Another satellite set to fall to Earth this weekend; 1.6 tonnes of debris to survive re-entry - Polidicks

• German satellite Rosat is set to fall to Earth over the weekend, with 1.6 tonnes of debris likely to survive re-entry - three times more than last month's UARS re-entry. • It could land anywhere between 53º North and South - a range encompassing most of the populated world. [img]http://imgkk.com/i/l6re.png[/img] The range is marked in red here. [url]http://www.bbc.co.uk/news/science-environment-15402157[/url] [quote=BBC News][b]A big German spacecraft is about to make an uncontrolled fall from the sky.[/b] The Roentgen Satellite (Rosat) is due to come back to Earth at some stage over the weekend - possibly Sunday. Just as for Nasa's UARS satellite, which plunged into the atmosphere in September, no-one can say precisely when and where Rosat will come in. What makes the redundant German craft's return interesting is that much more debris this time is likely to survive all the way to the Earth's surface. Experts calculate that perhaps as much as 1.6 tonnes of wreckage - more than half the spacecraft's launch mass - could ride out the destructive forces of re-entry and hit the planet. In the case of UARS, the probable mass of surviving material was put at only half a tonne (out of a launch mass of more than six tonnes). The difference is due to some more robust components on the German space agency (DLR) satellite. Rosat was an X-ray telescope mission and had a mirror system made of a reinforced carbon composite material. This mirror complex and its support structure are expected to form the largest single fragment in what could be a shower of some 30 pieces of debris to make it through to the surface. But again, as was the case with UARS, any Rosat wreckage is strongly tipped to hit the ocean, given that so much of the Earth's surface is covered by water. [b]Destructive design[/b] UARS' final resting place was tracked to a remote region of the Pacific, north-east of the Samoan islands. Rosat could come down anywhere between 53 degrees North and South latitude - a zone that encompasses the UK in the north and the tip of South America in the south. Future spacecraft sent into orbit may have to meet stricter guidelines that limit the amount of debris likely to fall back on to the planet, but these rules are still some way from being introduced said Prof Richard Crowther, an expert on space debris and adviser to the UK Space Agency. "Up until now we've designed satellites to survive the harsh environment of space, and we haven't given much thought to designing them for destructive re-entry," he told BBC News. "But in future, we will have to consider whether we have got this balance right, and perhaps satellites should be designed in such a way that we can ensure more of what comes down is destroyed in the atmosphere and doesn't hit the surface. "Unfortunately, there is a whole legacy of spacecraft - 50 years of satellites - and we are going to have to put up with this situation for quite some time, I'm afraid." [b]Science success[/b] Rosat was launched in 1990 to survey the X-ray sky. It mapped more than 100,000 sources of this high-energy radiation. X-rays tend to come from the hottest and most violent parts of the cosmos, such as the regions around exploded stars and the "edges" of black holes. The spacecraft worked for eight-and-a-half years before its star tracker failed and it could no-longer work out its position and point correctly. It was shut down in February 1999, and has been in descent ever since. Controllers do not have any contact with the craft; all they know is its altitude and path across the sky through radar tracking. The fall to Earth has accelerated in recent months and weeks as the spacecraft has experienced increased drag as a result of its passage through residual air molecules still found more than 200km above the planet. The deeper it reaches, the faster Rosat will be pulled in. But without a propulsion system, the precise timing and location of its impact cannot be influenced by controllers. [b]Tough materials[/b] Rosat will start to tumble rapidly when it engages the thicker parts of the atmosphere, about 80km up. Mechanical forces will first rip off its flimsiest structures, such as its solar arrays and antennas. The heating the satellite then experiences as it plunges downwards will deform and melt low-temperature materials and vaporise them. Only high-temperature metals such as stainless steel and titanium will put up much resistance. Tracking stations will typically witness the uncontrolled return of at least one piece of space debris every day; and on average, one intact defunct spacecraft or old rocket body will come back into the atmosphere every week. Something the size of Nasa's UARS satellite is seen to enter uncontrolled perhaps once a year. Much larger objects such as space station cargo ships return from orbit several times a year, but they are equipped with thrusters capable of guiding their dive into a remote part of the Southern Ocean.[/quote]

All I can say is this; hope it don't fall on me. Very unlikely, but nonetheless possible.

10 bucks says it hits the sea and we will never hear from it again.

tl;dr I'm/Estonia = safe

[QUOTE=GlebGuy;32905654]10 bucks says it hits the sea and we will never hear from it again.[/QUOTE] u are in mortal danger

I doubt it will kill someone.

