Only nobody said anything about continuous thrust, just using thrust to move it to a higher orbit.
The original poster specified an ion engine, which must operate continuously or nearly so in order to have any significant effect on the station's orbit.
Now, you could use normal thrusters (preferably from an external source to conserve Zvezda's fuel) to raise the orbit, but you cannot raise it significantly without affecting the ability of other servicing craft (Soyuz, Progress, ATV, HTV, Dragon) to utilize their full design capacity. (The higher the orbit, the lower the delivery capacity.) You can't raise it high enough to significantly reduce atmospheric drag without getting into the region where those craft, at best, no longer have a useful cargo capacity or may not be able to reach it at all.
The funny part, is the only reason the shuttle program exists is to visit the station, and the only reason the station exists is to have a place for the shuttle to go. Every other purpose had to be removed to save money in budget crunches.
Actually, that's 100% backwards. The original purpose of the Shuttle was to supply and support a space station performing research in space. (The orbital equivalent of an Antarctic research station or something like Sealab.) Which is why it's called a shuttle in the first place.* It was meant to travel back and forth between two points - station and launch/recovery site. All the other capabilities, satellite deployment and recovery, etc... etc..., were added to the Shuttle when the station (and the heavy lift boosters to build it) were axed from the budget in the late sixties and early seventies.**
That's why, if you examine the history of Shuttle designs, you see a sudden rise in weight, complexity, and cost*** in that time period. That's why the Shuttle was already moving in a direction that made it (relatively) easy to modify the design to bring the DoD onboard. That's why the Shuttle was marketed as being 'all things to all people'. That's why rising costs lead the Administration and Congress to cap the development budget.
The other functions (that shuttle had as built) were steadily cut back not due to budget cuts, but in reaction to the Challenger and Columbia accidents. The former is why NASA stopped lifting commercial satellites and payloads. The latter is why the Shuttle stopped flying independently, except for the controversial Hubble servicing mission.
No one makes money off a built station that has been budget crunched to the point that it does nothing.
Had the station been budget crunched to the point where it does nothing, you'd have a point. To be sure it's a hell of a lot less useful than it could have been, but does nothing is a bit extreme. You also have to realize that much of the cost of the station (as built) stems from two causes. The first is the constant changes to stations scope and function imposed by Congress in the 80's (leading to multiple expensive redesigns). The second is the decision to shift the station to an orbit the Russians could reach so as to funnel welfare in the direction of their space program and rocket engineers in order to keep them employed and thus unlikely to sell their services to states more interested in weapons than science.
* The definition of shuttle, uncontaminated by the current Shuttle, in the Webster's 1913 dictionary makes this even clearer.
** The Administration and Congress were actually right in this however - the heavy lift boosters used for station deployment would have had an extraordinarily low flight rate and thus would have been extraordinarily expensive. Which is why I've often thought that we should revisit the original shuttle concept now that heavy lift boosters are commercially available.
*** Complexity and cost in particular are strongly bound. When you have to use 'extreme engineering' to meet your performance goals, your costs are going to rise sharply. As Elon Musk is attempting to demonstrate (and already has to some extent) when you can simplify your design, engineering, and manufacturing, launch costs can drop dramatically.
While certainly you could operate an ion thruster to 'balance' atmospheric drag (AIUI) that won't raise it to a higher altitude as specified by the OP. However, it consumes a great deal of power (and the ISS doesn't have all that great an excess over requirements). It would also potentially contaminate the environment around the ISS and reduce the usefulness of the experiments requiring exposure to space. (Not that evaluating the effects of an ion engine local contamination wouldn't be useful mind you.)
You need to keep in mind that most of the time the ISS operates in a condition where it is held in a fixed inertial attitude to maximize microgravity purity. Because of this, an onboard ion thruster would only be pointed in the proper direction for a few minutes each orbit, if it were ever pointed in a useful direction at all. I supposed you could mount it on an articulated mount, but then the vibration issue needs to be addressed.
And yes, atmospheric drag does reduce the quality of the micro gee environment onboard ISS. This is taken into account when designing and operating experiments onboard.
The electric thruster onboard is (AIUI) either non propulsive or operates at such a low level that it doesn't violate the microgravity thresholds.
The ISS uses thrust to adjust it's orbit already. It won't 'ruin' anything. The Zvezda module already has two main engines used for orbital adjustments.
