SpaceX rocket launches era of private spaceflight
Three, two, one, take-off: a new frontier was breached yesterday with the launch of the first commercial cargo flight to space. Its destination is the International Space Station.
Yesterday morning at 3.44am, a SpaceX Falcon 9 rocket roared away from its mooring in Cape Canaveral, Florida. Slowly, the 55-metre cylinder faded to an orange speck and disappeared into the night sky. Loaded with food and supplies, the ‘Dragon’ spacecraft at the rocket’s tip is now hurtling towards the International Space Station.
This is a milestone in the history of space travel: the Dragon, with its load of food and supplies, is the first ever cargo space flight by a commercial organisation. Private companies will soon be carrying not only food, but astronauts – and perhaps even tourists.
SpaceX spent over $300 million developing the rocket; and each launch costs around $50 million. ‘Space,’ as a rival executive puts it, ‘is hard.’ But why?
Because space is a long way off. With gravity constantly working to pull the rocket back to Earth, an enormous upward force must be created to propel the rocket into space. And creating this force takes fuel – lots of it.
The entire Falcon 9 rocket is packed with super-cooled liquid oxygen and kerosene – two of the most combustible materials in the world. As they burn, they create a constant explosion directed at the Earth. As Isaac Newton‘s famous third law of motion dictates, every action has an equal and opposite reaction: the downward explosion triggers an upward thrust, forcing the rocket towards the sky.
Since the Falcon 9 weighs 340 tonnes – equivalent to 300 cars – an unbelievable amount of energy is needed. And paradoxically, the fuel itself is a heavy burden: it is both essential for lift-off, and a major obstacle.
To counter this, the rocket is split into two ‘stages.’ After 170 seconds, the first stage runs out of fuel, detaches, and plummets into the Pacific. Then the secondary thrusters fire up. Once the rocket has exited the atmosphere, these too detach, leaving the tiny Dragon spacecraft alone in the endless vacuum of space.
Each voyage is a monumental effort, consuming over $200,000 worth of fuel. Unsurprisingly, many scientists are keen to find alternatives. The ‘space elevator’ is one idea: a capsule attached to a cable that could zoom passengers into orbit from the equator. Or even more outlandish, the ‘orbital ring’ – a cosmic train track encircling the entire globe.
A blank space
Space enthusiasts are thrilled. Soon, they say, rockets will be buzzing around our Earth, carrying everything from wide-eyed tourists to nuclear waste.
Not so fast, say sceptics: do we really want to clutter up our atmosphere with more needless satellites and trash? We have done more than enough damage by polluting Earth, they say – leave the rest of the solar system in peace.
- How much would you pay for a trip into orbit?
- Is there anything wrong with filling the solar system with litter?
- Choose a spacecraft from science fiction and compare it to the Falcon 9. What are the main differences? Why?
- Design an experiment to demonstrate the main principle of rocketry: creating a strong downward force to propel an object into the air. You can use any objects or materials you like – you do not have to carry out the experiment yourself.
Some People Say...
“Any place that humans set foot, we spoil and pollute.”
What do you think?
Q & A
- So what if there’s rubbish in space? It’s not like anybody lives there...
- Aside from the problems some people have with polluting untouched regions of the universe, space debris also presents some more tangible problems. Thousands of pieces of disused satellite and rocket are already floating above the Earth, constantly crashing into one another and dividing. This could make future rocket launches extremely dangerous.
- So when will I get to go into space?
- Richard Branson’s Virgin Galactic plans to be flying commercial flights into low orbit within two years, so your chance might not be far off. But only if you have a lot of money to burn: a seat on board its ‘SpaceShipTwo’ will cost $200,000.
- International Space Station
- The ‘ISS’ has been occupied continuously for longer than any satellite in history – over 11 years and counting. It is a cooperative effort by almost every country in the world with a space programme.
- Combustion is the scientific word for ‘burning.’ Oxygen is combined with a fuel (like petrol or wood) to produce energy in the form of heat and light. Processes that produce energy like this are known as an ‘exothermic reactions.’
- Isaac Newton
- British scientist Isaac Newton is usually seen as the inventor of modern physics. His three laws of motion form the basis for calculating how forces and objects interact. He also spent much of his career trying to turn lead into gold, and was by many accounts a very grouchy man – but nobody’s perfect.
- That is, sections that mostly operate independently of one another. Other rockets have three or more stages.
- Space elevator
- The idea of the space elevator was first formulated in 1895, inspired by the Eiffel Tower. The cable would reach from the equator to a space station, with an enormous weight further out in space to prevent the structure from being dragged back to Earth. It would require extremely strong materials and be an enormous challenge to build – nevertheless, many scientists predict that it will soon be a reality.