https://twitter.com/elonmusk/status/732042627445460992QuoteRaket_Mand @bittdk@elonmusk how did the recovery of the fairings go?Quote Elon Musk @elonmusk 1h1 hour ago@bittdk Better. Not there yet, but a solution is likely.
Raket_Mand @bittdk@elonmusk how did the recovery of the fairings go?
Elon Musk @elonmusk 1h1 hour ago@bittdk Better. Not there yet, but a solution is likely.
edit: removed GPS, apparently off-the-shelf models "self-destruct" upon nearing anything resembling ICBM speeds/altitudes, also removed completely redundant link to old article after re-reading the thread.
Quote from: RDMM2081 on 05/16/2016 04:39 pmedit: removed GPS, apparently off-the-shelf models "self-destruct" upon nearing anything resembling ICBM speeds/altitudes, also removed completely redundant link to old article after re-reading the thread.Self destruct??? More like become civilian off the shelf devices become inaccurate because they can not properly process the timing signals and arrive at the correct result. Once they slow down, like hitting terminal velocity or bobbing in the ocean, accuracy should be restored.
Quote from: kevin-rf on 05/16/2016 07:53 pmQuote from: RDMM2081 on 05/16/2016 04:39 pmedit: removed GPS, apparently off-the-shelf models "self-destruct" upon nearing anything resembling ICBM speeds/altitudes, also removed completely redundant link to old article after re-reading the thread.Self destruct??? More like become civilian off the shelf devices become inaccurate because they can not properly process the timing signals and arrive at the correct result. Once they slow down, like hitting terminal velocity or bobbing in the ocean, accuracy should be restored.Commodity GPS receivers have hard-coded speed and altitude limits and will shut down if they see they're moving too fast and/or too high. See, for instance, http://support.spectracom.com/articles/FAQ/Why-are-there-altitude-and-velocity-limits-for-GPS-equipmentReceivers without the limits are subject to export controls to ensure they don't end up guiding ICBM's.
Easiest solution, stick an iridium phone in each half and have it call home as soon as it splashed down. The phone will have gps.
Quote from: launchwatcher on 05/16/2016 08:44 pmQuote from: kevin-rf on 05/16/2016 07:53 pmQuote from: RDMM2081 on 05/16/2016 04:39 pmedit: removed GPS, apparently off-the-shelf models "self-destruct" upon nearing anything resembling ICBM speeds/altitudes, also removed completely redundant link to old article after re-reading the thread.Self destruct??? More like become civilian off the shelf devices become inaccurate because they can not properly process the timing signals and arrive at the correct result. Once they slow down, like hitting terminal velocity or bobbing in the ocean, accuracy should be restored.Commodity GPS receivers have hard-coded speed and altitude limits and will shut down if they see they're moving too fast and/or too high. See, for instance, http://support.spectracom.com/articles/FAQ/Why-are-there-altitude-and-velocity-limits-for-GPS-equipmentReceivers without the limits are subject to export controls to ensure they don't end up guiding ICBM's.Yeah, shut down is probably a better way to phrase it than "self-destruct", and that is the "feature" I was referring to, sorry if that was overly dramatic... Also, SpaceX probably does have access to the "military grade" receivers so GPS might still be an option, but definitely not as easy as gluing a Garmin inside the fairing and seeing what happens. Some sort of transmitter beacon seems much more likely to me. Assuming they are doing any tracking at all, but otherwise how would they find any fairing which did make it to the surface, either intact, or in large enough pieces to be found?
but otherwise how would they find any fairing which did make it to the surface, either intact, or in large enough pieces to be found?
Uuuuum... Radar, the range does track these things and they do know where they generally splashed. Add to that for a fairing to survive it's final speed will be slow enough that civilian gps systems will work. Impact will not be at mach 10.Easiest solution, stick an iridium phone in each half and have it call home as soon as it splashed down. The phone will have gps.
No need for even that much. If it's OK with the Coast Guard, they can just stick an off the shelf EPIRB in them with some sort of custom trigger.
Spidertracks Satellite TrackingSpidertracks is more than just a tracking system: as well as knowing exactly where people and valuable assets are at any moment in time, it can also tell you how they are. If something goes wrong, and the website loses contact with the spider device, the system will automatically send text and email alerts to the right people, including rescue services, within minutes of the accident occurring. Because the alert is generated by the system, it doesn’t rely on the device surviving an accident, so it will always be sent, enabling rescue services to locate the site quickly based on the last transmitted position. With Spidertracks, no one needs to be lost at sea, on land, or in the air again.It combines a portable tracking unit, the Spider, with a web-based client interface, enabling users to access their flight following and tracking details from anywhere at any time via the internet. Powered by a 10 V – 32 V power source, it has no external antenna and can be moved between aircraft or vehicles, so it doesn’t require expensive installation or certification. Partnered with Iridium, it offers global coverage.Spidertracks also offers simple two-way global communication. Customers can send and receive texts with a compatible phone from anywhere on earth, via Iridium, through the Spidertracks website—ideal for anyone who needs to communicate from a remote region without GSM/cellphone coverage.The unit is portable, with the tracks accessed from any internet connected device, and it is AFF compliant, offering a cost-effective, simple and reliable tracking-based safety system for anyone working or traveling in remote locations or risky situations.
Quote from: RDMM2081 on 05/16/2016 09:54 pmbut otherwise how would they find any fairing which did make it to the surface, either intact, or in large enough pieces to be found?They see it floating. If it sinks they don't care about it.
Uuuuum... Radar, the range does track these things and they do know where they generally splashed. Add to that for a fairing to survive it's final speed will be slow enough that civilian gps systems will work. Impact will not be at mach 10.Easiest solution, stick an iridium phone in each half and have it call home as soon as it splashed down. The phone will have gps. I don't know how fancy iridium phones are, but maybe they can write an app. Provide it a Twitter feed. Tweets like whoa, that was intense, and a shark just swam by. They did get a go pro back from one of the fairings.
It's also possible that Go Searcher's primary role is to capture telemetry from the fairing, and actual recovery of pieces is not a priority.
Go Searcher, which we believe to be the fairing recovery ship, has only gone out on the last few (three?) missions. The washed-ashore fairings were well before that, likely before the fairing recovery program was begin in earnest. In fact, it may have been those serendipitous discoveries which encouraged them to accelerate fairing recovery.The fact that two fairing pieces made it to the surface intact doesn't mean they all are doing so. There may have been luck involved. Further, they are now experimenting with active recovery mechanisms; it is possible that failures in the active control are leading to worse outcomes (at this early point) than the passive fairings. It's also possible that Go Searcher's primary role is to capture telemetry from the fairing, and actual recovery of pieces is not a priority.Lastly, the ocean is a very big place. They may well have trackers on board, but if the re-entry disables the trackers or tears them loose, Go Searcher might not be able to easily locate any remaining scraps even if they did make it to the surface. If they know that the pieces they are interested in tend to sink after X hours, then they might not even attempt to rendezvous with any piece further than X hours travel away, so there could be luck in the prelaunch positioning of Go Searcher as well.So there are lots of possible reasons (and I'm sure others can contribute more) why Go Searcher is still returning empty-handed despite a few instances of large fragments of fairing washing up on shore. I don't think SpaceX needs our advice on what style of tracker and/or trained dolphin they should be using.