Letter: Letter: Hubble telescope

From GR BONYE

I refer to the article by Helen Gavaghan (This Week, 7 July) and also
to a recent similar article in Physics World.

I have not seen any comment yet on the effect of zero gravity on the
Hubble telescope. Surely such a large mirror, figured within the Earth’s
gravitational field, would distort when placed in zero gravity, even if
it survived the high G of rocket takeoff? This would seem to be more likely
than a serious figuring error by the participants in the project.

Many complex solutions have been discussed in your pages and others.
Perhaps a simple aperture stop would reduce the spherical aberration significantly,
while enabling an acceptable compromise in resolution and light-gathering
power to be achieved, until a permanent solution can be installed.

One hopes that the august bodies now sitting will be able to find a
cost-effective solution without the strong smell of blame which seems to
pervade such expensive endeavours.

I suspect that such a large mirror might suffer from Moon tides!

GR Bonye Raggleswood Chislehurst, Kent