4
$\begingroup$

Micrometeorite and debris impacts on orbital spacecraft pose a threat to systems and crew. For example, a high velocity impact caused this chip in the International Space Station's Cupola.

enter image description here

The ISS and many other craft have extensive shielding to protect from debris impacts. There are, however, many systems which are difficult to shield because they require exposed parts. In particular, (optical) telescopes and cameras require exposed transparent materials in order to work[citation needed].

Has there been any recorded impact damage to a telescope or camera lens?

And in particular, is there any imagery of such an impact taken by the same camera?

Clearly if the impact is severe enough, the camera may be destroyed. Also, depending on the focus of the camera, any damage to the lenses may not be visible.

For example, see TESS's imaging assembly which consists of four cameras with seven lenses each - plenty of opportunity for cracked glass!

Edit: To clarify, I'm looking specifically for damage to a lens or transparent covering that is part of the camera assembly itself, although information on related impact damage is always a welcome supplement!

This related question discusses protection for Hubble's primary which may have produced similar image effects in the event of impact damage.

$\endgroup$
  • 2
    $\begingroup$ For the compound lens systems used in cameras and telescopes, there's usually a large distance between the front surface exposed to space and the pupil, so a bad spot on the lens will be out of focus but still potentially visible (spatially localized) at the focal plane in some situations. $\endgroup$ – uhoh Aug 15 '18 at 1:24
  • 1
    $\begingroup$ However it depends a lot on the amount of Sun shielding, The image of the chip in @Hobbes 's answer is blue because it is (probably) scattering Earthshine. Without illumination it might only be detected by missing stars, or by the impact (no pun intended) on the OTF. $\endgroup$ – uhoh Aug 15 '18 at 5:27
  • $\begingroup$ Only a few satellites have been retrieved from orbit, those are the only possible sources of external images of impact damage - and none of them were telescopes (space.stackexchange.com/questions/15094/…). I haven't found photos of lens damage taken by the camera using that lens. $\endgroup$ – Hobbes Aug 15 '18 at 9:42
  • $\begingroup$ @Hobbes yeah I thought an image of lens damage from the same camera would be a long shot. I'm now trying to think of a way of detecting damage to a lens by other means without recovering it! Can gyros and accelerometers pinpoint the impact site to the camera assembly? On-board microphones? Edit: yep. $\endgroup$ – Jack Aug 15 '18 at 9:50
  • $\begingroup$ @Hobbes any thoughts? Is it impolite to link to a deleted answer? $\endgroup$ – uhoh May 15 '19 at 6:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.