5th April 2010 – Discovery mission to the International Space Station
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2:04 “At the dock the shuttle weighed more than 4.5 million pounds…” That’s 2,000 tonnes for those of us at least semi-metric in outlook. In the first 90 seconds of the flight the shuttle burns 1,000 tonnes of fuel.
2:45 The solid fuel booster rockets separate at this point. Now the shuttle uses her own engines and burns fuel from the huge tank of liquid hydrogen and liquid oxygen strapped to her underside.
3:21 “Discovery. Two engine TAL” At this point, if one engine fails, they can still land the shuttle in Morón de la Frontera, a town in Andalusia, Spain, and jolly nice at this time of year. TAL stands for Transoceanic Abort Landing – gosh I love a good acronym.
4:35 “Discovery. Houston. You are negative return.” What a message! This is the point at which the shuttle is at a distance and speed from which it is impossible to return safely anywhere on earth if an engine were to fail. I am going to adopt a similar phrase for missing work. “Jones. Randolph. You are negative prep.” At this point the only option is escape to orbit.
7:00 The shuttle is now licking along at a healthy 16,000 kph at an altitude of about 100 kilometres. The silence is broken only by a list of places now reachable with different numbers of engines…
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Zaragoza on one engine
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Low orbit on two engines
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Back across the atlantic on no engines
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What happened to negative return? I’m confused…
9:20 “Discovery. Houston. Nominal MECO, OMS 1 – not required.” So the Main Engine Cut off was successful and no trajectory alteration with the Orbital Manouvering System was required – but you knew that, right?
9:24 The huge fuel tank is successfully ejected as the shuttle reaches orbit at 106 km above the Earth’s surface travelling at over 27,360 kph.
What a few days it has been for science. The LHC has collided protons at 7 trillion electron volts and has been able to detect the consequences of the collisions. Discovery has made it into space to visit the International Space Station. The importance and profound nature of these achievements is difficult to put into words.
You can do your bit to make sure that we continue to push back the boundaries of our understanding. As a country we spend a very tiny proportion of our budget on funding science research but we reap perhaps as much as 30% of our income (GDP) from science. With a little more investment we could become the number one science nation in the world. Perhaps, with a general election looming, we should all be asking our MPs and rival candidates how they feel about the future of science in the UK.
Questions…
- The main engines burn a mixture of liquid oxygen and liquid hydrogen. What will be the product of this combustion?
- What technique is probably used to extract the pure oxygen from air?
- Why does it take less fuel to accelerate a rocket in space than it does on Earth?
- There are plans for a manned mission to Mars. What might be some of the problems that will need to be overcome for such a mission to be successful?
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