Page 89 - 6748

b Manfred Haug, an aeronautical engineer, is describing his early rocket experiments.
Read the description and explain what is meant by the expressions in bold.
Relying on trial and error isn’t always the best way to improve technology, but I found it was
an effective way to develop rockets. Especially as rocket science was unfamiliar territory for
me. I was on a steep learning curve, hence the numerous explosions.

c Read more of the description. What kinds of rocket did they build and how do you think
they worked?
I should say that this had nothing to do with NASA, and happened a long way from Cape
Canaveral. It was just me and a few friends on a windswept football field near Hamburg. But the
plastic bottle water rockets we built and launched went through an impressive R&D programme,
bearing in mind we were only 12 years old!

8a ►9.3 Read an interview with Manfred about building and launching water rockets and
answer the following questions.
1 How full were the bottles?
2 What coincidence was helpful?
3 How powerful was the rocket?
4 What problem occurred?

Manfred: The first time we launched one of these things, er, we basically just got a plastic
washing-up liquid bottle, filled it about half full of water, then pumped it up with an ordinary
foot pump.
Interviewer: So it was just ordinary household stuff?
Manfred: Oh, yeah, nothing too technical.
And, actually, there was a bit of a coincidence, because the opening in the bottle was just slightly
bigger than the fitting at the end of the pump, so there was quite a good seal. So we pumped it up
- one of us held the bottle while someone else worked the pump. And we released it, and it went
up, literally, like a rocket. I mean, we expected it would shoot up reasonably fast, but we didn’t
anticipate just how powerful it would be. It just went whoosh and totally exceeded our
expectations. So you can imagine us, a group of 12-year-olds, we were absolutely ecstatic. And
having said that, there was one problem. Once all the water had come out, which happened
virtually in a split-second, the bottle - because it was very light - started tumbling over in the air.
Interviewer: So it wouldn’t fly straight?
Manfred: That’s right. But we quickly came up with a solution to that problem.

b Read the following extracts from the interview. What is meant by the words in bold?
1 ... we expected it would shoot up reasonably fast...
2 ...we didn’t anticipate just how powerful it would be.
3 It totally exceeded our expectations.

9a In pairs, discuss two or three solutions to the problem experienced with the rocket,
based on basic materials and simple assembly techniques. For each potential solution,
explain how you would expect the rocket to perform and why, describing potential
problems for each solution.

b ► 9.4 Manfred goes on to describe how he and his friends solved the problem. Read the
description and summarise the solution, explaining why it was effective. How does the
solution compare with your ideas in Exercise 9a?

Manfred: What we did was to get a plastic cup, a strong one not a disposable cup, and pushed it

87