Actually, I think they're just trying to justify it's price. If it's not a console any longer, then they aren't competing in the $300-$400 price range. "Oh, a $600 computer? That's a bargain!! Where do I sign up?"
Does writing apps using the Cocoa windowing toolkit provide any substantial performance boost over SWT by chance? I'm seriously ignorant on the topic, and I only ask because it seems from my perspective that the Azureus Bit Torrent client on Mac OS X is a resource hog, not to mention very sluggish in launching. I would say the user interface is even somewhat unresponsive. I believe this application uses SWT, but I could be mistaken. Are Java apps in general just this way on Mac OS X, or are there benefits to be had by switching to a Cocoa Java implementation?
Thanks.
Actually, the rules of driving have changed a bit since perhaps you last had to study for a driving exam. The last nitpick about turning into the closest lane at an intersection when not posted otherwise has not been a rule of driving in many states for quite some time. Though, some states still keep it It is a good rule-of-thumb nonetheless. But if you're driving in a state in which it isn't a law, then you certainly have no leg to stand on if you begin complaining about the driver who ignores doing so.
There is no performance benefit gained from the addition of DDR2 RAM to the Powerbooks today since the FSB at 167Mhz remains a bottleneck of system component communication. However, this addition does allow Apple's engineers to extend the cycle life of the battery as has been touted as one of the features of these new laptops. The old DDR interface I believe drew 2.5V; whereas DDR-2 draws only 1.8V
Also, windows viruses can be propagated to other windows-based machines via a mac that has received the virus; though, it doesn't affect the macintosh. Being a good netizen, we often decide to install something like Virex to help the rest of the windows-using population keep their computers free from 'infection'.
I guess I still don't understand this "escaping death" phenomena in Star Wars. I've heard that Yoda is aware of this Jedi power, but here it seems Sidious kills his master who was seeking such a power and lets Anakin know that a Jedi cannot have such a power, perhaps implying that it is a Sith force power. As you can see, I have become somewhat confused as to how and why Obi-Wan and Yoda just disappear as they seemingly leave the physical world, and how Anakin appears with them at the end of Return of the Jedi.
Usually at this early phase of a program the requirements are not too specific, because the funding office is looking for new ideas and approaches to their problem. They want the contractors to present them with a number of solutions from which they can say we like this approach or not. Or this solution is a bit too expensive for us and so forth. As as an engineer in the field I can say this can be somewhat frustrating at times, but it's just part of a process. Further details are eventually provided as the program advances.
I don't agree with you. I believe the paradigm is unchanged and the computer is the hub of digital content. You may take your pictures with your digitcal camera and can view those immediately via the camera's built-in LCD, but for editing and archival purposes I would imagine that a computer would still be preferable for most people. In which case, if you have a mac and you connect your iPod to it's dock or firewire cable, then you can now have your pictures automatically synched along with your music, so that if on the off chance you wish to share your photos with others you can simply show them via the small iPod display or connect it to your TV.
The iPod may make the functionality of your digital camera redundant in this way, but it is just a "bonus" feature if you will to have this functionality bundled with your stylish portable music player which you may, or may not, carry with you more frequently than your digitcal camera. Not to mention, the iPod's new color screen allows you to view album art of the currently playing song, which is also another nice feature. Is it worth the $500/$600 price tag? Well, that's for every one to ponder for themselves...
I really don't have the time to participate in something like this, but the Halo 2 back-story would be interesting reading in itself. Is there a site that has collated all the work done so far, so that I could chronologically read through the clips/storyline for myself?
Thanks,
RcktMan77
I live out in Lancaster, CA about 20 minutes from Edwards Air Force Base. I have a Bachelor's and Master's Degrees from Purdue University in Aerospace Engineering with emphasis in high speed (hypersonic) air-breathing propulsion and rocket propulsion. I've been working in the propulsion field for about 2 years with experience in conceptual design programs using a variety of propulsion analysis tools: CFD, Inlet Design, and Performance tools.
RcktMan77
I read today on CNN that the X-Prize has all of a sudden evolved into an annual "grand prix" event with the next competition in the '05-'06 timeframe. There will be cash prizes for accomplishing various tasks including making the fastest trip,carrying the most passengers, etc.
Being an aerospace propulsion research and design engineer myself, I was wondering if there were in any start-up projects envisioned to compete that could use some volunteer help, as I would see this as a neat sort of hobby to pass away my free time. Anyone here involved in an X-Prize project, or know of any that I might be able to seek out?
