Tag Archives: NASA

Radio Waves: NRAO Turns Scope System Into Planetary Radar, WBCQ Seeks Engineers, Deep Space Network Upgrades, and 2021 Propagation Summit

GBT-VLBA radar image of the region where Apollo 15 landed in 1971. The snake-like feature is Hadley Rille, a remnant of ancient volcanic activity, probably a collapsed lava tube. The crater at top, alongside the rille, is called Hadley C and is about 6 kilometers in diameter. This image shows objects as small as 5 meters across.
(Credit: NRAO/GBO/Raytheon/NSF/AUI)

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!


Successful Test Paves Way for New Planetary Radar (NRAO)

The National Science Foundation’s Green Bank Observatory (GBO) and National Radio Astronomy Observatory (NRAO), and Raytheon Intelligence & Space conducted a test in November to prove that a new radio telescope system can capture high-resolution images in near-Earth space.

GBO’s Green Bank Telescope (GBT) in West Virginia — the world’s largest fully steerable radio telescope — was outfitted with a new transmitter developed by Raytheon Intelligence & Space, allowing it to transmit a radar signal into space. The NRAO’s continent-wide Very Long Baseline Array (VLBA) received the reflected signal and produced images of the Apollo 15 moon landing site.

The proof-of-concept test, culminating a two-year effort, paves the way for designing a more powerful transmitter for the telescope. More power will allow enhanced detection and imaging of small objects passing by the Earth, moons orbiting around other planets and other debris in the Solar System.

The technology was developed as part of a cooperative research and development agreement between NRAO, GBO, and Raytheon.

“This project opens a whole new range of capabilities for both NRAO and GBO,” said Tony Beasley, director of the National Radio Astronomy Observatory and vice president for Radio Astronomy at Associated Universities, Inc. (AUI). “We’ve participated before in important radar studies of the Solar System, but turning the GBT into a steerable planetary radar transmitter will greatly expand our ability to pursue intriguing new lines of research.”

Using the information collected with this latest test, the participants will finalize a plan to develop a 500-kilowatt, high-power radar system that can image objects in the Solar System with unprecedented detail and sensitivity. The increased performance also will allow astronomers to use radar signals as far away as the orbits of Uranus and Neptune, increasing our understanding of the Solar System.

“The planned system will be a leap forward in radar science, allowing access to never before seen features of the Solar System from right here on Earth,” said Karen O’Neil, the Green Bank Observatory site director.

“Raytheon’s radar techniques could ultimately improve our ability to explore the Solar System,” said Steven Wilkinson, Principal Engineering Fellow at Raytheon Intelligence & Space. “Working with the astronomy community allows us to apply decades of radar know-how to a project that provides high-resolution images of near-Earth objects.”

“We are excited to be partnering with Raytheon and applying their radar expertise to transform our observatories’ telescopes in new science areas,” said AUI President Adam Cohen.

The National Radio Astronomy Observatory and the Green Bank Observatory are facilities of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.[]

WBCQ: Radio transmitter engineers wanted

WBCQ Radio is seeking radio transmitter engineers to work at our 500KW shortwave station. Come to northern Maine and get away from it all. Nice working environment, good pay, great people, fun work with BIG transmitting and antenna equipment. Contact Allan and Angela Weiner at 207-538-9180. Please send resumes to wbcq@wbcq.com.

Deep Space Network upgrades and new antennas increase vital communication capabilities (NASA)

NASA’s Deep Space Network, commonly referred to as the DSN, has welcomed a new dish, Deep Space Station 56, to its family of powerful ground listening stations around the world.

The now-operational 34-meter antenna joins the network’s Madrid Deep Space Communications Complex located 60 kilometers west of Madrid, Spain while other dishes within the network undergo critical upgrades.

The new dish is part of an ongoing series of enhancements to the DSN, which traces its roots back to January 1958 when the U.S. Army’s Jet Propulsion Lab was tasked with standing up a series of communications stations in Nigeria, Singapore, and the U.S. state of California to support orbital telemetry operations for the Explorer 1 mission.

This precursor to the Deep Space Network was transferred to NASA along with the Jet Propulsion Lab on 3 December 1958. The DSN was then formally commissioned by the U.S. space agency as a way to consolidate the pending deep space communication needs through centralized locations to avoid each mission having to create its own ground listening station(s).

The three Deep Space Network ground locations are spaced roughly 120 degrees from each other in Canberra, Australia; Goldstone, California; and Madrid, Spain. The location of the three facilities ensures deep space missions with a line of sight to Earth can communicate with at least one of the locations at any time.

Updates throughout the decades have increased the network’s capabilities, most notably for the two Voyager probes that continue to operate and send back science data having both long-passed out of the heliosphere and into the interstellar medium.

The network, nonetheless, is showing its age, with upgrades and refurbishments needed to ensure continuous operations. Part of this initiative is the recent addition of the new dish, Deep Space Station 56 (DSS-56), at the Madrid complex.

