Registered: Jul 2005
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posted May 18, 2007 06:00 PM
   
Does anyone have the statistics showing how many shuttle flights have launched during their first attempt vs. launched during their second or third or fourth (etc.) attempts? |
Ken Havekotte
Member Posts: 1368
From: Merritt Island, Florida, Brevard
Registered: Mar 2001
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posted May 18, 2007 06:36 PM
There is a release that contains such info., however, NASA's Space Shuttle Mission Chronology outlines each shuttle launch attempts. If you can't find a copy of it (online as well), let me know and I could either mail you a copy, or if time permits, check my own notes/etc. for you. Many of the earlier shuttle missions from the 1980s were not on time, however, most of the Shuttle-Mir missions of the 90s and others were, overall, on time during their first launch attempts. |
Ken Havekotte
Member Posts: 1368
From: Merritt Island, Florida, Brevard
Registered: Mar 2001
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posted May 19, 2007 07:32 AM
Just for the fun of it, the following listed shuttle missions (we'll start with the early ones, first 25 from 1981-86, for now) that were not launched on time once NASA firmly had their launch dates set months in advance: - STS-1 (a timing skew delay of 2 days)
- STS-2 (nearly 1 month of delays)
- STS-3 (liftoff delayed 1 hr.)
- STS-6 (long 2+ months delay due to hydrogen leak at first)
- STS-8 (a 17-minute delay due to weather)
- STS-9 (28 day delay due to suspect exhaust nozzle on right SRB)
- STS-41B (launch delay while Challenger still in OPF to allow changeout of all 3 APUs)
- STS-41D (four delay problems within a 2 month period)
- STS-51A (1 day delay due to wind shears in upper atmosphere)
- STS-51C (1 day delay due to freezing weather conditions -- most interesting, huh!)
- STS-51E (was later canceled with the orbiter re-manifested with 51-B payloads; 51-B launch delayed 18 seconds due to a launch processing system failure)
- STS-51F (launch delayed just over 2 weeks when countdown was halted at T-3 seconds when #2 main engine colant valve shutdown)
- STS-51I (3 day delay due to in-area thunderstorms and a general purpose computer failure)
- STS-51J (launch delayed for almost 23 seconds because of a main engine LH2 prevalve close "on" indicator)
- STS-61C (delayed for almost a month due to a variety of concerns)
- STS-51L (6 day delay ---)
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tfrielin
Member Posts: 71
From: Athens, GA
Registered: Feb 2007
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posted May 21, 2007 11:02 AM
Just for a basis of comparison:Thirteen Saturn V launches. Zero scrubs. Two delays: Apollo 14 -- delay for weather to clear;
Apollo 17 -- computer glitch |
Ben
Member Posts: 1756
From: Daytona Beach, FL
Registered: May 2000
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posted May 21, 2007 12:42 PM
And of those Saturn V launches, I believe 7 went into totally overcast skies and one got struck by lightning.  I'll stick with a scrub so I can see it and get a safe ride. The problem with scrub stats is the launch windows. In my mind, if it goes on the first try that's enough to say on time. But the ISS and Mir flights, you have to realize, had/have just five or ten minute windows. So many of those launches that had 2.5 hour windows would not have gone under those circumstances. |
Robert Pearlman
Editor Posts: 16931
From: Houston, TX
Registered: Nov 1999
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posted August 07, 2007 04:27 AM
From the Associated Press:  A database analysis by The Associated Press showed that 47 of the 118 previous space shuttle missions have taken off on their originally scheduled day. Technical glitches account for more than half the delays. (Endeavour was held back because of a leaky valve in the crew cabin.)Bad weather at Kennedy Space Center is to blame for about a third. |
moorouge
Member Posts: 94
From: U.K.
Registered: Jul 2009
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posted August 26, 2009 12:38 PM
How many launches have taken place at the originally planned date and time?Editor's note: Threads merged. |
Delta7
Member Posts: 585
From: Bluffton IN USA
Registered: Oct 2007
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posted August 26, 2009 12:45 PM
There are 3 things certain in life. Death. Taxes. Shuttle launch scrubs.  How often do Soyuz launches get scrubbed? I can't remember a case of a crew having to egress after being strapped in to their spacecraft. And weather never seems to be a factor. Or maybe it's just not publicized as much. |
ilbasso
Member Posts: 639
From: Reston, Virginia USA
Registered: Feb 2006
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posted August 26, 2009 01:01 PM
I was perusing the NASA Press Book for the latest mission the other day, particularly the launch abort section. I was interested to find that they classified the several situations where the SSME's started and then shut down as "Return To Launch Site" aborts. |
Tom
Member Posts: 934
From: New York
Registered: Nov 2000
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posted August 26, 2009 03:37 PM
I believe they are called RSLS Aborts. |
webhamster
Member Posts: 61
From: Ottawa, Canada
Registered: Jul 2008
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posted August 26, 2009 09:58 PM
Yes, RSLS (Redundant Set Launch Sequencer) vs. RTLS (Return To Launch Site). The former has happened several times, the latter has never happened (thankfully). |
issman1
Member Posts: 216
From: UK
Registered: Apr 2005
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posted August 27, 2009 01:40 PM
Weather has not been a major factor in Soyuz launches. I recall that Soyuz TM-18 lifted in very poor visibility in January 1994. While the first ISS crew disappeared into fog as soon as their Soyuz TM-31 vehicle left the pad on Halloween 2000. Just out of curiosity, will Orion be as finicky as the Shuttle? |
Blackarrow
Member Posts: 1198
From: BELFAST, UNITED KINGDOM
Registered: Feb 2002
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posted August 27, 2009 06:28 PM
My one and (so far) only shuttle launch was STS-117 and the statistics show only too clearly that I was fortunate that "my launch" was one of the 40% which made it off the pad on the first attempt. I realise that if I manage to get back to KSC for another launch, the odds favour a scrub. I distinctly remember a feeling creeping over me as the STS-117 countdown reached about T-3 minutes that Atlantis was definitely going to launch, and nothing was going to interfere with the experience. How right I was! |
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