Re:The remaining wheels are still used
on
Hack in Space
·
· Score: 2
Thanks for the extra info!
It turns out that although the torquer bars are not designed for fine control (their control bandwidth is 15 times lower than the reaction wheels), the satellite is also heavy compared to the MTB's torque. So, the pointing stability is in fact quite good, and the jitter is not much worse than what we had before... as long as the satellite is not pointed in a part of the sky where gravity gradient disturbances are strong.
An oversight on my part;-) I have only worked on the smaller variants of satellites (100kg to 500kg) - dwarfed by the FUSE of course! The smaller sized S/C poses interesting problems at times. E.g. on one satellite the imager had its own stepper moter used to rotate the optics to enable stereo imaging (scanning the earth's surface from different angles). The dynamics of the small stepper moter had to be considered in the control loop as it had a gyro effect on the rest of the S/C due to the satellites relative small size (about 80kgs if I recall correctly)!
Sorry, the Preview screwed up the URL. Here is the link to the original NASA Press Release.
The remaining wheels are still used
on
Hack in Space
·
· Score: 5, Insightful
At first I was quite surprised at the quoted pointing accuracy achieved (1/4000th of a degree) by using only the magneto-torquers - as implied by the article. The original intended use for these torquer rods are clearly explained in other comments, so I will not repeat them here.
What the article omits is that the fine pointing accuracy is achieved using the magneto-torquers in combination with the two still operational reaction wheels. From the original NASA press release (dated 14 Dec 01) where the anomalies with the two reaction wheels were reported the strategy was laid out to rescue the science mission:
One of the new control mode concepts being investigated is to use the two operational reaction wheels in conjunction with the satellite's magnetic torquer bars to provide control in all three axes. The magnetic torquer bars are presently used to manage the momentum of the reaction wheels by applying a torque on the satellite against the Earth's magnetic field. The torques necessary to make up for the failed wheel would be in addition to that required for momentum management. This is well within the capability of the magnetic torquer bars.
What they probably managed to do is to use the two remaining wheels to do the fine pointing but the satellite will tend to slowly spin 'of course' lacking the two other wheels to compensate. By bringing the torquers into the loop they cancel the spin and attain the fine pointing.
It is nowhere mentioned but I wonder if they can maintain the pointing accuracy long enough to get maximum exposure time. Since they've said that the spacecraft has been restored to full operations I guess it is not a problem.
I'm not trying to take anything away of what they achieved, only to clarify what is omitted from the article (possibly not to make it too technical I guess). It still is an impressive feat and indeed a super hack!
Re:Where to put angular momentum
on
Hack in Space
·
· Score: 3, Informative
You have to know that not all satellites have their own dedicated launch vehicle with a perfectly controlled release mechanism - first by the last stage of the launch vehicle and then by the S/C itself.
In fact, the majority of satellites share a ride with other satellites. The satellites are in fact clamped to the last stage of the launch vehicle. At the moment of separation so called piro bolt cutters (in fact an anvil propelled by a small amount of explosive to cut through the bolts) will cut through the bolts fixing the satellite to it and a passive spring loaded mechanism (in most cases) will slowly and safely push the satellite on its way.
...once things have settled down after release of the satellite...
It is this initial release from the last stage that causes the initial angular momentum and there is nothing but these control mechanisms on the satellite to help 'things to settle down'.
Re:Where to put angular momentum
on
Hack in Space
·
· Score: 5, Informative
All of these are known techniques. It sounds like this satellite had four inertia wheels and an electromagnet for torquing against a planetary magnetic field. The plan was presumably to maneuver with the inertia wheels, and slowly drain off unwanted angular momentum with the magnetic torquer.
In most cases at least 3 single axis magneto-torquers are provided, one per axis and normally one extra for redundancy. They are indeed used to reduce body angular rates and to control the wheel angular momentum. The reaction wheels (or inertia wheels) of course are limited to a maximum speed and to avoid wheel saturation the magneto-torquers are used to 'dump' some excess angular momentum.