Those thrusters operate for short periods of time at great intervals. Considerable effort is expended to set up the schedule such that usage of those thrusters, docking and undocking visiting ships, station attitude changes and other such events occur in clusters with lengthy intervals between them in order to provide the maximum time of 'uncontaminated' micro gee. (There's even a vibration isolation system on some experimental racks to minimize disturbance in between those events for experiments that require an even higher level of micro gee.)
So yes, continuous usage of an ion thruster will ruin the micro gee environment, and yes this will be a great disruption to experiments onboard.
Now that the station on longer has to be in a shuttle-accessible orbit, could we not fit it with a nifty little ion engine and slowly boost it to a higher altitude?
Not really. Much higher and the other vehicles (Soyuz, ATV, etc...) won't be able to reach it either. On top of that, while under thrust the micro gee environment aboard the station will ruined, ruining practically every experiment onboard.
Correct. However the link in the summary is incorrect - dazzle camouflage was widely used in WWII. Some of the schemes used by the USN can be seen here.
It's worth pointing out however that proper studies of the effectiveness of dazzle camouflage seem to have never been carried out.
I was thinking the same thing... I already have four SSBN patrols under my belt. Thirty days away from my life? Pfft. I could practically do that standing on my head.
I may not be a scientist, but shouldn't a design cover the requirements?
It is an unprecedented scientific experiment, not the some sort of business logic application coded in Java that you undoubtedly do for a living.
The only people who believe business applications are trivial to code as those who don't actually code business applications. I.E. those without a clue.
I don't understand what the obsession with going to Mars is. Frankly I think Venus is where we should target our efforts. It has an atmosphere (albeit hazardous to human life) and is about 20% closer to us then Mars.
Well, there are three reasons for the 'obsession' with Mars.
Man has historically been more interested in Mars than Venus.
We can actually reasonably reach the Martian surface with both unmanned and [eventually] manned probes.
Mars is actually 'closer' than Venus. It's not absolute distance that matters in space travel, but relative velocity. Not only is Venus 'faster' than Mars, it's also closer to the sun which means we actually have to shed energy to reach it. This is harder and takes more fuel than sending the equivalent probe to Mars.
In most jurisdictions, you'd never have been seated on the jury in the first place.
Even if the only reputation they have is from always appearing in newspapers under unsavory conditions, I am not expected to forget all that when evaluating their testimony.
Actually, yes. You are. Your decision in the jury room is supposed to be based solely on what was presented in the courtroom, where both sides have had a chance to examine and rebut what was presented.
And yes, I am ignoring the idea that prior criminal history is not supposed to be part of a defendant's current trial, but I also think that is bunk -- if some guy has been to jail a half dozen times for beating people up, that sure as heck is significant.
In other words, you prefer prejudice over fairness.
The average Joe is 10 times more educated than 300 years ago and will use that education when forming his opinion. Allowing that person to read a dictionary, research terms, definitions, subjects, etc... allows for a TRUE jury of his peers.
Not only does it not create a 'true jury of peers' (whatever that means) but it also doesn't ensure that each and every fact considered by the jury is brought out in open court and the other side given a chance to rebut, express their opinion, or express their interpretation.
How in the world is a "normal" person supposed to know when the judge or attorney is trying to pull a fast one when they aren't even allowed to research what is being said?
Because the assumption is the other side will promptly call attention to such an attempt. And really, even if you had access to research materials - unless you look up each and every thing said by the judge or attorney (which is obviously impractical) you wouldn't know if they were pulling a fast one anyhow.
The real intent here anyhow is to prevent you from being swayed by information from outside the courtroom.
It is interesting that there has been a substance created harder than regular diamonds that has been published for seven years! I figured there would be saw blades everywhere which advertised "new, better than diamond tipped!"
Depends on how expensive/difficult to make/etc. the new 'diamonds' are. They could be too expensive to economically make. They could be so expensive that they are only used in specialized industrial/commercial applications. (I.E. people willing to pay seriously big, big bucks per blade.)
These are just examples, there's probably half a dozen more reasons why you aren't seeing the adverts.
No more clear coats, no more waxing, no more "rubberized under coating". If it is cheap, and light enough, you could coat every body panel and frame member with the stuff, virtually guarantying a rust proof existence.
Clear coats and waxing don't prevent rust, they merely give you a stiffy because your car looks spiffy.
This isn't some "let's try something out" experiment. It was an official test with requirements that needed to be met. If the test failed to verify the requirements the test officially failed and would be rejected.
As I pointed out, this is only true in a binary world. But we don't live in a binary world. If you were an engineer, as you claim, you'd know that. It's impossible to generate valid performance statistics if you lump Option 2 and Option 3 failures together as that means lumping in the false negatives with the real ones. That's poor statistics and even poorer engineering.
