Am I safe in assuming the limitation of reactants was a usage issue rather than the reactants decaying to useless over time? We've seen stories of drones that should be able to stay in flight for months at a time with in flight refueling.
It was a quantity issue - even with drastically reduced electrical consumption, there was only so much available onboard. To overcome this limitation, they did develop a set of "buddy tanks" that could be carried in the cargo bay.
If they can get this drone to do as I suggest then any drone which evades a shoot down attempt means you don't have to pay for a new satellite.
Other than the fact that any attempt to "evade by deorbit" will mean near certain loss of the drone - sure. (They only have a very limited amount of maneuverability once deorbit starts - 95%+ of the time they aren't going to be in range of a suitable landing field.) Not to mention there's no sensors onboard the drone that can detect a shootdown attempt, and no practical ones anywhere on the horizon. Nor do we have the requisite suite of (offboard) sensors *or* the command-and-control system to make use of them.... And developing and deploying the same will cost as much as 20-30 satellites, *before* figuring in annual operational and maintenance costs.
You also have to consider that unless you place the drone in an orbit which absolutely never flies above someplace interesting - there's going to be more than one shootdown attempt.
Can I be wrong? Most certainly. Is it a feasible idea? Probably.
Really? I urge you to look closely at them the next time.
Yes, really. I know this may be hard to believe, but just because my impressions are different than yours doesn't mean I haven't been observant.
Now, there are a few systems that, instead of all that, just punch a 'hanging hole' in the boxes once they get over here, after their trip. Boxes designed that way used to be the normal at the start of clamshells, but that requires actual US employees, and such a thing is almost unheard of now.
On the contrary, and as I indicated in my original reply, those are quite common - they're the vast majority of clamshells I encounter.
One thing that has been desirable has been to keep surveillance drones in flight for as long as possible. The longest shuttle mission was 17 days and 15 hours. This drone has been up there for a year before coming down.
Which raises the question of just how much the drone could accomplish up there... the primary limit on the Shuttle's on orbit lifespan was reactants for the fuel cells. The drone has no solar cells and very little space for reactants. Nor does it look like it has sufficient radiator space for RTG's...
3. The protective covering that was damaged was on the Enterprise, not the bridge.
And the "protective covering" that was damaged is actually part of Enterprise in the same way the [protective] bumper on the front of your car is part of your car. It's physically part of the vehicle.
NASA has a fully functional copy of Hubble "sitting around" at Goddard Space Flight Center as well. If something goes wrong in space, fabrication of replacement components and the training of the astronauts that will fix it does not occur in space. It is invaluable to have an exact duplicate on the ground for this reason.
That was standard practice back in the 60's and early 70's - but has since been largely discontinued as duplicate flight hardware is by it's nature very expensive. Hubble, since it was built to be serviced by manned flights, was a rare exception.
Chances are the main satellites that these are duplicates for have been decommissioned, so these are no longer needed.
Given the troubles the NRO has had with it's various advanced projects over the last decade... I'd wager these are leftovers from a program whose budget has been cut or which has been cancelled outright.
Our intelligence operations are not transparent, and are kept secret to deny our adversaries knowledge of our techniques, capabilities, sources, and methods.
Security through obscurity is neither.
That's what anonymous cowards (whose only real knowledge of security is the platitudes they quote) believe. It's also quite wrong. In the real world of security, obscurity is a valuable tool in the kit. You can't prepare to thwart a measure you don't know the existence of.
Those with any significant level of reading comprehension, or who at least do more than rote cut and paste, will note two things. First, your link does not falsify my statement - rather, it proves it true. Second, the increasing percentage of non-advertising revenue.
People didn't buy Facebook shares to "finance the vision". They bought them to make money, and for that, they need to have a business model (and I really doubt that advertising - at current levels - is enough to keep the lights on).
Why do people keep forgetting that advertising isn't Facebook's only source of revenue? There's also their slice of in-game microtransactions/subscriptions.
I spent six years in the U.S. Air Force flying a desk. To this day people are shocked that the only time I flew on a plane was a civilian airliner, and I never saw combat.
That's because, of all of the [US] armed services, the USAF has the absolute worst tooth-to-tail ratio. It's inherent in the nature of an air force, any air force, but it is an aberration.
BTW, I don't mind Jimmy Wales voicing his opinion in these situations, my beef is when he acts unilaterally ignoring any sort of consensus building process at all.
Haven't you figured it out yet? Wikipedia is, and always has been, Jimmy Wales's private chew toy.