With two inertia wheels down, there are still three torquing devices available, so control of orientation is theoretically possible. Tough, but possible. It's impressive that they made it work.
Actually, in smaller LEO (Low Earth Orbit) satellites this technique has been used for years to facilitate orientation control. It is normally used to reduce the spacecraft angular rates directly after separation from the launch vehicle. Using the magneto-torquers and a magnetometer monitoring the earth's magnetic field, the spacecraft can be controlled into a stable state with the minimum of hardware and with relatively simple control algorithms.
The idea is to get the spacecraft into a stable, known state (either earth pointing or aligned with the earth's magnetic field) before the more complex systems are powered and tested. You need to be sure your star camera, reaction wheels, propulsion systems and all the other cool hardware is in a nominal state before you enable the complex control algorithms required for more accurate orientation control.
The first satellite I've worked on we could not afford the more expensive magneto-torquers (compact electro magnetic rods) and instead opted for a self made magnetic coil without the assistance of ferrite material. Basically just a very long copper wire rolled into a coil and fixed to the frame of the solar panel (one coil per axis). Crude, but it had the desired effect!
What is really impressive is that they've managed to achieve this level of pointing accuracy with a system intended to achieve only basic orientation control and for desaturation of the reaction wheels.
It is clear that Intel is slipping away from their original core business and maybe even starting to lose the race. Frankly I don't see how they will manage to regain the market domination they used to have.
What else to do? Diversify is the key. Intel already makes the ARM processor (licensed from the UK's ARM holdings) and Intel will pretty soon have a big share in DSPC. What do these two companies (ARM and DSPC) have in common? Both are targeting the cellular market - and both have a good share in it already.
Instead of having all its eggs in one basket, I see this as a strategic move from Intel to diversify its equity. Getting a foot in the door you may say...
Forbes recently featured this article about DSP communications and its founder Davidi Gilo. DSP Communications is on Forbes' list of 300 most promising (small) global companies.
A nice read with some background on the company, how it came to be and noting the big breakthrough in 1994 - capturing a large piece of the digital cellular phone market in Japan. Their biggest focus is now on the American cellular market with US contracts that should contribute more than 24% of their estimated revenue for 1999.
...I don't feel inclined to apologise. I can't believe the waste of time (and here I am wasting even more...) just because you got upset about one spelling mistake.
I speak four languages and English is not my mother tongue - so the only way I can double check for spelling mistakes is with a spelling checker which of course would not pick up proofed as an error. Is it past tense for proof reading something - I think.
I'll try to be positive - at least I'll know the difference between proved and proofed in future;-p
I've submitted this article a few day's ago when it first appeared in The Register on 24/10.
The article has some interesting comments - my personal favourite is the possible impact this may have on companies dealing with the government. They might be forced to make more use of Open Source S/W and systems if they want to have their bids considered by the government.
I just think it's confusing and misleading when a generic app that is open source (and so runs on Linux) is labelled "A Linux app" in a way that makes it appear the two notions are deeply linked
Good point, and as my first post showed - it is indeed confusing! Thanks, for the comment.
However, as we see this more and more "Gnome, the linux desktop system" or "KDevelop, and IDE for Linux" it starts to look like people are thinking only in terms of Linux and its applications.
I'm afraid I don't get your point. I use my PC to get stuff done (and admittingly !waiste a lot of time just playing around;-) KDE, Gnome and all the *non* Linux apps appearing more and more gives me and a lot of other people the opportunity to actually use a kick-ass OS most of the time because I have more and more software available to use.
Just out of interest, what is your definition of a *pure* Linux app?
Most people in the UK uses off-peak hours to connect to the Internet. If you use BT and register your ISP (local call) phone number as a so-called best friend number you'll be entitled to 20% discount to all calls made on this number. I'm just using this as an example, BT has more discount options on offer than any sane person would like to care - all at a cost of course.