I agree on the general use of the term "test", but what this article refers to and what the OP was questioning isn't general use. It's DoD and it has a very specific meaning. Pass/Fail, that's it.
I rather suspect that it's either your field, your education (or lack thereof), as I've heard the criteria that I outlined widely used in and out of the DoD.
Because this would be far better as filler than the existing crap that's used in the 24-hour news cycle.
So yes, I do want to hear about these things. And occasionally, I do (usually in the form of: local man tries to break X record).
Fascinating. You don't realize the extent to which these statements are mutually exclusive, and you don't realize that stunts like breaking a record have absolutely nothing to do with science and exploration.
Part of me feels like I've just missed one of the greatest eras of mankind.
I thought that too when I was twenty and had just lived through the 70's.
There was a time when Astronauts were hailed as heros, now our generation views them as simple scientists in the ISS. They're lucky if their launches or arrivals get 15 minutes of airtime.
It just saddens me that it is no longer "Big News" sending people into space
Are you sad when an oceanographic research vessel sets off on an expedition without even rating a mention on the local news? When a geological field team pitches it's tents and there isn't breathless 24/coverage on CNN? When a biologist checks into a local hotel before heading out into the woods, and the desk clerk just yawns and goes back to his book?
It's kind of like exploring the interior of the US. Lewis and Clark got all the glory for crossing it the first time - but it wasn't until decades later that surveyors, cartographers, geologists, and biologists fanned out across the country. (The latter two categories are *still* out there exploring.) But they didn't make the history books and don't make the news, they're lucky if they get passing mention on a Discovery Channel special. Nobody will ever raise a statue to them, celebrate the 200th anniversary of their work, or stage a re enactment of their work. Only exploration geeks like myself know the names of some the most famous among them. But they're the ones that got the real work done.
A great deal of the problems with out space program stem from the fact that for so long it's been heavily publicized and politicized, misleading people into believing that if it isn't worthy of news coverage then it isn't worthy of being done. It's past time we washed out hands of these romantic and sterile 'great leaps' and got on with hard, dirty, day in and day out work of engineering and exploration. It's going to be expensive, and slow*, and dangerous - and not at all romantic or glamorous, but we won't make progress until we do.
*Far more expensive and far slower than the 'great leap' showpieces. Which is the main reason we don't do it.
Even my minimal 3 years as a test engineer knows that your pedant tag doesn't apply. If a test fails that doesn't mean you didn't get any information at all, it means you have pass/fail criteria set for a specific test and if you didn't meet the pass criteria (e.g., you didn't intercept the threat cluster) your test fails.
Well, that's not entirely true because the situation is trinary not binary.
To drag out the old standby of Slashdot, an auto analogy, lets say I want to test if my car will reach 100mph on the highway. There are three possible outcomes:
Pass - I get on the highway and reach 100mph.
Fail - I get on the highway and do not reach 100mph
No Test - something prevents the test from completing successfully. (I get in an accident on the way to the highway, my speedometer fails which means I cannot measure my speed, etc. etc..)
Or in other words, the OP is correct - you can have a failed test (option 3) without failing the test (option 2). His pedant tag is in fact correctly applied, and his question a valid one.
Our hatred of these projects is a recent thing too. The Hoover Dam wasn't met with this kind of derision. The Apollo Program wasn't met with this kind of derision
Of course the Hoover Dam wasn't met with this kind of derision - it produced jobs and a useful product (electric power), and flood control services. The Apollo program produced jobs, technology, and a sense of national pride.
A massive bullet train network produces jobs (for a while), and after trillions of dollars and years of work - leaves us with a national white elephant hanging around our neck and requiring billions a year in subsidies to keep alive. The other projects you mention were also short term project with clear goals, while a train system is a long term project without a finish line, let alone a clear purpose.
Slashdot Mirror
The original poster specified an ion engine, which must operate continuously or nearly so in order to have any significant effect on the station's orbit.
Now, you could use normal thrusters (preferably from an external source to conserve Zvezda's fuel) to raise the orbit, but you cannot raise it significantly without affecting the ability of other servicing craft (Soyuz, Progress, ATV, HTV, Dragon) to utilize their full design capacity. (The higher the orbit, the lower the delivery capacity.) You can't raise it high enough to significantly reduce atmospheric drag without getting into the region where those craft, at best, no longer have a useful cargo capacity or may not be able to reach it at all.
