There is some speculation that the AR2-3 may not be the engine used in current flights (see other replies to you post).
However, the AR2-3 is human rated. The X-37 is nominally unmanned, but hey the missions are classified, and because Halo Orbital Drop Shock Troopers.
Of course some of the alternative engines you mentioned have been used on stages of previous manned flights and are thus presumably man-rated as well.
I did some Binging on the AR2-3 and found a NASA/Rocketdyne/OSC presentation that looks to be drafted around 2000.
Here that seem to make the case high test peroxide (HTP) technologies are the way of the future for upper stage propulsion:
Hydrogen peroxide was selected over liquid oxygen because it is dense, storable, capable of tolerating months in orbit, and meets safety restrictions for being part of the payload in the Space Shuttle.
Of course the Shuttle aspect is no longer a factor, but the other factors still seem to be in play.
Further into the paper, the USFE 10k peroxide motor is mentioned as a project to develop new HTP technologies. These technologies would be used for future HTP-based upper stages. They even have a goal of over 100 uses of an engine before it has to be removed for overhaul. Is that a lot in the world of rockets? As this paper was drafted around 2000 I would guess that the X-37 is using something a bit different that the bog-standard AR2-3 or has moved away from HTP technologies altogether.
Now to say that rocket science has moved away from HTP is not quite true. I don't think there are any big HTP engines used in lower stages. However, the Bloodhound SSC is using a HTP hybrid motor they are designing.
There is also research in to using HTP as a monopropellant for thrusters using a catalytic bed. I suppose the advantage here is that you have HTP as your oxidizer for an upper stage and then it can be used for maneuvering once on orbit. Similar, as you mentioned, to UDMH.
Take a look at the Introduction from the ESA paper referenced above. They cite several reasons why HTP is desirable and advantageous. Cost and safety being paramount. They also mention that Soyuz has been using HTP in its maneuvering systems for over 40 years. I think that HTP safety concerns have been effectively mitigated from the "explode because you looked at it funny" era.
As for performance it seems that HTP is as good as some other technologies, but it's no dog either and it seems to be a good fit for the X-37 or other small stages. Quote from the ESA paper:
The propulsive
performance of hydrogen peroxide monopropellant rockets is about 20% lower than hydrazine, but the volume
specific impulse achievable with 90% H2O2 is higher than most other propellants due to its high density. This is
particularly useful for systems with significant aerodynamic drag losses and/or stringent volume constraints. With
respect to bi-propellant and hybrid rocket engines, hydrogen peroxide yields a specific impulse comparable to other
liquid oxidizers like dinitrogen tetroxide, nitric acid and even liquid oxygen..
It seems that HTP has many uses and rocket science has not moved away from HTP, indeed, it is being actively researched. It may or may not be used on the X-37 right now. It may or may be used on the X-37 in the future. With further attention to cost, safety, and, increasingly, environmental impact, HTP seems to be coming for you...
The show was probably about the Okavango River which empties into the Okavango Delta in Botswana.
You're right, none of the water makes it to any sea or ocean. Some of it simply evaporates. However, the majority of the water allows for a thriving ecosystem to exist in an otherwise arid region.
From the first issue of an approved design document that itself was based on the first issue of software requirements as approved by the customer. How quaint.
The problem is that GCC will always give you a different binary every time you compile from the same source.
I tried compiling "Hello World" using GCC 4.4.3 and then building it again five minutes later. The executables were binary identical. Is what you said only for non-trivial cases such as "Hello World"?
Maybe it's a matter of language, but ad-hominem arguments ("any fool") don't work either. You weaken your argument. (Who keeps modding you up?) Which, I have to admit, I'm not entirely sure that you are debating anything to the heart of the matter, but... here we are.
I think you're going a little personal on someone's flippant slippery slope comment.
No one ever said stop judging, but a real think about statutes need to come into play rather your gut-feeling/Miller Test.
If you want to post in generalities, then I guess, yeah, you admit that hate speech laws will be used to censor.
One man's cheeky Mohammad cartoon is another man's hate speech/blasphemy.
Just because people speak in proverbs or or logical fallacies doesn't mean that they don't happen.
Please elaborate how, since the ratification of the US Constitution, speech freedoms are greater today.
If you do not believe that once given more control (laws), then one party (government) will not seek more control.
Well, I see your logic, but you should bone-up on more history and less philosophy.
i can tell the difference between homosexuality and necrophilia. i can tell the difference between marijuana and meth. and i can tell the difference between political speech and hate speech
the slippery slope is an idea that only works in a world where nobody can think and identify different topics. therefore, the slippery slope never works as a persuasive argument
Your argument seems to assume that we can all argree on objective definitions of sexuality, drugs, and speech. Differences in drugs can be objectively determined. Sexuality I'll give you as well. Can you honestly say we all agree on what is hate speech? If not, then yes, hate speech laws can, and most likely will be, abused to censor one party. It may not be a slippery slope, but the infringement of rights will occur.
