You are right. There is a bunch of stuff on NASA's website about the USAF' reuirement for single orbit capability and the ability to launch specialised satellites as well as MOL components (the USAF space station).
The thing is that NASA does create work. There is a lot of labour going into the construction of a space vehicle. Even when the work isn't being done by NASA, the prime contractors through to the subcontractors are working on it and this directly contributes to the economies of several states.
was a good example of NASA improvisation at work. They were aware that things were pretty bad (although they didn't know the real state of the service module until it was jettisoned just before reentry). They bodged things getting an emergency CO2 scrubber working and saving power.
I know that NASA has problems, but had they discovered the 'ding' on the leading edge, I agree with you and I'm sure something could have been done.
In an engineering led process any engineer has the right to say "stop, I believe we have a problem". The problem may be proved to be non-existant, but someone must address it and escalate it.
Regrettably, many organisations insist that you be "Part of the solution" not "Part of the problem" (I think this was an AC buzz-phrase). This meant that unless you could deliver a problem with a solution, you were associated with failure. At the bottom engineers may gripe but unless the PHBs supervsing them help the problems be escalated, nothing will happen.
In the end if we want public money spent responsibly, then projects have to be managed and accountants must count the beans. However, engineering must have a voice that is equal to that of the manager and the accountant. It is right that an experimental program takes risks, but they must be informed.
Lastly, the space program has provided some very good examples of the managed delivery of quality projects. With Columbia and Challenger we have two major counter-examples. It is both useful and a good memorial to those who died if everyone, both inside and outside NASA learned from this.
In high-school physics, we did the powers and Giga was always with a hard G. Later when discussing RF thingies with hams, we used the hard G version. My friends studying physics or eletrical engineering at University used the hard G. We still used Megas in comp sci (this was some time ago). However, this was the UK.
Originally, there were to be two parallel projects, one military for the USAF and the other civil for NASA. The cost of doing both projects was seen to be much too large so the requirements were merged.
The USAF/NRO needed reconnaisance capability that comes between the U2 or SR71 spy planes and spy satellites. The spy planes were vulnerable and spy satellites take too long to get into position. Also they have a limited 'retasking' capability because of the fuel that is needed for orbit changes. Also, older generation spy satellites used film and it could take a week for pictures to be taken, returned to earth and processed.
So the USAF/NRO wanted something that could fly one orbit and then reenter. The problem is that they needed to be able to land back in the continental US. A capsule can land at sea, but a shuttle needs a runway. The problem was that to find a runway, they needed to be able to fly the shuttle 'cross-range' so that they could always get back to a runway. This means the shuttle comes in relatively shallow, but this means the reentry lasts longer. They also wanted to fly polar orbits as the planning was taking place during the cold war and the USSR was the enemy and the earth would rotate about 2000Km during the orbit.
What NASA originally wanted was a vehicle that came in steeper, essentially in a controlled stall. The problem is that you lose both height and velocity quite quickly so you need to be close to your landing runway. In fact, I understand that one design had a cross range capability of just over 300Km (i.e. distance from de-orbit burn to landing). If you weren't in the right orbit, you had to wait for the earth to rotate completely, which the USAF didn't want.
The other issue was that the steeper profile would mean more heat, albeit for a shorter time and a smaller section of the craft. The leading edges would not have experienced significant heating levels.
If you want to read more, a lot of this is published on NASAs web site. A somewhat sanitised view is here. The full texts of some reports are also available if you hunt around and these show that NASA's reentry experts were rather unhappy with the USAF's requirement.
Another critical requirement was the need for a large payload capability. This essentially prevented the use of "lifting bodies" - large aerodynamic structures that generate lift from the fuselage.
In the 1980s the knowledge of writing secure multi-user, mulit-taskign OSes were locked away in Unix commerical versions not for public examination by those studying Computer Science..
Ding, wrong! Many universities had at least partial Unix sources in the eighties. In fact, that is how BSD got started and then we all had Unix sources. In the latter part of the eighties, AT&T disputed the use of Unix source code in OS classes, which is why Tannenbaum wrote Minix.
At the same time, Digital gave you the complete sources to OpenVMS on fiche if you had a license and they *published* an excellent book on VMS internals. Both BSD and VMS were both used as examples on OS Design. Although complete source code was hard to come by for some other operating systems, there was usually enough published to get the idea. Essentially you work on the basis of least access and when you take something passed to you from a lower access level, you have to be anal about checking it.
But Microsoft were too clever. All those other people were idiots. Why check user supplied parameters for protection violations in kernel calls - it is slower.
