APRS Receiver Champion / Challenger Experiment

What’s a better receiver for an APRS receiver for packets from the ISS? Let’s do a side by side test.

Left is the challenger Baofeng, Right is the RTL-SDR Champion

For several months now, I have been running signals from a discone antenna on my roof into a RTL/SDR receiver connected to a Raspberry Pi. On a good day, I pick up a few packets from the ARISS digipeater running on the ISS at 145.825 MHz.

I was wondering if I could hear more packets with a different receiver so I decided to create a side/-by-side A/B test. Here’s the configuration:

Discone Antenna fed into my “Tech Center” / Ham Shack
Split antenna with a coax “T” – one goes to champion setup, one to challenger. Using equal length coax with SMA connectors.

Champion Setup: $30 RTL/SDR dongle direct into a Raspberry Pi 4 B (8 GB) running Raspbian with the Direwolf software.

Challenger Setup: Baofeng UV5R ($20) connected via audio cable to a UGreen USB audio jack ($14) into a Raspberry Pi 4 B (8 GB) running Raspbian with the Direwolf software.

Both are tuned as best I can for audio quality using data on 144.390, and then switched to the ISS frequency.

The experiment was configured on Wednesday, December 21 in anticipation of a predicted 83 Degree Elevation pass on 22-Dec-22 at 17:26 UTC. I’ll update this blog as I get pass data in.

Update: 23-Dec-22 at 0955 UTC – A moderate height ISS pass (32 deg El) coming through this morning at 1007 UTC. Couldn’t gather data Wednesday because the ISS radios were off for the space walk.

Update: 23-Dec-22 at 1023 UTC – ISS radios were still off during the pass. Trying again later today (Friday).

Challenger radio on left, champion SDR on the right.

Update: 23-Dec-22 at 17:00 UTC – Good pass with many packets caught. There was an obvious winner in the SDR. You can see on the screen show it captured many packets while the Baofeng only reported 1 for the entire pass. Going to change HT’s and try again on a later pass.

Lunar Eavesdropping, Curious Marc, and Tracking Artemis 1 Via RF

Originally published 27-August-22 at 5:00 PM ET
Updated 28-August-22 at 12:25 PM ET

Apollo 16 Command Module “Casper” at Space and Rocket Center in Huntsville, AL – Picture by N4BFR

Back in the days of Apollo, hams were listening in to Apollo 11 and other space flights. An article entitled “Lunar Eavesdropping” from the ARRL talks about how a couple of hams listened in on Apollo 11, and outside of getting a 10 second head start on the rest of the world, made it work but didn’t hear anything unique.

Over the last few months I’ve watched as Curious Marc on YouTube, known as AJ6JV in Ham Radio circles, has completely reconstructed signals from the Apollo gear in his basement. It’s been fascinating to understand the “RF Black Arts” as he says, of the really complex ways the capsules and LEM sent back their signals in a multiplexed method of FM and PM data. One thing I noted that this frequency range was around 2.287 GHz, in the “S-Band” frequency range.

NASA has had 50 years to be more sophisticated with it’s communications. It now breaks down comms into their “Near Space Network” which handles the communications around the globe, and the “Deep Space Network” which handles communications beyond earth orbit.

I’ve spend the last few hours going through documents on the NSN from as far back as 2000 and from what I can tell, they still primarily use S-Band frequencies. Here’s an example of frequencies listed in a doc related to Wallops Island, VA – part of the NSN.

11.3M Antenna (WGS 11.3M)
  TX 2.025 Ghz to 2.120 GHz 
  RX 2.220-2.400 GHz (S-Band)
     8.025-8.400 GHz (X-Band)
  Modes: PM, FM, BPSK, QPSK, 

4.7M Antenna (LEO-T)
  TX 2.025-2.210 GHz
  RX 2.200-2.300 GHz

So, there may be something there to trying to pick up some Artemis 1 or NSN signals while it’s in near Earth orbit on Monday. I do have some omni-directional 2 GHz receive coverage with an SDR. My mission would be to capture anything unique and record it for later analysis, though I expect it to be encrypted, since SpaceX encrypted their telemetry feeds after hams started to listen in.