There is a fine, but important distinction you need to state in your case against using the slippery slope.
the slippery slope is an idea that only works in a world where nobody can objectively and uniformly identify different classes.
The slippery slope argument is, by nature, not logical, but if you're going to take the time to dissect a piece of rhetoric, then get it right.
I work in a team of 7. We're a mixed bag of software, hardware, and systems engineering types, but we all have to do some programming as our primary function.
When a team member leaves, the replacement gets all the lovely FNG assignments as their secondary role. That is, documentation, testing, and/or QA.
I got shoved into software QA when I arrived on the team. I joke about how I hate it and how my teammates hate me in that role, but I secretly relish it and my team mates know it has to be done.
Ask yourself these questions:
- Do you love processes?
- Do you find code reviews interesting?
- Do you like tearing into others' designs and implementation?
- Does it really jack your nads when the documentation doesn't jive with the implementation?
- Do you like audits?
- Do you like meetings?
- Do you like ISO 9001?
- Don't you just hate having to reverse-engineer a product because someone was lazy with the documentation?
- Do you like making/maintaining support tools?
Then Software QA is the move for you!
It is also a skill you can shop around regardless of the development environment (although some environments lend themselves to QA better than others).
I was circumcised as an infant. My wife and I were born and raised in the US. 5 years ago we moved to the UK.
We had our first child a few years ago and we discussed the topic of circumcision. We did some research online and we came across similar data as presented in TFA. We didn't care about the aesthetics, but my wife did say that maybe we should circumcise due to the potential reduction of risk for UTIs, STDs, and other infections.
I thought for a second and then said that if we're relying on elective and unnecessary surgery to prevent our son from getting an STD, then we're doing it wrong. We stopped considering the cut after that and now both of our boys are healthy and intact. We were also never pressured to go for the cut by any of the medical professionals here either.
My NHS blag....
Getting off-topic, but reading this parent post brought me back to all of the events surrounding the pregnancies, birth, and ante-natal care for our boys.
Throughout it all, the NHS has been OUTSTANDING.
Overall caring, professional, and knowledgeable staff from the GYN, midwives, EMTs, and ward staff.
The midwives, especially, deserve the bulk of the credit as they are the backbone of birth in the UK. I can't believe they aren't as prevalent in the US. An OB/GYN seems like overkill for most pregnancies. Our second son was born at home in a birthing pool. This was done on advice from the NHS as this was a low-risk pregnancy. The midwives showed up to our house and saw us all the way through.
Did I mention that we never had to worry about paying for any of this? I suppose I did make tea for the midwives; a fair bargain.
Now suppose there had been complications in the birth of either of our boys. Also taken care of by the NHS. My wife says she never wants to give birth again unless it's with the NHS (or other single-payer system). Mind you that we've never used the US system for birth so we have no basis for comparison.
I'm a true NHS/single-payer convert.
Sure it has some problems, but those problems are also present in the US system.
I'll take the higher taxes. I get good service when necessary, an increasing culture of evidence-based medicine (not just tradition/religious based), and not having to worry about being bankrupt.
I rue the day of going back to the US or having a future government dismantle the NHS.
...of the "tech literate". Politicians invariably answer more to certain interests of their constituency more than others. In this case Mr. Hansen may well end up listening mostly to those constituents which can use computers. So he will be giving those people their voice. It may not be an ideal, equitable representation, but I think it will be an interesting experiment* in the least. And judging by the comments I've seen on just about every news website there doesn't seem to be a bias to the left or right. You get the full spectrum of crazy.
* For those that think we shouldn't be experimenting with government, we've been dragging this one out for over 200 years...
There are already some efforts in place around the USA, you just have to _look_ find them.
I remember the the Velocipede Bike Project in Baltimore.
Plenty of tools and advice to fix your bike from what I remember so long as you mind all the damn hipsters.
Also, support your local Tool-Lending Library!
Slashdot Mirror
There is some speculation that the AR2-3 may not be the engine used in current flights (see other replies to you post).
However, the AR2-3 is human rated. The X-37 is nominally unmanned, but hey the missions are classified, and because Halo Orbital Drop Shock Troopers. Of course some of the alternative engines you mentioned have been used on stages of previous manned flights and are thus presumably man-rated as well.
I did some Binging on the AR2-3 and found a NASA/Rocketdyne/OSC presentation that looks to be drafted around 2000.
Here that seem to make the case high test peroxide (HTP) technologies are the way of the future for upper stage propulsion:
Hydrogen peroxide was selected over liquid oxygen because it is dense, storable, capable of tolerating months in orbit, and meets safety restrictions for being part of the payload in the Space Shuttle.