“After the lengthy process of commissioning, the DSN’s most-capable 34-meter antenna is now talking with our spacecraft,” said Bradford Arnold, DSN project manager at the Jet Propulsion Laboratory.[]

2021 Propagation Summit Session Recordings Available (ARRL News)

YouTube recordings and PDF files from the 2021 Propagation Summit hosted on January 23 by Contest University are available. More than 1,000 logged in for the sessions. Each presentation begins approximately on the hour. You can advance the video to the presentation you wish to view.

  • 11 AM – “Update on the Personal Space Weather Station Project and HamSCI Activities for 2021” by Dr. Nathaniel Frissell, W2NAF
  • 12 Noon – “Solar Cycle 25 Predictions and Progress” by Carl Luetzelschwab, K9LA
  • 1 PM – “Maximizing Performance of HF Antennas with Irregular Terrain” by Jim Breakall, WA3FET
  • 2 PM – “HF Propagation: What to Expect During the Rising Years of Solar Cycle 25,” by Frank Donovan, W3LPL.

Slides decks are available for each presentation in PDF format: FrissellLuetzelschwabBreakall, and Donovan. []


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A Universe of Sound

This deep image from NASA’s Chandra X-ray Observatory shows the Vela pulsar, a neutron star that was formed when a massive star collapsed. (Source: NASA)

Many thanks to SWLing Post contributor, Roger, who writes:

Hello Thomas,

I thought you, along with some others in the SWLing community, might be interested in the musical renditions, or sonifications, that were released 9/22/2020 by NASA’s Chandra X-ray

Center Universe of Sound website.
https://chandra.si.edu/sound/index.html

I found it utterly fascinating, and hope you do too.

Source: ScienceNews, Vol. 198 ? No. 8 (November 7, 2020) p. 4.

Many thanks, Roger for sharing this! Below, I’ve copied one excerpt with one pulsar sound. I’d encourage you to check out the others by clicking here.

Listen to a Pulsar Clock

Turning a pulsar’s rotational data into sound makes it easier to observe patterns and make comparisons between different nebulous pulsar rotational speeds. as a pulsar ages it spins at a slower speed. listen to the different pulsar heartbeats. what can you guess about how fast these different pulsars rotate? Which pulsar is the oldest? How about the youngest?

Neutron stars are strange and fascinating objects. They represent an extreme state of matter that physicists are eager to know more about. Yet, even if you could visit one, you would be well-advised to turn down the offer.

The intense gravitational field would pull your spacecraft to pieces before it reached the surface. The magnetic fields around neutron stars are also extremely strong. Magnetic forces squeeze the atoms into the shape of cigars. Even if your spacecraft prudently stayed a few thousand miles above the surface neutron star so as to avoid the problems of intense gravitational and magnetic fields, you would still face another potentially fatal hazard.

If the neutron star is rotating rapidly, as most young neutron stars are, the strong magnetic fields combined with rapid rotation create an awesome generator that can produce electric potential differences of quadrillions of volts. Such voltages, which are 30 million times greater than those of lightning bolts, create deadly blizzards of high-energy particles.

These high-energy particles produce beams of radiation from radio through gamma-ray energies. Like a rotating lighthouse beam, the radiation can be observed as a pulsing source of radiation, or pulsar. Pulsars were first observed by radio astronomers in 1967. The pulsar in the Crab Nebula, one of the youngest and most energetic pulsars known, has been observed to pulse in almost every wavelength—radio, optical, X-ray, and gamma-ray.

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NASA Video: The Solar Cycle as seen from space

Many thanks to SWLing Post contributor, Dave (K4SV), who shares this video courtesy of NASA Goddard:

The Sun is stirring from its latest slumber. As sunspots and flares, signs of a new solar cycle, bubble from the Sun’s surface, scientists are anticipating a flurry of solar activity over the next few years. Roughly every 11 years, at the height of this cycle, the Sun’s magnetic poles flip — on Earth, that’d be like the North and South Poles’ swapping places every decade — and the Sun transitions from sluggish to active and stormy. At its quietest, the Sun is at solar minimum; during solar maximum, the Sun blazes with bright flares and solar eruptions. In this video, view the Sun’s disk from our space telescopes as it transitions from minimum to maximum in the solar cycle.

Fascinating! Thanks for sharing, Dave!

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NASA Science Live presents “Our Next Solar Cycle”

Many thanks to SWLing Post contributor, Paul Evans, who writes:

On Tuesday, September 15, 2020 Science at NASA had a presentation on the next solar cycle predictions.

It’s available on YouTube and other outlets without needing a login or Zoom serial number:

Fascinating! Thanks for the tip, Paul!

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NASA’s SCAN testbed was an orbiting multi-function SDR

SCAN Testbed (Source: NASA)

Many thanks to SWLing Post contributor Dan (VR2HF) who writes:

“This looks like the world’s most expensive SDR to me. And a little mysterious. Like quantum computing!”

(Source: NASA)

Space Communications and Navigation (SCAN) Testbed

The SCAN Testbed, formerly known as Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT), served as a test facility for NASA research on radio communications and the Global Positioning System (GPS).

