First Photos of the Reentry of the ATV "Jules Verne" 87
White Yeti writes with news of the reentry breakup of the ESA's Automated Transfer Vehicle. All went as planned, and the ESA blog has preliminary photos. An international team of observers, in two aircraft south of Tahiti, saw a series of explosions and over a hundred small pieces of debris. Observations were mostly made using optical cameras and spectrographs. The two images on the ESA site are low-res samples, so we should get more spectacular images soon.
Camera phone funding (Score:4, Funny)
this [esa.int] is the "Hi res" 28k JPG image on the site. Anyone else get the feeling that they rushed up there to watch it and then someone said "I thought you said you'd bring the cameras" so it was then out with the mobile phones.
The only real surprise is that these clips didn't hit Youtube first with a Tramps "Disco Inferno" sound track. Very cool stuff and it practically demands HD for a fireworks display with a billion dollar budget
Re:Camera phone funding (Score:4, Insightful)
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Re:Camera phone funding (Score:4, Insightful)
this [esa.int] is the "Hi res" 28k JPG image on the site. Anyone else get the feeling that they rushed up there to watch it and then someone said "I thought you said you'd bring the cameras" so it was then out with the mobile phones.
Nice speculation, but the image you refer to is probably cut out from a much larger raw image. The URL has something about "800mm" in the name, which probably refers to an already somewhat decent telephoto lens having been in use. Definitely not your mobile phone!
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A wide-angle 12.1 Mpixel image taken with a diffraction grating and cropped to 778x500 pixels would explain the image quality.
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The EXIF data says it was taken with a Nikon D700 DSLR and a 20mm lens. A wide-angle 12.1 Mpixel image taken with a diffraction grating and cropped to 778x500 pixels would explain the image quality.
Wow.
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Perhaps esa isn't as media-oriented as one would expect from a space agency. I guess the tight budget (compared to nasa) makes esa more discrete in it's media-machine.
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Though I can't help but think: what a waste of a valuable resource! If they sent up additional fuel for it, it could be re-used
again and again - not to mention - why destroy the solar cells? Is it out-with the bounds of possibility to re-use the ATV
(by refueling it) or even to make it recyclable (remove solar cells before burning the rest of the ATV up)?
I realise they used it to also burn up a load of waste from the ISS, but really, what makes
Re:Camera phone funding (Score:5, Informative)
For what? Its primary mission is to deliver supplies from Earth. Oxygen, water, food, fuel. While docked it acts pretty much as a walk-in wardrobe. Once its supplies are exhausted there's no further use for it; they load it up with rubbish and send it off to burn up. Then another one gets launched.
It would probably be possible to redesign the ATV with a heatshield to allow it to come home intact. But that adds a lot of weight and drastically reduces its capacity as a cargo carrier; you'd only do that if you wanted to use it to carry human crews. Maybe that'll be done some day, but not right now.
The only other use for the ATV while in orbit is for station-keeping. It can boost the Station's orbit, and some day an ATV may be given the mission of de-orbiting the entire structure. But there's no sense sending up more fuel to allow the ATV to continue working as a tugboat - that fuel would be delivered by, er, another ATV. So you might as well let that do the job.
If there were other stations in near-Earth space, then keeping a spare ATV in orbit might make sense. It could ship equipment and perhaps crews between them. But right now there's nowhere to go from the Station except for back to Earth.
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Looks like the partnership they had in mind with Russia has been jeopardized by the last Georgian-Russian Skirmish and an overall feeling concerning Russia (Lately a dispute with the Czcech Republic).
http://science.slashdot.org/article.pl?sid=08/07/23/1319205 [slashdot.org]
ATV was clearly an outsider compared to the ESA-Russian program...Now this is totally different. ESA wants to be independent as far as I understand.
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Well, they could leave it docked to the ISS. Extra space always comes in handy, and the ATV's solar panels are useful too. They'd have to add a second airlock so the modules can be daisychained, though.
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Extra space always comes in handy
Don't they fill it with trash before jettisoning it?
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Then it would be more weight added to the station, and more fuel needed to correct its orbit.
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That, and as NASA discovered, re-usability in practice costs more than burning it up and building a new one, no matter how counter-intuitive that may be.
Even when humans are to be on board (naturally requiring recoverability), the costs to clean it up, refurbish and re-test to a human rating is more than making a new one.
Intentional Break-Up (Score:5, Informative)
Question about atmospheric friction (Score:4, Interesting)
At what speed do you have to travel in the atmosphere before the cooling effect of air rushing past is overtaken by the friction effect and you start heating up again? I remember reading that concorde used to heat up on the outside but subsonic airliners don't. Does it have anything to do with the speed of sound?
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Walls tend to create a lot of friction when you're trying to fly through them.
Re:Question about atmospheric friction (Score:5, Informative)
Logical and correct, although supersonic heating has nothing to do with friction.