About 2.5 hours after launch, Artemis 1 will start toward the moon and switch to the DSN according to NASA PR data. (Update: On the 8/27 media conference they mentioned this was right after the TLI event and could be 90 minutes in to the mission) DSN also has S-Band communications but needs to use X-Band or higher at least part of the time according to this JPL document:

X-Band, K and Ka-Bands are out of my range at the moment, but I will be checking in on the S-Band segment from time to time. If I was communicating, I probably wouldn’t be turning radios on and off, but instead looking at simulcasting the streams.

So, lots of fun to be had this week as I begin a look to peek at space comms! If you have something to add or share, hit me up on Twitter @N4BFR or on Facebook.

AP: Who’s an astronaut?

I wrote in a previous blog post that non-professional space travelers (space tourists) should have a term other than “Astronaut.” This AP article takes on the topic.

The dividing line for me seems to be, “are you going to work for a public or private space agency.” If yes, Astronaut, if no, Astrotaxedia is my preferred term.

Examples:
Bill Nelson current NASA admin and former shuttle rider, Astrotaxedia

Inspiration 4 crew Astrotaxedia

Pilot of Virgin Galactic Spaceplane Astronaut

Passenger on Virgin Galactic Spaceplane Astrotaxedia

Proposed: Space Tourists should be named Astrotaxida for “Space Wanderer”

With several new commerical space trips coming on the agenda, particularly the SpaceX Inspiration 4 and the new Virgin Galactic “Spaceship 3”, I’d like to discuss the use of the word “Astronaut” (and I guess “Cosmonaut”) would fit too.

Wikipedia defines Astronaut as :

An astronaut (from the Greek “astron” (ἄστρον), meaning “star”, and “nautes” (ναύτης), meaning “sailor”) is a person trained, equipped, and deployed by a human spaceflight program to serve as a commander or crew member aboard a spacecraft.

I’m glad that people are getting to live their dreams of going to the stars. However I think it’s time we distinguish someone who paid for their seat or are a “space tourist” with someone like Neil Armstrong, Buzz Aldrin or Chris Hadfield who make their careers going into space. So, to differientiate I propose the following:

An astrotaxida (from the Greek “astron” (ἄστρον), meaning “star”, and “taxida” (ταξίδια), meaning “wanderer”) is a non-crew person traveling via a human spaceflight program.

I’m not trying to diminish anyone who goes to space, but I do think we should have unique terms for those who work among the stars. We distinguish between airplane pilots and airplane passengers. Let’s move that distinction to the space realm.

I would love to hear your thoughts, find me on Twitter at @n4bfr or Reddit at /u/N4BFR.

Scanning the NASA/SpaceX Crew Demo 2 Launch

Uniden Scanner

With the NASA/SpaceX Crew Demo 2 coming up, I thought it was a good time to revisit the ability to listen to NASA on the radio.

I dug out this Monitoring Times PDF last updated in 2006 to use as a starting point. Other resouces include RadioReference.com, the SpaceX Reddit and some folks at the Johnson Space Center ARC.

If you have any updates or additions please email me at N4BFR at arrl.net.
(Updated 5/27)


Mission Audio

Florida Space Coast

  • 146.940 MHz FM repeater rebroadcasts NASA Audio and Launch information
    (Confirmed February 2020) > http://www.titusvillearc.org/
  • N1KSC plans to relay audio in conjunction with NASA’s Public Affairs office. This will be on 444.925 MHz. > List of Planned Events

Houston

  • W5RRR carried some audio in the shuttle days, but has not yet published if they would carry the DEMO-2 audio. If they do, it would likely be on 146.640 MHz FM.

