Stargazing Could Elon Musk's Starlink orbitals piggyback telescopes?

[Gfellow]

TL;DR Summary

The Starlink orbital internet communication system is presently seen as a detriment of observing the cosmos for ground observers, but what if...

Elon Musk's Starlink orbital internet communication system is presently seen as a detriment for observing the cosmos by ground observers, but have astronomers thought asking Elon Musk if he would consider mounting compact low-energy telescopes on the back of his orbitals, facing away from Earth?
Then create an algorithm so that they could all be synchronized to focus on individual objects in the cosmos?
He might think that was pretty cool.
Thoughts?

 

[.Scott]

James Webb: 6.5M diameter, 42.25(pi/4) square meters.

Starlink constellation:
Requested constellation size: 42,000
To get the same light gathering capacity, each satellite would need about a 10(pi/4) square centimeters - about 3cm diameter.
Plus they would each need a pointing system.
It would certainly increase the mass of the satellite - currently 260Kg.

A then a system would be required to combine the images.

As complicated as JWST is, it would be much simpler to launch a few more of them.

 

[Gfellow]

James Webb: 6.5M diameter, 42.25(pi/4) square meters.

Starlink constellation:
Requested constellation size: 42,000
To get the same light gathering capacity, each satellite would need about a 10(pi/4) square centimeters - about 3cm diameter.
Plus they would each need a pointing system.
It would certainly increase the mass of the satellite - currently 260Kg.

A then a system would be required to combine the images.

As complicated as JWST is, it would be much simpler to launch a few more of them.

So...a concept for the trash can?

 

[Ibix]

So...a concept for the trash can?

It's a while since I studied long baseline interferometry, but as I recall you need to control the relative positions of your telescopes precise to better than one wavelength. With satellites that might be doable in microwave or lower frequencies, maybe, but I find it difficult to imagine in optical ranges. And the telescope elements are bigger and heavier in longer wavelengths.

I also suspect it's a non-starter, I'm afraid. Also, given the existence of space based telescopes and the profusion of ground based interferometric telescopes, I tend to suspect someone would have built a space based interferometer by now if it were practical.

 

[Gfellow]

It's a while since I studied long baseline interferometry, but as I recall you need to control the relative positions of your telescopes precise to better than one wavelength. With satellites that might be doable in microwave or lower frequencies, maybe, but I find it difficult to imagine in optical ranges. And the telescope elements are bigger and heavier in longer wavelengths.

I also suspect it's a non-starter, I'm afraid. Also, given the existence of space based telescopes and the profusion of ground based interferometric telescopes, I tend to suspect someone would have built a space based interferometer by now if it were practical.

These piggy-backing telescopes would of course have to be relatively inexpensive, disposable and replaceable as the Starlink orbitals (I am told,) only have a three year operational lifetime before they break up on re-entry.
On an aside, was musing on the aspect individual use, allowing astronomers to tap into individual Starlink orbitals in order to observe into space.
Do you have any thoughts on that?

 

[Ibix]

Do you have any thoughts on that?

We recently had a thread where someone was suggesting consumer space based telescopes. I think consensus was that you could get a lot better ground-based telescope for the same cost. Can't find the thread at the moment - maybe someone else's search fu is stronger.

 

[seth]

I tend to suspect someone would have built a space based interferometer by now if it were practical.

It is practical, and there is a space-based interferometer scheduled for launch in 2034 (LISA). There has already been a successful test mission (LISA pathfinder).

I would be inclined to ask whether any use can be made of the satellite constellation as-is, before asking about what could be added to the satellites. For instance, what is the granularity of location data? Would it be possible to grant academic access to study realtime location data? If this is extremely precise, it might be possible to look for anomalous wobbles from gravitational wave events in the whole megaconstellation. This would not require any optical receivers added to the satellites, since it would affect the space they're flying through.

I very much doubt the satellites are capable of providing sufficiently precise location information, though. (LIGO has sensitivity to within the width of a proton, it's arguably the most sensitive instrument ever built.) You also only need three nodes for an interferometer, I doubt adding more would make it any better.

Musk's real game here is providing internet access to the military in space. I don't think anyone at SpaceX would respond to serious academic inquiries.