Local boy’s rocket a triumph; few casualties.

There is a chance this post won’t indirectly be about Florence; I know I go on, but I’m proud of her.  I also know there is no need to talk about her all the time.  Anyway, Florence can count backwards from 5.  After that she shouts ‘Blast-off!’  Yes, I have been playing with rockets.  Well, sort of playing; there is a serious side to it.  I was persuaded, I forget how, but I was persuaded to enter a team in to the National Physical Laboratory’s Water Rocket Challenge.  Fine I thought.  I came up with the team name of ‘One Giant Beep’, paid my entrance fee (it’s a charity event) and read a few sites on the principles of bottle rockets.  Then the problems started.

My god!  The tech!  I know they’re just bottles with water, and air that’s been squashed, but the stuff you can get?  Strap on boosters, multi stagers, flight computers.  No really.  Flight.  Computers.  I’ll let that sink in for a bit.  Of course, lacking supervision, all of this was very tempting.  A serious case of engineers blight was about to ensue; then there was a week and a half to go and we had not even bought a bottle as a starting point!

So, I’ll say now, in print, that next year’s entry will be a two stage rocket with side boosters.  The nose will have an HD camera and parachute, and the whole thing will be instrumented with live video and telemetry being streamed in flight on to the internet.  I’m trying to learn Java (post on that coming) so this will give me a proper goal.

This year we have a Tesco lemonade bottle painted green.  But my, does it fly!

With only days left the first prototype was ready; a coke bottle with cardboard fins taped on.  I had bought a launcher off eBay to save on development time, so we headed to a field and disappointment.  With a whoosh it set of quickly, tumbled for a bit, lost all its airspeed, and fell a few feet from where we started.  Oh dear.  There was only one thing for it.

Science!

One of our team members is ten years old, and the idea of this competition is to teach them a thing or two, and besides I am a STEM ambassador, so I must hold aloft the sword of knowledge and shout ‘by the power of Newton’.  Rockets, you see, are pure third law.  The water is the reaction mass, the compressed air the energy store.  Make the water leave suddenly in the down direction and the rocket leaves suddenly in the up; equal and opposite, and in our case, tumble and crash.  Rockets that tumble do so because the centre of mass is behind the centre of pressure; that’s aerodynamic pressure.  So you need to move the mass forward, which I did by taping pennies inside the nose, and the pressure backwards with bigger fins.  I went for curved, Flash Gordon fins.  And painted the whole thing in neon colours.

Our first two test flights were awesome; good height, long range, and straight, and so as is the way of space programs, I junked the prototypes and cut them up to make nose cones for our shiny new fleet.  I’d gone for detachable nose cones so we could replace them after each flight if necessary, since with the coins up front the thing comes down like a jdam.  The fins are attached to a removable ring so that the whole assembly can be swapped should it receive critical damage.

The big day arrived, and so did the team t-shirts.  Yes, I understand I may have been taking it a bit seriously, but that has always been my nature.  If an engineer doesn't take making something seriously then… well I don’t know what that is as it’s never happened.

Resplendent in our matching shirts we made our way in Madge to London’s low emission zone.  I've not been sent my hundred pound bill yet for daring to approach my own capital; we shall wait and see.   I've driven past the NPL a few times, but never had cause to enter, but now having lost my NPL cherry, I can honestly say this is one of the best things I have been to in a long time.  It was fantastically well organised, and a pleasure from end to end and the NPL staff who volunteer were clearly enjoying it too, despite having been stood in a playing field for ten hours at that point.  Next year we’re all going; children, wives, the lot.

That day, firing station 17 became the scene of triumph and tragedy.  Our first launch was right on the mark, and we were in third place at the end of round one.  The scoring system is as simple as it is subtle.  Different areas of the field are worth different points, and the number of seconds in the air is simply added to points you land on.  The area furthest is not worth the most points, but getting there does give an impressive flight time.  Do you aim for the highest point zone and risk missing it, or just go for maximum parabola?

We had three fuselages with us so we shot them all off, each flying well, but betraying a flaw in the tail fixings.  Round two and with fresh duct tape we launched, turned hard left and fell short.  Nooooo!!  Nothing to do but carry on; keep putting them down range and learn.

By round three we were confident and ready, our launch protocol well-rehearsed.  The expendable members of my team were positioned closest to the rocket.  Garry, who is not water soluble lying, on the ground holding the launch tube itself, and Tyler, mud stained but enthusiastic, pulling the pin out from directly behind in the back wash.

Our drill pays off and we drop straight in to the twenty point zone.  Having run at sixty pounds per square inch all day we try seventy and hit the bulls eye thirty point zone.  For the very last flight of the day we take it past eighty, and moments after launch the hull implodes.  Brave Fireball XL3 had given all it had.

Filled with the satisfaction of a grand day we made our way to the prize giving, seventh out of seventeen, a darn good showing for a raw team.  But then an honour, a double honour; we win the design award for modular construction, but more importantly, most luminous rocket!