Space to Ground

The Monitoring Times article lists these frequencies for Space to Ground communications for the US “On-Orbit Segment”

  • S-band
    2265.00 MHz – Downlink (6 MHz Bandwidth)
    2287.5 MHz Telemetry Downlink (Also listed as TDRSS Downlink Frequency)
  • Ku-band
    15.0034 GHz Downlink (100 MHz bandwidth)
  • Ka-band
    22.55-23.55 GHz TDRSS
    25.25-27.50 GHz Proximiy Link / TDRSS

Special Temporary Authority Frequencies

SpaceX (Space Exploration Technologies Corp.) recieves special use permits for some frequencies related to launch. Thanks to Reddit for documenting them. >https://old.reddit.com/r/spacex/wiki/permits/fcc/missions

  • WF9XGI – Telemetry from the Dragon2 Capsule
    • 2203.2 MHz, 2216.0 MHz, 2287.5 MHz “Dragon S-Band Directional Array”
      20 Watts
  • WG9XHP – Telemetry for sub-orbital first stage and orbital second stage.
    • 2247.5 MHz, 2255.5 MHz, 2232.5 MHz, 2272.5 MHz – 3.5 to 4.167 Mbps Signal
  • WJ9FXQ – Autonomous Drone Ship
    • 2090.0 MHz – 600 kbps signal
      One Watt
  • WI2XUB – “Commanding to Spacecraft”
    • 2106.40625 Mhz – 12 Kbps Signal
      One Watt. Authorized for Cape Canaveral including Port Canaveral Recovery Dock Ship, Vandenberg AFB; Kodiak AK; Pensacola FL including Pensacola NAS Dock Ship; Inarajan Guam; Boca Chica TX; Daytona Fl Recovery Location Ship; Jacksonville FL Recovery Location; Panama City Recovery Location; Tallahassee Recovery Location; Tampa Recovery Location.

HF Operations

@MilcomMP on Twitter this morning (5/27) that “Cape Radio” on 10780 Khz is active.

Echolink

For Ham Radio operators, Twitter user @KO4AQF says listen to Echolink node 3082 for NASA.


Monitoring in Brevard County

Digital Trunked

There are several digital trunked systems in Brevard County that show up on the RadioReference.com website of interest > https://www.radioreference.com/apps/db/?ctid=320#cid-7120

  • Kennedy Space Center
    • 406.2375 MHz Primary Control Channel (P25 II)
      Based on the Radio Reference list, this appears to cover talk groupsused for SpaceX, Orion, SLS and other operations frequencies.
  • SpaceX 900 MHz
    • 935-939 MHz (Moto TRBO)
      Radio Reference only reports an “Operations” talk group.
  • SpaceX 400 MHz
    • 464.7375 Primary Control Channel for Cape Canaveral (Moto TRBO)
      Radio Reference lists 2 “Operations” talk groups
  • 45th Space Wing – US Space Force
    • 386.375 MHz Primary Control Channel (P25 I)
      Radio Reference lists mostly security, fire and base operations talk groups.

Associated Frequencies

(Also see NOTAM / NTM information below)

  • Air Traffic Control
    • KXMR – Cape Canaveral AFS Skid Strip
      118.625 MHz AM
      143.150 MHz AM
      239.05 MHz AM
    • KCOF – Patrick SF Station
      133.750 MHz AM Ground
      269.375 MHz Ground
      132.650 MHz AM – Orlando ATC Departure and Arrival
    • TTS – Shuttle Landing Facility
      128.550 MHz AM Tower
      284.000 MHz Tower
      134.95 MHz Orlando ATC Departure and Arrival
    • Aviation Emergency / GUARD frequencies
      121.500 MHz AM
      243.000 MHz
  • Coast Guard Emergency
    • 15.6800 MHz FM

Amateur Radio on the ISS

ARISS is ham radio communications to and from the ISS, not mission audio. This is also used when schools “Talk to an astronaut.” More on ARISS > https://www.ariss.org/

  • 145.800 MHz FM Voice & Slow Scan TV Repeater Downlink
    • 145.490 MHz Voice Uplink (Americas, Pacific, S. Asia)
    • 145.200 MHz Voice Uplink (Europe, Russia, Africa)
  • 145.825 MHz Packet Uplink and Downlink
  • 437.550 Mhz Packet Uplink and Downlink
  • 437.800 Mhz Repeater Downlink
    • 145.990 MHz Repeater Uplink (Requires PL of 67 Hz)

Notice to Mariners / Notice to Airmen

Because of risks to aviation and marine traffic, notices are published to avoid the areas of launch and rocket landing. While not specifically radio related they may at times carry frequency information.

