A treat of a challenge - a rocket to lift up an egg, and some mechanism to keep the egg intact.
I'm using water under pressure as a propellant, Mikey B is using gas and Jonathan using steam.
Jonathan isn't sounding enthusiastic about steam, but he's giving it a go. Mikey B is working like a trooper again, missing lunch to keep working. And I'm getting to play around with a bike pump, a ridiculous spanner-release system and empty plastic drinks bottles.
It's stonkingly good fun. The crew and production team can barely keep their hands off, they so badly want to make rockets too. Kate's enjoying it enormously as well - and we all just keep getting covered with water: me , Ellen, Kate, Iain, the crews, and the cameras.
Need to combine the parachute with the rocket, so chat with Ellen and Iain to tie the two together - to make sure the rocket's big enough, the parachute can fit in and is able to bring it all back to Earth.
Really fun all working together like this, and it's great to finally get the chance to work with Ellen again. It feels good to all be working towards the same goal.
At the start of the day it seemed like it should all be so easy. Ellen and Ian's parachute worked and needs about five metres to deploy. My rocket which went up over 20 metres and Mike B and Jonathan's rockets may have even got even higher. So putting a parachute and rocket together should have been easy. We "just" had to find some way to make sure the parachute got deployed at the top of the rocket's path.
"Just" ... We thought it should be easy, and it just wouldn't do it. Either the cap holding the parachute came off too early and didn't make it to the top of the trajectory; or it stuck determinedly on.
We tried all sorts of different ways of fixing it, gently reducing and increasing the friction between the cap of the parachute and the rocket. Ian, unable to resist incorporating rock into the final design, started throwing dirt onto the whole rocket, to increase the friction between the cap and rocket body.
The production team really wanted me to build a better launcher. A better launcher would mean we could get to higher water pressures, which would mean the rocket would go higher, which would be more dramatic. But I thought, "What's the point?". We have to crack the parachute deployment mechanism first, or we'll lose the egg whatever height we get to.
Absurd to get so het up and excited about something as ridiculous as an egg ... but that's how it goes with this series. We all care so much about making it work - the programmes, the challenges, for the science to be shown clearly - that we'll go to insane lengths for small things. I worry a lot about it all ending up too much like a 'Famous Five' episode, with so much enthusiasm and eagerness. We're all so damn goodie-goodie. But we can hardly pretend not to care; we all do so much!
It's been an astonishing trip - almost everyone, even the two film crews who do "trips" for a living, is saying it's the best work trip they've ever been on. Truly special. So, whether 'Famous Five' or not, I hope the passion we all feel for it comes over in the series. Without us all seeming like mad scientists.
And – in the last vestiges of warm evening light, we try for real. We have one attempt. The parachute has only deployed a couple of times at the top of the rocket’s flight...and that was without the egg in the rocket. We’re unconvinced it’ll work when it’s for real. But, we can’t stay perfecting it all night.
... and it works. The parachute flies, the egg survives, and I can almost weep with delight at this special feat, done with this special bunch of people.