Friday, September 23, 2011

Space Junk - a point of view

Sometime today, probably this evening, about 26 tons of disintegrated satellite will plummet to earth (or, more likely, ocean) as it drops out of orbit after 20 years.

This is, of course, a simple by-product of the space industry, the left-overs have to go somewhere and the nearest and easiest thing to do is to allow them to fall through the upper atmosphere where a majority of debris will burn up. The alternative, which is considerably more expensive and equally environmentally questionable, is to push it on a path away from the Earth and eventually off into deep space.

In this case, the satellite is a big bugger and the aforementioned 26 tons of metal is expected to impact somewhere, although no one is quite sure where as I write, in several pieces.

NASA says that the risk of someone (anyone) being hit is 1 in 3200, so the risk is pretty small that anyone's going to get hurt.

This just worried me a little. Not that I might get hit, nor that anyone I know is likely to get hit. What worried me is that someone, presumably several someones, inside NASA decided that this is an acceptable level of risk. It is that actual decision that concerns me.

The odds of winning the national lottery worse than 1 in 13,000,000. The odds of being hit by this lump of metal is officially 1 in 3200. 

Where is the line of acceptable risk to human life? Who makes that decision?

The immediate comparison that occurs to me is the death toll on our roads. We, as a society, kill over 2000 a year in return for the freedom to use our cars and other vehicles. We, as a society, obviously consider this to be an acceptable figure. The risk to each of us of being killed on the road every time we go out is in the ball park of 1 in 27000.

As a society, we seem to accept that as a reasonable risk-to-return trade off. I offer no opinion. It's roughly democratic - if we disagreed that this risk were acceptable, we'd abandon our cars in our droves; I don't see that happening.

However, we don't have an awful lot of say in what NASA does or decides - and, yes, the UK is on the potential crash path. So somebody has sat in a boardroom in another country and decided that a risk 9 times worse than that which we face every day on the road is acceptable for us to face.

I don't consider that a decent risk-to-return trade off, and I certainly don't like the idea of any life being considered worthwhile collateral to a foreign and unaccountable organisation. I hope the "somebody" is personally financially and criminally accountable for any damage caused, or for any death or injury. I somehow doubt it, though. If that were the case, my guess is that the risk factor of 1 in 3200 would suddenly be far too high to be acceptable.

photo nicked from


Antony Mann (The Sump) said...

I think your figures are all wrong. There is a 1 3200 chance of some one on the Earth getting hit.
England is 130,395 Sqm
The land surface of the earth is148,940,000 so I think there is only a 1 in 3655110 chance of someone in England being hit. I did not include Scotland and Wales cause I don’t care 

steve O said...

If you are the 'one' in 3,200tonight and happen to be in a nightclub or concert or theatre, just think of the additional collateral damage!! dont be selfish - everyone stay in, and impose on themselves a 50 meter exclusion zone, for the love of humanity.

Frankenkeith said...

Well - it's come down and as I have not heard a bang and Millbrooker Towers is still visible from my window I assume it missed you?
Interesting point of view about risks but perhaps a discussion of statistics next time we meet? 1:3200 chance of hitting anyone which means chance of you personally being hit is 1: Trillions and trillions. Ie. comparison with car risk is vamishingly small (which is what the thing seems to have done)Sorry to miss film club last week.