Ever drive a car from the late '80s-early '90s? Rather than a knob, the volume control was buttons! Unlike earlier and modern car radios, you couldn't change the volume without taking your eyes off the road!
Worse, your ac/heat controls used to have knobs, too.
My cars from back then had volume knobs. My 2006 Grand Voyager has both volume control knobs, *and* temperature control knobs.
The "new" method has the problem of immediately favoring the first design to get a positive response.
Only if you're stupid enough to only show the design with the highest score. Something as simple as choosing randomly among the top.75n results (where n=number of designs under test) fixes that.
SpaceX is commercializing technology that we've been hammering out since Project Mercury in the late 1950s.
Well if you put it that way, SpaceshipOne is just a bigger version of X-15 from the 1950's also.
Well, other than being a rocket propelled airplane... they have pretty much nothing in common. Different engines, different aerodynamics, different structures, different... well, pretty much everything. Not bigger, different. Very different.
Falcon on the other hand is, as the OP says, scaling up and refining design concepts going back to Mercury-Redstone.
I know Burt Rutan and crew have the engineering skill to get this thing done, what's been holding them back?
They're doing something much harder, with fewer resources, while being tied to scaling up an existing design. And Rutan retired over a year ago.
And what time machine are you using to "know" they have the skill to pull off something never done at that scale before? I could next week's stock prices.
Is this the next step toward militarizing our law enforcement agencies?
I've finally figured it out - "militarization" is a buzzword for "cops doing anything but walking a beat with no radio, no gun, and no other technology".
From TFS: On top of the four Falcon Heavy launches planned for the U.S. Air Force this year, the Intelsat contract represents the true dawn of the commercial space age.
Only if you somehow handwave away the decades we've already had of private companies contracting with other private companies for launch services.
So are large numbers of small rockets preferable, efficiency wise, to a few large ones (think the five F-1s of the Saturn V first stage). Or they cheaper in aggregate? Or are they more reliable?
In general, smaller numbers of larger engines are the preferred choice. It's more reliable, and cheaper to design and manufacture. (All that extra plumbing and thrust structure runs up the cost and weight.)
Or did Space-X just not have the funds to develop a really big engine (In which case couldn't they have licensed the design for the F-1 or J-1 from NASA?).
No, they didn't have the funds or the time or the experience to develop a larger engine, so they made lemons out of lemonade.
The F-1 would have required extensive re-desgn to be manufactured with modern methods and materials, and is a very expensive and complex design. The J-2 is a LOX/LH2 engine, and on top of also requiring an expensive re-design and requalification program (same as the F-1), would have had considerably increased operational costs.
From what I've heard, there's no trade off between reliability and cost. The cheaper vehicles will probably be the more reliable ones as well, due to learning effects from increased launch frequency.
That's the theory. (Along with it's handmaiden, "simpler is safer than more complex".)
To date however, there's no evidence that either is true. The Russian Soyuz family of launchers (and the R7 family they're derived from) are cheap, relatively simple, and the oldest and most flown design in the world - but their reliability is hardly distinguishable from that of the Space Shuttle or any other booster.
No, but they do make endless excuses as to why it's wrong, but it's OK for them to pirate anyhow. So, the end result is the same as if they were claiming the pirates are in the right, because they won't admit the pirates are wrong. This has resulted in endless posts like the original and your reply where those whose legal rights are being trampled on are made out to be at fault.
*yawn*, just the kind of thoughtless and ignorant reply I expected. The law doesn't allow "the people" to obtain the fruit of other's labors for free and obstinately requires "the people" to respect other's rights - so the law must be wrong.
Slashdot Mirror
It was a quantity issue - even with drastically reduced electrical consumption, there was only so much available onboard. To overcome this limitation, they did develop a set of "buddy tanks" that could be carried in the cargo bay.
Other than the fact that any attempt to "evade by deorbit" will mean near certain loss of the drone - sure. (They only have a very limited amount of maneuverability once deorbit starts - 95%+ of the time they aren't going to be in range of a suitable landing field.) Not to mention there's no sensors onboard the drone that can detect a shootdown attempt, and no practical ones anywhere on the horizon. Nor do we have the requisite suite of (offboard) sensors *or* the command-and-control system to make use of them.... And developing and deploying the same will cost as much as 20-30 satellites, *before* figuring in annual operational and maintenance costs.
You also have to consider that unless you place the drone in an orbit which absolutely never flies above someplace interesting - there's going to be more than one shootdown attempt.
You're not so much wrong as blithely clueless.
Yes, really. I know this may be hard to believe, but just because my impressions are different than yours doesn't mean I haven't been observant.