Actually, the problem with Scramjets is far greater. Not only is it difficult to create the ram pressure required for this particular mode to operate--by either introducing a RBCC (rocket-based combined cycle) accelerator, or TBCC (turbine-based combined cycle) engine, you are usually restricted to using hydrogen fuel to maintain such high speeds. Using hydrogen fuel over carbon fuels such as JP-8 increases the vehicles volume dedicated to storing fuel since the vast discrepancy between heating values and density between the two different fuel-types. Needless to say the amount of free volume available for a payload is restricted to such a point as to have very limited applications--carrying a cargo to space not being one of them. Because such a vehicle will be travelling in a region in the atmosphere which is less dense, it is also much more difficult to maintain the dynamic pressure (Q) necessary to operate a Scramjet. However, the primary detractor of these engines is withstanding the heat generated in the combustor and doing so over a period of time.
Lastly, why this article is important to the world is beyond me. The U.S. has already demonstrated Scramjet technology more than 20 years ago. The trades have already been performed, and although the capability has existed it has been deemed by the U.S. government to be of little benefit with a limited scope. Repeating what has already been done is just not very noteworthy, and will probably end in the Indian nation wasting money and time in coming to either the conclusion the rest of the world has already acknowledged, or with a product that has no use other than to say we have an aircraft that can speed to orbit with some dust on board...
I think Pogue fairly and comprehensively sums up the mac's detractiions and benefits and brings them in into the present with this article.
I do agree a number of mac users are miffed about paying out $130 for the third time since initially upgradaing to OS X. I think the new finder does bring some uniformity into the interface as mentioned; though, many may not like the new brushed aluminum taking over their desktops recently. Panther certainly does borrow some functionality from Windows, and the wheel does keep turning about whether the cost of a mac desktop system is worth it's price. Windows is lacking as far as security is concerned, especially considering it's widespread use. All in all, I think the mac experience is summed up pretty well.
Your professor is correct. Engineering utilizes numbers. However when expressing these results to an audience without the technical background in a specific area, these numbers aren't going to get your point across. So, it's rarely good form to explain things in such terms. Furthermore, you're rarely going to see a publication, such as Popular Science, providing such information since it's purpose is to describe new and noteworthy developments in technology so the person without any formal technical training can appreciate such things.
That being said, as I mentoned earlier if you take the equation for efficiency of the Brayton cycle, which is the constant pressure thermodynamic cycle that models today's turbofan engines:
Brayton_eff = 1 -T_0/T_1
where T_0 and T_1 are the absolute temperatures at their respective engine stations (or cycle stations if you're a thermo geek) with the constant volume Humphrey cycle efficiency which the PDE cycle closely follows:
you will see that the difference between these cycle efficiencies is the multiplier:
gamma*[(T2/T1)^(1/gamma) -1/((T_2/T_1)-1)]
For typical detonation combustion, the value of this multiplier is always less than one; therefore, resulting in a higher cycle efficiency than the efficiency of the Brayton cycle.
Furthermore, pulse detonation engines offer the potential to operate at very high densities, allowing the designer to use very compact combustor designs which has been desirable in the aerospace industry to allow for lengthening the nozzle.
As far as typical numbers with regards to specific impulse, you'll find that the time-averaged values are very comparable to those of an arcjet on the order of 10^4/sec. You might not find too many specifics with regards to performance as more than likely this sort of detail is proprietary still at this point.
My personal research didn't delve into the noise problem--I don't think the technology has evolved yet enough to grant research attention on the matter as of yet. I can say that in testing we scared a lot of kids at a nearby day care =) A lot of the ideas surrounding the use of PDE's normally involve integration into an existing engine scheme.
For example, one of the novel ideas we were interested in was the use of pulse detonation in a hypersonic aerospace plane (such as NASP). The concept involved 4 modes of operation covering take-off to very high Mach numbers and altitudes. The 4 modes included an ejector-augmented PDR for take-off to low supersonic flight, a pulsed normal detonation wave engine for Mach numbers between 3 and 7 which corresponds to combustion chamber Mach numbers less than than the Chapman-Jouguet Mach number, and a pure PDR mode of operation for very high Mach numbers and altitudes. I don't think this technology has been envisioned for use in commercial applications, and I would also point out that many here are confusing pulse jets with pulse detonation. There is a clear distinction between the too, namely the mode of combustion each uses.
