Some in the media claim that the move by SpaceX to launch a Tesla sports car into space, is pollution because it adds to the space debris problem. It certainly does not add to the problem of space debris orbiting in LEO (Low Earth Orbit), because the car left LEO for deep space. But one could always argue that it would be the start of adding (more) pollution to the inner solar system, between here and Mars.
Warning: rant ahead. I kept it as concise as possible.
Space litter?
Because the question also came up at a dinner party, I saw it necessary to adress the question:
Let us put the claim into perspective, quantitatively and in principle:
Back of the envelope calculation proves: Space is big
We all agree a Tesla, nor its parts, take up a lot of room on the surface up the Earth. It is a small sports car, it takes up a single spot in a parking lot.
Picture you standing on Earth. Picture the size of the Earth. Now picture a Tesla Roadster. If you can’t readily; just read along.
- The diameter of Earth is 12,742 km.
- A Tesla Roadster 2009 sports car is…
- Length 3.946 m (155.4 in)
- Width 1.873 m (73.7 in)
- Height 1.127 m (44.4 in)
- Curb weight 1,305 kg (2,877 lb)
- The closest distance between the Earth and Mars is, on average (but this varies) about 54.6 million kilometers. (furthest about 401 million km, on average about 225 million km).
- Divide 54.6 million by 12 742 and we notice there are 4285.04159473 Earth diameters between Mars and Earth.
- You can fit 4285 Earths between here and Mars.
- Swing this number around in a slice of orbits between Mars and the Sun, you’ll get an idea where this debris could end up.
- Even if a Tesla falls apart, it is difficult to hit an object in that amount of space even if you try (NASA and RUSSIA can attest to that. They frequentlly missed Mars before they finally managed to send a probes nearby or land on it).
- SpaceX is one of a handful companies reducing the orbital debris in a precautionary manner by landing used components back on Earth. This is essential to their whole reusability mode of operations and it does not add to the space debris problem.
SpaceX sent one Tesla.
Some people seriously underestimate the size of space. A cure would be to visit it.
I am sure it will not convince a lot of people, but there it is.
Oh, and there are thousands of known ‘natural’ asteroids the size of houses and bigger orbiting between LEO and the Moon, or between the Moon and Mars, and between MARS and Jupiter (asteroid belt). Maybe some of them have a garage for a sports car. (One could Google the word asteroid for an introduction to their classification). Maybe they too would have to be considered to be space litter. Millions more are meteoroids, the size of dustgrains, that enter the Earth sky on a daily basis. They too can be very dangerous for a more delicate satellite.
At this exact point of the dinner party, an angry staring contest ensued… and numbers started flying.
Caution: These kinds of debates never are very rational.