On the contrary, and as I indicated in my original reply, those are quite common - they're the vast majority of clamshells I encounter.
Which raises the question of just how much the drone could accomplish up there... the primary limit on the Shuttle's on orbit lifespan was reactants for the fuel cells. The drone has no solar cells and very little space for reactants. Nor does it look like it has sufficient radiator space for RTG's...
And the "protective covering" that was damaged is actually part of Enterprise in the same way the [protective] bumper on the front of your car is part of your car. It's physically part of the vehicle.
That was standard practice back in the 60's and early 70's - but has since been largely discontinued as duplicate flight hardware is by it's nature very expensive. Hubble, since it was built to be serviced by manned flights, was a rare exception.
Given the troubles the NRO has had with it's various advanced projects over the last decade... I'd wager these are leftovers from a program whose budget has been cut or which has been cancelled outright.
That's what anonymous cowards (whose only real knowledge of security is the platitudes they quote) believe. It's also quite wrong. In the real world of security, obscurity is a valuable tool in the kit. You can't prepare to thwart a measure you don't know the existence of.
Those with any significant level of reading comprehension, or who at least do more than rote cut and paste, will note two things. First, your link does not falsify my statement - rather, it proves it true. Second, the increasing percentage of non-advertising revenue.
Or for Slashdot's hit count and ad revenue.
Why do people keep forgetting that advertising isn't Facebook's only source of revenue? There's also their slice of in-game microtransactions/subscriptions.
That's because, of all of the [US] armed services, the USAF has the absolute worst tooth-to-tail ratio. It's inherent in the nature of an air force, any air force, but it is an aberration.
Haven't you figured it out yet? Wikipedia is, and always has been, Jimmy Wales's private chew toy.
Only in vanishingly small percentage of the clamshells I've encountered.
My cars from back then had volume knobs. My 2006 Grand Voyager has both volume control knobs, *and* temperature control knobs.
This is Slashdot. We don't need evidence if the story confirms our prejudices.
Only if you're stupid enough to only show the design with the highest score. Something as simple as choosing randomly among the top .75n results (where n=number of designs under test) fixes that.
I hope the hell they don't - there's plenty of useful work to be done in LEO yet. (Even though it doesn't give space fanbois any wood.)
Well, other than being a rocket propelled airplane... they have pretty much nothing in common. Different engines, different aerodynamics, different structures, different... well, pretty much everything. Not bigger, different. Very different.
Falcon on the other hand is, as the OP says, scaling up and refining design concepts going back to Mercury-Redstone.
They're doing something much harder, with fewer resources, while being tied to scaling up an existing design. And Rutan retired over a year ago.
And what time machine are you using to "know" they have the skill to pull off something never done at that scale before? I could next week's stock prices.
Naw, you just haven't a clue what "militarized" actually means.
I've finally figured it out - "militarization" is a buzzword for "cops doing anything but walking a beat with no radio, no gun, and no other technology".
No, the police aren't turning in a military.
From TFS: On top of the four Falcon Heavy launches planned for the U.S. Air Force this year, the Intelsat contract represents the true dawn of the commercial space age.
Only if you somehow handwave away the decades we've already had of private companies contracting with other private companies for launch services.
In general, smaller numbers of larger engines are the preferred choice. It's more reliable, and cheaper to design and manufacture. (All that extra plumbing and thrust structure runs up the cost and weight.)
No, they didn't have the funds or the time or the experience to develop a larger engine, so they made lemons out of lemonade.
The F-1 would have required extensive re-desgn to be manufactured with modern methods and materials, and is a very expensive and complex design. The J-2 is a LOX/LH2 engine, and on top of also requiring an expensive re-design and requalification program (same as the F-1), would have had considerably increased operational costs.
That's the theory. (Along with it's handmaiden, "simpler is safer than more complex".)
To date however, there's no evidence that either is true. The Russian Soyuz family of launchers (and the R7 family they're derived from) are cheap, relatively simple, and the oldest and most flown design in the world - but their reliability is hardly distinguishable from that of the Space Shuttle or any other booster.
No, but they do make endless excuses as to why it's wrong, but it's OK for them to pirate anyhow. So, the end result is the same as if they were claiming the pirates are in the right, because they won't admit the pirates are wrong. This has resulted in endless posts like the original and your reply where those whose legal rights are being trampled on are made out to be at fault.
*yawn*, just the kind of thoughtless and ignorant reply I expected. The law doesn't allow "the people" to obtain the fruit of other's labors for free and obstinately requires "the people" to respect other's rights - so the law must be wrong.