Avalanche of space junk collisions ‘inevitable’ without action
By Jake Evans Posted about an hour ago | Updated about an hour ago A catastrophic space junk collision that would render the upper reaches of the atmosphere unusable is not a matter of if, but when, space environment experts warn.“When” is easy. During WW-III or preparations for same.
“Which” with be either low earth orbit or geostationary.
“How bad” – well it will have no effect on our “upper atmosphere”, but severely hamper space operations in either LEO or geostationary orbit. Geostationary orbit is not too severe because we can always switch to geosynchronous orbit. LEO is not too severe because about 99% of fragments (depending on collision altitude) will be removed by burning up within a week or two.
“Anything new about this?” – no.
> Researchers from across the globe are meeting in Canberra today to try to solve the problem, and develop a model to manage space traffic.
Excellent. Wake me when they come to some conclusions, particularly if the conclusions involve moving “graveyard orbits”.
> Professor Jah said it was like comparing a semi-trailer to a scooter
When it’s hitting you at a velocity of 8 kilometres per second, it doesn’t really matter if you’re being hit by a semitrailer or a scooter. Speed is the key to classifying space junk, not size.
mollwollfumble said:
> Professor Jah said it was like comparing a semi-trailer to a scooterWhen it’s hitting you at a velocity of 8 kilometres per second, it doesn’t really matter if you’re being hit by a semitrailer or a scooter. Speed is the key to classifying space junk, not size.
I’d have thought that momentum and energy were the keys, rather than one of size or speed.
Energy is proportional to the square of speed.
mollwollfumble said:
Energy is proportional to the square of speed.
and proportional to mass.
And momentum is also important in the effects of a collision.
The Rev Dodgson said:
mollwollfumble said:
Energy is proportional to the square of speed.
and proportional to mass.
And momentum is also important in the effects of a collision.
I did a study using a “chicken gun” to fire various objects at various objects. Some unexpected results, but damage of ductile materials was always directly proportional to energy.
roughbarked said:
Avalanche of space junk collisions ‘inevitable’ without action By Jake Evans Posted about an hour ago | Updated about an hour ago A catastrophic space junk collision that would render the upper reaches of the atmosphere unusable is not a matter of if, but when, space environment experts warn.
More here.
Discussions will include at least five different topics:
1. Detection of space junk from Earth
2. More accurate prediction of space junk orbits
3. Characterisation of space junk by danger level
4. Establishment of clear paths avoiding “graveyard orbits”
5. Clearing space junk out of orbit.
This is an annual conference, so don’t get too excited.
I get that the bits are moving really fast. Would it be as simple as having them move in the same direction so relative speeds in the same altitude of orbit are the same or similar.
Or is it bits that are hitting geosynchronous orbits?
AwesomeO said:
I get that the bits are moving really fast. Would it be as simple as having them move in the same direction so relative speeds in the same altitude of orbit are the same or similar.Or is it bits that are hitting geosynchronous orbits?
most satellites go from west to east, they are launched that way because the spin of the Earth saves on fuel. The problems are, different orbit inclinations for different tasks. some go over the poles, some at varying angles until you get ones that roughly follow the equator (not the geosynchronous or geostationary ones, they are much higher than the space junk orbits). These can be at the same altitude, so their paths will cross at some point. then you have failed to reach orbit satellites. boosters. bits and pieces that have come adrift. paint. Eccentric orbits.
http://www.alexras.info/code/orbital_objects/
stumpy_seahorse said:
http://www.alexras.info/code/orbital_objects/
That’s a cool image, wonder how long does it take for those bits closest to the Earth to hit the atmosphere and burn up?
stumpy_seahorse said:
http://www.alexras.info/code/orbital_objects/
have you noticed that if you zoom in all the points are CUBES!!!!
ChrispenEvan said:
stumpy_seahorse said:
http://www.alexras.info/code/orbital_objects/
have you noticed that if you zoom in all the points are CUBES!!!!
