This is indeed serendipitous
Defence applications, perhaps?
Also, it allows me to use the word serendipitous, which is nice.
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 …
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.
"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.
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.
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":
http://www.fas.org/spp/military/program/track/graves.pdf
Mike
"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."
Neat trick.
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 ;-)
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.
as long as it doesn't hit somebody's vital organ.
And
"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.
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?
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.
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...