Whats the reason for this? What is it about a satellite that causes it to produce flares that the new ones don't have. (I always thought flares were sunlight reflections off solar panels. Is it that the new ones have less panels? Or is it about positioning?)
Iridium flares are reflections from the antennas, not solar panels. The new satellites have a different antenna arrangement which doesn't flare.
Having a solar panel that flares seems like an easy way to get an inefficient solar panel…
Is there a heat dissipation reason why satellites are painted white instead of black? And if so, why are they white instead of a completely reflective surface?
Is there a heat dissipation reason why satellites are painted white instead of black? And if so, why are they white instead of a completely reflective surface?
Why do you think they’re painted white? The flare itself is the result of reflections from the polished antennae which aren’t painted at all.
I used to have a cron job that ran a little perl script that screen scraped heavens-above once a day and then set up 'at' jobs to send me an SMS when a visible pass of the ISS or an Iridium flare was going to show up over me in the next 5 minutes. Was a great party trick at times and I got to see some great flares and also saw the ISS and a space shuttle a few miles from each other.
This is going to sound weird, but... One of the best nights of my life, I was on the beach at Bellows in the middle of the night with this Israeli chick the week after I got back from my last tour in Iraq. We were laying there in the sand, doing what people do on the beach at night and talking about the stars and the universe and smoking dope. I was just talking about the launch of one of the shuttles about half an hour before, and right there over our heads the ISS tracked across the sky with the shuttle right behind it, preparing to dock. I thought it was such an odd configuration and impossibly bright for anything smaller, so I checked my phone and sure enough, that's what it was. I'd give anything for more nights like that. Just the most incredible coincidence, perfect timing. Perfect night.
I used to have a cron job that ran a little perl script that screen scraped heavens-above once a day and then set up 'at' jobs to send me an SMS when a visible pass of the ISS or an Iridium flare was going to show up over me in the next 5 minutes. Was a great party trick at times and I got to see some great flares and also saw the ISS and a space shuttle a few miles from each other.
The "Sky Guide" iPhone app will send you push alerts for Iridium flares, as well as when the ISS will be visible.
The app in Google's Play Store by the same name is apparently a different app by a different company.
The website that this HN post links to has their own app called Heavens-Above which is free and helps "identify lights in the night sky, predict Iridium flares, ISS and sat passes."
An interesting fact is why the name Iridium? When they were in the planning stages for this set of satellites, they estimated that they would need 77 of them to completely cover the Earth (including the poles), evoking an image of 77 electrons circling the nucleus of an atom. The atomic number for the element Iridium is 77. The number of satellites needed was paired down to 66, so the satellites should actually be na…
I pointed this out when I interviewed for a job at Iridium. I didn't get an offer.
Does the tracker actually model the directed reflections or just the relative angle of the viewer, the satellite and the sun and let chance take care of the rest?
An interesting fact is why the name Iridium? When they were in the planning stages for this set of satellites, they estimated that they would need 77 of them to completely cover the Earth (including the poles), evoking an image of 77 electrons circling the nucleus of an atom. The atomic number for the element Iridium is 77. The number of satellites needed was paired down to 66, so the satellites should actually be na…
I pointed this out when I interviewed for a job at Iridium. I didn't get an offer.
You may not have gotten an offer, but you do get something else of incalculable value: my upvote!
Rooftop parties in the city, drinking beer from bottles, strings of vintage lightbulbs, people wearing plaid, taking out your phone to say “Hey look at this!” and pointing out a spot in the sky where an iridium flare streaks across while everyone gasps “Wwwooww!!” High fives
The University of Sydney Physics Society (physoc) used to have some great rooftop parties (in the late 80s). Invariably someone would raid the dry ice freezer and put it in the empty bottles and screw the lids on to make "depth charges". These would get dropped over the edge and go off with a resounding boom sometime later, scaring the wits out of anyone at ground level. University Security would invariably arrive to…
That's one of those things that wouldn't fly at universities these days.
At least in NZ, all the traditional student events and activities have been slowly neutered over the past decade or so, to ensure that nobody gets hurt, and that everything is tame and hurts nobody's sensibilities.
Whats the reason for this? What is it about a satellite that causes it to produce flares that the new ones don't have. (I always thought flares were sunlight reflections off solar panels. Is it that the new ones have less panels? Or is it about positioning?)
The original Iridium satellites had large metal panels (which contained the phased array antennae) that were at a bit of an angle to the ground, this made it possible for reflected sunlight to hit the Earth, causing a "flare" for whoever happened to be in that beam. The Iridium NEXT satellites have an antenna panel that is much closer to parallel to the surface of the Earth, so any reflected sunlight beams will pass at a glancing angle and won't intersect the Earth.