SCAN Testbed on International Space Station (Source: NASA)

The SCAN Testbed was launched on July 20, 2012 on a Japanese H-IIB Transfer Vehicle and installed in the International Space Station to provide an on-orbit, adaptable software-defined radio (SDR) facility with corresponding ground and operational systems. This permitted mission operators to remotely change the functionality of radio communications through software once deployed to space, offering them flexibility to adapt to new science opportunities and recover from anomalies within the science payload or communication system.

The SCAN Testbed payload was used to conduct a variety of experiments with the goal of further advancing other technologies, reducing risks on other space missions, and enabling future mission capabilities.

After seven successful years, and more than 4,200 hours of testing, it was decommissioned June 3, 2019 as it burned up in the trunk of SpaceX CRS-17 upon reentry into Earth’s atmosphere.

To learn more:
Communications Testbed Leaves Legacy of Pioneering Technology 
2019 Space Technology Hall of Fame: Ka-Band Software-Defined Radio (SDR)/Harris AppSTAR™ Architecture
NASA’s Space Communications Testbed
Unique Testbed Soon will be in Space
SCAN Testbed Celebrates One Year Anniversary
Glenn Research Center SCAN Testbed

Thank you for sharing this, Dan! I had never heard of the SCAN testbed. I can only imagine what it might have been capable of accomplishing from orbit. I dare say there are even more powerful SDRs orbiting the planet at this moment!

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NASA’s SDO produces a 10 year time-lapse video of the sun

Many thanks to SWLing Post contributor, Ahmet (KD2AQU), who shares the following item from NASA:

As of June 2020, NASA’s Solar Dynamics Observatory – SDO – has now been watching the Sun non-stop for over a full decade. From its orbit in space around Earth, SDO has gathered 425 million high-resolution images of the Sun, amassing 20 million gigabytes of data over the past 10 years. This information has enabled countless new discoveries about the workings of our closest star and how it influences the solar system.

With a triad of instruments, SDO captures an image of the Sun every 0.75 seconds. The Atmospheric Imaging Assembly (AIA) instrument alone captures images every 12 seconds at 10 different wavelengths of light. This 10-year time lapse showcases photos taken at a wavelength of 17.1 nanometers, which is an extreme ultraviolet wavelength that shows the Sun’s outermost atmospheric layer – the corona. Compiling one photo every hour, the movie condenses a decade of the Sun into 61 minutes. The video shows the rise and fall in activity that occurs as part of the Sun’s 11-year solar cycle and notable events, like transiting planets and eruptions. The custom music, titled “Solar Observer,” was composed by musician Lars Leonhard.

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Quindar Tones: Those iconic NASA PTT confirmation beeps

Photo credits: NASA/Bill Ingalls

Yesterday, my family watched the successful launch of the NASA Demo-2 SpaceX Dragon via YouTube.

As astronauts Robert Behnken and Douglas Hurley communicated with Mission Control, we heard PTT confirmation beeps after each transmission.

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.

Quindar Tones

Source: honeysucklecreek.net

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.

Turns out, they’re called “Quindar Tones.”

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.

I found this archived post on the NASA’s Apollo Lunar Surface Journal wesbite:

Re: Apollo beeps

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.”

Journal Contributor Mike Dinn provides an MP3 clip ( 123k ) from a network audio check that includes numerous quindar tones.

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’. Their purpose is to trigger the ground station transmitters when there is an outgoing transmission from Earth. 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. ‘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. (The crews back during Apollo – and also today – usually communicate via PTT as well, but they also have the so-called ‘VOX mode’ at their disposal, in which their microphones are voice-triggered by a certain adjustable threshold volume levels. VOX is used when they don’t necessarily have their hands free.)

When the CapCom presses his PTT button to start a transmission, an intro tone (2.525KHz sine wave with a length of 250ms) is generated and triggers the ground station transmitters to send. And when he is finished talking and releases the button again, a slightly lower outro tone (2.475KHz, sine, 250ms) is generated to trigger the ground station transmitters to turn off. So in short, these are remote control trigger tones.

CU! Markus”

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:

The story behind the “Beep”

Steve Schindler, an engineer with voice systems engineering at NASA’s Kennedy Space Center, offers the following history of [Quindar Tones] origins.

“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.) that were used to communicate with the Mercury through Apollo spacecraft and, in some cases, are still used with the Space Shuttle.”

[…]”Although it usually worked well, there were a couple of peculiarities with this system. If the transmitter was keyed and the telephone line connection broken, the transmitter would never get the tone to turn off. To prevent this there was a “transmitter on” light at each remote site that would come on when the transmitter was keyed. 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. 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. 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.

The Quindar system was actually built from a piece of equipment that was used to put multiple teletype circuits on a single phone line by means of frequency domain multiplexing. 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. This system uses a continuous tone that is below the normal audio frequency range. When the tone is present, the transmitters are keyed. When the tone is not present, the transmitters are unkeyed. 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. 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.

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.

The Internet Archive also has a massive collection of Apollo audio free to stream and download.

Quindar Music

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.

Quindar: Mikael Jorgensen & James Merle Thomas. Photo by Chad Ress, Spacesuits by Cassandra C. Jones

Science Friday featured an extended interview with the group in 2017. 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.

Anyone else fascinated with Quindar Tones and NASA audio? Feel free to comment and share any other resources or projects you’ve found.


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