Space Station & Shuttle Evade Debris

T.Hobbes writes: "There's an article at the BBC about the shuttle had to take evasive maneuvers to avoid the close (5km) transit of some rocket debris, and how the fuel consumed has cut short the shuttle's stay in orbit by one day. NASA also has an article about it." I know that minor maneuvers are common, but this one seems like a rather major move. Anyone want to bet on how long it will be before we have to establish some sort of clean-up effort in space?

Comments

Space Junk

[standards]

The real problem is that space junk leads to more space junk.

Space junk by itself isn't too bad. It's just some stuff that's floating around Earth's orbit.

The problem is that this space junk will collide with other space junk, leading to smaller, faster moving pieces of junk. This small, undetectable junk will smack into good equipment, leading to even more space junk. Before you know it, there's a chain reaction, and near earth orbit becomes an unsuitable wasteland of high velocity particles.

Just what we don't need.

And trust me, it's one thing to get and send down a spent rocket. It's a bit harder to remove a few thousand small shards of aluminum, paint and ceramic.

There is an immediate need to de-orbit as much space junk as possbile.

natural debris

[Veteran]

By far the biggest problem with collision in space comes from micro meteorites. The formula for the quantity of meteors of a given size is that the number of meteors is inversely proportional to the mass of the meteor. If there are 1000 1 Km asteroids in near earth orbit there would be about one million 100 meter asteroids. (Remember the mass of a sphere is proportional to the cube of its diameter.) That means that there are about a billion 10 meter rocks in near earth orbit - a trillion 1 meter rocks, 10 to the 15th 10 cm rocks, 10 to the 18th 1 cm rocks etc.

One of the problems that we humans have is over estimating our importance in the cosmic sphere - the universe hardly notices us - indeed the Earth hardly notices us; from low earth orbit it is very difficult to see anything that man has done on the Earth.

The space station - because of its size - has about 1/2 lb of drag due to the nascent atmosphere 250 miles up. This drag is why experiments in the station are referred to as "micro gravity" instead of "zero g"; there is a tiny gravitational field due to the drag. One of the reasons for the periodic shuttle trips is to reboost the space station to make up for the lost velocity from the residual drag.

Re:natural debris

[Scott Ransom]

> Geosync is the most crowded orbital position we have.
> This is the last place you want to be if you are trying to avoid junk.
> Check your facts.

Geosync may be crowded, but the space junk problem is not nearly as severe up there. There are a couple reasons why:

1. The density of small non-trackable debris (i.e. rivets, bolts, metal pieces from booster separation) is _much_ lower than in low-Earth orbit. The small debris causing events happen much lower -- possibly enroute to Geosync.

2. The distribution of relative velocites between spacecraft is much narrower (and hence better for survivability) since the purpose of Geosync is to effectively "park" a spacecraft over a fixed point on the equator. So everything is travelling in pretty much the same direction at the same velocity. In low-Earth orbit there is crap flying every which way.

Re:natural debris

[Schemer]

> As it stands the shuttle is strained to the limit to get to the station. Infact Columbia (the heaviest of the four shuttles) can't reach the station [space.com] where it is. Move it any higher, and you wouldn't be able to get to it. Check your facts.

Actually, the ISS's original planned orbit would have allowed all of the shuttles to reach it, and they would have been able to carry much more cargo than they can now. When russia became involved in ISS's construction, the orbit of the system was changed so that Russia's weaker rockets could barely reach it. The problem is that the final orbit is not an optimal orbit for the shuttle and as a result they can't carry as big of a load, and columbia can barly make it at all.