Actually, that's 100% backwards. The original purpose of the Shuttle was to supply and support a space station performing research in space. (The orbital equivalent of an Antarctic research station or something like Sealab.) Which is why it's called a shuttle in the first place.* It was meant to travel back and forth between two points - station and launch/recovery site. All the other capabilities, satellite deployment and recovery, etc... etc..., were added to the Shuttle when the station (and the heavy lift boosters to build it) were axed from the budget in the late sixties and early seventies.**
That's why, if you examine the history of Shuttle designs, you see a sudden rise in weight, complexity, and cost*** in that time period. That's why the Shuttle was already moving in a direction that made it (relatively) easy to modify the design to bring the DoD onboard. That's why the Shuttle was marketed as being 'all things to all people'. That's why rising costs lead the Administration and Congress to cap the development budget.
The other functions (that shuttle had as built) were steadily cut back not due to budget cuts, but in reaction to the Challenger and Columbia accidents. The former is why NASA stopped lifting commercial satellites and payloads. The latter is why the Shuttle stopped flying independently, except for the controversial Hubble servicing mission.
Had the station been budget crunched to the point where it does nothing, you'd have a point. To be sure it's a hell of a lot less useful than it could have been, but does nothing is a bit extreme. You also have to realize that much of the cost of the station (as built) stems from two causes. The first is the constant changes to stations scope and function imposed by Congress in the 80's (leading to multiple expensive redesigns). The second is the decision to shift the station to an orbit the Russians could reach so as to funnel welfare in the direction of their space program and rocket engineers in order to keep them employed and thus unlikely to sell their services to states more interested in weapons than science.
* The definition of shuttle, uncontaminated by the current Shuttle, in the Webster's 1913 dictionary makes this even clearer.
** The Administration and Congress were actually right in this however - the heavy lift boosters used for station deployment would have had an extraordinarily low flight rate and thus would have been extraordinarily expensive. Which is why I've often thought that we should revisit the original shuttle concept now that heavy lift boosters are commercially available.
*** Complexity and cost in particular are strongly bound. When you have to use 'extreme engineering' to meet your performance goals, your costs are going to rise sharply. As Elon Musk is attempting to demonstrate (and already has to some extent) when you can simplify your design, engineering, and manufacturing, launch costs can drop dramatically.
While certainly you could operate an ion thruster to 'balance' atmospheric drag (AIUI) that won't raise it to a higher altitude as specified by the OP. However, it consumes a great deal of power (and the ISS doesn't have all that great an excess over requirements). It would also potentially contaminate the environment around the ISS and reduce the usefulness of the experiments requiring exposure to space. (Not that evaluating the effects of an ion engine local contamination wouldn't be useful mind you.)
You need to keep in mind that most of the time the ISS operates in a condition where it is held in a fixed inertial attitude to maximize microgravity purity. Because of this, an onboard ion thruster would only be pointed in the proper direction for a few minutes each orbit, if it were ever pointed in a useful direction at all. I supposed you could mount it on an articulated mount, but then the vibration issue needs to be addressed.
And yes, atmospheric drag does reduce the quality of the micro gee environment onboard ISS. This is taken into account when designing and operating experiments onboard.
The electric thruster onboard is (AIUI) either non propulsive or operates at such a low level that it doesn't violate the microgravity thresholds.
Those thrusters operate for short periods of time at great intervals. Considerable effort is expended to set up the schedule such that usage of those thrusters, docking and undocking visiting ships, station attitude changes and other such events occur in clusters with lengthy intervals between them in order to provide the maximum time of 'uncontaminated' micro gee. (There's even a vibration isolation system on some experimental racks to minimize disturbance in between those events for experiments that require an even higher level of micro gee.)
So yes, continuous usage of an ion thruster will ruin the micro gee environment, and yes this will be a great disruption to experiments onboard.
Not really. Much higher and the other vehicles (Soyuz, ATV, etc...) won't be able to reach it either. On top of that, while under thrust the micro gee environment aboard the station will ruined, ruining practically every experiment onboard.
Correct. However the link in the summary is incorrect - dazzle camouflage was widely used in WWII. Some of the schemes used by the USN can be seen here.
It's worth pointing out however that proper studies of the effectiveness of dazzle camouflage seem to have never been carried out.
I was thinking the same thing... I already have four SSBN patrols under my belt. Thirty days away from my life? Pfft. I could practically do that standing on my head.
The only people who believe business applications are trivial to code as those who don't actually code business applications. I.E. those without a clue.
