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Amateur Astronomers Flash the Space Station with 1W Blue Laser

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Is that tiny white dot in the sky from 2:25-3:00 where they're pointing the searchlights, the International Space Station?

If it is, why is it as bright as a star? It's not like it's burning up or shining lights back down on Earth...
 
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bootleg2go

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I'm not impressed!
Did anyone watch the video?
They used two 800 million lumen searchlights.
The addition of a 1 Watt beam (or I should say 750mw beam as none of WL actually output 1W and all of them have terrible 1.5 to 1.7mrad divergence) is just a tiny drop in the bucket compared to 1.6 billion lumens from the two combined searchlights.

The only way a WL or even a lab system that really outputs several watts is going to be see from the space station is if they are in a dark location and the crew member on board knows exactly where to look and is using binoculars to do so.
 

Sigurthr

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Is that tiny white dot in the sky from 2:25-3:00 where they're pointing the searchlights, the International Space Station?

If it is, why is it as bright as a star? It's not like it's burning up or shining lights back down on Earth...
Many satelites are far enough away from the surface that when in orbit they are still illuminated by the sun when on the "dark side" of the earth. They only see true darkness for a few minutes each rotational cycle. Most solar powered satelites go into a low power mode during this time as they have to rely entirely on battery power. In this case the ISS is reflecting sunlight back to the earth.
 

HIMNL9

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..... time that someone here that had a 5W green, in the past, take out it and shine them ..... and then ask NASA "hey, have they seen some green light lately ?" :whistle:

:p :D
 

yobresal

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..... time that someone here that had a 5W green, in the past, take out it and shine them ..... and then ask NASA "hey, have they seen some green light lately ?" :whistle:

:p :D
Seriously though, 5W of green is sooooo much brighter than 1W of 445
 

bootleg2go

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Where is RHD's conversion page? I searched but no luck.
You can do a google search on "human eye wavelength response"
You'll find lots of charts.
If I remember correctly, the human eye is over 6x more sensitive to 532nm than 445nm; so 1000mw of 445nm would be about as bright visually as 166mw of 532nm at best.
 

ixfd64

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It appears that a beam expander was not used. A 1-km-wide spot at 500 km corresponds to a divergence of 2 mrad, which is not inconsistent with a multi-mode 445 nm laser.

I imagine that a high-end Hercules would be far more visible. A beam expander would make it even more so, although that would also make it much harder to track the space station due to the smaller spot.

That having been said, I do feel bad that the astronomy club probably got ripped off. They should have bought from a more reputable company instead, such as Laserglow, Optotronics or CNI.
 

tsteele93

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That having been said, I do feel bad that the astronomy club probably got ripped off. They should have bought from a more reputable company instead, such as Laserglow, Optotronics or CNI.
CNI makes it very hard for the hobbyist to buy from them, optotronics makes a nice green laser - I have one and it is the crown jewel of my collection - but I dont think they have high wattage blues.

Don't know much about Laserglow personally...
 
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Can i ask please how is this possible when blue lasers have really bad divergence? You see i did an experiment a few months ago - a friend of mine drove over to a hill where there was a perfect view of my house (5-6 miles away straight) the experiment was to see which laser would be brightest at that distance. It involved a focusable 200mw red, 50mw green, 200mw green and 1w focusable blue.

The result was the 200mw green laser pen was brightest by FAR! I mean FIVE times the blue. The 200mw red and blue were almost the same (like looking at a blue/red motorbike light in the distance but not overly bright at all) the 50mw green was almost as bright but a slightly weaker (but neater) light in the distance.
 

tsteele93

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Seriously though, 5W of green is sooooo much brighter than 1W of 445
According to this,

Dot: (445nm 1000mw) vs. (532nm 5000mw)

About 150x as bright!

Can i ask please how is this possible when blue lasers have really bad divergence? You see i did an experiment a few months ago - a friend of mine drove over to a hill where there was a perfect view of my house (5-6 miles away straight) the experiment was to see which laser would be brightest at that distance. It involved a focusable 200mw red, 50mw green, 200mw green and 1w focusable blue.

The result was the 200mw green laser pen was brightest by FAR! I mean FIVE times the blue. The 200mw red and blue were almost the same (like looking at a blue/red motorbike light in the distance but not overly bright at all) the 50mw green was almost as bright but a slightly weaker (but neater) light in the distance.
Dot: (445nm 1000mw) vs. (532nm 200mw)

The 200mW of 532 green appears 6x as bright as 1 watt of 445 blue.
 
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bootleg2go

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Everything else aside, don't you know these Amateur Astronomer laserpointer guys will have a real conversation piece with a poster size copy of the photo image below (taken from the ISS no less) with that signature bright blue dot marking that space/time event with their name on it? Sure beats shining a dot on a water tower from a couple of miles away.
http://www.universetoday.com/wp-content/uploads/2012/03/Picture-0861.jpg

Albeit, NASA doesn't seem to mind having the ISS flashed with lasers.


The one thing that bothers me about this kind of publicity is what is the likelyhood for some high level functioning nut job to read about this and then get the idea to attempt a copycat stunt with a seriously high power laser and target not so remote flying objects. :(
All I see in that picture is the light from the 2 800 million lumen spotlights.
The truth is the ~750 actual milliwatts from a 445nm laser with large divergence and very low visual response to the human eye most likely totally pooped out within 5-10 miles.
I'll trell you right now, any 532nm green pointer outputting over 150mw and a divergence of 1.2mrad is going to kick ass on 750mw of 445nm even if it had the same low divergence of 1.2mrad as far as visibility distance. Just try it and see for yourself.
 

electron

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So I guess Obama is going to make another Federal Law, it's Illegal to point a laser at an aircraft for sure. I guess now they need another Law that says it's Illegal to point a laser at a spacecraft, Imagine interferring with a spacewalk:crackup:
 




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