Sensors are highly reliable, especially the high-performance variety used in aviation/aerospace apps. However, human error sometimes interferes. It seems that failure to install angular velocity sensors correctly in the Russian Proton-M rocket resulted in a crash on July 2.
What happened? A source involved with the commission investigating the crash told the Interfax news service that angular velocity sensors were "connected the wrong way round" and delivered incorrect data to the guidance system.
The Russian space agency Roscosmos has not confirmed the cause. A source with links to the commission told Interfax that it is investigating a number of possibilities, including a problem with the navigation system, engine malfunction, and an error in the equipment at launch control.
A Proton-M booster rocket with a DM-03 upper stage and three Russian GLONASS-M satellites sits on the Baikonur Cosmodrome launch pad. (Source: RIA Novosti/Roskosmos press service)
Whether the cause was inverted sensors or something else, three navigation satellites and $1.3 billion of equipment was destroyed in the crash, according to Interfax. Just 17 seconds after takeoff, the rocket rapidly veered off course and tried to correct, but it plummeted towards Earth and exploded on contact only 2.5km from the launch site.
The Voice of Russia radio service said the rocket carried 172 tons of highly toxic heptyl fuel and oxidizer. Interfax said 100,000 residents were evacuated, and efforts are under way to detoxify the soil.
ETmax, Karen: Do you really think that Americans (half of whom apparently think public healthcare is a socialistic concept) would be willing to switch to metrics -- throwing out their beloved tape measures and rulers in the process and recasting every property measurement in the country? Consider American football alone: can you imagine the Super Bowl played on a 91.44-meter field?
Cost aside, I think it is a noble but unobtainable goal. (Besides, what are you going to do about that pesky Imperial Gallon in Canada -- 20% larger than the US gallon) There is need for change in America. I'm not sure this one tops my list. What do others think?
@ETmax I don't disgree with you that it's costing a bundle of money to run a dual system, but unless those costs appear as a line item on somebody's balance sheet, there isn't much impetus for government or industry or somebody to pony up and do something about it. Since nobody can measure these hidden costs, how can the ROI of a massive, one-time investment be calculated? Sorry, but it's just the way our financial systems are wired--do nothing until our back is up against the wall, and even then, only maybe do something.
I'm a take the bull by the horns sort of guy, so I would suggest that the cost of changing will get ever larger while the cost of doing nothing will grow larger still, sort of like global warming (if you subscribe to the idea). I think the cost of change as a percentage relative to GDP is probably near a contant, where as the cost of not changing will just continue to go up. When I started in design all part footprints were imperial, now virtually all new footprints are metric, even new ones from US design houses. Even though the US is the worlds largest economy, if you do a "size of imperial economy" vs. "size of metric economy" and factor in how much of the US output goes into export goods to metric economies, it soon becomes clear that there must be a significant financial burden in running dual systems. Add to that I was watching an air crash investigation episode where a airport attendant was refueling a metric plane and did his fuel calculations as if the tank level reading he was getting was gallons and as a result the plane was forced to land without fuel at a desert airport. If it would have been an ocean landing all on board would have died. These sort of things can only happen in a dual measurement world and are extremely costly my guess is $350million per plane and maybe $10 million per passenger (how much is a life really worth). The ESA crashed a Mars lander because the landing computer was metric and someone did the calculations in imperial, that was $3billion. I don't mean to harp on this issue, but there are just so many examples of this, some we just don't hear about. What would the additional cost of insurance be if this was deemed an additional cost of doing business with the US?
@etmax Good question about English versus metric units. I remember back in grade school the U.S. preparing to "go metric," and that was more years ago than I care to admit. I think the cost of conversion would be so great at this point, that it's simply easier to not deal with it. Not that it's the right thing to do.
Were the sensors mounted backwards or connected backwards? Seems to me for something like this the connectors would be keyed so that they could not be put together incorrectly. Anyhow, it would explain why the rocekt made a beeline for the goournd when is should've been going in the other direction.
There was also an Ariane rocket that died due to Metric/Imperial issues. I can't understand why anybody is using imperial any more in science. The whole world's science community is supposed to be metric now. Australia went metric in 1970 (enacted into law) and made it illegal to use metric offically. All packaging had to have metric measure and good were sold by metric measure. Even building products which were often imperial sized had their metric equivalent printed on them. The end result was it all happened and very few look back on it as a negative thing. The Russians are of course metric so that one is ruled out but the argument for testing is a difficult one in an assembled rocket. It probably wasn't electrical orientation but rather mechanical, but how do you rotate a fully assembled rocket fast enough to test gyros? I guess the more complex these things become the more difficult an ideal testing regime becomes. BTW, I replied to your post only to mention the metric issue, sorry to add so much more :-)
Actually it is not a cliché but an adage or epigram according to Wikipedia.
Here is an interresting link.
I have been a techie for 50 years and when designing or building things, always keep Murphy's Law in mind. No insult intended.
Join our online Radio Show on Friday 11th July starting at 2:00pm Eastern, when EETimes editor of all things fun and interesting, Max Maxfield, and embedded systems expert, Jack Ganssle, will debate as to just what is, and is not, and embedded system.