HAMNET Report 10th October 2021

Here’s a problem that hadn’t dawned on me before, and which is going to prevent future Mars explorers from easily phoning home.

It appears that every two years Mars and Earth end up on opposite sides of the Sun at a distance of 245 million miles in what is called a Mars solar conjunction.

During this conjunction, in Earth’s sky, Mars is close to the Sun, as the Earth is close to the Sun in the Martian sky. This is more than a bit of astronomical trivia; it’s also a major headache for space engineers. Mars doesn’t actually pass behind the Sun, but it is close enough for the Sun to interfere with radio communications between the two planets. Not only does it take 22 minutes for a radio signal to travel one way between Earth and Mars, but the proximity of the Sun affects communications because it is a major radio wave emitter and the ionized gas that makes up its giant corona acts like a barrier to radio signals.

Though this solar interference isn’t total, it can degrade communications to the point where data and command signals can be distorted and might cause robotic spacecraft to start acting in unpredictable ways – which is something you definitely don’t want to happen on a hostile alien planet hundreds of millions of miles away.

To prevent this, NASA mission control will stop sending signals after ordering its Mars spacecraft to go into a go-slow mode until the conjunction passes. Give or take a couple of days for particular missions, the communications shutdown will start on October 2 and end around October 16.

Though mission control will not be sending signals, the probes will send status updates and some data back to Earth at a low transmission rate. During this time, the Perseverance and Curiosity rovers will sit still and take weather, radiation, and other sensor measurements, the Ingenuity Mars helicopter will be grounded, and the InSight lander will continue seismic measurements. Meanwhile the Odyssey, Mars Reconnaissance Orbiter, and MAVEN orbiters will gather data and relay transmissions from the surface.

Once the conjunction is over, the spacecraft will transmit their backlog of images and other data to Earth through NASA’s Deep Space Network for about a week before resuming normal operations.

Thank you to New Atlas for this revelation to me.

The ARRL says that the oft-cited figure of 3 million radio amateurs worldwide may need updating. That number was what the International Amateur Radio Union (IARU) published in 2000 for the global head count. The IARU once regularly collected amateur radio population statistics, but stopped the practice around the point when the worldwide amateur radio population began to decline.

Data available elsewhere for a few major countries shows a steady decline in radio amateurs since 2000, with the exception of the US, where ham licenses — not necessarily licensees — number some 780,000 to date in 2021. Japan’s ham radio population has dropped by more than 600,000 over the past 2 decades; as of 2015, it was 435,581, according to JARL. China boasts more than 174,000 radio amateurs as of 2021. According to 2018 statistics, Thailand has 101,763 hams; the UK has 75,660, and Canada has 70,198.

But, the specific size of the worldwide amateur radio population remains open to speculation, although a 2021 figure of 1.75 million may be closer to the truth. The ARRL thanks Southgate Amateur Radio News, and other sources for these details.

Evidence that South African sporting life may just be returning to some semblance of normality comes in the invitation in Cape Town, from the organisers of the annual 99er Cycle Tour, to HAMNET to assist at next year’s event, to be held on 12th February, if the wretched Coronavirus will let it. We are hoping it will take place, having missed 2021’s event because of COVID-19. In 2020, the race happened just before the disease took off in South Africa. Let’s hope 2022 will signal a return to relative sporting freedom.

The Western Cape Repeater Working Group is running a raffle to raise funds to assist with the maintenance and repair of the repeaters they manage. Tickets are R50 each, and the lucky one whose ticket is drawn will win a brand new Baofeng UV-R 9 Plus, donated by ZS1DDK and ZS1F. If you buy two tickets for R100, you’ll get three chances in the draw, so don’t delay. Use your call sign and UV9 as a reference when you make an EFT into the Working Group’s bank account, which is available on www.wcrwg.co.za  The draw will take place once 100 tickets have been sold!

Here’s a doggy rescue story to end this week’s bulletin.

A pug sparked a widespread rescue mission involving two coastguard teams and a social media campaign after it got stuck in the mud.

The dog went missing near Rhyl’s promenade in North Wales and an online appeal found its way to both Rhyl and Flintshire coastguard teams who sprung to action.

The dog’s family was greatly concerned over his whereabouts, especially 12-year-old James, who is autistic and relies on Buddy to keep his anxiety levels low.

Thankfully, Buddy was soon found near the River Clwyd where it was discovered he had become stuck in the mud.

Rescuers were able to free him allowing owner Sarah to share the good news on Facebook.

Speaking to North Wales Live, she said: “I would just like to say thank you to everyone from the bottom of our hearts. We are over the moon with finding Buddy and James is the happiest boy alive right now.

“Nobody ever gave up and they travelled out to help look, they phoned, visited, messaged and shared anything they could to help.

“We were given the best support anyone could wish for, so thank you to everyone; you kept me going all night and day.”

After his ordeal, Buddy was given a much-needed bath.

Sarah added: “James and Buddy have been snuggling since being back together and slept right through the night.

“Buddy means the world to the entire family and helps keep James calm and his anxiety levels low, giving him comfort and making James feel safe.”

I’m sure you’ll agree this is altogether a better story than last week!

This is Dave Reece ZS1DFR Reporting for HAMNET in South Africa.