Hello Raoul -

Let's examine your question:
"Asteroid detection:
"Why not ESL1 and ESL2 ? Finally, a satellite aimed at things around our planet, with a stargraph hiding the Earth for the glare! And another camera could be aimed a the Full Earth...

First off, it's comets and comet fragments, not asteroids, that make up most of the impact risk. The NASA estimates stating that comet impact comprises only 10-15% of the total impact hazard are as bad as their foam damage estimates. If you go back to the citation given in a previous post here, you can see that the analysis of impacts on Jupiter's moons show this comet risk pretty clearly.

It was a comet which killed the dinosaurs, not an asteroid - and comets appear to be implicated in a number of extinction level events.

Asteroids are relatively easy to find compared with comets and comet fragments (such as carbonaceaous chondrites). With comets, they're massive, and you need the earliest possible warning. With comet fragments, they're dark and small, and they're not on regularly repeating short term orbits, but instead simply appear out of nowhere on a 1 way course.

So why not use telescopes at ESL1 or 2? Servicing and capabilities. Since you could not service the telescopes, you would be faced with replacement costs.

Finally, look at mission requirements for total payload mass (mirror size), communciation, power, and imaging. Mazanek and his team at Langley have looked at this problem in depth, and they're actually trained engineers, and not the hopelessly fixated "Mars Enthusiats" one runs into out here on the net.

They concluded that Moon based facilities are best. Now since what we're talking about here is preventing the extinction of mankind, do you really want a second best system to be used?

ep