[QUOTE=Stick it in her pooper;32905663]tl;dr I'm/Estonia = safe[/QUOTE] It'd be sort of cool if it hit an unpopulated place though, and someone caught it on film maybe. Sadly its not heading up here.

Sea impact is likely, though don't be surprised if it lands somewhere less moist, like Eastern Europe or the Outback.

[QUOTE=Rapist;32905691]It'd be sort of cool if it hit an unpopulated place though, and someone caught it on film maybe. Sadly its not heading up here.[/QUOTE] I would kill to see that tbqh

it'd be cool to have a satellite crash into the field in front of my house :v:. Though Holland is on the very edge of the map, so I guess it won't land there if it doesn't land in the sea.

fuck yeah Scandinavia

oh you know just highlight 3/4 of the earth as a "prediction"

It will land in the sea.

Don't worry, as long as you're not cloud watching, you'll be safe from the satellite!

Safe.

How much force would this impact with then?

[QUOTE=smurfy;32905626]• It could land anywhere between 53º North and South - a range encompassing most of the populated world.[/QUOTE] [media]http://www.youtube.com/watch?v=CV7CTlIcKlw[/media]

[IMG]http://imgkk.com/i/l6re.png[/IMG] Oh for fuck's sake, with the computing power they have you'd think they could narrow that down to at least one continent. As in this joke here: [url]http://www.colbertnation.com/the-colbert-report-videos/397769/september-22-2011/defunct-satellite-hurtles-toward-earth[/url]

Fucking Scandinavian cunts have beaten us all again, how do they do it?

[QUOTE=Eudoxia;32907411][IMG]http://imgkk.com/i/l6re.png[/IMG] Oh for fuck's sake, with the computing power they have you'd think they could narrow that down to at least one continent. As in this joke here: [url]http://www.colbertnation.com/the-colbert-report-videos/397769/september-22-2011/defunct-satellite-hurtles-toward-earth[/url][/QUOTE] You would need it's exact position, rotation and rotational velocity to work out just how it would interact with the air and on what trajectory. It's a little dificult.

So what actually happens when it lands on a house? Do houses have insurance for this sort of stuff?

Awesome, I'm outside of the danger area!

[QUOTE=smurfy;32907487]Fucking Scandinavian cunts have beaten us all again, how do they do it?[/QUOTE] Sacrificed a virgin and a copious amount of bacon to Odin.

I'm actually just outside the range :smug:

[QUOTE=Fatal-Error;32907542]You would need it's exact position, rotation and rotational velocity to work out just how it would interact with the air and on what trajectory. It's a little dificult.[/QUOTE] They have all that, and no that simulation wouldn't be difficult for anyone with a physics or engineering degree. What is difficult (read impossible) is predicting the properties of the atmosphere, since it constantly changes due to various gasses and radiation from the sun hitting it. Because they dont know how much atmosphere the satellite will have to re-enter through, they dont know the speed or location it will drop out of the sky.

[QUOTE=Tolyzor;32907678]They have all that, and no that simulation wouldn't be difficult for anyone with a physics or engineering degree. What is difficult (read impossible) is predicting the properties of the atmosphere, since it constantly changes due to various gasses and radiation from the sun hitting it. Because they dont know how much atmosphere the satellite will have to re-enter through, they dont know the speed or location it will drop out of the sky.[/QUOTE] And then you need to know how the air would deflect off it when it's at certain orientations and how that would affect its flight path... Even if you take a goog guess at the atmospheric composition, windspeed, direction and pressure at certain altitudes it would be far more accurate.

This is like Russian Roulette

[QUOTE=Fatal-Error;32908155]And then you need to know how the air would deflect off it when it's at certain orientations and how that would affect its flight path... Even if you take a goog guess at the atmospheric composition, windspeed, direction and pressure at certain altitudes it would be far more accurate.[/QUOTE] Well yeah, simulations that account for all of that and much more, along with the associated errors/probability are how NASA knows it is coming down in the next day or two.

This is silly, it is likely to hit the ocean of course, but it is also a possibility that it hits land, this could in theory be really, really, REALLY bad.

As I type this message now, we are assembling an elite team of Kerbals to go into space and find this satellite and prevent it from re-entering the earths atmosphere. God speed Kerbals. (It will most likely land in the ocean like everyone else is saying.)