Tag Archives: Space

Radio Waves: Solar-Powered Broadcast Transmitters, Decommissioning Arecibo, and HWN in the path of an International Broadcaster

Arecibo Observatory’s 305-meter telescope in November of 2020 (Credit: University of Central Florida)

Radio Waves:  Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Jerome van der Linden, Zack Schindler, and Wilbur Forcier and  for the following tips:


Powering communication networks using solar power (BAI Communications)

BAI Communications (BAI) is committed to reducing emissions and contributing to a more sustainable future.

Over the past four years, BAI has invested in a number of initiatives that reduce power consumption as well as the carbon released into the atmosphere.

This year, four solar-powered sites were introduced in BAI’s broadcast transmission network; Yatpool, Victoria; Mawson, Western Australia; Minding, Western Australia; and Brandon, Queensland.

The annual reduction in CO2 emissions from our recent solar investment is 698 tonnes, equivalent to reducing:

  • Greenhouse gas emissions from 2.7km driven by an average passenger vehicle
  • CO2 emissions from charging 89 million smartphones
  • Greenhouse emissions from 237 tonnes of waste sent to landfill

Find out how BAI implemented this solar power initiative as part of our commitment to managing our energy use and reducing consumption.

Click here to download case study (PDF).

The complexity of sending sounds to (and from) space (Mashable)

Communication with astronauts in space is vital, whether it’s during travel, when they’re doing experiments on the International Space Station, or just want to chat. It’s also pretty tricky.

That’s the topic of the latest episode of Twenty Thousand Hertz, where host Dallas Taylor speaks with International Space Station commander Peggy Whitson, NASA audio engineer Alexandria Perryman, and astrophysicist Paul Sutter to get an idea of how communication between astronauts and Earth works across the vacuum of space.[]

NSF to decommission Arecibo radio telescope (Space News)

WASHINGTON — The National Science Foundation announced Nov. 19 it will perform a “controlled decommissioning” of the giant radio telescope at the Arecibo Observatory in Puerto Rico, citing recent damage that made it unsafe to operate or even repair.

In a call with reporters, NSF officials said two broken cables used to support a 900-ton platform suspended over the telescope’s 305-meter main dish put the entire structure at risk of collapse. One cable slipped out of its socket in August, falling to the dish below and damaging it, while the second broke Nov. 6

Both cables are attached to the same tower, one of three surrounding the main dish. “The engineers have advised us that the break of one more cable will result in an uncontrolled collapse of the structure,” said Ralph Gaume, director of the NSF’s Division of Astronomical Sciences, referring to cables attached to that same tower. That would result in the platform crashing down to the main dish and potentially toppling one or more of the towers.

Engineers advising the NSF and the University of Central Florida (UCF), which operates Arecibo for the NSF, concluded that it was not possible to safely repair the structure because of the collapse risk. “After the recent failure, WSP does not recommend allowing personnel on the platform or the towers, or anywhere in their immediate physical vicinity in case of potential sudden structural failure,” stated WSP, one engineering firm involved in that analysis, in a Nov. 11 letter to UCF.

“NSF has concluded that this recent damage to the 305-meter telescope cannot be addressed without risking the lives and safety of work crews and staff, and NSF has decided to begin the process of planning for a controlled decommissioning of the 305-meter telescope,” said Sean Jones, assistant director of the NSF’s Mathematical and Physical Sciences Directorate.

Engineers are working on a plan to carry out that controlled decommissioning, which will take several weeks to complete.[]

International Broadcast Station Interference Overwhelms Hurricane Watch Net (ARRL News)

As Category 4 Hurricane Iota neared landfall in Central America on November 16, the Hurricane Watch Net (HWN) was forced to suspend operations at 0300 UTC because of what HWN Manager Bobby Graves, KB5HAV, described as “deafening interference from a foreign AM broadcast station that came out of nowhere at 0200 UTC.” At the time, the net had shifted to its 40-meter frequency of 7.268 kHz, collecting real-time weather and damage reports via amateur radio.