However, I agree with the last point, open source does allow skills to propagate. Even when the AT&T Unix sources floated around in University, it was very difficult to get them outside.
In Europe, the French have been very active with smartcard technology. Both the French and Germans have had smartcards that were credit-cards and also some form of debit card at the same time. For example a telephone card combined with credit card. These were all of credit card size (not larger like a PDA) and supported multiple uses (as the patent does).
You forget that one of the main problems with the Shuttle's reentry profile is that it is too long. The shuttle was designed with single orbit capability in mind, so that USAF could go up, take some photos and come down as quickly as possible for them to be processed (remember this was pre-CCD) However, they needed the ability to ensure that they could land in the continental US so a long reentry was selected.
An alternative is to design for steeper/shorter reentry and to use multiple orbits to ensure correct positioning so that the landing could take place somewhere reasonable. This is what NASA wanted but it was nixxed by the USAF as they needed to be able to fly all the way down.
The ESA could select something more like the original NASA flight profile and thus make something reusable, for less money. Purely ballistic reentry vehicles are fine, but they don't scale up so easily.
Chai is just tea, in a number of languages. This was converted into Char by the British whilst they were in India. If you want a particular type of tea, just add an adjective, i.e. Chai Chornoya - Black Tea in Russian.
All BBC non-News/current affairs productions use the normal TV contract of a fee for the series plus residuals (repeat prices plus something from eventual media sales). I don't know how long the contract goes on for but this would prevent BBC Drama from putting stuff out. Even if the BBC still had Dr Who 1, they couldn't do anything without paying off the heirs of William Hartnell.
Also, what about the excellent Horizon - sorry, most of those programs are coproductions. The coproduction company would probably have to also agree.
What does this leave, I guess just the news. Which would still be fascinating and good for historians in particular. It would be great if some of the rest of the archives could be made available, but how could they do this without copyright issues.
Well, it doesn't seem to match up for me. If you went a definition for piracy, you can always try sailing in the Malacan Straits. There you will find it somewhat different to copying without permission.
I would love to know when copying without permission became known as "Piracy". For me, an act of piracy is what a hijacker does on an aircraft or what someone does stealing from ships at sea (and murdering people in the process).
Piracy was a much more emotive word in the 18th and 19th Century when it started appearing in relation to books. Piracy was a capital offence then, travellers and merchants were in fear of it. It meant murder, rape and theft (poss. even slavery) a long way from home. How this became associated with copying, I don't know.
This time even OpenVMS was affected, because they can be trying to do something legitimate with DCE and whilst an attack by the worm doesn't get very far, denial of service remains that. However only varients of window can be infected and propagate these worms.
Even with OpenBSD, you are still fcked if every other packet thrown at you by your ISP is an attempted exploit. The attack may not get further but it won't help your connection!!!
First, the disclaimer on safety critical systems was always there on a lot of EULAs, it was definitely on the full MS Win EULA as well as specifically the JVM.
What this mean in reality, was that if you bought a computer for hard-real-time in safety critical situations, you may be advised to use older and possibly more stable versions of the OS. You may also have to stick to particular hardware vendor who is prepared to qualify the system.
For JVM, the issue was the garbage collector. You have limited control of when the GC comes in and the application may be unresponsive for some seconds. An airplane or a even just a train can travel a long way in those few seconds.
Not quite correct, RH ISOs are still free to copy. All RH subscription customers get is the chance to start downloading a week or two earlier. With the advent of ISOs on P2P, I'm not sure whether this is much of an advantage (there is nothing stopping you from d/ling an ISO and then sharing it).
RHN updates go on the subscribed machine only (their network load, their problem), but rpms are still available for manual updating. If you want to go automatic and not pay, then apt-get seems to work fine.
Didn't Novell's NETWARE used to do this as well? Is this something to do with Utah companies?
Seriously I also remember a number of companies that used to do something like this with LAN based multicasts. Often the license itself was tied to a MAC address, so woe betide you if you swapped a lan adapter.
Good point, I was actually thinking about handhelds (Iridium) and the luggable INMARSET rigs. With handhelds like IRIDIUM you just need to know which way is up. With the INMARSAT terminal, you just open the lid containing the antenna, face it towards the equator and tip at the angle recomended for your latitude. Satellite land stations would need standby power and stable connections into the fixed network.
I would agree with you about propagation. This is one area where there are still a lot of hams building and doing things for themselves, however the elctronic thing is becoming (at least below 1GHz) a lost art.
There is still a role for the hams, but pure experimentalism isn't what will sell the hobby to the FCC and the ITU.