The BORG!!
AwesomeO said:
ChrispenEvan said:
stumpy_seahorse said:
http://www.alexras.info/code/orbital_objects/
have you noticed that if you zoom in all the points are CUBES!!!!
The BORG!!
resistance is futile..
poikilotherm said:
stumpy_seahorse said:
http://www.alexras.info/code/orbital_objects/
That’s a cool image, wonder how long does it take for those bits closest to the Earth to hit the atmosphere and burn up?
I used to know the answer to that. It’s in a book I used to own. It’s quite quick in LEO.
I’ll see if it’s on the web.
One example on the web is a 100 kg satellite at 300 km altitude. It crashes back to Earth in 46 days. At 200 km it takes 1.5 days, and 250 km altitude 10.5 days.
Another example was the Solar Max spacecraft. From an altitude of 440 km it took 245 days to crash into the atmosphere.
> http://www.alexras.info/code/orbital_objects/
Comments.
1. I don’t see any sign of the “graveyard orbit” out near geostationary orbit. I wonder where it is.
2. I only see a single piece of space junk outside geosynchronous orbit.
3. The planets with rings are Jupiter, Saturn, Uranus, Neptune, and now Earth.
4. Lousy colour scheme for someone red-green colourblind.
5. Love the way I can rotate and zoom.
6. I don’t know whether that track of 20 space objects in a 65 degree orbit through no-mans land is a real orbit or a statistical fluke.
Tiangong-1’s descent is accelerating … I would reckon it will reach 200 km by November and after that will crash out pretty quickly.
http://www.heavens-above.com/TiangongHeight.aspx
dv said:
Tiangong-1’s descent is accelerating … I would reckon it will reach 200 km by November and after that will crash out pretty quickly.
http://www.heavens-above.com/TiangongHeight.aspx
That’s the space station isn’t it? Weighs 8 tons.
Be quite a sight when it does come down.
Could it be that the number of pieces of space junk is already on the decline, because so much of the older stuff is falling back to Earth? “Most orbital debris reside within 1,250 miles (2,000 km) of Earth’s surface. Within this volume, the amount of debris varies significantly with altitude. The greatest concentrations of debris are found near 500-530 miles (800-850 km).”
Amount of space debris is not coming down. This graph is a bit old, but shows the trends. No new collisions since iridium.
Check this out NASA Orbital Debris Quarterly News. From Mar 2017.
https://www.orbitaldebris.jsc.nasa.gov/Quarterly-News/pdfs/ODQNv21i2.pdf
53% of space debris is from spacecraft breakup, which is quite common but has only been serious for 10 of the thousands of space launches. Some breakups are deliberate, some are collisions, but the majority are propulsion explosions, some are battery explosions, and about a quarter of breakups have unknown cause.
About 30% of all space debris produced in an orbital trajectory is still up there. The remaining 70% has come down.
A medium size spacecraft comes down from a height of 680 km in 100 years.
Turned up in my email.
Space Debris: Why it’s a problem and what the European Space Agency is doing about it
26-06-2017 07:00 PM
Caulfield RSL, Victoria
This is the free monthly meeting of the Space Association of Australia – all welcome!
The meeting will be streamed live and then made available on-demand via the Space Association’s YouTube channel – SAA.TV.
Our guest speaker, Kjetil Wormnes, is a mechatronics engineer working at the European Space Agency (ESA)
Kjetil leads technology research and development activities at the European Space Agency’s automation and robotics section of ESTEC – the European Space Research and Technology Centre.
He has been in charge of activities for developing space debris capturing technologies and has supported both early mission studies for a space debris removal mission as well as e.Deorbit, a European Space Agency mission to remove a space debris currently under development.
Kjetil also leads research and development activities in other areas of space robotics, and in particular orbital and low gravity robotics.
Prior to working for ESA, Kjetil was employed in Australia at the CSIRO where he was working on the early designs of the Australian Square Kilometre Array Pathfinder radio telescope.