Probe Crash Due to Misdesigned Deceleration Sensor 374
squirrelhack writes "Seems as though the Genesis spacecraft was able to launch from earth, travel through space, avoid aliens, and cruise back into the atmosphere to be caught by stunt pilots waiting patiently with their helicopters. Alas, the brakes didn't work because a sensor was designed upside down.
There is a bright side (Score:5, Interesting)
The primary limitation is the maximum weight we can get to the Earth/Moon Lagrange points. Once at the L-points, the cargo pretty much travels one gravity slingshot to the next with nearly no fuel expenditure. This could be a massive boon for sending Interplanetary mission cargo, especially when staging manned missions!
The only down side is that the IPSHwy is simply too slow for manned travel. Not too bad of a tradeoff, however, when you consider the amount of mass that can be more easily staged at Mars in advance! It's certainly reasonable that we could have a complete microsat network at Mars before a human ever sets foot there. Services that could be provided include:
- Mars GPS system
- Deep Space Network [wikipedia.org] Uplink
- Satellite Radio Communicators for landing teams
- Detailed mapping and emergency surveillance of problem areas
In short, we could have a complete technological infrastructure on Mars before we risk anyone's life going there. It wouldn't have to be like the moon mission. We could go to stay.
Blame game... (Score:5, Interesting)
Jonah Hex
Why does Lockheed Martin continue to get NASA work (Score:5, Interesting)
Thought we still use Imperial for SPACE WORK (Mars Climate Orbiter IIRC?)
Recently dropped a sat because it wasn't bolted down when they moved it.
Now this.
Can I get like a billion dollars to fail repeatedly? PLEASE?
Re:wtf (Score:2, Interesting)
I caught that too. What I don't understand is what was wrong with the design. Is the crash investigation team saying, "Yeah, the sensors were designed wrong, but, huh, check it out, they were installed backwards too, but that doesn't matter" or what? It seems like them (the sensors) being in backwards would be a big deal, but the article seems to imply that the design flaw was the only relevant mistake.
Anybody have any idea what the flaw was or why the sensors would still work when installed backwards?
Re:wtf (Score:4, Interesting)
For some reason, I'm reminded of the origins of Murphy's Law [improb.com]. I recall that too was the result of some sensors being installed backwards...
Re:There is a bright side (Score:5, Interesting)
Fill a large container with radioactive waste, send it up the elevator, tow / launch it to the nearest lagrange point, and send it down the superhighway.
When it gets to it's exit, thrusters fire and it flies directly into the sun. No more radioactive waste.
Re:It seems ... (Score:5, Interesting)
Mistakes happen, as you say. As is commonly accepted my many software developers, software has bugs.
The parent notes that mistakes happen in even the most expensive projects. I think it's more likely to happen in complex (and therefore expensive) projects.
Redundant logic (Score:5, Interesting)
But recently it looks like they kind of dropped this concept, at least partially. Probably as a cost-cutting measure. The success of the whole mission now depends on the reliability of several single components, like the sensor in discussion.
BTW, did you know that a Mars Rover has a single CPU that carries out all the computation? I found this puzzling. Today, you add redundance in every piece of equipment - even in web blades.
Re:Not expected... tolerated (Score:3, Interesting)
Yes. But the real lesson here is that when you are designing something of this sort, don't design it so that it only works one way round. Make sure that it works in both directions, with the output only enabled for the correct direction...
Re:This stuff is EXPECTED (Score:3, Interesting)
The carburator wouldn't work, it would be removed and replaced, and nobody would think anything untoward had happened.
The problem here is that there's no way to test something like this on, say, a half-dozen demo models before it goes out the door. Every single thing has to work right the first time, without ever going through a full test of all systems. The Mars lander, for example -- we'd have known that the legs bounce hard if we'd landed one before, but guess what? We only got one chance!
Considering this unique design parameter -- make it work without the ability to do a full-scale test -- I think NASA's done a heckuva job.
Re:This stuff is EXPECTED (Score:2, Interesting)
This is the NASA equivalent of accidentally filling your car with diesel instead of gasoline.
I did that to a tractor once. Hey, nobody told me it was the one gas-powered tractor on the farm.
Re:There is a bright side (Score:4, Interesting)
I wonder though if that technique of solidly encasing nuclear waste posted not to long ago might work as a means of jettisoning waste into the Sun?
Re:Redundant logic (Score:1, Interesting)
Re:There is a bright side (Score:3, Interesting)