The thing is that ham emergency nets also help provide coordination at events as well as actual emergencies, interestingly, the ability to coordinate comms between emergency services is seen by many as useful (especially when the service doesn't have to pay).
This, as opposed to education and experimenting is where ham radio can be sold to the public interest and thus can prevail upon the FCC.
No, I disagree. We have about five minutes of previews in Germany and another twenty-five of miscellaneous advertising. Some of which is appalling bad when you see it twice (i.e, the ads are retained for far too long at a theatre) The previews do not give a serious idea about a film but just condense it into a handful of loud action events.
OTOH, we have a place nearby where they do a breakfast cinema. Have a champagne breakfast (well, sparkling wine anyway) and see a good film for a little over $10.
Evacuated, but with a working fluid and a wick as a liner. It gives better heat transfer than solid copper. The idea is that it just dumps the heat into the housing, which happens itself to be a very large heatsink (at least the sides).
IDE drives may not need individual coolers, but they definitely like significant airflow. As there isn't a fan, you need to be sure that they don't cook or cook anything else in the cab.
As for airflow inside the case, yes there is still some because of convection. The air is relatively cool because most of the the heat is being dumped elsewhere, so a measily little Northbridge shouldn't have problems.
Lastly, zero fans is perhaps too much, but some of the ideas could be used to reduce case fan rpm and to maybe get rid of the CPU fan.
Last I heard, this was only for those working at the extremes - low-power or microwave frequencies. The standard frequencies (HF to UHF) are well handled by commercial equipment that would be difficult to surpass.
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The thing is that NASA does create work. There is a lot of labour going into the construction of a space vehicle. Even when the work isn't being done by NASA, the prime contractors through to the subcontractors are working on it and this directly contributes to the economies of several states.
I know that NASA has problems, but had they discovered the 'ding' on the leading edge, I agree with you and I'm sure something could have been done.
Regrettably, many organisations insist that you be "Part of the solution" not "Part of the problem" (I think this was an AC buzz-phrase). This meant that unless you could deliver a problem with a solution, you were associated with failure. At the bottom engineers may gripe but unless the PHBs supervsing them help the problems be escalated, nothing will happen.
In the end if we want public money spent responsibly, then projects have to be managed and accountants must count the beans. However, engineering must have a voice that is equal to that of the manager and the accountant. It is right that an experimental program takes risks, but they must be informed.
Lastly, the space program has provided some very good examples of the managed delivery of quality projects. With Columbia and Challenger we have two major counter-examples. It is both useful and a good memorial to those who died if everyone, both inside and outside NASA learned from this.
In high-school physics, we did the powers and Giga was always with a hard G. Later when discussing RF thingies with hams, we used the hard G version. My friends studying physics or eletrical engineering at University used the hard G. We still used Megas in comp sci (this was some time ago). However, this was the UK.
The USAF/NRO needed reconnaisance capability that comes between the U2 or SR71 spy planes and spy satellites. The spy planes were vulnerable and spy satellites take too long to get into position. Also they have a limited 'retasking' capability because of the fuel that is needed for orbit changes. Also, older generation spy satellites used film and it could take a week for pictures to be taken, returned to earth and processed.
So the USAF/NRO wanted something that could fly one orbit and then reenter. The problem is that they needed to be able to land back in the continental US. A capsule can land at sea, but a shuttle needs a runway. The problem was that to find a runway, they needed to be able to fly the shuttle 'cross-range' so that they could always get back to a runway. This means the shuttle comes in relatively shallow, but this means the reentry lasts longer. They also wanted to fly polar orbits as the planning was taking place during the cold war and the USSR was the enemy and the earth would rotate about 2000Km during the orbit.
What NASA originally wanted was a vehicle that came in steeper, essentially in a controlled stall. The problem is that you lose both height and velocity quite quickly so you need to be close to your landing runway. In fact, I understand that one design had a cross range capability of just over 300Km (i.e. distance from de-orbit burn to landing). If you weren't in the right orbit, you had to wait for the earth to rotate completely, which the USAF didn't want.
The other issue was that the steeper profile would mean more heat, albeit for a shorter time and a smaller section of the craft. The leading edges would not have experienced significant heating levels.
If you want to read more, a lot of this is published on NASAs web site. A somewhat sanitised view is here. The full texts of some reports are also available if you hunt around and these show that NASA's reentry experts were rather unhappy with the USAF's requirement.
Another critical requirement was the need for a large payload capability. This essentially prevented the use of "lifting bodies" - large aerodynamic structures that generate lift from the fuselage.