Something moving through air pushes that air out of the way. At subsonic speeds (i.e. below the maximum speed the air as a fluid can move) this carries heat away from the aircraft. At supersonic speeds, the air simply cannot get out of the way quick enough, so piles up against the fuselage. This compression (not friction) creates heat.
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According to Top Gear's Jeremy Clarkson, at least.
Concorde widens during flight (Score:3, Interesting)
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As an attraction, there are only 5 of these British Airways aircraft in the world (in fact the comment was made that a B.A. crew who toured the facility had never been on the Concorde before) so to have this here in Barbados can only be a positive for our tourism product.
There are actually 7 BA Concordes (G-BOAA to G-BOAG) and 7 Air France Concordes (F-BTSC, F-BVFA to F-BVFD, F-BTSD and F-BVFF). There are also 6 development aircraft. All BA Concordes are on show, and 5 of the seven AF Concordes are on show (one is in storage, and one crashed).
Considering that BAs fleet consists of over two hundred aircraft, and Concorde was considered 'pick of the crop', its not really surprising that a particular BA crew had never been on her.
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The flight engineers cap story is real - during the last flight of each Concorde at their retirement, each flight engineer placed his cap in the space between their console and the rear compartment bulkhead. The caps can be seen to this day, stuck there.
Re:Question about atmospheric friction (Score:5, Interesting)
Another example is the SR71 "Blackbird". It was designed so that all parts would fit perfectly only when it was very hot during flight. And since it lacked a heat resistant fuel containment seal, it would leak fuel in the ground until it took off, flew for some time to heat up and then it had to be refueled on air.
Re:Question about atmospheric friction (Score:5, Informative)
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Reposting this (posted as AC) because I can't stand someone being wrong on the internet.
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Sorry, I am going to call BS on this.
Friction is not a basic concept - it has to do with the behavior of large number of atoms. It is thus basically a thermodynamic concept - ordered motion gets converted into heat via turbulence.
So, there can be fluid friction, even fluid-fluid friction (a useful concept in meteorology) and when the fluids are supersonic, shock effects become important. There is no reason you can't call that friction too.
In modeling real systems, you can almost never estimate friction from
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Re:Question about atmospheric friction (Score:4, Informative)
Here is a simple way to think about it -
The kinetic energy of your (or an airplane's) motion gets converted into friction through turbulence and shock effects. Heat is just the velocity of atoms bouncing off each other, and the sound speed depends on the velocity of those atoms, and thus on the temperature.
In an ideal gas, the absolute temperature is a measure of the energy, and thus is a constant times the square of the rms gas velocity. By the same consideration, for an idea gas, the speed of sound is (a constant) times the rms particle velocity. (That constant is the square root of the (adiabatic index /3), or about 0.7 for a monatomic gas.)
So, you are correct. Speeds much slower than the speed of sound will generally be associated with small amounts of heating, which may be negligible compared to other effects, such as cooling caused by the air flow, while speeds much higher than the sound speed will generally involve heating to something much above the ambient temperature. (Generally, of course, airplanes are designed not to convert all of their kinetic energy into turbulence, but during re-entry, that is done pretty effectively.)
The real gases in air are very non-ideal in the temperatures and pressures in re-entry so this simple theory is not realistic for speeds much above Mach 3 or so. It turns out that an engineer's rule of thumb is that the temperature in K is roughly equal to the speed in meters / sec, based on more realistic models of specific heat in the ionized plasma formed at these high speeds.
Link to video (Score:3, Informative)
Re:Link to video (Uploaded to Youtube as well) (Score:2)
Why explode? (Score:1, Funny)
Re:Why explode? (Score:4, Insightful)
It was designed to break up on re-entry, so if it made it to the ground in one piece some people would have been very angry.
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Re:Why explode? (Score:5, Informative)
The Jules Verne was carrying nothing but rubbish; it was intentionally burned up on re-entry. It's just a supply ship: it carries stuff up to the Station, serves as a little extra habitable volume while docked (I hear some of the crew have found it a very quiet place and have pressed it into service as sleeping quarters), and finally carries away waste and junk and incinerates the lot in the atmosphere.
With the uncertainty over the future of the American manned capability, there is now talk of developing an upgraded ATV which would include a re-entry module, and make ATV into a complete manned spaceflight system. Mind you, there's always talk; ESA headquarters is full of extremely expensive paperwork relating to manned spacecraft that never flew. At least in this case there's something concrete to point at, though.
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I've said it before and I will say it again: The UK is the weak link. All manned programmes in Europe have received enough backing from France and Germany that they would've succeeded if we had the vision to chip in our share.
The Italians, developing their new Vega launch vehicle, are demonstrating more aerospace competence than we are - and no offence meant to Italians but that is shameful for a country that considers itself the economic success story of the continent.