I personally worked on the first mode, which was an ejector augmented PDE, so I know there's still a lot of work left to be done. I think my initial statement with regards to the complexity of turbofan engines of today was made using the PDE for comparison. Af far as fuel delivery goes, I believe my initial impression was that at this point sustaining the required frequency of fuel injection reliably has been one hurdle that still needs some work regardless of some of the methods currently being utilized that the second poster of this thread pointed out. However supplying fuel to these injectors is no more complicated than what we see in today's vehicles. Having said this, I do feel that the future challenges to bring this technology to usability are ones that can certainly be worked through, and I do feel this technology does have promise for future high speed aerospace applications.
I actually did my Master's Research on a Pulsed Detonation Engine (Rocket actually, since we were providing the oxygen). It is a more efficient form of propulsion (for thermo geeks, detonation can be modeled by a constant volume Humphrey thermo cycle, rather than the constant pressure Brayton cycle and a comparison of efficiencies results in a vast improvement for the pulsed detonation engine). It certainly isn't too new as far as the idea being thrown around, but it certainly is gaining momentum as being more and more plausible. Aside from the efficiency benefits, the engine itself results in a much simpler design and weight savings rather than relying on today's complex turbomachinery. Furthermore, pulsed detonation engines offer the potential for substantiative performance increases; finally bringing hypersonic flight to within a practical reach.
A detonation is different than a deflagration in basically the speed at which combustion occurs. Deflagration occurs at relatively low flame speeds on the order of 1 or 2 m/sec.; whereas, detonation is a supersonic mode of combustion. Most forms of combustion that we are familiar with today utilize the deflagrative mode.
The article was accurate in stating that this technology still has a few hurdles to overcome. Primarily, the pulsed detonation engine is an unsteady flow phenomenon that requires a periodic input to control fuel injection into the detonation chamber coupled with a very large energy input to ignite the fuel and reach a critical Chapman-Jouguet velocity. Such energy input has been accomplished so far using an arc igniter, but doing so on a reliable basis at frequencies of at least 100Hz, necessary for practical use have been somewhat of a challenge thus far.
Do NOT blame NASA for it's aging programs. They are only aging due to lack of public interest and funding. NASA's budget has been strictly limited for more than a decade. Absolutely no growth nor research and development have occurred in this time. NASA operates with just enough to complete approximately 7 missions per year, and they are hardly staffed to operate these missions safely.
These accidents can be avoided, but only with generous funding and interest from the public to allow congress to provide NASA with the money it needs. The shuttle is based upon 50 year-old technologies--not 30 as previously indicated. The space shuttle certainly needs to be updated, but who's willing to pay for the research and development needed to do so?
And do not go blaming our nation's quality of engineering schools or programs. Our nation has the best schools in engineering of the world. NASA has been on a hiring freeze for more than a decade, and most of the engineers currently employed there are near retirement. There are very few who will be able to receive the torch so-to-speak when this mass exodus of retiring engineers does occur. The public needs to simply decide on what is important to it--do we continue our exploration of space, or is that no longer important to us? If it is the former, then money should be given in ample amounts to support the related programs of exploration in a safe manner.
There's no possible way that a tile impact upon launch could have caused any structural integrity to the shuttle. If you've ever seen one of these tiles you would know that they are about as dense as styrofoam. Furthermore, the shuttle was inspected by high definition cameras on the ISS, and it was concluded that such a panel did not pose any risk to the shuttle crew. Otherwise, the crew would have returned on the ISS's escape pod, or another shuttle would have been launched to return the crew.
My personal feeling is the pilot--this being his first trip to space--was inexperienced at re-entry and entered the atmosphere at an angle too steep, and the stresses placed on the shuttle were too extreme. Video indicates that early on a piece of the shuttle became detached before the contrails were visible. Being able to see such a piece from such a great distance away, indicates that this piece is rather large. If this indeed turns out to be the case, I highly doubt NASA, or it's independent investigation team, will admit this to the public out of respect for his family.
Needless to say, the event is certainly tragic and I feel sorry for the families and those close to the astronauts. I hope that this event will have positive outcomes for our space program, and the public will perceive this event as a reason to modernize our space exploration programs.
Slashdot Mirror
The guy's a male nurse... I mean c'mon, did you really expect more from him?
Actually, I think they're just trying to justify it's price. If it's not a console any longer, then they aren't competing in the $300-$400 price range. "Oh, a $600 computer? That's a bargain!! Where do I sign up?"
