Did you hook up the fuel line to the in-port or the drain-port?
- LRK -
Murphy's law ---
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http://en.wikipedia.org/wiki/
Murphy's law is an adage or epigram that is typically stated as:
"Anything that can go wrong will go wrong".
It is used as either a purely sarcastic musing that things always go wrong, or, less frequently, a reflection of the mathematical idea that, given a sufficiently long time, an event which is possible
(non-zero probability) will almost surely take place. Although, in this case, emphasis is put on the possible bad occurrences.
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Sometimes we complain about the cost of human rating a rocket.
I wonder if we take into account just how hard it is to make something mechanical work as designed, 100% of the time?
- LRK -
I have been reading a number of books recently, some factual about the Moon, some fiction.
Some of you have made suggestions about what might be of interest The stack of books by Robert A. Heinlein is rising with more coming in the mail, but there are others that are of interest as well.
The book "Prey" by Michael Crichton was mentioned and I have had it on a book shelf for some time but had not read.
I picked it up today and started reading about the nanotechnology that goes bad. This was copyrighted in 2002.
- LRK -
In the introduction, Michael Crichton makes the comment, "The total system we call the biosphere is so complicated that we cannot know in advance the consequences of anything we do." He has footnote 1' to that statement that starts out ---
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1. This uncertainty is characteristic of all complex systems, including man-made systems. After the U.S. stock market dropped 22 percent in one day in October 1987, new rules were implemented to prevent such precipitate declines. But there was no way to know in advance whether the rules would increase stability, or make things worse. ...
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Well the stock market has had some fluctuations since, right? Ummm, I think some regulations were done away with also.
- LRK -
On the next page (x) Michael Crichton makes another observation.
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We think we know what we are doing. We have always thought so. We never seem to acknowledge that we have been wrong in the past, and so might be wrong in the future. Instead, each generation writes off earlier errors as the result of bad thinking by less able minds---and then confidently embarks on fresh errors of its own. ....
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This set me to thinking. When I first went on active duty in the Navy I was given a task to fix all the gasoline combustion nose heaters in the S2F airplanes we were using. I remember connecting the fuel line up after checking out a heater for cracks. When I flipped the heater switch, I ported fuel out the drain line. The two hose connections were next to each other and the same size fittings with no special color coding. No big deal, just changed them around but not a good thing to spill gasoline on the cement below.
- LRK -
I remember working with the data from the Lunar Prospector mission where I was looking at a data stream that was about five minutes old. My PC looked at a file of data that had been transferred to a Digital Corporation Micro VAX from the secure network the operators looked at.
(no one wanted my PC anywhere near their workstation data.) I came in one morning and the hexadecimal display of a portion of the data stream was fixed, not changing.
Normally the numbers and letters would be different as different data came in. I asked the operators if anything was wrong. Nothing noted, until they looked at their data stream. Frozen, not changing. After they consulted with the Primary Investigators it was decided to send commands to Lunar Prospector to reset the buffer counters. It seems that the counter could not handle the size of the count for how long the spacecraft had been running. The data had been frozen about 3 hours. I seem to remember this happened again during the mission but now they knew what was wrong.
No big deal, you just looked at my 5 minute old web site data repeated every 5 minutes for the time that no new data arrived. The scientists missed some data but that happened if there was a break in coverage from the Deep Space Network. The mission was a year and a half, so the Moon was seen many times and data averaged.
When you think that ten fingers is enough to count the number of tick marks and you find you need your toes also, problems can arise. It is hard to think of everything, but gets to be more important if you have humans on board.
- LRK -
I did programing for a company that wanted to test gas control valves for the etchers that are used to make your integrated circuits. I wrote some code that I thought worked just fine. My supervisor would test it and make the code malfunction. I had not checked for humans entering commands in wrong ways, or out of sequence or just wrong numbers. You had to think of all the ways entries could be done wrong and help them make the correct entries or not allow wrong ones. It was important the the control valves worked properly or corrosive gases could make a mess of your etch job. If you took the valves out of the system when they didn't work correctly, they would often become corroded by exposure to air after having corrosive gasses in them. It was to the buyers advantage to be able to test the valves in clean nitrogen before putting them to work with the real stuff.
- LRK -
We went to the Moon and the Astronauts had to enter numbers in the proper sequence with the correct values or you weren't going to land on the Moon in a pleasant way. Entries were read back and checked by ground personnel. Still, leaving some equipment on that wasn't needed can cause a problem.
- LRK -
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http://en.wikipedia.org/wiki/
snip
DSKY interface
Apollo computer DSKY user interface unit.
LM DSKY interface diagram.
The user interface to the AGC was the DSKY, standing for display and keyboard and usually pronounced dis-key. It had an array of indicator lights, numeric displays and a calculator-style keyboard. Commands were entered numerically, as two-digit numbers: Verb, and Noun. Verb described the type of action to be performed and Noun specified which data was affected by the action specified by the Verb command.
snip
PGNCS generated unanticipated warnings during Apollo 11's lunar descent, with the AGC showing a 1201 alarm ("Executive overflow - no vacant areas") and a 1202 alarm ("Executive overflow - no core sets").[5] In both cases these alarms were caused by the AGC running out of resources, due to the rendezvous radar, which had been left on during the descent, requesting cycles from the AGC via an interrupt. When the separate landing radar acquired the lunar surface and the AGC began processing this data too, these overflow errors aborted the computer's current task, but the frequency of radar data still meant the abort signals were being sent at too great a rate for the CPU to cope.[6]
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My dad, as a school teacher, would take summer classes to improve his skills. He took a math class at the University of Washington in Seattle Washington. There was only one test for the class and only one problem. It was written on the black board. (they had black chalk boards back then) Dad copied the problem, and worked correctly the problem he copied. The teacher gave him a 'C' for the class.
