Why is SpaceX still using Quindar tones? Someone was supposed to monitor the circuit and if the audio dropped, but the “transmitter on” light was still on, they would have to manually unkey the transmitter. Journal Contributor Markus Mehring replies: “‘Other space missions’ is quite an accurate observation, since the ‘beeps’, in fact, are still in use today on Shuttle flights, at least on the UHF frequencies.”, “These beeps are called ‘Quindar-Tones’. Last year, after spending a couple of days at the US Space and Rocket Center (and attending the Huntsville Hamfest), I heard numerous NASA audio clips and that lead me down the path of researching those PTT confirmation tones. SelCal being a selective-calling radio system that can alert an aircraft’s crew that a ground-based radio station wishes to communicate to the aircraft. This was done before the audio was patched to the tracking station’s line so it wasn’t heard in the control room or on NASA Select audio. As astronauts Robert Behnken and Douglas Hurley communicated with Mission Control, we heard PTT confirmation beeps after each transmission. Quindar: Mikael Jorgensen & James Merle Thomas. Communications centers and tracking stations were built around the world, each with the ability to talk directly to the space capsule as it orbited on by. The CapCom in the Mission Control Center, who is taking care of communications with the crew, uses his communication gear in a PTT mode exclusively. Science Friday featured an extended interview with the group in 2017. Because replacement parts are no longer available, an “out-of-band signaling” system was installed in 1998 for the transmitters located in the U.S. Many of our links now function as affiliate links. Many of you have suggested in the past that the SWLing Post join an affiliate links program. Yesterday, my family watched the successful launch of the NASA Demo-2 SpaceX Dragon via YouTube. They make all radio calls into the “blind” so to speak, hoping that some ground tracking station is picking them up. * Astrophysics The July Comet C/2020 F3 NEOWISE: Quite a Show! What now? Posts will be delivered to your inbox in daily batches. Yep – those beeps are Quindar Tones. The SelCal codes are transmitted as two consecutive pulses that consist of paired audio tones. CCD Spectroscopy: How these Spectra were Taken, https://regulusastrocom.files.wordpress.com/2018/09/quindar_tones.ogg. We hope you understand, and are grateful for your support. * Space Exploration Ads are what helps us bring you premium content! Their purpose is to trigger the ground station transmitters when there is an outgoing transmission from Earth. Well, it all boils down to older technology. It worked fine, but the Astronaut Office complained about the lack of tones which everyone had become accustomed to as an alert that a transmission was about to start. I found this archived post on the NASA’s Apollo Lunar Surface Journal wesbite: Journal Contributor Mark Burckhard writes: “I’ve always wondered what purpose the ‘beeps’ served that one heard intermittently during the voice communications with the Command and Lunar Modules during the Apollo missions, as well as other space missions.”. So, the Quindar tone generator, which was still installed in case it was necessary to key the transmitters at an overseas site, was re-enabled. Steve builds a simple SWL antenna tuner that pairs brilliantly with the Belka-DX, Icom IC-705: Let’s see how long it’ll receive with supplied BP-272 Li-ion battery pack, Peter demonstrates SDR# Co-Channel Canceller with FM DX, BELKA-DX: A Pocket-Sized Radio for Pocket Change, A review of the lab599 Discovery TX-500 QRP transceiver, The Reciva Internet radio station aggregator is closing down. Fun fact: the astronauts cannot hear that tone because it is not until after the tone that it starts transmitting. The remote transmitter is off. I don't, for example, think it's required to talk to Dragon... but they like it so you don't always have to flap your lips. There is no need for audible tones these days. If you listen carefully, the tones are not the same pitch: there are two distinct tones, one at 2525Hz and the other at 2475Hz. Click here to view a list of all sponsors. I couldn’t find any information about Quindar Tones at the US Space and Rocket Center–although, admittedly, the place is massive and I could have easily overlooked it–so I did a little research when I returned home. Thank you! Thank you, too, for your support of these sites. With new methods of telecommunications (i.e. If you’re fascinated with the NASA audio soundscape in general, you might check out the electronic music duo Quindar featuring longtime Wilco member Mikael Jorgensen, and art historian-curator James Merle Thomas. Those beeps, of course, reminded me of past NASA missions and those iconic confirmation tones we heard in audio from the Mercury, Gemini, and Apollo days all the way into Space Shuttle missions. The astronauts do not initiate any of the tones. Ever watched footage of the Mercury, Gemini or Apollo space projects? not perfect, by any means, but it worked, generally. Your email address will not be published. so engineers made their best effort to prevent the tones from even reaching the astronauts by placing a filter into the stream of all uplinked audio sent to the capsule. Please support this website by adding us to your whitelist in your ad blocker. Mission Control then had telephone lines to each of these stations around the world. The tones were used as a method to control when the remotely located transmitter was transmitting, and used the phone lines to send these remote control tones as audible beeps. This send a 2525Hz intro tone to the system. Feel free to comment and share any other resources or projects you’ve found. Why the beeps? Here is a link to an article about it. It also states how that is no longer required as multiple communication channels can be carried on the medium. Yep – that was a problem(!) Back when they were shooting astronauts into space on top of missiles (some more controlled than others), eventually they got people into orbit. Cookies help us deliver our Services. https://www.hq.nasa.gov/alsj/quindar.html. When the tone is not present, the transmitters are unkeyed. Also, just before communications was handed over to a new tracking station, the