Europe’s Ion Driven Satelitte
The European Space Agency has launched a satellite, named SMART 1, toward the moon, Sunday, 28 September, 2003. This will be their first moon mission. This is also their first attempt at using ion drive propulsion for a spacecraft. The spacecraft is more like a toy because it is only a metre square in size and weighing just 367 kilograms.
One spectacular aspect about this satellites journey is that it will travel to the moon in a spiral trajectory reaching the moon sometime in 2005. That’s right, the trip will take over a year to reach the moon. The purpose of SMART 1 is to prove that the moon was created by the “Giant Impact Theory”. The Giant Impact Theory is that a Mars-sized object crashed into early Earth. The debris thrown into space aggregated into the Moon. The miniaturized equipment on SMART 1 will gather data about the moon that will determine the moon’s exact make-up.
It is a technology demonstrator and has been built in a short time and very cheaply.
The total bill has come to just 110 million euro (£76m), including launch fees.
This has been achieved partly by using new management methods but also by using novel techniques of miniaturisation and design.
At only a metre square in size and weighing just 367 kilograms, it could almost be a space toy.
But Smart is packed with kit that will change the nature of future high-budget missions from Europe.
For such a small craft, SMART 1 has some very sophisticated equipment.
D-CIXS
The Demonstration of a Compact Imaging X-ray Spectrometer (D-CIXS) is an innovative instrument designed for high throughput X-ray spectroscopy. It is being developed for the SMART-1 mission by an international team of scientists led by principal investigator Dr Manuel Grande of the Rutherford Appleton Laboratory in the United Kingdom. Co-investigator is Juhani Huovelin from the University of Helsinki Observatory which will provide an X-ray Solar Monitor (XSM).
The collecting area of D-CIXS (pronounced ‘Dee-Kicks’ !) and its large aperture make it particularly suitable for lunar spectrometry. The Moon is a very weak source of fluorescence X-rays. D-CIXS will enable the instrument to obtain high quality spectra with a good spatial resolution even when the SMART-1 spacecraft is moving rapidly above the lunar surface.
[via ESA]
The ion drive is probably the most impressive thing about SMART 1. Below is a diagram of its workings and a brief outline on how it works. There is so much to read about this satellite so if you are interested, try starting your readings with the links provided below.
HOW SMART 1′S ION DRIVE ENGINE WORKS
1. Xenon gas atoms are pumped into a cylindrical chamber, where they collide with electrons from the cathode. The electrons - which are negatively charged - knock electrons off the Xenon atoms, creating Xenon ions - which are positively charged.
2. Coils outside the chamber create a magnetic field, which causes electrons from the cathode to spiral and become trapped at the mouth of the chamber.
3. The build-up of negatively-charged electrons at the mouth of the chamber attracts the positively-charged ions, accelerating them out of the chamber.
4. The stream of accelerated ions leaving the chamber thrusts the spacecraft forward. Although the force is small, over time it creates great speed in the frictionless environment of space.