We have now seen several instances of software failing or generating
anomalies while undergoing vibration testing. This "White Paper" is
an effort to explain this phenomenon in relatively non-technical terms.
Spacecraft flight software (s/c fsw) may encounter a severe vibration
environment during launch. In order to ensure that the software is
robust enough to survive this environment we subject it to vibration
tests which simulate the launch stresses.
As we all know software consists of binary numbers, ones and zeros,
which make up the data and instructions of a program. The ones are of
particular interest in vibration testing. Zeros, being nothing, are
not affected by vibrations or accelerations. But binary ones, being
tall and skinny, are particularly susceptible to transverse vibrations,
although vibration along other axe may also exhibit resonances,
depending on the font utilized.
Of special interest in the study of binary vibration response is the
case where ones are surrounded by zeros. Again, zeros being nothing,
provide no support for neighboring ones. For example a fragile byte
like 0xAA is much more prone to failure than the more robust byte 0xFF.
Also one must take into account the mass of the individual bits. MSBs
(most significant bits), having more inertia, are more susceptible to
failure when not sufficiently braced. For example a 0xAA byte will
usually fail to a 0x2A.
There are, as usual, trade-offs to be made. The addition of ones to
act as bracing can adversely effect the s/c mass budget, as well as
complicate the role of an optimising compiler.
Yeah thats ridiculous its making it sound as thou the 1 in a binary is a real object that can be shooken enough to fall over and a zero is indeed something and not nothing and are every bit important as a 1.
If 0 was nothing then only 1's would be present therefore never changing from on to off and visa versa so there could not be any data if every signal is on
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Binary code can't vibrate around on a disk any more than letters can vibrate around on a page.
Vibration can cause hardware failures, not software failures.
thats what i was thinking... i mean vibrations can cause physical damage to the disk, thus losing data.. but the actual binary code vibrating out of place...i dont think thats possible..
yeah...wtf? thats gotta be a joke of one kind or another. it clames that on/off pulses(binary) are suspeptible to jarring because they have mass and volume...thats just stupid.
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