Depending on which options you would like to take the call to your ISP may cost from 1pence/min up to 5pence/min. If you're online for an average of 15 minutes per evening (and we all know it is MUCH more than that;-) your monthly fee to BT just for the calls adds up to £22 (about $13.50). Doesn't sound like much, but this is an example for 15 minutes only.
Personally I spend at least $20 a month just for the calls to my ISP. Add to that line rental, costs for all the discount options and the monthly fee to the ISP it really starts to add up!
Luckily my company is based at an University an we're basically sitting on the campus backbone. The bulk of my downloads is done from work, if not for that perk I shudder to think what my monthly phone bill would have been!
I would love to believe that they've regained contact. But according to all my news sources they've not yet managed to do so! The latest update I have from Space Online is time stamped at 8:55 ETD and the news is still NO contact!
Moderators please! Don't give unfounded news items such a high score. The AC didn't even give a link to his news source!
Florida Today's Space Online is running a regularly updated journal for the orbiter. The last entry was made at 7:45 ETD, stating that no contact has been re-established yet...
I hope they manage to re-establish contact... Moments like these are the worst, racking your brains thinking of ways how to solve the problem, wondering what went wrong.
Anyway, for those interested, if they do manage to make contact again here is a link to the real time telemetry of the orbiter.
Not at all - our core businesses differ too much. Landsat sells images at $400-$600 an image - I think. We build and sell micro (100kg) and mini (300kg-500kg) satellite systems to a client interested in his own satellite. Including launch and with a guaranteed turnaround time of 18 months, we supply a complete satellite with ground station for less than 6 million pounds ($10M ?). The fact that we have a very good imager is an added bonus.
Apologies, the images on the web site are mostly 50m resolution images taken by our micro-satellites. The 30m and better images are not yet available on the official page. But you'll find some of the processed images (be warned, some are huge!!) here.
Note that most of these are NIR red, green false-colour images - i.e. red regions are grass/vegetation and the light blue is the built up areas.
My favourite is the one image of Washington DC and surrounding area captured in July, clearly showing the White House, Jefferson Memorial and National Mall leading to the US Capitol.
These are all JPG's - if you have the bandwidth to burn you can download the bitmaps here.
I have been working in the (micro/mini!) satellite environment for some years now and I'll try to comment on your quite valid question: How can this possibly be useful?...
As someone in one of the threads replied the application as stated in the article is for post-evaluation of an incident so I won't dwell on that.
You are quite right that the satellite will only be covering a certain area at a certain time - all dependant on the orbit... As some of you may be aware, a satellite (or any object orbiting the earth) has an orbit period determined by its altitude. The higher the altitude - the longer it takes to orbit the earth. Some figures: a typical LEO (Low Earth orbit) satellite at an altitude of about 800km will have an orbit period of approximately 100 minutes. Geo-stationary satellites on the other hand has a 24 hour orbit period but has to be at a very high altitude - 35786 km to be precise!
To get back to the point. For high resolution imaging you would like to be as close as possible to earth. Obviously this will bring the complexity and cost of your optics down - and believe me, it is expensive! But you have to consider that a LEO implies a fast orbit with some advantages and disadvantages.
A LEO orbit (600-1200km) has the advantage that the satellite's footprint will cover most of the earth in approximately 12 hours. As you need daylight for good imaging, your coverage (for imaging at least) goes up to 24 hours in practice. Allowing for good weather you can see the problem for a quick turnaround time for images e.g. car pile up example stated in the article.
Even a constellation of imaging satellites may proof to be impractical, you'll need quite a few satellites ($$$) to have an image within a few hours. In a previous/. article about this 1m resolution imager (Ikonos) you'll notice that they claim to have the image ready within 30 minutes. What they don't say is that they'll have it ready in 30 minutes after the image has been captured. Impossible to take the image of a certain target within 30 minutes of requesting it!!