Of course the Shuttle aspect is no longer a factor, but the other factors still seem to be in play.
Further into the paper, the USFE 10k peroxide motor is mentioned as a project to develop new HTP technologies. These technologies would be used for future HTP-based upper stages. They even have a goal of over 100 uses of an engine before it has to be removed for overhaul. Is that a lot in the world of rockets? As this paper was drafted around 2000 I would guess that the X-37 is using something a bit different that the bog-standard AR2-3 or has moved away from HTP technologies altogether.
Now to say that rocket science has moved away from HTP is not quite true. I don't think there are any big HTP engines used in lower stages. However, the Bloodhound SSC is using a HTP hybrid motor they are designing.
There is also research in to using HTP as a monopropellant for thrusters using a catalytic bed. I suppose the advantage here is that you have HTP as your oxidizer for an upper stage and then it can be used for maneuvering once on orbit. Similar, as you mentioned, to UDMH.
Take a look at the Introduction from the ESA paper referenced above. They cite several reasons why HTP is desirable and advantageous. Cost and safety being paramount. They also mention that Soyuz has been using HTP in its maneuvering systems for over 40 years. I think that HTP safety concerns have been effectively mitigated from the "explode because you looked at it funny" era.
As for performance it seems that HTP is as good as some other technologies, but it's no dog either and it seems to be a good fit for the X-37 or other small stages. Quote from the ESA paper:
The propulsive performance of hydrogen peroxide monopropellant rockets is about 20% lower than hydrazine, but the volume specific impulse achievable with 90% H2O2 is higher than most other propellants due to its high density. This is particularly useful for systems with significant aerodynamic drag losses and/or stringent volume constraints. With respect to bi-propellant and hybrid rocket engines, hydrogen peroxide yields a specific impulse comparable to other liquid oxidizers like dinitrogen tetroxide, nitric acid and even liquid oxygen..
It seems that HTP has many uses and rocket science has not moved away from HTP, indeed, it is being actively researched. It may or may not be used on the X-37 right now. It may or may be used on the X-37 in the future. With further attention to cost, safety, and, increasingly, environmental impact, HTP seems to be coming for you...
DBF (Debian Boxes Forever)
The show was probably about the Okavango River which empties into the Okavango Delta in Botswana.
You're right, none of the water makes it to any sea or ocean. Some of it simply evaporates. However, the majority of the water allows for a thriving ecosystem to exist in an otherwise arid region.
Include this into your analogy as you see fit.
From the first issue of an approved design document that itself was based on the first issue of software requirements as approved by the customer. How quaint.
...is out of production. These would have suited it quite well for the evil mastermind on the go.
I use my HOSTS file to block these kinds of posts...
...from Everest. Because it's there.
The problem is that GCC will always give you a different binary every time you compile from the same source.
I tried compiling "Hello World" using GCC 4.4.3 and then building it again five minutes later. The executables were binary identical. Is what you said only for non-trivial cases such as "Hello World"?
Rotten zinc lobby. Sometimes I think we'd all be better in a World Without Zinc...
Maybe it's a matter of language, but ad-hominem arguments ("any fool") don't work either. You weaken your argument. (Who keeps modding you up?) ... here we are.
Which, I have to admit, I'm not entirely sure that you are debating anything to the heart of the matter, but
I think you're going a little personal on someone's flippant slippery slope comment. No one ever said stop judging, but a real think about statutes need to come into play rather your gut-feeling/Miller Test.
If you want to post in generalities, then I guess, yeah, you admit that hate speech laws will be used to censor. One man's cheeky Mohammad cartoon is another man's hate speech/blasphemy.
Just because people speak in proverbs or or logical fallacies doesn't mean that they don't happen. Please elaborate how, since the ratification of the US Constitution, speech freedoms are greater today.
If you do not believe that once given more control (laws), then one party (government) will not seek more control. Well, I see your logic, but you should bone-up on more history and less philosophy.
i can tell the difference between homosexuality and necrophilia. i can tell the difference between marijuana and meth. and i can tell the difference between political speech and hate speech
the slippery slope is an idea that only works in a world where nobody can think and identify different topics. therefore, the slippery slope never works as a persuasive argument
Your argument seems to assume that we can all argree on objective definitions of sexuality, drugs, and speech. Differences in drugs can be objectively determined. Sexuality I'll give you as well. Can you honestly say we all agree on what is hate speech? If not, then yes, hate speech laws can, and most likely will be, abused to censor one party. It may not be a slippery slope, but the infringement of rights will occur.
There is a fine, but important distinction you need to state in your case against using the slippery slope.
the slippery slope is an idea that only works in a world where nobody can objectively and uniformly identify different classes.
