NASASpaceFlight.com Forum

General Discussion => Q&A Section => Topic started by: mgfitter on 12/01/2014 01:42 am

Title: Can you see lights on satellites from the ground?
Post by: mgfitter on 12/01/2014 01:42 am

Does anyone know if it is possible to see man-made lights aboard spacecraft as they pass overhead in full darkness, as opposed to reflected sunlight?

For example, are the navigation strobe lights on Dragon visible from the ground?

-MG.

Title: Re: Can you see lights on satellites from the ground?
Post by: rdale on 12/01/2014 02:02 am

No. I suppose maybe if you are looking in a high powered telescope, but remember the distances involved here. If someone pops up a AA flashlight just 5 miles away from you on a mountain top, you aren't going to see it :)

Title: Re: Can you see lights on satellites from the ground?
Post by: kevin-rf on 12/01/2014 12:09 pm

There was a Japanese cubesat, FITSAT-1 a couple of years back that blinked morse code messages to ground. Don't remember the results. Did anyone spot it with the unaided eye?

Official website: http://www.fit.ac.jp/~tanaka/fitsat.shtml

Title: Re: Can you see lights on satellites from the ground?
Post by: pericynthion on 12/01/2014 05:02 pm

AIUI the FITSAT LEDs were observed through binoculars and telescopes but not the unaided eye.

Title: Re: Can you see lights on satellites from the ground?
Post by: mgfitter on 12/02/2014 01:02 am

I wonder what it would take to make some light bright enough to be seen from the ground with the unaided eye? And how much energy would that require?

-MG.

Title: Re: Can you see lights on satellites from the ground?
Post by: pericynthion on 12/02/2014 01:11 am

I'm pretty sure the OPALS laser com experiment would be visible if it were in the visible spectrum rather than IR.  Of course, the spot size is only about 1 km wide so you'd have to be standing in the right place.