Does writing apps using the Cocoa windowing toolkit provide any substantial performance boost over SWT by chance? I'm seriously ignorant on the topic, and I only ask because it seems from my perspective that the Azureus Bit Torrent client on Mac OS X is a resource hog, not to mention very sluggish in launching. I would say the user interface is even somewhat unresponsive. I believe this application uses SWT, but I could be mistaken. Are Java apps in general just this way on Mac OS X, or are there benefits to be had by switching to a Cocoa Java implementation? Thanks.
Actually, the rules of driving have changed a bit since perhaps you last had to study for a driving exam. The last nitpick about turning into the closest lane at an intersection when not posted otherwise has not been a rule of driving in many states for quite some time. Though, some states still keep it It is a good rule-of-thumb nonetheless. But if you're driving in a state in which it isn't a law, then you certainly have no leg to stand on if you begin complaining about the driver who ignores doing so.
The Skunk Works is still around...just moved from Burbank.
There is no performance benefit gained from the addition of DDR2 RAM to the Powerbooks today since the FSB at 167Mhz remains a bottleneck of system component communication. However, this addition does allow Apple's engineers to extend the cycle life of the battery as has been touted as one of the features of these new laptops. The old DDR interface I believe drew 2.5V; whereas DDR-2 draws only 1.8V
Also, windows viruses can be propagated to other windows-based machines via a mac that has received the virus; though, it doesn't affect the macintosh. Being a good netizen, we often decide to install something like Virex to help the rest of the windows-using population keep their computers free from 'infection'.
That would be Skunk Works... http://www.saiproject.com/
I guess I still don't understand this "escaping death" phenomena in Star Wars. I've heard that Yoda is aware of this Jedi power, but here it seems Sidious kills his master who was seeking such a power and lets Anakin know that a Jedi cannot have such a power, perhaps implying that it is a Sith force power. As you can see, I have become somewhat confused as to how and why Obi-Wan and Yoda just disappear as they seemingly leave the physical world, and how Anakin appears with them at the end of Return of the Jedi.
Usually at this early phase of a program the requirements are not too specific, because the funding office is looking for new ideas and approaches to their problem. They want the contractors to present them with a number of solutions from which they can say we like this approach or not. Or this solution is a bit too expensive for us and so forth. As as an engineer in the field I can say this can be somewhat frustrating at times, but it's just part of a process. Further details are eventually provided as the program advances.
I don't agree with you. I believe the paradigm is unchanged and the computer is the hub of digital content. You may take your pictures with your digitcal camera and can view those immediately via the camera's built-in LCD, but for editing and archival purposes I would imagine that a computer would still be preferable for most people. In which case, if you have a mac and you connect your iPod to it's dock or firewire cable, then you can now have your pictures automatically synched along with your music, so that if on the off chance you wish to share your photos with others you can simply show them via the small iPod display or connect it to your TV.
The iPod may make the functionality of your digital camera redundant in this way, but it is just a "bonus" feature if you will to have this functionality bundled with your stylish portable music player which you may, or may not, carry with you more frequently than your digitcal camera. Not to mention, the iPod's new color screen allows you to view album art of the currently playing song, which is also another nice feature. Is it worth the $500/$600 price tag? Well, that's for every one to ponder for themselves...
RcktMan77
I really don't have the time to participate in something like this, but the Halo 2 back-story would be interesting reading in itself. Is there a site that has collated all the work done so far, so that I could chronologically read through the clips/storyline for myself? Thanks, RcktMan77
I live out in Lancaster, CA about 20 minutes from Edwards Air Force Base. I have a Bachelor's and Master's Degrees from Purdue University in Aerospace Engineering with emphasis in high speed (hypersonic) air-breathing propulsion and rocket propulsion. I've been working in the propulsion field for about 2 years with experience in conceptual design programs using a variety of propulsion analysis tools: CFD, Inlet Design, and Performance tools. RcktMan77
I read today on CNN that the X-Prize has all of a sudden evolved into an annual "grand prix" event with the next competition in the '05-'06 timeframe. There will be cash prizes for accomplishing various tasks including making the fastest trip,carrying the most passengers, etc.
Being an aerospace propulsion research and design engineer myself, I was wondering if there were in any start-up projects envisioned to compete that could use some volunteer help, as I would see this as a neat sort of hobby to pass away my free time. Anyone here involved in an X-Prize project, or know of any that I might be able to seek out?