The slippery slope argument is, by nature, not logical, but if you're going to take the time to dissect a piece of rhetoric, then get it right.
...application of technology and not one utterance of "boffin"??!?!?
I demand satisfaction!
Abortions for some, miniature American flags for others.
I would say they will just have to suck it up and pay up for borrowing ideas.
Pay up for borrowing ideas. I understand the patent system, but you should really hear yourself speak.
If anything he's a plant from their side, imo.
MacDailyNews is over that way...
Welcome to MacDailyNews. You must be new here.
Investigate the regenerative properties of some sea slugs?
I work in a team of 7. We're a mixed bag of software, hardware, and systems engineering types, but we all have to do some programming as our primary function. When a team member leaves, the replacement gets all the lovely FNG assignments as their secondary role. That is, documentation, testing, and/or QA.
I got shoved into software QA when I arrived on the team. I joke about how I hate it and how my teammates hate me in that role, but I secretly relish it and my team mates know it has to be done.
Ask yourself these questions:
- Do you love processes?
- Do you find code reviews interesting?
- Do you like tearing into others' designs and implementation?
- Does it really jack your nads when the documentation doesn't jive with the implementation?
- Do you like audits?
- Do you like meetings?
- Do you like ISO 9001?
- Don't you just hate having to reverse-engineer a product because someone was lazy with the documentation?
- Do you like making/maintaining support tools?
Then Software QA is the move for you!
It is also a skill you can shop around regardless of the development environment (although some environments lend themselves to QA better than others).
My anecdote....
I was circumcised as an infant. My wife and I were born and raised in the US. 5 years ago we moved to the UK.
We had our first child a few years ago and we discussed the topic of circumcision. We did some research online and we came across similar data as presented in TFA. We didn't care about the aesthetics, but my wife did say that maybe we should circumcise due to the potential reduction of risk for UTIs, STDs, and other infections.
I thought for a second and then said that if we're relying on elective and unnecessary surgery to prevent our son from getting an STD, then we're doing it wrong.
We stopped considering the cut after that and now both of our boys are healthy and intact. We were also never pressured to go for the cut by any of the medical professionals here either.
My NHS blag....
Getting off-topic, but reading this parent post brought me back to all of the events surrounding the pregnancies, birth, and ante-natal care for our boys.
Throughout it all, the NHS has been OUTSTANDING.
Overall caring, professional, and knowledgeable staff from the GYN, midwives, EMTs, and ward staff.
The midwives, especially, deserve the bulk of the credit as they are the backbone of birth in the UK. I can't believe they aren't as prevalent in the US.
An OB/GYN seems like overkill for most pregnancies. Our second son was born at home in a birthing pool. This was done on advice from the NHS as this was a low-risk pregnancy.
The midwives showed up to our house and saw us all the way through.
Did I mention that we never had to worry about paying for any of this? I suppose I did make tea for the midwives; a fair bargain.
Now suppose there had been complications in the birth of either of our boys. Also taken care of by the NHS. My wife says she never wants to give birth again unless it's with the NHS (or other single-payer system). Mind you that we've never used the US system for birth so we have no basis for comparison. I'm a true NHS/single-payer convert. Sure it has some problems, but those problems are also present in the US system.
I'll take the higher taxes. I get good service when necessary, an increasing culture of evidence-based medicine (not just tradition/religious based), and not having to worry about being bankrupt.
I rue the day of going back to the US or having a future government dismantle the NHS.
...of the "tech literate". Politicians invariably answer more to certain interests of their constituency more than others. In this case Mr. Hansen may well end up listening mostly to those constituents which can use computers. So he will be giving those people their voice. It may not be an ideal, equitable representation, but I think it will be an interesting experiment* in the least. And judging by the comments I've seen on just about every news website there doesn't seem to be a bias to the left or right. You get the full spectrum of crazy.
* For those that think we shouldn't be experimenting with government, we've been dragging this one out for over 200 years...
Walking to buy a drink and some candy, rather than driving, may also incur the death penalty as provided by your neighborhood watch captain.
...
And why is every word capitalised? Was this submitted by some spambot of sorts?
Because it's one of the generally accepted elements of style?
http://www.writersblock.ca/tips/monthtip/tipmar98.htm
Folks just don't understand proper writing anymore (my own posts notwithstanding)...
There are already some efforts in place around the USA, you just have to _look_ find them. I remember the the Velocipede Bike Project in Baltimore. Plenty of tools and advice to fix your bike from what I remember so long as you mind all the damn hipsters. Also, support your local Tool-Lending Library!
...you really haven't experienced Hitler until you have read him in the original Klingon.
I might ask a cop for directions or report a traffic light being out, because that's something that is immediately useful.
You sure you want to do that?
I thought pancreatic cancer was killing jobs. (Too soon?)