Well, now there is only a year or two to view Iridium Flares as those 66 low orbit satellites are being replaced by newer ones launched through Space X. The new Iridium Flares are not capable of providing Iridium Flares as this BBC News article points out: LINK. In the article, Matt Desch, the CEO at Iridium states:
"One thing the new satellites will not be capable of doing, however, is producing Iridium "flares". These are the flashes in the sky that result when sunlight glints off the antennas of the old spacecraft.The new satellites do not have the same configuration, so once the original constellation is de-orbited the flashes will cease."I'm afraid those who've been tracking that phenomenon over the past 20 years have another year or two to see it," Mr Desch told BBC News."As someone who's seen a couple myself, you can imagine what a thrill it is to be the CEO of a company like this and watch your satellite go overhead. But we weren't going to spend money just to make angular shiny things on our satellites, so that phenomenon will go away - but it's been fun."
You can use Heavens Above LINK to detect when and in what location of the sky to see an Iridium Flare if your interested. The original 66 satellites will be decommissioned and sent into the atmosphere to end their careers. So if your out observing, at an outreach event or anything similar take the time to look up when oen flies over and enjoy watching the flare! There isn't much time left to see this fun observation.