key-unkey tone pair was sent 10 times to ensure that everything was functioning correctly. Pingback: Kort radioamateurnieuws - week 23, 2020 - VERON. Please consider supporting us via Patreon or our Coffee Fund! Discussion. This site uses Akismet to reduce spam. If you love electronic music–especially if you’re a fan of Wilco, it’s well worth a listen: Check out their latest video, Choco Hilton: Speaking of Mikael Jorgensen and Wilco, I should note here that their album yankee hotel foxtrot has a deep shortwave motif. Please read the article below, it explains it better. Photo by Chad Ress, Spacesuits by Cassandra C. Jones. Quindar tones both come from mission control. Even though you won’t hear the same Quindar tones in present-day space missions, you can listen until your heart is content at the website Apollo In Real Time. “Quindar tones, named after the manufacturer of the tone generation and detection equipment, are actually used to turn on and off, or “key,” the remote transmitters at the various tracking stations (Merritt Island Launch Area–now Kennedy Space Center, Bermuda, Australia, etc.) Now, you might wonder about the issues here. You can hear both of them during Apollo even when there's no communication. It also states how that is no longer required as multiple communication channels can be carried on the medium. […]”Although it usually worked well, there were a couple of peculiarities with this system. ‘PTT’ is short for Push-To-Talk, which means that the CapCom presses a button every time and as long as he wants to talk. * Cosmology They push the push-to-talk switch. Turns out, they’re called “Quindar Tones.”. Learn how your comment data is processed. like these: What are these tones for? When done, Mission control releases the PTT switch, and the 2475Hz outro tone is sent, thus turning off the system. Since we could hear those even today, any specific reason why? Can you identify this radio in Goldfinger? that were used to communicate with the Mercury through Apollo spacecraft and, in some cases, are still used with the Space Shuttle.” Both tones originated at Mission Control…. “Quindar tones, named after the manufacturer of the tone generation and detection equipment, are actually used to turn on and off, or “key,” the remote transmitters at the various tracking stations (Merritt Island Launch Area–now Kennedy Space Center, Bermuda, Australia, etc.) The Internet Archive also has a massive collection of Apollo audio free to stream and download. I think it's just how nasa designed there comms network. When Houston talks to the astronauts, there is a beep, then some talking then another beep? fiber optics, satellite feeds, etc), sending command and control statements to remotely located transmitter sites is a lot easier. https://www.hq.nasa.gov/alsj/quindar.html, Share & discuss informative content on: Thank you! The SWLing Post now participates in two affiliate advertising programs with two large retailers that still sell shortwave radios, the Amazon Services LLC Associates Program and the eBay Partnership, designed to provide a means for sites like ours to earn advertising fees by advertising and linking to these retailers of radio products. Press question mark to learn the rest of the keyboard shortcuts. like this: An example for you is below. fiber optics, satellite feeds, etc), sending command and control statements to remotely located transmitter sites is a lot easier. in Apollo, I always thought it was just a "yes.. the radios still see each other" kind of thing.. an audible ping.. communications are normal. I obviously can’t speak on behalf of NASA but I really wouldn’t be surprised if certain important conversations were had on a one way channel. The Quindar-Tones purpose — to trigger the ground station transmitters when there is an outgoing transmission from Earth — sounds similar to the purpose of the SelCal audio tones used in Aero communications. Comet C/2020 F3 NEOWISE the July 2020 Surprise. If an astronaut were to also talk at the same time, they might pick up a Quindar tone on their audio and retransmit it back to the ground and cause all sorts of troubles down on the Earth side of things. Based on a simple Wiki search, Quindar tones were used for a PTT (Push To Talk) mechanism to transmit signals. I then discovered this article via the Internet Archive Wayback Machine, which gave more detail about the Quindar Tones’ name and some of the idiosyncrasies of the system: Steve Schindler, an engineer with voice systems engineering at NASA’s Kennedy Space Center, offers the following history of [Quindar Tones] origins. More information on the About/Contact Page. Your support makes articles like this one possible. my thinking is.. what if it's a rest period and the astronauts are asleep that ping is an active signal that you still have comms. Based on a simple Wiki search, Quindar tones were used for a PTT (Push To Talk) mechanism to transmit signals. One way communication is still a big feature on safety critical vehicles like Trains and Planes, in the case of Trains(In the UK at least) all emergency calls are still made with one way push to talk systems so that whoever is talking can get their message over uninterrupted. When the tone is present, the transmitters are keyed. Quindar tones were used from the early flights of Merucry through the Space Shuttle program. Note that the Quindar tones only take place just before and after Mission Control speaks. With new methods of telecommunications (i.e. Journal Contributor Mike Dinn provides an MP3 clip ( 123k ) from a network audio check that includes numerous quindar tones. But please note that we will never create a post and product link explicitly to receive a commission. List of QRP General Coverage Amateur Radio Transceivers, List of VHF/UHF Multimode Amateur Radio Transceivers, NASA’s Apollo Lunar Surface Journal wesbite, https://swling.com/blog/wp-content/uploads/2020/05/hskquindar.mp3, https://www.podtrac.com/pts/redirect.mp3/media.pri.org/s3fs-public/science-friday/segment-audio/scifri-soundtrack-spaceflight.mp3, The SDR.hu web SDR portal is no more, but we have several excellent alternatives, Kort radioamateurnieuws - week 23, 2020 - VERON, Grace Digital Internet Radios made between 2007 and 2017 “will stop working”, Dan’s initial review of the Belka-DSP portable shortwave radio.