“This was heartbreaking for our team, as the eyewall of Iota was just barely offshore,” Graves said. “The storm had weakened slightly to a Category 4 hurricane with sustained winds of 155 MPH.” After activating at 1300 UTC, the net was able to collect and forward reports from various parts of Nicaragua and Honduras via WX4NHC throughout the day for relay to forecasters at the National Hurricane Center in Miami. Iota was the most powerful storm on record to make landfall this late in the hurricane season.

Graves said the very strong AM signal was on 7.265 MHz. “From my location, it was S-9,” he told ARRL. “You could not hear anything but the BC station.” The source of the signal was not clear, but as he noted, other foreign broadcast stations are to be heard from 7.265 to 7.300 MHz and splattering close by.

Stations handling emergency traffic during the response to Category 5 Hurricane Iota had requested clear frequencies on November 16 to avoid interfering with the HWN and with WX4NHC, as well as with a Honduran emergency net operation on 7.180 MHz and a Nicaraguan emergency net operating on 7.098 MHz. It’s not known if those nets were also affected by interference from the numerous broadcasters on 40 meters. “Thank you to all who allowed us a clear frequency,” Graves said on behalf of the HWN.[]

[Personal note: I understand that this is very late in the season for the Hurricane Watch Net to activate. Normally, they operate on 20 meters, but moved to 40 meters for the evening. I don’t believe net control was aware that this portion of the 40 meter band is shared with international broadcasters. I don’t believe the international broadcaster could be called “interference”–they operate on a publicly available schedule–ham radio nets are actually the ones who are frequency agile. This seems to have just caught them off guard. I believe the HWN will be using frequencies below 7.2 MHz moving forward.]


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“NASA considers this 80-year-old radio buff part of the astronaut family”

(Source: ABC News via Michael Bird)

To NASA personnel, he is VK5ZAI. To his neighbours at Pinks Beach, a small coastal town in South Australia, he goes by Tony.

In his 30-year association with the US space agency, Tony Hutchison has been called upon to help in times of crisis, moderate calls between astronauts and their families, and run a worldwide schools program.

He’s shared a beer with first commanders, had barbecues with mission specialists, and watched the space shuttle launch from the bleachers at Kennedy Space Centre.

Looking back, it’s a life he never expected.

Mr Hutchison, 80, fell in love with radio at age 10, had his amateur radio licence by 21, and became involved with satellite communication a few years later.

In October 1992 he made his first contact in space — cosmonaut Anatoly Solovyev onboard the Mir space station.

“You could talk up to them as they passed over and they’d talk back to you.”

He became good friends with one of them, Aleksandr Serebrov.

“He would call me probably a couple times a week as he passed over. Of course they keep to Russian time, which is almost the opposite time to us, so it would be in the middle of the night and Alex would call.”

NASA eventually caught on and had Mr Hutchison doing communications for Andy Thomas while he was onboard Mir.[…]

Click here to continue reading the full story.

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Radio enthusiasts receive images from the Longjiang-2 in lunar orbit

Image received by astronomer Cees Bassa (@cgbassa) using the Dwingeloo Telescoop

Many thanks to SWLing Post contributor, Eric McFadden (WD8RIF) who shares the following story from The Planetary Society:

Earlier this week, on October 10, radio amateurs all around the world worked together to get the Chinese Longjiang-2 spacecraft to take an image of the Earth and the far side of the Moon. Radio commands were generated by MingChuan Wei in China, transmitted to the spacecraft by Reinhard Kuehn in Germany after which they were received by the spacecraft in lunar orbit. In turn, the spacecraft transmitted the image back to Earth, where it was picked up by radio amateurs in Germany, Latvia, North America and the Netherlands.

Since June this year, the Chinese Longjiang-2 (also known as DSLWP-B) microsatellite has been orbiting the Moon. The satellite is aimed at studying radio emissions from stars and galaxies at very long wavelength radio waves (wavelengths of 1 to 30 meters). These radio waves are otherwise blocked by the Earth’s atmosphere, while the lunar environment offers protection from Earth-based and human-made radio interference. Longjiang-2 was launched to the Moon together with an identical twin, Longjiang-1 (DSLWP-A), together acting as a radio interferometer to detect and study the very long wavelength radio waves by flying in formation in lunar orbit.

