NASA Upgrades VHF Communications for International Space Station

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NASA Upgrades VHF Communications for International Space Station


https://www.rrmediagroup.com/News/NewsDetails/NewsID/16804

Monday, April 30, 2018

NASA is implementing upgrades to VHF communications ground stations that back up the International Space Station (ISS) primary communications system, the Space Network and communicate with Soyuz spacecraft when out of Russia’s range. The ISS’s first component launched in 1998.


NASA’s VHF ground stations provide two-way, audio-only communications and transmit over two frequencies, VHF1 and VHF2. VHF1 is used for emergency communications with the ISS; VHF2 communicates with Soyuz spacecraft.


Russia also operates a VHF network independently from NASA's. The combination of the two networks ensures VHF communications are available on every orbit of the space station and Soyuz.


The space station hosts two VHF1 antennas, 180 degrees apart. They flank the Zvezda Service Module, an early Russian contribution to the station that served as an early cornerstone for its habitation. Astronauts and cosmonauts can communicate with mission control from any module of the station via VHF1.


“Maintaining the availability of utility-like communications between the crew and the ground is paramount to enabling mission success and ensuring crew safety,” said Mark Severance, human spaceflight communications and tracking network director. “The NASA VHF network, in combination with the VHF network operated by our Russian partners, does just that.”


Under normal circumstances, the station relies on NASA’s Space Network, a series of tracking and data relay satellites in geosynchronous orbit. The network provides near-continuous communications coverage between the station and mission control centers around the world that make sure the station’s systems function properly. The Space Network also enables the transmission of high-resolution science data, ultra-high definition video and special downlinks such as student contacts with astronauts. VHF1 would only be used in the unlikely event that the space station was unable to communicate via the Space Network.


Russian Soyuz spacecraft sport a single VHF2 antenna towards their tail. Russia uses VHF2 as its primary system for voice communications from launch at the Baikonur Cosmodrome in Kazakhstan to docking with the space station and upon undocking and returning to Earth.


On most Soyuz missions, the spacecraft docks with the space station prior to exiting Russia’s VHF network coverage. The same is true on return to Earth. However, on Soyuz missions that require a longer, 34-orbit rendezvous, the NASA VHF network stands by to provide emergency communications while the Soyuz is outside of Russia’s range, orbiting over the continental United States. NASA’s VHF network could also provide emergency communications in the event a problem required the Soyuz to stay in orbit for an extended period of time.


NASA’s upgrades to VHF network ground antennas involve improvements to numerous electronic components and installation of new software for tracking the space station and Soyuz. Additionally, new antennas at the ground stations, able to operate at VHF1 and VHF2 simultaneously, will add redundancy to the network so that if one system fails, the other system will be able to take over immediately.


“The purpose of these upgrades is to ensure the VHF ground stations remain a robust capability for backup and emergency communications,” said Severance. “The addition of redundancy, the ‘belt and suspenders’ approach, is particularly important given that these systems would only be employed due to failure of the primary space station communications system or an emergency onboard the Soyuz.”


NASA maintains VHF ground stations in Wallops Flight Facility in Wallops Island, Virginia, and NASA’s Armstrong Flight Research Center in Edwards, California. These ground stations are strategically placed to maximize contact with the station and Soyuz as they orbit above North America. The Russian VHF ground stations are located throughout Russia, providing contact as the space station and Soyuz orbit above Asia and Europe.


NASA’s VHF system is managed by NASA’s Goddard Space Flight Center’s Exploration and Space Communications projects division. NASA’s Space Communications and Navigation program office provides programmatic oversight to the network.



NNN
 

N2AL

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This is an excellent article and knowledge to share. Thanks for submitting and giving me better insight to NASA ISS communications.
 

rbrtklamp2

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Anyone know what frequencies they are using ? Even if Encrypted it would be interesting to see it pop up when in use and is within RX range.

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kma371

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Do they still use 143.625? I haven't tried to monitor that one is years.


EDIT
Whoops, I thought the article was about amateur freqs, but it's the comms with mission control. They used to use VHF1 quite a bit in the mid-late 90's. Haven't tried to listen in a long time.
 
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Chris-KH2PM

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Regarding 143.625, I've heard them a few times over the past 10 years using that frequency during EVA's (spacewalks) unencrypted analog FM. The most recent was within the past few months. Here's a short audio clip from a 2013 EVA. http://kh2pm.dynip.com/ISS-SpaceWalk-143-625.mp3

The Civil Air Patrol uses that allocation as well though, so I pick up their local comms more often.
https://wiki.radioreference.com/index.php/Civil_Air_Patrol

I have a BCD-396T on 24/7 recording with ProScan and several ISS FM frequencies are in it, but only 143.625 and 145.800 are the ones I've heard lately.
 

Bhawk27

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During preparations for the most recent Soyuz undocking, I heard Russian comms on 130.167 as they passed over our region (northern Illinois).
 
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During preparations for the most recent Soyuz undocking, I heard Russian comms on 130.167 as they passed over our region (northern Illinois).
so that got me thinking, as having caught traffic on 121.75FM as a fluke months back has gotten me real interested in catching some more. Next week there is to be an EVA and i have never really found anything as to what the US folks use during an EVA. Same as rooskies? Unknown? anything i have found has never been clear or likely outdated. anyone know more?

since i now know there is a SCHEDULE posted publicly for these sorts of things i might pay more attention. (yeah i didn't know there was a posted schedule, i am not ready for the 21st century quite yet.)
 
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