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Probe Crash Due to Misdesigned Deceleration Sensor
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.
I read the same story here earlier today, and it also says that it was installed backwards.
(S(SKK)(SKK))(S(SKK)(SKK))
You didn't read the article very well. It says that the specs said the part should go in backwards. From the article:
The sensors, which are estimated to be less than an inch (2.5 centimetres) wide, were apparently installed in a circuit board in the wrong orientation - rotated 180 from the correct direction. But the problem stemmed not from the installation but the design, by Lockheed Martin, based in Bethesda, Maryland.
Javascript + Nintendo DSi = DSiCade
This isn't a trick question on your high school physics quiz. Just because the term deceleration is not preferred because it is ambiguous does not mean that it doesn't exist. Maybe it's *acceleration* that doesn't exist!
From Dictionary.com:
3 entries found for deceleration.
decelerate Audio pronunciation of "deceleration" ( P ) Pronunciation Key (d-sl-rt)
v. decelerated, decelerating, decelerates
v. tr.
1. To decrease the velocity of.
2. To slow down the rate of advancement of: measures intended to decelerate the arms buildup.
v. intr.
To decrease in velocity.
Lest I get a bunch of "What are you talking about?" responses:
a y_0410 11.html
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For them dropping the NOAA sat:
http://www.space.com/spacenews/businessmond
(first link I found)
Climate Orbiter:
http://www.space.com/news/mco_report-b_
-- IANAEG - I am not an elder god.
Said another way, When they installed the part, they installed it with the "Up Arrow" pointing up like the directions said, but the people who designed the part had the "Up Arrow" pointing the wrong direction.
So the failure was in design, not installation. The net result still being it ended up backwards.
At least that's what I'm reading.
Always with the sun. What did the sun ever do to you?
Seriously, a solar or even a high earth orbit is fine for storing waste indefintely. Don't need to waste delta vee directing it into a star. Stuff is heavy.
I hate to tell you this, but NASA HAS been using proven parts in spacecraft, there is a strong push for COTS (Commercial Off-The-Shelf) Hardware, it's much cheaper than designing every op-amp from scratch. But this COTS stuff has to be beyond military spec, it has to be rad-hard, withstand severe thermal and vibrational stresses, etc. It's easy to make a reusable op-amp or logic gate in a desktop computer, but for a satellite they have to be MUCH more rugged.
Regarding this accelerometer, not sure why it had to be different, but like I said before, it definitely needed to be rad-hard, endure strong vibrational and thermal extremes, and still function flawlessly upon re-entry. That's not easy to design, and there are 100000000 things to go wrong, one of which is that it's installed backward.
Now as to the reason they don't re-use spacecraft designs is that every craft has different operating parameters. Some are very far from Sun and Earth, and need higher-gain antennas (ie, parabolic dishes that can retract) and RTG's (solar panels become inefficient beyond Jupiter). Some operate close to Earth orbit and use solar panels and smaller antennas. Some will never re-enter earth, some will burn up on re-entry when their use is finished, and some need to survive re-entry intact. Some craft close to the sun (eg SOHO) need special rad-hard thermally-shielding designs. The inclusion or exclusion of each of these items will drastically change the structure of the craft.
So basically, each mission is so different that it's very unfeasible to come up with a reusable 'strawman' design from which to start all NASA craft. And this is just considering operating environment, power, and communications. That's not even including the scientific instruments, all of which need specialized heating or cooling or shielding or vibrational-isolation requirements, etc.
make world, not war
I remember trying to put plastic containers in a field to use as markers for trees (long story) and after about 2 years had to be replaced as they had decomposed
1) Some plastics are designed to decompose.
2) Most plastics that aren't designed to decompose... don't. Instead they undergo weathering by the elements and 'vanish' as they are ground down by sun, wind, rain, and snow into plastic dust which then remains in the environment for hundreds/thousands of years. This is a worldwide problem.
This flies against all the enviromentalists saying they will stay here forever
It flies against nothing. Just because something is too small for you to see does not mean that it is 'gone'. Weathering does not equal decomposition. Choice quote from the BBC article: "...this study suggests that practically everything really is made of plastic these days - even the oceans."