Scott Tilley

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Chang'e 6 remains active in its very distant HEO of the Earth.

In fact it is passing by the Moon just outside the eclipsed area tonight. Imagine below at peak lunar eclipse at 11:34UTC.

A new space race could turn our atmosphere into a ‘crematorium for satellites’ Planned ‘megaconstellations’ of satellites could cause unforeseen harm to the ozone layer and climate systems. Global regulation is needed before it’s too late.

Excellent piece from @astrokiwi.bsky.social @sundogplanets.mastodon.social.ap.brid.gy & Laura Revell.

This one sentence is the crux of it all 👇

"There is no public mandate for a single company in one country to make changes on that scale to the planet’s atmosphere."

Highly recommended.

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There and Back Again INDEED!

We seem to have caught DRO-B returning its twin DRO-A in DRO of the Moon after documenting a journey to the Lonely Mountain and back.

Nice catch my Graham G8FXB!

Observing Schedules Weekly JWST observing schedules organized by cycle

70cm sensor would be tough but possible with JWST in perfect conditions and setup. JWST has a very modest signal at S-band.

Schedule here:
www.stsci.edu/jwst/science...

DRO-B appears to have returned to DRO orbit of the Moon after it's wander to a 3:2 resonance touring EM L3-L5 orbit in Spring 2025. Then is took to a high Earth orbit in Fall 2025 and back this winter. Graham G8FXB picked it back up on a routine monitoring of KPLO the other day.

Tuning up for @NASAArtemis
using JWST’s S-band emission. Its schedule is public.

Its motion is in the Doppler.

Overlay the two and they match.

Spacecraft geometry, revealed in RF. 📡🛰️✨

Unless you are changing the vantage point of observation in a systemic way. OR! You are beginning a new lower fuel burn station keeping model to prolong their operational lives (most likely).

Based on the orbital data alone, the change in apogee drift looks deliberate. RF behaviour across the EKS/TUNDRA constellation remains nominal, with no shift in emissions or operating pattern. That strongly suggests this is an operational adjustment rather than a failure. 🛑

Three of the EKS/TUNDRA missions appear to have conducted a co-ordinated end of their westward apogee drift. COSMOS 2552 data hasn't been updated since mid-January before this tend became obvious in @SpaceTrackOrg data.⬇️

In January @russianforces.org pointed out odd behaviour from the Russian ELS/TUNDRA satellite early warning system. The co-ordinated westward drift in apogee longitude appears to have ended in a co-ordinated manner. 🧵⬇️

bsky.app/profile/coas...

I finally observed IBEX the other day on S-Band. It appears to dump for an hour then turn off. It uses 320 and 160ksps. The latter at levels I could decode and confirm the spacecraft ID using @aang23.satdump.org's satdump once I tuned up a pipeline to do it.

SCID = 0x02A7

CHANG'E 6 has given me the slip!

After an extensive search yesterday, I wasn't able to find in anywhere close or far from it's expected trajectory or around the Moon.

I suspect the last known orbit was a transfer orbit into some sort of Earth/Moon resonance orbit...

NASA enlists Canadians to help track Artemis 2 Moon mission NASA enlists Canadian agencies and volunteers to help track Artemis 2 as the Deep Space Network faces scheduling pressures.

NASA enlists Canadians to help track Artemis 2 Moon mission spaceq.ca/nasa-enlists...

Indeed. I didn’t think much of it until I used it and saw what it can do. For a causal telescope to explore the sky it is pretty cool!

Jude and I go adventurous with the Seestar S50 and used the framing feature to do a deep dive into Markarian’s Chain.

NASA Selects Participants to Track Artemis II Mission - NASA NASA has selected 34 global volunteers to track the Orion spacecraft during the crewed Artemis II mission’s journey around the Moon.

NASA Selects Participants to Track Artemis II Mission.

www.nasa.gov/technology/s...

The PRS10 uses it's Rb reference to steer its own low phase noise SC-cut VXCO and then provides a highly stabilized 1PPS reference to the Ettus B200 without all the short term noise from the Bodnar LPE-1420.
Providing highly stable timing and frequency w/ low jitter/phase noise🛑

Experimented with a few different setups and found that the Bodnar LPE-1420 with FLL OFF gave the best long term stability and as you can see in that region the Rb standard wants to start to drift. So that's why the PRS10 as it allows me to discipline the Rb where it needs it.⬇️

Timing and frequency reference is feed into the Ettus B200 to allow for control of the start of IQ recording and ensure the B200 is disciplined to the Rubidium standard. I can monitor performance during the mission from both reference devices. ⬇️

The Bodnar GPSDO is used to keep the PRS10 long term stable as it's good at that. Meanwhile the PRS10 Rubidium standard with it's SC-cut quartz oscillator provides excellent short and medium term stability and low phase noise.⬇️

Testing systems for #Artemis2 data collection by decoding KPLO in lunar orbit.

I'll be using the Ettus B200 referenced with my Stanford Research PRS10 Rb standard which is disciplined with a Bodnar LPE-1420 for the Artemis Doppler gather mission. 🧵⬇️

AMSAT-CA is in the process of launching as a Canadian amateur radio satellite organization. Members of that community, myself included, are actively contributing technical work relevant to missions like Artemis II as it informs our strategic vision. 🛑
amsat-ca.org
Image

Some of the reporting here will be straightforward status updates. Some will go deeper—technical observations as we push the limits of what can be independently observed and analyzed from the ground. Catch up on our Artemis 2 participation here: github.com/ScottTilley/...
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This mission includes Canadian astronaut Jeremy Hansen (@Astro_Jeremy), marking Canada’s first participation in a crewed lunar mission. The Canadian Space Agency has released details on the current Artemis II launch opportunities.⬇️
www.asc-csa.gc.ca/eng/news/art...

Artemis II - NASA Four astronauts will fly around the Moon to test NASA's foundational human deep space exploration capabilities, the Space Launch System rocket and Orion spacecraft, for the first time with crew.

Artemis II launch preparations are accelerating, with launch windows now being released. We’ll be monitoring the mission closely and sharing updates here as they become available.🧵⬇️
www.nasa.gov/mission/arte...

Finally, measured timings differ significantly from predictions based on an aging Dec 29, 2025 state vector. Most likely due to the fairly short arc of data used to develop the orbital model. Or maybe a burn occurred at some point between then and now? 🛑

That envelope-defined, phase-beating transition appears only at loss and recovery, exactly what partial lunar obstruction produces.
Result: confirmed lunar occultation 😉📡🌖🛰️

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No distinct fringes doesn’t mean no diffraction.
Instead, we pivoted to a low-SNR method:

IQ → mix → low-pass → decimate → |IQ|.

At ingress/egress, phase-beating between the direct and edge-diffracted fields produces a brief amplitude “bump.” 🤯⬇️

You’d expect classic Fresnel diffraction fringes at lunar occultation edges. We looked carefully and did not observe clear fringes. Low SNR and a very short partial-obstruction interval prevented a clean fringe train from forming in the data. 🤔⬇️
x.com/coastal8049/...