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.
Larry - re: "We can't necessarily be too smug about this. I seem to remember an American Mars probe that sailed right past that planet..." There was also the Mars probe that crashed because of a Imperial vs. Metric mix up. And there was also the Genesis solar wind sample & return mission that crashed because the G sensor used to trigger parachute deployment was installed backwards.
@DrQuine: I agree that a simple thing like keying the package should help ensure proper mounting. In this case, the source stated the "angular velocity sensors" may have been the wrong way around. The only way to test those after they're installed may be to rotate the rocket, as they only respond to dynamic rotational motion - sitting on the launch pad, they will report zeros. (although the Proton system seems to include rotating the rocket in place, I'm not sure of the feasibility of having the navigation systems in a test mode during that operation).
I'm sure there will be an analysis to prevent this from happening in the future.
@Kevin N: Okay if all redundant sensors were mounted backwards, this could be due to manual error that instructions for installation were not followed appropriately or instruction for installation was dubious; Also then, there was a process gap that the installation was not reviewed by somebody independently.
By the way...will there be any official report released some point of time?
Interesting comment--this type of thing happens often? It's a bit amazing that the systems that we look at to be in the forefront of innovation can be brought down by such errors. I really appreciate all of these comments. At first I thought this couldn't be true, but the more I read from those of you in the know, it seems pretty possible.
It is very difficult to believe that such a mistake could have been made !
It will be interesting to know the design of the sensors- where there was an indication of how to mount them . If the basic instructions has been overlooked then it shows a poor standard of inspection and testing of a billion dollar product
Good point, Sanjib. You would think that there would be redundant systems. In the US, it's standard practice to have triple redundancy on space probes. And the monitoring stations on the ground watch every indicator. There is certainly a possibility that this report is true, but I think there is a larger chance that the report is based on poor information.
@Tom: I agree with you. I am a bit skeptic about the source, which has pointed to an important sensor getting installed "Up-side Down" as the cause of the failure. Why I think so?...several reasons. One is already mentioned by Tom. Also:
1. There should have been well-established processes for design, development and manufacturing space equipments as this kind of space programs deal with huge money, reputation and safety. The process should have been rugged enough to prevent this kind of human error. If not prevented, atleast, it should have been caught in inspection or some kind of quality checking/reviews.
2. Even if it was a mistake, I think design should have had redundant sensors to take care of this kind errors. Hope not all of those were mounted "upside-down"...otherwise there must had been a serious process gap somewhere.
I don't think this kind of error getting un-detected is something which could be expected from a well settled space organization isn't it?