Proposed Space Telescope Uses Huge Opaque Disk To Surpass Hubble

Required Snark writes NASA has funded a study of a geo-sychrounous orbit telescope that uses a half-mile diameter opaque disk to provide images with 1000 times the resolution of the Hubble. It uses diffraction at the edge of the disk to focus light, resulting in a very high quality image. It's named the Aragoscope, after the scientist Francois Arago, who first noticed how a disk affects light waves. "When deployed the Aragoscope will consist of an opaque disk a half mile in diameter parked in geostationary orbit behind which is an orbiting telescope keeping station some tens to hundreds of miles behind that collects the light at the focal point and rectifies it into a high-resolution image. 'The opaque disk of the Aragoscope works in a similar way to a basic lens,' says CU-Boulder doctoral student and team member Anthony Harness. 'The light diffracted around the edge of the circular disk travels the same path length to the center and comes into focus as an image.' He added that, since image resolution increases with telescope diameter, being able to launch such a large, yet lightweight disk would allow astronomers to achieve higher-resolution images than with smaller, traditional space telescopes."

Comments

Opposite of a pinhole camera

[Anonymous Coward]

Looks like the opposite of a pinhole camera

AFFECTS

[Anonymous Coward]

Not "effects" you illiterate dumbshit!!!

Bless you.

[The Last Gunslinger]

This was my immediate reaction to skimming the front-page blurb.

Seriously, differentiation of "effect" and "affect" is neither a difficult nor novel concept. This just reflects editorial laziness, which does call into question in the mind of the audience the quality of information being conveyed.

Re:No

[Rei]

I would presume that the bulk material in the inside has no need for accuracy, only the very rim. The question is more of whether you can have a coiled material that when uncoiled (deployment) can return to a shape with that level of accuracy. I would think it possible, but I really don't know.

I would forsee a super-precise rim with just a small bit of light shielding on its inside, deployed via uncoiling, and then attached to a much stronger, less precise uncoiled ring to which the bulk shielding material (and stationkeeping ion thrusters) are attached. The attachment between the two would need to provide for vibration and tension isolation (even the slowest adjustments in angle of such a huge, thin shield are going to set in motion relevant vibrations, you've got almost no damping - you want the structural ring to deal with those and not transfer them through to the precision ring). Not to mention that your shield will be acting as a solar sail whether you like it or not (unless you're at L2... but then your craft better be nuclear powered).

Your telescope behind it is going to need to do some real precision stationkeeping (either extreme precision on the whole spacecraft positioning, or merely "good" positioning of the whole spacecraft plus extreme precision adjustment of the optics within) . This means long development times and costs to demonstrate that you can pull it off before you actually build the shield. But I would think that also possible - just very difficult. If they take the latter route they could probably demonstrate that here on Earth, which would be a big cost-saver.