IMHO visual forensics (using satellite imaging) will only be practical if the 'crime scene' stay's the way it is for a prolonged time. I can't imagine rescue services waiting for hours until an imaging satellite comes over the horizon before clearing up the debris!!
If you're interested please visit my company's homepage for some earth observation images taken with our LEO satellites over the years. Please note we're not close to 1m resolution - currently 30m multi-spectral and a 10m b/w experimental imager.
I'll be happy to answer more questions if anyone's is interested.
This may be a bit off-topic as the post is obviously targeted to an American audience. But I thought that some of you may be interested how engineering certification works in South Africa.
Disclaimer;-) - most of this is from personal experience as well as from some of my friends. If things have changed in the last couple of years please feel free to correct me. I've been working in the UK for a few years now and I may be a bit out of touch!
In SA the term used is Professional Engineer. You register as a Engineer in Training after you graduate. No need to take an additional exam. I guess they assume that if you have graduated you can at least register;-p
The step from EIT to fully certified Professional Engineer is where the problems start. You have to pay a yearly subscription fee (and you receive some newsletters and documentation - if you're lucky). To be considered for certification you need at least three years professional experience. After three years you have to submit a written report detailing your experience. Having a sort of mentor (who is a Professional Engineer himself) is preferred but not required.
Most of my EE colleagues never bother to go through this. Apart from a few large corporations it has no influence on your compensation package. If you want to go private/consulting you need to be certified though - I think this is required by law.
PS. Just curious: from reading the posts I assume that you have to take an EIT exam (in the USA) to register. But how does it work after that? What do you have to do to become a certified engineer?
I've asked around here at work as well as some friends around the globe and it seems to be the trend. I.e via a MP3 sample they find out if they like it, if they do they buy it. Cool. But what is the motivation behind this? Is it a feeling (integrity, if you like) that some financial recognition should filter back to the artist. Or is the portable convenience (of a CD) the prime motivation for actually buying the original. I would like to believe it is the first, thereby encouraging artists to make their work freely and widely available but only if they have the confidence that enough people will actually buy their stuff in the end. If portability is the prime concern, what would widely available (embedded/portable) MP3 players have on this? Personally I would like to see money flow back to the artists, but to make this a reality the music industry has to change its modus operandi. In such a way at least that the internet can be used as a medium to distribute music, but that the artists get some recognition in the end.
According to the executive director of the Electronic Frontier Foundation (EFF) piracy is not the key issue facing the music industry. She feels that by locking down internet music distribution people might be encouraged even more to 'steal' [music].
I've seen a lot of arguments for the free electronic distribution of music via the internet. One that usually surfaces is that people will be encouraged to buy the original after having easy&free access to it.
My question is: will people or are people currently doing this? I have to admit that the most of the MP3's on my workstation != the CD's in my car!
From a project manager's point of few outsourcing work to contractors have some clear advantages. E.g. if part of the project requires experience not available inside the company this may be contracted to a consultant without the added overhead of employing someone new explicitly for the job (which may be a one-off). It can be argued that it is better (long term) to develop and establish the knowledge base inside the company by training your full time employees. But more often than not in the real world projects have deadlines and limited budgets, making it very difficult for the PM to justify such a long term financial commitment.
BUT, the PM should be aware of the added risks when using contractors. I've seen many projects running into serious problems because of insufficient/bad contractor management. If you think about it the risks involved are most of the time just common sense:
(i) Is he good enough? You normally have quite a good idea of your own employees' experience and strengths. A contractor may have a good reference etc. but some more background research may be needed to establish confidence that he will be up for the job. (ii) Problem definition and design. Too often a badly defined contract causes a lot of delays downstream when you realise that what is delivered is not really what was requested, causing a lot of time for rework and integration. This is often made worse by a PM not willing to commit to the extra overhead and ensuring there is REGULAR feedback (e.g. staggered design reviews and deliverables) from the contractor and good communication between him and your own people who will be using his module.