Besides the scientific instruments, both Longjiang satellites carry a VHF/UHF amateur radio transmitter and receiver (a transceiver) built and operated by the Harbin Institute of Technology (in Chinese). The Longjiang-2 transceiver also includes an onboard student camera, nicknamed the Inory Eye. The Harbin team built on experience gained with the Earth-orbiting LilacSat-1 and LilacSat-2 nanosatellites, which allow radio amateurs to receive satellite telemetry, relay messages and command and download images taken with an onboard camera.

While receiving signals from satellites in low Earth orbit requires only relatively simple antennas, doing so for satellites in orbit around the Moon (a thousand times more distant), is much harder. To this end Longjiang-1 and 2 transmit signals in two low data-rate, error-resistant, modes; one using digital modulation (GMSK) at 250 bits per second, while the other mode (JT4G) switches between four closely spaced frequencies to send 4.375 symbols per second. This latter mode was developed by Nobel-prize winning astrophysicist Joe Taylor and is designed for radio amateurs to relay messages at very low signal strengths, typically when bouncing them off the surface of the Moon.

[M]any radio amateurs have been able to receive transmissions from Longjiang-2. Usually, the transceiver is powered on for 2-hour sessions at a time, during which GMSK telemetry is transmitted in 16-second bursts every 5 minutes. After some testing sessions in early June, the JT4G mode was activated, with 50 second transmissions every 10 minutes.

Specialized open source software written by MingChuan Wei and the Harbin team enables radio amateurs to decode telemetry as well as image data and upload it to the Harbin website.

The JT4G mode has allowed radio amateurs with small yagi antennas to detect signals from Longjiang-2 (using custom software written by Daniel Estévez).[…]

Click here to read the full article at The Planetary Society.

This is fascinating, Eric!  Thank you for sharing. It would be amazing fun to grab one of these Lunar signals! Anyone up to the task?

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Radio Moscow: New Year’s Day, 40 years ago

Happy New Year SWLing Post community!

A few months ago, I published a post about Colin Anderton’s excellent Radio Moscow recordings from the late 1970s. Being a space flight enthusiast, all of Colin’s brief off-air recordings feature news from the 1977-1978 Soyuz 26 mission to the Salyut 6 space station.

Recently, I started posting Colin’s recordings on a schedule so that each recording is being published exactly 40 years from the original broadcast date. Check out the Shortwave Radio Audio Archive each day (or subscribe via iTunes) to listen to the recordings.

Below, I’ve embedded the recording from New Year’s Day 1978 where we learned that Yuri Romanenko and Georgi Grechko toasted the New Year with fruit juice (for obvious reasons, champagne was not allowed on the station!).

Click here to listen via the Shortwave Radio Audio Archive.

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Today: Sixty year anniversary of Sputnik 1

Radio Moscow QSL Card (Credit: Richard Langley)

(Source: NASA History Archives)

Sputnik and The Dawn of the Space Age

History changed on October 4, 1957, when the Soviet Union successfully launched Sputnik I. The world’s first artificial satellite was about the size of a beach ball (58 cm.or 22.8 inches in diameter), weighed only 83.6 kg. or 183.9 pounds, and took about 98 minutes to orbit the Earth on its elliptical path. That launch ushered in new political, military, technological, and scientific developments. While the Sputnik launch was a single event, it marked the start of the space age and the U.S.-U.S.S.R space race.

The story begins in 1952, when the International Council of Scientific Unions decided to establish July 1, 1957, to December 31, 1958, as the International Geophysical Year (IGY)because the scientists knew that the cycles of solar activity would be at a high point then. In October 1954, the council adopted a resolution calling for artificial satellites to be launched during the IGY to map the Earth’s surface.

In July 1955, the White House announced plans to launch an Earth-orbiting satellite for the IGY and solicited proposals from various Government research agencies to undertake development. In September 1955, the Naval Research Laboratory’s Vanguard proposal was chosen to represent the U.S. during the IGY.