USCG District 7 reports in LMN07202020

ATLANTIC OCEAN - FLORIDA - CAPE CANAVERAL: EASTERN RANGE OP# X0053 FALCON 9 CREW DEMO-2

Eastern range will be conducting hazardous operations surface to unlimited within portions of Warning Areas W497A, W497B, W137F/G, W138E,W139E/F, W140, W141, W122 and the following Hazard Areas. 

THIS IS A MANNED SPACE LAUNCH

A: From 2838 25.89N 8037 17.06W
TO 2839N 8037W
TO 2901N 8014W
TO 2858N 8011W
TO 2834N 8029W
TO 2833 32.69N 8034 1.72W to beginning

B: From 3122N 7744W
TO 3201N 7716W
TO 3218N 7641W
TO 3212N 7634W
TO 3142N 7652W
TO 3117N 7740W to beginning

Hazard periods for primary launch day and backup launch days;
Primary launch day: 27 / 2022Z thru 27 / 2107Z May 20. Preferred T-0 is 2032Z.
Backup launch day (1): 30 / 1911Z thru 30 / 1956Z May 20. Preferred T-0 is 1921Z.
Backup launch day (2): 31 / 1849Z thru 31 / 1934Z May 20. Preferred T-0 is 1859Z.

Related Frequency Information:

If a vessel equipped with AIS is determined to be entering the launch hazard area, an addressed safety message 14 with the text "REGULATED
AREA 33 CFR 165.775 ACTIVE STAY CLEAR" will be transmitted to the vessel. All provisions of the safety zone remain in effect; no person or vessel may enter, pass through or remain within the safety zone unless authorized by the Captain of the Port. Mariners are required to contact the Coast Guard via VHF FM channel 16 to arrange for this authorization.

Marine Channel 16 is on 156.800 MHz using FM modulation.

The FAA has published Facility ZJX (Jacksonville Center) NOTAM 0/1729 for 5/27/20. It reads in part:

!FDC 0/1729 ZJX PART 1 OF 6 FL..AIRSPACE CAPE CANAVERAL, FL..TEMPORARY FLIGHT RESTRICTIONS. 
MAY 27, 2020 LOCAL. 
PURSUANT TO 49 USC 40103(B)(3), THE FEDERAL AVIATION ADMINISTRATION (FAA) CLASSIFIES THE AIRSPACE DEFINED IN THIS NOTAM AS 'NATIONAL DEFENSE AIRSPACE'. PILOTS WHO DO NOT ADHERE TO THE FOLLOWING PROCEDURES MAY BE INTERCEPTED, DETAINED AND INTERVIEWED BY LAW ENFORCEMENT/SECURITY PERSONNEL. ANY OF THE FOLLOWING ADDITIONAL ACTIONS MAY ALSO BE TAKEN AGAINST A PILOT WHO DOES NOT COMPLY WITH THE REQUIREMENTS OR ANY SPECIAL INSTRUCTIONS OR PROCEDURES ANNOUNCED IN THIS NOTAM

...

THE FOLLOWING OPERATIONS ARE NOT AUTHORIZED WITHIN THIS TFR: FLIGHT TRAINING, PRACTICE INSTRUMENT APPROACHES, AEROBATIC FLIGHT, GLIDER OPERATIONS, SEAPLANE OPERATIONS, PARACHUTE OPERATIONS, ULTRALIGHT, HANG GLIDING, BALLOON OPERATIONS, AGRICULTURE/CROP DUSTING, ANIMAL POPULATION CONTROL FLIGHT OPERATIONS, BANNER TOWING OPERATIONS, SIGHTSEEING OPERATIONS, MAINTENANCE TEST FLIGHTS, MODEL AIRCRAFT OPERATIONS, MODEL ROCKETRY, UNMANNED AIRCRAFT SYSTEMS (UAS), AND UTILITY AND PIPELINE SURVEY

No specific frequencies are given, but the Aviation “GUARD” frequencies are 121.500 MHz AM for civil aviation and 243.0 for Military.

Excited for SpaceX Manned Launch

I have been looking forward to seeing SpaceX launch someone into space for years. I distinctly remember a conversation with my old boss saying, “This is happening soon, and I will be taking time off to go and watch.”