I'm sure there are many more issues, but I'll stand with the above two. Do the effort for some background research on the possible contractors, don't take one because he's cheap and available NOW;-) But the most important for me personally is a good contract/problem definition (which makes it easier for the consultant as well) and regular feedback and status reports to give you continuous visibility on project progress.
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It turns out that although the torquer bars are not designed for fine control (their control bandwidth is 15 times lower than the reaction wheels), the satellite is also heavy compared to the MTB's torque. So, the pointing stability is in fact quite good, and the jitter is not much worse than what we had before... as long as the satellite is not pointed in a part of the sky where gravity gradient disturbances are strong.
An oversight on my part ;-) I have only worked on the smaller variants of satellites (100kg to 500kg) - dwarfed by the FUSE of course! The smaller sized S/C poses interesting problems at times. E.g. on one satellite the imager had its own stepper moter used to rotate the optics to enable stereo imaging (scanning the earth's surface from different angles). The dynamics of the small stepper moter had to be considered in the control loop as it had a gyro effect on the rest of the S/C due to the satellites relative small size (about 80kgs if I recall correctly)!
Sorry, the Preview screwed up the URL. Here is the link to the original NASA Press Release.
What the article omits is that the fine pointing accuracy is achieved using the magneto-torquers in combination with the two still operational reaction wheels. From the original NASA press release (dated 14 Dec 01) where the anomalies with the two reaction wheels were reported the strategy was laid out to rescue the science mission:
One of the new control mode concepts being investigated is to use the two operational reaction wheels in conjunction with the satellite's magnetic torquer bars to provide control in all three axes. The magnetic torquer bars are presently used to manage the momentum of the reaction wheels by applying a torque on the satellite against the Earth's magnetic field. The torques necessary to make up for the failed wheel would be in addition to that required for momentum management. This is well within the capability of the magnetic torquer bars.
What they probably managed to do is to use the two remaining wheels to do the fine pointing but the satellite will tend to slowly spin 'of course' lacking the two other wheels to compensate. By bringing the torquers into the loop they cancel the spin and attain the fine pointing.
It is nowhere mentioned but I wonder if they can maintain the pointing accuracy long enough to get maximum exposure time. Since they've said that the spacecraft has been restored to full operations I guess it is not a problem.
I'm not trying to take anything away of what they achieved, only to clarify what is omitted from the article (possibly not to make it too technical I guess). It still is an impressive feat and indeed a super hack!
You have to know that not all satellites have their own dedicated launch vehicle with a perfectly controlled release mechanism - first by the last stage of the launch vehicle and then by the S/C itself.
In fact, the majority of satellites share a ride with other satellites. The satellites are in fact clamped to the last stage of the launch vehicle. At the moment of separation so called piro bolt cutters (in fact an anvil propelled by a small amount of explosive to cut through the bolts) will cut through the bolts fixing the satellite to it and a passive spring loaded mechanism (in most cases) will slowly and safely push the satellite on its way.
It is this initial release from the last stage that causes the initial angular momentum and there is nothing but these control mechanisms on the satellite to help 'things to settle down'.
In most cases at least 3 single axis magneto-torquers are provided, one per axis and normally one extra for redundancy. They are indeed used to reduce body angular rates and to control the wheel angular momentum. The reaction wheels (or inertia wheels) of course are limited to a maximum speed and to avoid wheel saturation the magneto-torquers are used to 'dump' some excess angular momentum.
With two inertia wheels down, there are still three torquing devices available, so control of orientation is theoretically possible. Tough, but possible. It's impressive that they made it work.
Actually, in smaller LEO (Low Earth Orbit) satellites this technique has been used for years to facilitate orientation control. It is normally used to reduce the spacecraft angular rates directly after separation from the launch vehicle. Using the magneto-torquers and a magnetometer monitoring the earth's magnetic field, the spacecraft can be controlled into a stable state with the minimum of hardware and with relatively simple control algorithms.