Which doesn't help at all with the problem of getting there in the first place.
And when the analysts look at the bell curve, the outliers that are the weird are easily isolated and discarded from the analysis.
Well, there are three reasons for the 'obsession' with Mars.
In most jurisdictions, you'd never have been seated on the jury in the first place.
Actually, yes. You are. Your decision in the jury room is supposed to be based solely on what was presented in the courtroom, where both sides have had a chance to examine and rebut what was presented.
In other words, you prefer prejudice over fairness.
Not only does it not create a 'true jury of peers' (whatever that means) but it also doesn't ensure that each and every fact considered by the jury is brought out in open court and the other side given a chance to rebut, express their opinion, or express their interpretation.
Because the assumption is the other side will promptly call attention to such an attempt. And really, even if you had access to research materials - unless you look up each and every thing said by the judge or attorney (which is obviously impractical) you wouldn't know if they were pulling a fast one anyhow.
The real intent here anyhow is to prevent you from being swayed by information from outside the courtroom.
If normal English would serve for laws, we wouldn't need courts in the first place.
Depends on how expensive/difficult to make/etc. the new 'diamonds' are. They could be too expensive to economically make. They could be so expensive that they are only used in specialized industrial/commercial applications. (I.E. people willing to pay seriously big, big bucks per blade.)
These are just examples, there's probably half a dozen more reasons why you aren't seeing the adverts.
Clear coats and waxing don't prevent rust, they merely give you a stiffy because your car looks spiffy.
As I pointed out, this is only true in a binary world. But we don't live in a binary world. If you were an engineer, as you claim, you'd know that. It's impossible to generate valid performance statistics if you lump Option 2 and Option 3 failures together as that means lumping in the false negatives with the real ones. That's poor statistics and even poorer engineering.
I rather suspect that it's either your field, your education (or lack thereof), as I've heard the criteria that I outlined widely used in and out of the DoD.
Fascinating. You don't realize the extent to which these statements are mutually exclusive, and you don't realize that stunts like breaking a record have absolutely nothing to do with science and exploration.
I thought that too when I was twenty and had just lived through the 70's.
Are you sad when an oceanographic research vessel sets off on an expedition without even rating a mention on the local news? When a geological field team pitches it's tents and there isn't breathless 24/coverage on CNN? When a biologist checks into a local hotel before heading out into the woods, and the desk clerk just yawns and goes back to his book?
It's kind of like exploring the interior of the US. Lewis and Clark got all the glory for crossing it the first time - but it wasn't until decades later that surveyors, cartographers, geologists, and biologists fanned out across the country. (The latter two categories are *still* out there exploring.) But they didn't make the history books and don't make the news, they're lucky if they get passing mention on a Discovery Channel special. Nobody will ever raise a statue to them, celebrate the 200th anniversary of their work, or stage a re enactment of their work. Only exploration geeks like myself know the names of some the most famous among them. But they're the ones that got the real work done.
A great deal of the problems with out space program stem from the fact that for so long it's been heavily publicized and politicized, misleading people into believing that if it isn't worthy of news coverage then it isn't worthy of being done. It's past time we washed out hands of these romantic and sterile 'great leaps' and got on with hard, dirty, day in and day out work of engineering and exploration. It's going to be expensive, and slow*, and dangerous - and not at all romantic or glamorous, but we won't make progress until we do.
*Far more expensive and far slower than the 'great leap' showpieces. Which is the main reason we don't do it.
Well, that's not entirely true because the situation is trinary not binary.
To drag out the old standby of Slashdot, an auto analogy, lets say I want to test if my car will reach 100mph on the highway. There are three possible outcomes:
Or in other words, the OP is correct - you can have a failed test (option 3) without failing the test (option 2). His pedant tag is in fact correctly applied, and his question a valid one.
You forgot the real Living Dead of the comics pages - Blondie. Eighty years of recycling the same material over, and over, and over...
On the other hand, the additional thickness and weight increases fatigue and interferes with mobility.
Of course the Hoover Dam wasn't met with this kind of derision - it produced jobs and a useful product (electric power), and flood control services. The Apollo program produced jobs, technology, and a sense of national pride.
A massive bullet train network produces jobs (for a while), and after trillions of dollars and years of work - leaves us with a national white elephant hanging around our neck and requiring billions a year in subsidies to keep alive. The other projects you mention were also short term project with clear goals, while a train system is a long term project without a finish line, let alone a clear purpose.
If the budget was being balanced, you'd have a point.