When dad asked why the 'C' the instructor told him he should have flunked him. It was an algebra problem and dad had copied an exponent wrong. Never mind that he worked his
problem correctly, the instructor said that this was an Engineering Class and copying the data wrong and using that data to make a bridge, does not count if the bridge does not cover the span.
Using the wrong units of measurement does not make for a correct spacecraft orbit if one writes data in metric and someone else thinks it is in English units.
- LRK -
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http://www.spaceref.com/news/
NASA Advisors Explain Mars Mission Failures to a Concerned Congress
Keith Cowing
Wednesday, April 12, 2000
snip
At the core of the Committee's concerns was the failure of the Mars Climate Orbiter (MCO) mission because of simple metric Vs English units conversions and its subsequent crash on Mars; the loss of the Mars Polar Lander (MPL) apparently due to one bad line of software and its crash on Mars; and the disappearance of the twin DS-2 probes which were simply not ready for launch in the first place.
snip
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What is that I hear hissing?
- LRK -
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http://spaceflightnow.com/
Valve problem threatens to delay April shuttle launch
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: March 13, 2010
Engineers are troubleshooting the apparent failure of a helium isolation valve in the shuttle Discovery's right-side orbital maneuvering system rocket pod, officials said Saturday. If the problem cannot be resolved at the pad - and sources said the engineering options are limited - NASA could be forced to haul the shuttle back to its hangar for repairs, delaying a planned April 5 launch.
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And then there were those WWII Gremlins, but that might have been before your time.
- LRK -
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http://groups.google.com/
Rob Arndt
Nov 2 2008, 2:36 pm
Newsgroups: rec.aviation.military
From: Rob Arndt
Date: Sun, 2 Nov 2008 13:36:10 -0800 (PST)
Local: Sun, Nov 2 2008 2:36 pm
Subject: WW2 "Gremlins" Originated from Spitfire Pilots???
WW II aircrew were telling stories about them as early as the 1940's, and Ronald Dahl, an ex-RAF-pilot, wrote "The Gremlins," a fairy tale about the hazards of combat flying, in 1942. The book was published by Walt Disney and serialized in Cosmopolitan. Disney wanted to do a movie on the book that even Eleanor Roosevelt read to her grandchildren, but could not figure out how to make creatures who destroyed Allied aircraft lovable.
A Poem from WWII known to some English PRU pilots who first encountered the Gremlins that caused many problems for flight crews in the war. (Gremlins were alleged to be mischievous, elf-like beings that were the "real" cause of engine trouble and other mechanical difficulties):
This is the tale of the Gremlins
As told by the PRU
At Benson and Wick and St Eval-
And believe me, you slobs, it's true.
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Have a great day and I hope the Gremlins don't bite you.
Thanks for looking up with me.
- LRK -
Web Site: http://lkellogg.vttoth.com/
BlogSpot: http://kelloggserialreports.
RSS link: http://kelloggserialreports.
Newsletter: https://news.altair.com/
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http://en.wikipedia.org/wiki/
The Gremlins
From Wikipedia, the free encyclopedia
The Gremlins is a children's book, written by Roald Dahl and published in 1943. It was Dahl's first children's book, and was written for Walt Disney, optioned for a film that was never made, in part because no one could establish exactly who owned the word "gremlin" and in part because they could not figure out how to make creatures who destroyed Allied aircraft lovable enough for a cartoon. On 25 September 2006, a reprinted edition of the book was released by Dark Horse Comics.
The story concerns mischievous little mythical creatures, the Gremlins of the title, that were often used by Royal Air Force pilots as an explanation for mid-air mechanical troubles and mishaps. In Dahl's book, the gremlins' motivation for sabotaging British planes is the destruction of their home, a forest, which was flattened to make way for an aircraft factory. The principal character in the book, Gus, has his plane destroyed over the English Channel by a gremlin, but is able to convince the gremlin as they parachute into the water that they should join forces against a common enemy—Hitler and the Nazis—rather than fight each other. Eventually, the gremlins are re-trained by the Royal Air Force to help repair, rather than sabotage, aircraft, and they also help restore Gus to active flight status after a particularly severe crash. (This was a kind of autobiographical reference for Dahl, who had flown as a pilot in the RAF, and was barred from flying after serious injuries sustained in a crash landing in Libya. He later returned to flying.) The book also contains picturesque details about the ordinary lives of gremlins: baby gremlins, for instance, are known as widgets, and females as fifinellas, a name taken from the great "flying" filly racehorse Fifinella, who won both the Epsom Derby and Epsom Oaks in 1916, the year Dahl was born.
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WHAT THE MIND CAN CONCEIVE, AND BELIEVE, IT WILL ACHIEVE - LRK
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