July 17. Four days before we leave for Moscow, Dave calls. “You’re not going to like this,” he says. “The sat phone weighs 15kg.”

I don’t like it at all. With the canoe, that’s our 20kg baggage allowance gone.

The trouble is, we need both - the canoe to get us down the Armu River and the phone to do the job we hired ourselves out to do: videoconferencing with summer schools in the UK. At prearranged times during our journey through the Siberian forest we will find a scenic location and call pupils back home to chat about the exploration project they’ll be doing over the summer break.

Along with various activities they’ll be working on, they’ll get the chance to interact with “real” explorers on location, maybe even make some suggestions about our route or give us some ideas on where we can forage for food. There’s potential for all sorts of things to happen, albeit by proxy: live encounters with some of the wildlife, even the experience of negotiating river rapids with us in “real time”.

To do all this needs a lot of fancy equipment. We’ll be smiling at a webcam wired to a laptop, which is in turn wired to the oversized satellite phone.

Power will come from a weighty storage battery, charged up (weather permitting) by solar cells. To get the power input to each piece of hardware involves various black boxes, all of which seem to be connected by their own leads (no logical simplicity of “one connection fits all” here).

If all this technology works, it should be great. It worries me that we will be lugging a lot of equipment in hostile conditions. I’m also concerned as to how we are going to get it to Vladivostok.

Dave and I agree to be ruthless. The suitcase and packaging for the satellite phone can go. Then we cut luxuries - shampoo and towels. And no more than two sets of clothes (one for day, the other for night). We’re still packing a lot of weight.

July 22. We’ve made it to Moscow - with all the equipment. We dump everything in left luggage and take a bus and the metro to the city centre - not easy as stations with undecipherable names fly past. We get off at one that looks on the map to be fairly central and head south. Luckily the plan works and Red Square is only a couple of blocks away. It’s too early to get in, so we circumnavigate it and trek miles of wide streets with imposing buildings and fountains. Moscow is impressive and very hot today.

It’s a shame all the cars are BMWs and Toyotas. I was expecting black sedans, Ladas and Trabants. That’s globalisation for you.

Tomorrow - Vladivostok.

Simon Chapman is head of physics at Morecambe high school, Lancashire, and author of The Monster of the Madidi (Aurum Press) and the Explorers Wanted! series for children (Egmont). Throughout his expedition he will be videoconferencing with summer schools in Knowsley via satellite phone. You can follow him every week in The TES