Scientists in Western Australia think they've cracked a way to use FM radio emissions from a youth station to track man-made garbage in low-Earth orbit. The boffins have demonstrated the technique using the International Space Station as a target. The newly built Murchison Widefield Array (MWA) in remote Boolardy sheep station …
This is indeed serendipitous
Defence applications, perhaps?
Also, it allows me to use the word serendipitous, which is nice.
Rock gods? Triple J? You're joking! They play nothing but electronic rubbish that drives me up the wall.
Australian widow spider, then?
I've not listened for a while, but the late night programs (ie during the day UK time) used to be pretty good, and very varied.
Mind you, I like electronic music.
Yoof oriented radio?
Playing SKA? I remember SKA, and I'm a doddering old bugger.
This is Spinal Tap?
It seems the Aussies may have replicated the unfortunate dimensional error which saw Spinal Tap sharing the stage with a rather diminutive Stonehenge! One square meter would certainly be a very concentrated grouping for large radio telescope antennae.
This is how the USAF "Space Fence" worked for 50 years
It emitted radio signals and then other receiving stations across the country picked up the reflections to detect satellites. It could spot stuff down to 4" and it could identify several hundred separate objects a second.
NASA has had to upgrade ISS to dodge space junk because the useless wankers in Congress shut the thing down.
Re: This is how the USAF "Space Fence" worked for 50 years
"NASA has had to upgrade ISS to dodge space junk because the useless wankers in Congress shut the thing down."
That made absolutely no sense whatsoever.
So, the idiots in the US Congress shut down the ISS and that made space junk threaten it?
No, accumulated debris from five decades of launches, dead satellites, collision debris from satellites smashing into one another and a few idiotic military satellite interception tests from several idiotic nations all added to the debris that threatens LEO satellites.
No, the idiots in the US Congress shut down the Space Fence and the ISS could no longer properly forecast where it needed to be a day in advance. That's why they had to upgrade the boosters.
At least, that's what he wrote.
It's a bistatic radar fence system.
Which is clever. I note there is no word on the size of debris that can be detected.
The (now shut down) US space fence worked at 400MHz and detected down to 10cm, but according to NASA object >1mm can do serious damage.
BTW Congress did not shut down the space fence. It was run by the USN and transferred to the USAF. They want the new shiny 2.1GHz space fence and shut it down. Conventional radars do bearing and range but the space fence only does bearing (which allows you to target the precision radars onto it and get range) and the software to support it is specialised.
The USAF said it was to save money.
It saved all of $16m.
Re: It's a bistatic radar fence system.
The French have a bi-static radar called GRAVES operating on 143.050MHz - from recollection it runs 1MW ERP. If you are a radio ham with a decent 2m (144MHz) system its fairly easy to receive meteor reflections from it.
There's an article on Wikipeadia as well as this more interesting "cook book":
Before the big bang? Really?
"One of its key tasks is to look back into the very early stages of the universe's development, about 350 to 800 million years aft the Big Bang."
Yeah, yeah, yeah, I know ... typoes R us. It's a hazard of this medium. Doesn't mean the late-night giggle factor is non-existent, though ;-)
Re: Before the big bang? Really?
Arrh, me hearties! There sure is a big bang going on aft of us! Methinks we ought to participate!
Larger space junk, maybe
They are using JJJ in Geraldton and Perth transmitting on 98.9 MHz and 99.3 MHz, with a wavelength about 3 meters.
They aren't going to detect space junk below 75 cm unless they have some new trickery.
Re: Larger space junk, maybe
A quarter-wavelength antenna... good thinking. And it must be a single piece of metal, too.
Not Possible in the UK
...... when (if?) we go over to DAB! Who would have thought the dross that passes for the majority of UK radio could be the savior of space tavel
Re: Not Possible in the UK
Another good reason for not turning off analogue radio then. I haven't read anywhere about people doing this with DAB transmissions. :o)
However, I fail to see the newsworthyness or even the science of this - reflecting radio signals off of objects in the atmosphere (or orbit) has been around almost as long as man has put objects into the atmosphere and been able to manipulate radio waves.