The idea is to get the spacecraft into a stable, known state (either earth pointing or aligned with the earth's magnetic field) before the more complex systems are powered and tested. You need to be sure your star camera, reaction wheels, propulsion systems and all the other cool hardware is in a nominal state before you enable the complex control algorithms required for more accurate orientation control.
The first satellite I've worked on we could not afford the more expensive magneto-torquers (compact electro magnetic rods) and instead opted for a self made magnetic coil without the assistance of ferrite material. Basically just a very long copper wire rolled into a coil and fixed to the frame of the solar panel (one coil per axis). Crude, but it had the desired effect!
What is really impressive is that they've managed to achieve this level of pointing accuracy with a system intended to achieve only basic orientation control and for desaturation of the reaction wheels.
What else to do? Diversify is the key. Intel already makes the ARM processor (licensed from the UK's ARM holdings) and Intel will pretty soon have a big share in DSPC. What do these two companies (ARM and DSPC) have in common? Both are targeting the cellular market - and both have a good share in it already.
Instead of having all its eggs in one basket, I see this as a strategic move from Intel to diversify its equity. Getting a foot in the door you may say...
A nice read with some background on the company, how it came to be and noting the big breakthrough in 1994 - capturing a large piece of the digital cellular phone market in Japan. Their biggest focus is now on the American cellular market with US contracts that should contribute more than 24% of their estimated revenue for 1999.
I speak four languages and English is not my mother tongue - so the only way I can double check for spelling mistakes is with a spelling checker which of course would not pick up proofed as an error. Is it past tense for proof reading something - I think.
I'll try to be positive - at least I'll know the difference between proved and proofed in future ;-p
The article has some interesting comments - my personal favourite is the possible impact this may have on companies dealing with the government. They might be forced to make more use of Open Source S/W and systems if they want to have their bids considered by the government.
Good point, and as my first post showed - it is indeed confusing! Thanks, for the comment.
I'm afraid I don't get your point. I use my PC to get stuff done (and admittingly !waiste a lot of time just playing around ;-) KDE, Gnome and all the *non* Linux apps appearing more and more gives me and a lot of other people the opportunity to actually use a kick-ass OS most of the time because I have more and more software available to use.
Just out of interest, what is your definition of a *pure* Linux app?
Depending on which options you would like to take the call to your ISP may cost from 1pence/min up to 5pence/min. If you're online for an average of 15 minutes per evening (and we all know it is MUCH more than that ;-) your monthly fee to BT just for the calls adds up to £22 (about $13.50). Doesn't sound like much, but this is an example for 15 minutes only.
Personally I spend at least $20 a month just for the calls to my ISP. Add to that line rental, costs for all the discount options and the monthly fee to the ISP it really starts to add up!
Luckily my company is based at an University an we're basically sitting on the campus backbone. The bulk of my downloads is done from work, if not for that perk I shudder to think what my monthly phone bill would have been!
I am on GMT myself...
Moderators please! Don't give unfounded news items such a high score. The AC didn't even give a link to his news source!
Anyway, for those interested, if they do manage to make contact again here is a link to the real time telemetry of the orbiter.
Note that most of these are NIR red, green false-colour images - i.e. red regions are grass/vegetation and the light blue is the built up areas.
My favourite is the one image of Washington DC and surrounding area captured in July, clearly showing the White House, Jefferson Memorial and National Mall leading to the US Capitol.
These are all JPG's - if you have the bandwidth to burn you can download the bitmaps here.
As someone in one of the threads replied the application as stated in the article is for post-evaluation of an incident so I won't dwell on that.
You are quite right that the satellite will only be covering a certain area at a certain time - all dependant on the orbit... As some of you may be aware, a satellite (or any object orbiting the earth) has an orbit period determined by its altitude. The higher the altitude - the longer it takes to orbit the earth. Some figures: a typical LEO (Low Earth orbit) satellite at an altitude of about 800km will have an orbit period of approximately 100 minutes. Geo-stationary satellites on the other hand has a 24 hour orbit period but has to be at a very high altitude - 35786 km to be precise!