I blame Thatcher. Her restructuring of
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You might find this interesting:
http://www.timesonline.co.uk/tol/news/uk/science/article3367800.ece [timesonline.co.uk]
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How are we supposed to afford it? We have benefits to pay to layabouts, public-sector pen-pushers' unfunded pensions to pay, not to mention all those PFI contracts for shit we don't need. And the Olympics...
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Anyone who thinks 'layabouts' are the chief cause of British economic woes reveals their far right political orientation. Benefit fraud costs the taxpayer about 200 times less than corporate fraud, and the vast majority of social funding goes on pensions not unemployment benefits.
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Do the benefit fraud figures count all the people who are fully able to work but can't be bothered? Or the people who have kids despite being unable to afford them and so rely on benefits?
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With the uncertainty over the future of the American manned capability, there is now talk of developing an upgraded ATV which would include a re-entry module, and make ATV into a complete manned spaceflight system.
It might be handy to be able to use the ATV as an emergency return vehicle, so perhaps a heat shield would not be so bad an idea on a supply ship.
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... there is now talk of developing an upgraded ATV which would include a re-entry module, and make ATV into a complete manned spaceflight system.
There is pretty serious talk - they put together a model they showed off in Berlin [bbc.co.uk].
They would be crazy not to pursue this.
Step One (Score:1)
At least in this case there's something concrete to point at
Step One: Stop making the capsule out of concrete.
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I'm curious... (Score:4, Interesting)
did *anybody* ever get hit by a falling satellite?
or radiation damage?
or property damage?
anybody know?
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Some parts of Skylab landed in inhabited parts of Australia; IIRC, an American newspaper had offered a prize for the first Skylab fragments handed in, and an enterprising citizen picked up some bits from the roof of his house and took them with him on the first flight over there.
The only bits I remember were found years later on a remote cattle station. The bloke who found them tried to return them to NASA but they weren't interested.
Skylab hit a cow (Score:3, Informative)
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So that's what it looks like... (Score:1, Funny)
So that's what it looks like when we bring down a goa'uld mothership... neat.
Wow ! (Score:5, Interesting)
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The video of the re-entry [esa.int] is just beautiful !
You can see the autofocus struggling about 2/3rds in.
Dude, just set it manually to infinity. If you're thinking you might need to focus somewhere closer, you've got more to worry about than getting a sharp picture.
No friction here (Score:2, Informative)
Friction is a force between two solid surfaces. There is no friction involved in fiery atmospheric re-entry.
The heating is caused by compression. When an object travels at supersonic speeds, it pushes air ahead of it faster than the air in front of that air can get out of the way. This compresses it and thus heats it.
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<sarcasm>Too bad we weren't notified about this effort before it happened.</sarcasm>
2008-09-26 16:04:37 The Re-Entry of ATV: One Final Experiment (Index,Space) (rejected)
Grouse, grumble.
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It isn't "silly" - I am well aware of that compression isn't the only component of the thing - it is simply the best explanation for most people. The phenomenon you describe is such a tiny factor in the heating of a spacecraft re-entering the Earths atmosphere that it is pointless even mentioning it to someone who isn't specifically interesting in fluid dynamics.
As it happens, I am sufficiently interested in fluid dynamics, but when correcting the common fallacy that "friction" causes spacecraft to heat up
hires video (Score:3, Informative)
http://webservices.esa.int/blog/blog/1 [esa.int]
Taking Extreme Sports to Extremes (Score:1)
This shows a failure of imagination. (Score:3, Insightful)
This was a 16 ton, 30 meter long habitable spacecraft, used to carry supplies. The idea that there is no further use for it than to deorbit garbage is crazy. Did they offer it to any private groups (or even to the Chinese) ? If we really want to become a spacefaring civilization, we have to stop thinking in terms of billion dollar garbage runs, and start thinking in terms of what can we do with what we have.
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Of course, this is the same civilization that makes it cheaper to scrap a printer and buy a new one than replace the ink.
Re:This shows a failure of imagination. (Score:4, Insightful)
I don't doubt that there may be better uses for the craft but just how would you propose getting rid of the junk that accumulates? Remember, you have to be *positive* the junk doesn't stay in orbit so you have to substantially decelerate it somehow.
That means some sort of rocket so either you have a "bus" that serves the function or you have a lot of little rockets slowing down the junk.
On second thought, I suppose if their was some sort of rocket engine on the space station that was designed to eject junk at high speeds, you could both speed up the space station and dispose of the junk with one pop but lacking such an engine, I'm at a loss to think of how to better dispose of junk.
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Why? That is exactly what it was designed for. It carries supplies to the ISS, then is a bit of storage/extension to the space station and uses its fuel to lift the ISS so it doesn't fall out of orbit. When the surplus fuel is burnt, it is loaded with garbage, does two deorbit burns and enters the atmosphere. And then provides a spectacular light show.
Of what use would a space craft without fuel and loaded with garbage be to anybo
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