Thanks,
RcktMan77
Why do the ten consecutive digits of e have to add up to 49, and where was this part stated in the problem? Thanks.
n/m
Actually, the problem with Scramjets is far greater. Not only is it difficult to create the ram pressure required for this particular mode to operate--by either introducing a RBCC (rocket-based combined cycle) accelerator, or TBCC (turbine-based combined cycle) engine, you are usually restricted to using hydrogen fuel to maintain such high speeds. Using hydrogen fuel over carbon fuels such as JP-8 increases the vehicles volume dedicated to storing fuel since the vast discrepancy between heating values and density between the two different fuel-types. Needless to say the amount of free volume available for a payload is restricted to such a point as to have very limited applications--carrying a cargo to space not being one of them. Because such a vehicle will be travelling in a region in the atmosphere which is less dense, it is also much more difficult to maintain the dynamic pressure (Q) necessary to operate a Scramjet. However, the primary detractor of these engines is withstanding the heat generated in the combustor and doing so over a period of time.
Lastly, why this article is important to the world is beyond me. The U.S. has already demonstrated Scramjet technology more than 20 years ago. The trades have already been performed, and although the capability has existed it has been deemed by the U.S. government to be of little benefit with a limited scope. Repeating what has already been done is just not very noteworthy, and will probably end in the Indian nation wasting money and time in coming to either the conclusion the rest of the world has already acknowledged, or with a product that has no use other than to say we have an aircraft that can speed to orbit with some dust on board...
Sorry, you're memory does not serve you well. 10.2 was prices exactly the same to educators, students, and government employees.
I think Pogue fairly and comprehensively sums up the mac's detractiions and benefits and brings them in into the present with this article.
I do agree a number of mac users are miffed about paying out $130 for the third time since initially upgradaing to OS X. I think the new finder does bring some uniformity into the interface as mentioned; though, many may not like the new brushed aluminum taking over their desktops recently. Panther certainly does borrow some functionality from Windows, and the wheel does keep turning about whether the cost of a mac desktop system is worth it's price. Windows is lacking as far as security is concerned, especially considering it's widespread use. All in all, I think the mac experience is summed up pretty well.
Your professor is correct. Engineering utilizes numbers. However when expressing these results to an audience without the technical background in a specific area, these numbers aren't going to get your point across. So, it's rarely good form to explain things in such terms. Furthermore, you're rarely going to see a publication, such as Popular Science, providing such information since it's purpose is to describe new and noteworthy developments in technology so the person without any formal technical training can appreciate such things.
That being said, as I mentoned earlier if you take the equation for efficiency of the Brayton cycle, which is the constant pressure thermodynamic cycle that models today's turbofan engines:
Brayton_eff = 1 -T_0/T_1
where T_0 and T_1 are the absolute temperatures at their respective engine stations (or cycle stations if you're a thermo geek) with the constant volume Humphrey cycle efficiency which the PDE cycle closely follows:
Humphrey_eff = 1 - gamma*T_0/T_1* [(T2/T1)^(1/gamma) -1/((T_2/T_1)-1)]
you will see that the difference between these cycle efficiencies is the multiplier:
gamma*[(T2/T1)^(1/gamma) -1/((T_2/T_1)-1)]
For typical detonation combustion, the value of this multiplier is always less than one; therefore, resulting in a higher cycle efficiency than the efficiency of the Brayton cycle.
Furthermore, pulse detonation engines offer the potential to operate at very high densities, allowing the designer to use very compact combustor designs which has been desirable in the aerospace industry to allow for lengthening the nozzle.
As far as typical numbers with regards to specific impulse, you'll find that the time-averaged values are very comparable to those of an arcjet on the order of 10^4/sec. You might not find too many specifics with regards to performance as more than likely this sort of detail is proprietary still at this point.
My personal research didn't delve into the noise problem--I don't think the technology has evolved yet enough to grant research attention on the matter as of yet. I can say that in testing we scared a lot of kids at a nearby day care =) A lot of the ideas surrounding the use of PDE's normally involve integration into an existing engine scheme.
For example, one of the novel ideas we were interested in was the use of pulse detonation in a hypersonic aerospace plane (such as NASP). The concept involved 4 modes of operation covering take-off to very high Mach numbers and altitudes. The 4 modes included an ejector-augmented PDR for take-off to low supersonic flight, a pulsed normal detonation wave engine for Mach numbers between 3 and 7 which corresponds to combustion chamber Mach numbers less than than the Chapman-Jouguet Mach number, and a pure PDR mode of operation for very high Mach numbers and altitudes. I don't think this technology has been envisioned for use in commercial applications, and I would also point out that many here are confusing pulse jets with pulse detonation. There is a clear distinction between the too, namely the mode of combustion each uses.
