Japanese robot space maid will incinerate Earth's dead satellites Good news: the latest resupply mission to the International Space Station has taken off without exploding or any of that kind of nonsense. Even better news: it is carrying 5.9 metric tons (6.5 US tons) of cargo, including a rather unusual device that boffins believe could be a great tool for dealing with space junk. After the …
A short near-future story about the potential of electrotethering for orbital insertion and maneuvering.
The Japanese engineers are applying the concept of "anything that can maneuver prograde, can also retrograde."
Late the beeb seems written and laid out by fuckwits. I read a para and the same words are repeated in larger type right below it. Further down, there's larger type I haven't read, until later when it shows up in the article itself, this time in the correct logical place instead of several lines ahead. I imagine that the kind of people who read newspapers with small pages and large type find it useful to only read the large bits.
That's due to the current fad of trying to make oneself look intelligent by extracting "key phrases" and making them into headers. Allows for the TLDN crowd to skim those and pretend that they read the article - enough to criticize it anyway, which is the only thing that kind can do.
There are some who even do that in these hallowed halls.
I'm hoping that this fad will fade away, but I'm also hoping that people will finally learn the difference between there, they're and their and other such modern literary nuisances. I'm stupid like that.
Those 'key phrases' in larger type are called "pull quotes", (as the quotation is 'pulled out' of it's place in the body of the text) and they've been around since the 60's* about as long as this new-fangled internet fad.
* The phrase seems to date from the 1970's, but I've found examples from the 1960's at least. For some reason no one ever seems to have recorded the history of the pull quote, so I can't give you an exact figure.
So you can't transport batteries on a plane but you can put them on a really big rocket, subject them to radiation, vacuum and 170 million "flecks of paint" space junk travelling at thousands of Mph. Hope that junk collector works.
hope the cells weren't from Galaxy Note's.
The way I understand it, the Li-Ion cells used for the ISS are not of the kind used for most mobes or the Boeing 787. There are two basic technologies, one saving some weight (which is why Boeing used it, only to have several planes go up in flames) and the other being more stable. I will assume the latter technology is being used to resupply the ISS.
I think that, if our mobile phones had space-rated batteries, there would be a lot less reporting of said batteries blowing up.
There would also be a lot less people with mobile phones, given the cost of said batteries - which might not be a bad thing after all.
I've had this sneaky feeling that something got to be fishy with the ton. This metric moniker showing here and there could not be a good sign. I'd never followed up on my suspicion though (figured that US ton was just 1000lbs). Now that everything is clear (thanks The Register) I can't even say I'm particularly surprised. US, the land of cheats (and dirty trick). 4 by 4, gallon, pure "anything" and now the ton. Our entrepreneurs will always find the way to cut some corners (and sell you less for more).
Huh? Is it hard to find out that a U.S./Imperial ton is 2000 lbs...
Yes, it's hard to find because it's wrong. US and Imperial tons (like US and Imperial gallons) are different.
I think you'll find that an Imperial ton is 2240lbs, a short ton (US usage) is 2000lbs and a metric ton (or tonne) is 1000kgs or 2204.6lbs.
You might want to stick to marketing.
Lord It's Hard To Be Happy When You're Not Using The Metric System. Why not use units of 10 an convert with ease? All cool stuff is in metrics anyway.
Let's make America metric again!
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...to be testing a system for dealing with space junk, but then leave the key component of it up there adding to the problem.
Just watched the video (hint: turn the sound off) and it seems as if before the cargo capsule is finally de-orbited they are going to release the "KITE" and its tether to float around in orbit for goodness knows how long. I dare say the drag of the device would make de-orbiting the cargo capsule a bit more unpredictable, but couldn't they release the tether after firing the rockets, and thus bring it down separately too?
M.
There is enough atmosphere at the altitude the experiment is conducted that a low mass high drag item like the cable will have a "lifetime" measured in months at most. Probably only a few weeks. Even the ISS is skimming the top of the atmosphere and needs frequent reboosting to keep it in orbit.
35kg of propellant isn't enough to de-orbit a satellite weighing many tonnes but it's plenty to drive around space with a tiny little fishing net satellite.
What's more interesting is what happens when we start deorbiting satellites and the process takes months to complete, and there is zero guarantee as to whether it's going to land in the middle of the ocean, or on a major city.
"zero guarantee as to whether it's going to land in the middle of the ocean, or on a major city"
Au contraire - I think it is definitely guaranteed to land in the middle of the ocean, or on a major city.
It's the only movie scenario that makes sense. Landing in the veldt, or the steppes, or just offshore, or in suburbia - those things are never mentioned, and probably wouldn't make the news if it did.
Reference: "Small earthquake in Chile — not many killed".
35kg of propellant isn't enough to de-orbit a satellite weighing many tonnes
Hmm. For a storable liquid, bipropellant rocket of typical performance (330 sec^-1 specific impulse), 35kg would provide an 11m/s delta-V to a 10-ton satellite; 23m/s for a 5-ton satellite; and 57m/s for a 2-ton satellite. In low Earth orbit, an apogee burn of 23m/s might be enough to kiss the atmosphere. It wouldn't help much at geosynchronous, but could your satellite to a higher graveyard orbit.
What's more interesting is what happens when we start deorbiting satellites and the process takes months to complete, and there is zero guarantee as to whether it's going to land in the middle of the ocean, or on a major city.
I would guess the opposite. With months of time you have months to fiddle with the current pumped through the tether, thus varying acceleration, thus allowing navigation to a preferred disposal site - e.g., at sea. The potential accelerations are on par with ion engines: low, but useful.
Since reading the article I've been puzzling about the direction in which the force appears. Fleming's rule says it will be at right angles to the direction of current flow and at right angles to the movement of the wire carrying the current through the magnetic field. Won't the force on the wire be sideways, causing the wire to bow and pulling the weight at the end back towards the satellite?
Hmm, "more years ago than I care to mention" permanent magnets were puny things. Now, today, if I can just prise this neodymium magnet off this steel table, let me show you how quickly it falls through this vertical copper pipe.
Non caveat: Try this at home with your kids.
Won't the force on the wire be sideways, causing the wire to bow and pulling the weight at the end back towards the satellite?
In the absence of other forces, yes. However, tidal effects in space try to orient long objects such that they remain pointed at Earth's core - a tether will orient itself radially outward from Earth. A 700-meter tether won't have a lot of tidal force acting on it, but it's something to help maintain the orientation of the tether. Operational designs would use 5,000 to 10,000 meters of tether, which would magnify the tidal loads.
Just watched the Video (sound off) and found it very interesting.... Couldn't spot the nets,
They're the cable you saw in the video. The cable is made of mesh by a fishing net company. It isn't a net itself.
given the hype about the nets wtf are they?
The Register recently had an article explaining them. Quoting: "KITE has been built to demonstrate electrodynamic tethering, whereby unshielded metallic lines extended in space pick up an electrical charge as they move through Earth's magnetic field. The principle has been used before to generate power, but now scientists want to try attaching a tether to larger pieces of space junk to de-orbit them."
The article claims 600 litres to be 105 gallons. I wonder what those gallons are as AFAIK 600 litres equates to just shy of 132 gallons.
Or 150 US gallons. About time to do away with this silliness and convert it to the internationally recognise Reg Units.
We hear in the news: the hard part of space is getting stuff up there.
followed by: water / materials better off in space as dont have to transport up there etc etc.
so logically why incinerate the stuff, why not stockpile it and re-cycle in space (a space junk yard if you will). strikes me a LOT of that material could be re-used.
I suppose i get that millitary items may want to be incinerated for security reasons / secrecy, but you get what i mean.
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