Raadio hams (yes, the beardy, sandle wearing ones) have bounced signals off metror trails and other high altitude debris for years, and UHF troposcatter systems were once widely used (they may still be) in the pre-satellite days to get comms to offshore structures like oil rigs. Over The Horizon Radar (OTHR) systems have been aroudn since the cold war too.
As others have said - detecting large objecs is easy.
Its' the myriad tiny items which are problematic. A single fleck of paint gouged a large chunk out of a shuttle windscreem in the 1980s and a 1cm object - whilst currently not trackable - would simply pass straight through the hull of the ISS and leave a trail of smaller debris behind it.
They could probably patch that hole
as long as it doesn't hit somebody's vital organ.
"Each day, gravity pulls the International Space Station, or ISS, a little closer to Earth."
Er - I suppose yes, but really that's atmospheric drag. So, stuff in that orbit doesn't -stay- in that orbit.
The Kessler thing happens in the film [Gravity], so is that for real? I thought it was not credible.
Like the Lamb reference in the sub-head. Who's the Genesis fan?
just google Daventry Experiment 1935
basically they've rediscovered something that had been done yonks ago...
Re: Old tech...
There is no shame in that!
You need a better headline.
1Direction Saves the International Space Station
Justin Beiber to Stop Alien Invasion.
Lady GaGa Guidence to Steer Space Station
Re: You need a better headline.
Yes, straight into the path of an asteroid or other fatal object if I were on-board forced to listen to that!
I wonder, is there any particular direction that you need to look to see back that far? according to my pretty patchy understanding of the current theories of the creation of the universe, galaxies are all moving, generally away from the big bang that formed spacetime. So, would it be that you should look backwards along the direction of travel of the milky way to see farthest back?
Or is that too simplistic?
"Or is that too simplistic?"
Slightly less simplistic :
Space is expanding in three dimensions so everything is moving away from everything else. The visual effect for an observer is that the observer is always at the centre no matter where they are.
The universe is also (in one model) currently thought to be the surface of a four-dimensional sphere, which would mean there's technically no middle and no edge to it in three dimensions. It might also be the surface of a four-dimensional torus. I'm not sure what difference that makes...
It's never stylish to look like a donut.
The issue, as far as I can tell with debris is a cascading effect. A small object smashes into another object which itself gets smashed into smaller objects, these objects continue to orbit the Earth, eventually you're going to have a major impact, let's say an object manages to blow up the ISS, the debris from that then starts to orbit the planet.
Soon you have a planet that is surrounded by small bits of debris which prevents people leaving the planet, or objects leaving the planet, as anything that tries to leave gets hit by orbiting debris and becomes part of the problem at hand. Can't find the article that explains it as I don't know the name, but it does have a fancy name so really, we should get onto removing the debris as quick as possible before something happens and we lose all ability to send anything into the sky.
It's called "Kessler Syndrome" or "Kessler Effect", described in 1978 by NASA scientist Donald Kessler.
Satellite equivalent of a snowtruck?
What's the issues with having a bloody great downward-facing ram on the front of a pong-like satellite, with it's only purpose to be deflecting small debris earthward?
Will things smaller than 75cm, even get to the ground?
Given the telemetry, angle, etc, would it be as simple as warning flights to divert from an area?
It wouldn't have to move far, just left/right (and height given the rebound two colliding space objects would cause) and let the debris approach it...
I would patent it, but I can figure out how to put "with a phone" in the description...
They should broadcast Disaster Area from the radio station.
Not only could they detect every piece of space junk going, they could blow it out of the sky at the same time.
The usual effect of a Disaster Area concert ---------------------------------->
Re: Disaster Area
+1 from me for the Adams reference.
"From where I'm standing on the stage, I can just see the audience cowering in a concrete bunker two miles away"
Classic Rock, Classic Douglas
Bug into feature
Do I detect an astronomical disappointment coming on? "They built this giant radio telescope miles out in the desert to hear sea shell noises from ancient space, and it turned out all they could hear was Rock FM reflected off pigeons...!"
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