The Sputnik launch changed everything. As a technical achievement, Sputnik caught the world’s attention and the American public off-guard. Its size was more impressive than Vanguard’s intended 3.5-pound payload. In addition, the public feared that the Soviets’ ability to launch satellites also translated into the capability to launch ballistic missiles that could carry nuclear weapons from Europe to the U.S. Then the Soviets struck again; on November 3, Sputnik II was launched, carrying a much heavier payload, including a dog named Laika.

Immediately after the Sputnik I launch in October, the U.S. Defense Department responded to the political furor by approving funding for another U.S. satellite project. As a simultaneous alternative to Vanguard, Wernher von Braun and his Army Redstone Arsenal team began work on the Explorer project.

On January 31, 1958, the tide changed, when the United States successfully launched Explorer I. This satellite carried a small scientific payload that eventually discovered the magnetic radiation belts around the Earth, named after principal investigator James Van Allen. The Explorer program continued as a successful ongoing series of lightweight, scientifically useful spacecraft.

The Sputnik launch also led directly to the creation of National Aeronautics and Space Administration (NASA). In July 1958, Congress passed the National Aeronautics and Space Act (commonly called the “Space Act”), which created NASA as of October 1, 1958 from the National Advisory Committee for Aeronautics (NACA) and other government agencies.

Click here to read at NASA’s history website.

Source: NASA

More on Sputnik

Check out this post by SWLing Post contributor Richard Langley in our archives.

Also contributor, Colin Anderton, has posted a vintage Radio Moscow recording on his website, Apollo Audio Highlights.

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The Voyager twins: weak signals and discovery from the depths of space

Artist’s concept of Voyager I (Source: NASA)

Yesterday, while listening to the BBC World Service, I heard this fascinating documentary focusing on the Voyager I and II spacecraft. It absolutely blows my mind that both of these spacecraft have been operating for 40 years and continue to send signals back to Earth. Talk about weak signal DX!

Note that you will have to visit the BBC World Service website to listen to the documentary via their media player.

(Source: BBC World Service)

Voyager 1 and 2: Still operating after 40 years in the depths of space. Voyager 1 is currently some 20 billion kilometres from Earth travelling at 15.5 kilometres a second. It takes 19 hours for a signal from the spacecraft’s 20 watt transmitter to reach home. Voyager 2 is 17 billion kilometres away and will soon leave the Solar System.

Launched in 1977, the twin spacecrafts have explored the giant planets and their strange moons, investigated the boundary of the Solar System and changed how we see our place in the Universe. The probes even carry a message for aliens in the form of a golden record.

Retired NASA astronaut Ron Garan meets many of the original team still working on the mission, nursing the twin spacecraft through their final years.

Click here to listen to the documentary via the BBC World Service website.

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Sean’s recording of an International Space Station EVA

ISSSean Gilbert, WRTH’s International Editor, recently shared this audio he originally recorded on June 19, 2014. Sean writes:

With all the interest in space and the ISS at the moment, I thought I would share a recording I made on 19 June 2014 @ 1715 UTC. This is from the Russian part of the ISS and the audio (which is in Russian) is of the cosmonauts talking during a spacewalk (EVA as they are known). The person speaking is actually in space, outside of the ISS. The audio begins about 2 mins into the recording and lasts for about 5 mins.

[Listen via the embedded player below, or click here for the MP3 version.]

[…]This was received on 143.625MHz NFM (+/- a few kHz due to doppler shift). Receiver here was a Funcube Dongle Pro + into a 2 element circular polarised turnstile in the attic. Signal was lost at a distance of 2000km (to the East of my location in IO92ma) at 3 degree elevation. Altitude of ISS was 418km above earth. 

Sean-Gilbert-ISS-Screen-Cap-Spectrum

The image [above] shows a grab of the signal, exhibiting doppler shift due to the ISS orbit in relation to the earth.

 […]I would be interested to know what they are saying. […]To me this was far more exciting than receiving SSTV pictures from the ISS. I may never hear another EVA – I am just thankful that I found this as it was an announced/schedules EVA.

That is very cool, indeed, Sean! At some point, I must make an effort to venture up to the VHF neighborhood and attempt to hear the ISS.

I hope there’s a Russophone reader out there who can help Sean interpret the EVA dialog! Please comment!

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