I personally worked on the first mode, which was an ejector augmented PDE, so I know there's still a lot of work left to be done. I think my initial statement with regards to the complexity of turbofan engines of today was made using the PDE for comparison. Af far as fuel delivery goes, I believe my initial impression was that at this point sustaining the required frequency of fuel injection reliably has been one hurdle that still needs some work regardless of some of the methods currently being utilized that the second poster of this thread pointed out. However supplying fuel to these injectors is no more complicated than what we see in today's vehicles. Having said this, I do feel that the future challenges to bring this technology to usability are ones that can certainly be worked through, and I do feel this technology does have promise for future high speed aerospace applications.
I actually did my Master's Research on a Pulsed Detonation Engine (Rocket actually, since we were providing the oxygen). It is a more efficient form of propulsion (for thermo geeks, detonation can be modeled by a constant volume Humphrey thermo cycle, rather than the constant pressure Brayton cycle and a comparison of efficiencies results in a vast improvement for the pulsed detonation engine). It certainly isn't too new as far as the idea being thrown around, but it certainly is gaining momentum as being more and more plausible. Aside from the efficiency benefits, the engine itself results in a much simpler design and weight savings rather than relying on today's complex turbomachinery. Furthermore, pulsed detonation engines offer the potential for substantiative performance increases; finally bringing hypersonic flight to within a practical reach. A detonation is different than a deflagration in basically the speed at which combustion occurs. Deflagration occurs at relatively low flame speeds on the order of 1 or 2 m/sec.; whereas, detonation is a supersonic mode of combustion. Most forms of combustion that we are familiar with today utilize the deflagrative mode. The article was accurate in stating that this technology still has a few hurdles to overcome. Primarily, the pulsed detonation engine is an unsteady flow phenomenon that requires a periodic input to control fuel injection into the detonation chamber coupled with a very large energy input to ignite the fuel and reach a critical Chapman-Jouguet velocity. Such energy input has been accomplished so far using an arc igniter, but doing so on a reliable basis at frequencies of at least 100Hz, necessary for practical use have been somewhat of a challenge thus far.
Do NOT blame NASA for it's aging programs. They are only aging due to lack of public interest and funding. NASA's budget has been strictly limited for more than a decade. Absolutely no growth nor research and development have occurred in this time. NASA operates with just enough to complete approximately 7 missions per year, and they are hardly staffed to operate these missions safely. These accidents can be avoided, but only with generous funding and interest from the public to allow congress to provide NASA with the money it needs. The shuttle is based upon 50 year-old technologies--not 30 as previously indicated. The space shuttle certainly needs to be updated, but who's willing to pay for the research and development needed to do so? And do not go blaming our nation's quality of engineering schools or programs. Our nation has the best schools in engineering of the world. NASA has been on a hiring freeze for more than a decade, and most of the engineers currently employed there are near retirement. There are very few who will be able to receive the torch so-to-speak when this mass exodus of retiring engineers does occur. The public needs to simply decide on what is important to it--do we continue our exploration of space, or is that no longer important to us? If it is the former, then money should be given in ample amounts to support the related programs of exploration in a safe manner. There's no possible way that a tile impact upon launch could have caused any structural integrity to the shuttle. If you've ever seen one of these tiles you would know that they are about as dense as styrofoam. Furthermore, the shuttle was inspected by high definition cameras on the ISS, and it was concluded that such a panel did not pose any risk to the shuttle crew. Otherwise, the crew would have returned on the ISS's escape pod, or another shuttle would have been launched to return the crew. My personal feeling is the pilot--this being his first trip to space--was inexperienced at re-entry and entered the atmosphere at an angle too steep, and the stresses placed on the shuttle were too extreme. Video indicates that early on a piece of the shuttle became detached before the contrails were visible. Being able to see such a piece from such a great distance away, indicates that this piece is rather large. If this indeed turns out to be the case, I highly doubt NASA, or it's independent investigation team, will admit this to the public out of respect for his family. Needless to say, the event is certainly tragic and I feel sorry for the families and those close to the astronauts. I hope that this event will have positive outcomes for our space program, and the public will perceive this event as a reason to modernize our space exploration programs.