I agree that XP firewall is a big improvement.
At the same time, Digital gave you the complete sources to OpenVMS on fiche if you had a license and they *published* an excellent book on VMS internals. Both BSD and VMS were both used as examples on OS Design. Although complete source code was hard to come by for some other operating systems, there was usually enough published to get the idea. Essentially you work on the basis of least access and when you take something passed to you from a lower access level, you have to be anal about checking it.
But Microsoft were too clever. All those other people were idiots. Why check user supplied parameters for protection violations in kernel calls - it is slower.
However, I agree with the last point, open source does allow skills to propagate. Even when the AT&T Unix sources floated around in University, it was very difficult to get them outside.
In Europe, the French have been very active with smartcard technology. Both the French and Germans have had smartcards that were credit-cards and also some form of debit card at the same time. For example a telephone card combined with credit card. These were all of credit card size (not larger like a PDA) and supported multiple uses (as the patent does).
An alternative is to design for steeper/shorter reentry and to use multiple orbits to ensure correct positioning so that the landing could take place somewhere reasonable. This is what NASA wanted but it was nixxed by the USAF as they needed to be able to fly all the way down.
The ESA could select something more like the original NASA flight profile and thus make something reusable, for less money. Purely ballistic reentry vehicles are fine, but they don't scale up so easily.
Chai is just tea, in a number of languages. This was converted into Char by the British whilst they were in India. If you want a particular type of tea, just add an adjective, i.e. Chai Chornoya - Black Tea in Russian.
Also, what about the excellent Horizon - sorry, most of those programs are coproductions. The coproduction company would probably have to also agree.
What does this leave, I guess just the news. Which would still be fascinating and good for historians in particular. It would be great if some of the rest of the archives could be made available, but how could they do this without copyright issues.
Well, it doesn't seem to match up for me. If you went a definition for piracy, you can always try sailing in the Malacan Straits. There you will find it somewhat different to copying without permission.
Piracy was a much more emotive word in the 18th and 19th Century when it started appearing in relation to books. Piracy was a capital offence then, travellers and merchants were in fear of it. It meant murder, rape and theft (poss. even slavery) a long way from home. How this became associated with copying, I don't know.
Even with OpenBSD, you are still fcked if every other packet thrown at you by your ISP is an attempted exploit. The attack may not get further but it won't help your connection!!!
What this mean in reality, was that if you bought a computer for hard-real-time in safety critical situations, you may be advised to use older and possibly more stable versions of the OS. You may also have to stick to particular hardware vendor who is prepared to qualify the system.
For JVM, the issue was the garbage collector. You have limited control of when the GC comes in and the application may be unresponsive for some seconds. An airplane or a even just a train can travel a long way in those few seconds.
RHN updates go on the subscribed machine only (their network load, their problem), but rpms are still available for manual updating. If you want to go automatic and not pay, then apt-get seems to work fine.
Seriously I also remember a number of companies that used to do something like this with LAN based multicasts. Often the license itself was tied to a MAC address, so woe betide you if you swapped a lan adapter.
Good point, I was actually thinking about handhelds (Iridium) and the luggable INMARSET rigs. With handhelds like IRIDIUM you just need to know which way is up. With the INMARSAT terminal, you just open the lid containing the antenna, face it towards the equator and tip at the angle recomended for your latitude. Satellite land stations would need standby power and stable connections into the fixed network.
There is still a role for the hams, but pure experimentalism isn't what will sell the hobby to the FCC and the ITU.
This, as opposed to education and experimenting is where ham radio can be sold to the public interest and thus can prevail upon the FCC.
OTOH, we have a place nearby where they do a breakfast cinema. Have a champagne breakfast (well, sparkling wine anyway) and see a good film for a little over $10.
sort of like the German design school of the thirties, form follows function.
IDE drives may not need individual coolers, but they definitely like significant airflow. As there isn't a fan, you need to be sure that they don't cook or cook anything else in the cab.
As for airflow inside the case, yes there is still some because of convection. The air is relatively cool because most of the the heat is being dumped elsewhere, so a measily little Northbridge shouldn't have problems.
Lastly, zero fans is perhaps too much, but some of the ideas could be used to reduce case fan rpm and to maybe get rid of the CPU fan.
Last I heard, this was only for those working at the extremes - low-power or microwave frequencies. The standard frequencies (HF to UHF) are well handled by commercial equipment that would be difficult to surpass.
If the bums are paid to fight then they have income! They should be taxed on their earnings like all upstanding citizens.