Well, with the world of social distancing I may not be able to get down to the Space Coast, but I have been watching all the press conferences and reading all the #LaunchAmerica tweets. With so many changes, that motivated me to produce a video about the event with all the changes from the shuttle days and a few other interesting items.

I hope you enjoy it! Please share with your friend and leave video comments or write me on Facebook https://www.facebook.com/N4BFRVision/ and Twitter @n4bfr_vision.

Follow Friday

I have been heavily into the YouTube thing over the last few months, and I have some old and new favorites. Enjoy this week’s nerd-heavy list of things to watch.

SpaceX

Want to watch cool rocket stuff regularly? SpaceX is about to become the first American company to send american Astronauts to the ISS in over 10 years. Plus their launching an internet satellite constellation and working on this little “trip to Mars” thing.

The Modern Rogue

This has a “Mythbusters meets Magic and other Scams” vibe as two “Professional Idiots” do things like making homemade thermite to cook steaks, play with RFID, discuss everyday carry items and even a little ham radio.

The Lockpicking Lawyer

The Lockpicking Lawyer has an artists touch. His videos are super basic, pretty much a camera and a lock, but he gives you a lot of different insights on build quality and how some things are safer than others (avoid TSA locks). Great way to get under the mechanics of how these things work in our daily lives.

Techmoan

I think he’s most well known for his camera reviews, but I really get into all the retro-tech items that he covers. This particular video shows a German 8-track style record player, but he’s covered old computers, hi-fi and phones as well.

TWIT

I feel like Leo Laporte is my older “brother from another mother.” He’s successfully put together a podcast network, TWIT, that covers tech news, photography, internet security, Apple, Android and more every week. I greatly enjoy his Tech Guy radio show podcasts every Saturday and Sunday.

And a plug for me

Part photography, part ham radio and Raspberry Pi tech, part cat videos, Space stuff, just what interests me that day. I’m having fun sharing and making new stuff, so please subscribe just to see what the hell I am going to do next.

More next week!

Space “Fan” Milestones

Somewhere there is a Polaroid my father took of our TV in New Milford Connecticut. It shows Apollo 11 landing on the moon in 1969. You can say I’ve been a space fan since then.

In the last few years I have tried to step up my game a bit and I think I am doing OK. I thought it might be nice to track a few of my space fandom milestones.

Visits to “Space Centers”
– Kennedy Space Center – December 2019
– Space Center Houston – February 2020
– Space & Rocket Center Huntsville – August 2014
– Kansas Cosmosphere – Circa 2000

Moon Rocks Touched
– Kennedy Space Center – December 2019
– Space Center Houston – February 2020
Smithsonian – To Be Accomplished

Space Shuttles Visited
– Discovery, June 2015, Udvar-Hazy Center, Fairfax, VA. (OV-103)
– Enterprise, June 2019, Intrepid Air and Space Museum NYC (OV-101)
– Atlantis, December 2019, Kennedy Space Center, Florida. (OV-104)
Endeavour, To Be Accomplished, California Science Center (OV-105)
– Replicas: Kansas Cosmosphere, Johnson Space Center (Independence), Space and Rocket Center (Pathfinder)
– Special Mention: NASA 747 Shuttle Ferry Plane – N905NA

Apollo Command Modules Visited
– Apollo 11 – Kennedy Space Center
– Apollo 17 – Space Center Houston

Apollo 11 – Kennedy Space Center
Apollo 17 – Space Center Houston

More to come.


Challenger Memorial & Mother Earth Sculpture

Google Photos Album: https://photos.app.goo.gl/4dnuxQbSfUQpS8Aj6

Took a ride about 2 miles from the hotel to see the Challenger 7 Memorial Park in the suburbs of Houston. I found a huge park (at least by my standards) with this memorial placed prominently. – More pictures in the link –

In one of those “Let’s see what else is in the park” moments we came across signs for the “Mother Earth Sculpture.”

No wild hogs were seen.

The sculpture is a clay rendering of Mother Earth laying on her back, covered by grass, looking up at the heavens. Check the album for pictures, but definitely not what I expected near an astronaut memorial.