International Space Station to be visible on Sept. 19-20

The International Space Station to be visible on Sept. 19-20. The key word being "visible" and is not the only time you can see the ISS though.

Radio amateurs can listen via wireless during most passes with the hope to either listen in during a scheduled astronaut contact with a school or to use the digital packet relay system known as a "digi-peater" to bounce short text messages through the ISS and back down to Earth.


Non-Visual Voice Communication

The astronauts do not have much time for casual amateur radio operation, but you might be lucky if you give the station a call on 144.490 MHz in North America or 145.200 MHz elsewhere in the world. You will need to listen to 145.800 MHz for transmissions from the Astronauts.

Using different receive and transmit frequencies is known as split operation.  Astronauts have the ISS radio programmed the opposite was as you would on Earth.   The reason for this is to minimize interference and increased reliability.

The below photo is of a post card confirming a contact with the ISS and a local amateur radio operator.  The "QSL" card was sent from a ground station on Earth and was not dropped 220 Miles above from the ISS, if you were wondering.

Non-Visual Data Communication

If you are interested in non-voice communication, tuning in to 145.825 MHz will allow you to receive APRS data through the ISS.  Your AX.25 capable radio will use the same frequency on transmit and receive.  A path of "ARISS" will help ensure your transmission is received by the ISS and passed back down to Earth automatically.


Viewing the ISS

Applications such as "ISS Detector" for Android smartphones, tablets and Chromebooks work great to "predict" when the next pass will come over your area.  Apple device users may use "ISS Spotter".  Many computer programs also exist such as "Orbitron" for Windows users,  "Gpredict" for multiple platforms and "Nova" as being the three most popular or easy to use options.

There are also additional augmented reality and web based tracking tools available that are easy to find.

It is best to adjust your eyesight to the dark for at least 10-15 minutes before looking at the night sky. This gives your eyes some time to adjust for maximum viewing benefit.

On September 19th, the pass coming over the Eastern United States will track from South to North

The following day at just about the same time will see the ISS pass over yet again, but just lower in the sky compared to the night before.

Beyond visual observation, it would also be good to keep an eye on the APRS activity via the APRS.fi website to see if radio amateurs are "bouncing" signals from the space station.

You can track the space station and APRS activity via the RS0ISS call sign which broadcasts from the Russian module of the ISS. It is not always active though.  The best way to confirm recent activity is by looking at the AMSAT satellite status page or by looking at the very active Facebook group focused on the International Space Station A.R.I.S.S experiments.

If anyone would like to take some pictures of the upcoming ISS pass, it would be great if they can be shared in the comments or emailed to info@hvdn.org for a future article.

Presentation: Radio Astronomy

It was fantastic to get invited to the Mid Hudson Astronomical Association meeting and be given an opportunity to present about radio astronomy on August 20th 2019.

What is radio astronomy?

People staring up at the night sky or through a telescope has been around for practically forever.  As early as 1860 was it speculated that wireless signals may be received from the universe. 

While the earliest forms of wireless communication were only just starting here on planet Earth,  this form of now ubiquitous communication did not start to see major exploration until the 1900's and get more interesting just before the outbreak of WWII.

It was not until 1932 by accident that radio interferometry was actually coined by Karl Jansky of Bell Laboratories.   At this time in history, so called "shortwaves" were the pinnacle of radio communication technology.

Mr. Jansky was tasked in finding a source of interference between 2 and 30 MHz.  While pointing a high gain antenna upwards did he then notice a signal source coming from somewhere else.

Fast forward to 1945 and the theory of Dutch scientist H C van de Hulst regarding the frequency of the most common element of  Hydrogen at 1420 MHz which may be used to determine the size of the universe and accurate location or formation of various interstellar bodies such as black holes or stars.

It only took six years for theory to become fact, thanks to a scientist at Harvard University named E M Purcell.  His use of the most sensitive radio receiver a the time along with a nine foot long "horn antenna" is all it took to become in some circles, one of the parents of "radio astronomy".

Modern Radio Astronomy

There has been way too much progress since 1951 regarding radio astronomy, so will leave that to you to further discover.

The rest of this article is only going to focus on how you can assemble a basic radio telescope using much lower cost equipment and obtain even better results.

Here are the slides that Steve Bossert K2GOG presented at the Mid Hudson Astronomical Association meeting for those interested in having a look.

Your Next Antenna Project: Upgraded Space Station Communications

This came up on the weekly North American astronomy net and now I know what my next antenna project will be. Not sure if NASA will be willing to share the plans with me or not though. 😉

Here is a nice article from April 27th 2018 with more detail.

NASA Upgrades Space Station Emergency Communications Ground Stations

Since the launch of the International Space Station’s first component in 1998, communications infrastructure has been critical to the station’s success and crew safety. NASA is currently implementing upgrades to very high frequency (VHF) communications ground stations that backup the station’s primary communications system, the Space Network, and communicate with Soyuz spacecraft when out of Russia’s range.

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 International Space Station. 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 controlcenters around the world who 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 like 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 their 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, currently underway, 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 two locations: 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.

Banner image: The International Space Station. Credit: NASA

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By Danny Baird
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Last Updated: April 26, 2018

Editor: Rob Garner

https://www.nasa.gov/feature/goddard/2018/nasa-upgrades-space-station-emergency-communications-ground-stations 

Discussion Review: North American Astronomy Net

This is the first, of hopefully many reviews of scheduled "On The Air" discussions to help grow interest in topics that are not just about talking about radio and related equipment.

The North American Astronomy Net meets on talk group 31175 every Wednesday evening at 9:00 PM Eastern US time.

The format includes the moderator sharing some interesting news summaries about everything floating out there above planet Earth, including natural or man-made objects or phenomena.

Following a news summary and related quick comments,  trivia questions are posed for participants to answer over the air or by using the https://www.feature-segment.com/  web page.

Any user of DMR can either access the 31175 talk group through a hot spot or via local area repeaters that carries this talk group.

Local DMR Access in the Hudson Valley

The N2MCI has added TG 31175 thanks to the scheduled talk group function that Brandmeister now supports.  Pete's repeater is on 448.625 MHz with a negative 5 MHz offset and uses Color Code 1 and time slot 1 for access to this interesting content.

NOTE:  The schedule function prioritizes TG 31175 from 9:00 PM to 10:30 PM local time, so others looking to use the repeater will be unable to communicate on any other talk group during this time period each Wednesday.

Summary of the February 22nd 2018 North American Astronomy Net

A record high of 18 participants, besting the previous record of 12.  Most all participated in the trivia session, where multiple virtual prizes were awarded.   Moderator, Mark KB9WLX did a fantastic job of moving through a range of content pretty quickly.

Additional Perspectives

Space related and astro focused topics are in demand in the amateur radio community.  The NA Astronomy Net is just one.  Two others that HVDN is aware of, but are not currently carried on a digital network include the:

The South West Astronomy Observers Group (S.W.A.O.G.)

Located in the Chicago Metropolitan Area
on the DuPage  (DARC)  Repeater 145.430 MHz. (TX offset -600KHz. / 107.2 Hz. PL) every Thursday evening at 8:30 PM

The Long Island Mobile Amateur Radio club (LIMARC)

Located in the New York City area on the W2VL Repeater 146.850 MHz (TX offset -600KHz. /136.5 Hz PL) every 1st and 3rd Thursday evening at 8:30 PM. The net is also accessible via Echolink via  node 487981 W2VL-R

HVDN will continue to focus on finding the best content available in the Hudson Valley via local repeaters as well as those that can be easily accessed via DMR repeaters.

Make a suggestion for a topic focused net on the HVDN Activity page