To get back to the point. For high resolution imaging you would like to be as close as possible to earth. Obviously this will bring the complexity and cost of your optics down - and believe me, it is expensive! But you have to consider that a LEO implies a fast orbit with some advantages and disadvantages.
A LEO orbit (600-1200km) has the advantage that the satellite's footprint will cover most of the earth in approximately 12 hours. As you need daylight for good imaging, your coverage (for imaging at least) goes up to 24 hours in practice. Allowing for good weather you can see the problem for a quick turnaround time for images e.g. car pile up example stated in the article.
Even a constellation of imaging satellites may proof to be impractical, you'll need quite a few satellites ($$$) to have an image within a few hours. In a previous /. article about this 1m resolution imager (Ikonos) you'll notice that they claim to have the image ready within 30 minutes. What they don't say is that they'll have it ready in 30 minutes after the image has been captured. Impossible to take the image of a certain target within 30 minutes of requesting it!!
IMHO visual forensics (using satellite imaging) will only be practical if the 'crime scene' stay's the way it is for a prolonged time. I can't imagine rescue services waiting for hours until an imaging satellite comes over the horizon before clearing up the debris!!
If you're interested please visit my company's homepage for some earth observation images taken with our LEO satellites over the years. Please note we're not close to 1m resolution - currently 30m multi-spectral and a 10m b/w experimental imager.
I'll be happy to answer more questions if anyone's is interested.
Disclaimer ;-) - most of this is from personal experience as well as from some of my friends. If things have changed in the last couple of years please feel free to correct me. I've been working in the UK for a few years now and I may be a bit out of touch!
In SA the term used is Professional Engineer. You register as a Engineer in Training after you graduate. No need to take an additional exam. I guess they assume that if you have graduated you can at least register ;-p
The step from EIT to fully certified Professional Engineer is where the problems start. You have to pay a yearly subscription fee (and you receive some newsletters and documentation - if you're lucky). To be considered for certification you need at least three years professional experience. After three years you have to submit a written report detailing your experience. Having a sort of mentor (who is a Professional Engineer himself) is preferred but not required.
Most of my EE colleagues never bother to go through this. Apart from a few large corporations it has no influence on your compensation package. If you want to go private/consulting you need to be certified though - I think this is required by law.
PS. Just curious: from reading the posts I assume that you have to take an EIT exam (in the USA) to register. But how does it work after that? What do you have to do to become a certified engineer?
According to the executive director of the Electronic Frontier Foundation (EFF) piracy is not the key issue facing the music industry. She feels that by locking down internet music distribution people might be encouraged even more to 'steal' [music].
This was said in front of a lot of music industry suits at the recent Digital Distribution and the Music industry '99 conference.
I've seen a lot of arguments for the free electronic distribution of music via the internet. One that usually surfaces is that people will be encouraged to buy the original after having easy&free access to it.
My question is: will people or are people currently doing this? I have to admit that the most of the MP3's on my workstation != the CD's in my car!
BUT, the PM should be aware of the added risks when using contractors. I've seen many projects running into serious problems because of insufficient/bad contractor management. If you think about it the risks involved are most of the time just common sense:
(i) Is he good enough? You normally have quite a good idea of your own employees' experience and strengths. A contractor may have a good reference etc. but some more background research may be needed to establish confidence that he will be up for the job.
(ii) Problem definition and design. Too often a badly defined contract causes a lot of delays downstream when you realise that what is delivered is not really what was requested, causing a lot of time for rework and integration. This is often made worse by a PM not willing to commit to the extra overhead and ensuring there is REGULAR feedback (e.g. staggered design reviews and deliverables) from the contractor and good communication between him and your own people who will be using his module.
I'm sure there are many more issues, but I'll stand with the above two. Do the effort for some background research on the possible contractors, don't take one because he's cheap and available NOW