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ESA and ANU make space propulsion breakthrough


Copyright ESA

The European Space Agency and the Australian National University have successfully tested a new design of spacecraft ion engine that dramatically improves performance over present thrusters and marks a major step forward in space propulsion capability.

Ion engines are a form of electric propulsion and work by accelerating a beam of positively charged particles (or ions) away from the spacecraft using an electric field. ESA is currently using electric propulsion on its Moon mission, SMART-1. The new engine is over ten times more fuel efficient than the one used on SMART-1. “Using a similar amount of propellant as SMART-1, with the right power supply, a future spacecraft using our new engine design wouldn’t just reach the Moon, it would be able to leave the Solar System entirely,” says Dr Roger Walker of ESA’s Advanced Concepts Team, Research Fellow in Advanced Propulsion and Technical Manager of the project.

The new experimental engine, called the Dual-Stage 4-Grid (DS4G) ion thruster, was designed and built under a contract with ESA in the extremely short time of four months by a dedicated team at the Australian National University. “The success of the DS4G prototype shows what can be achieved with the passion [...]

SMART-1 detects calcium on the Moon


Copyright ESA

Thanks to measurements by the D-CIXS X-ray spectrometer, ESA’s SMART-1 spacecraft has made the first ever unambiguous remote-sensing detection of calcium on the Moon.

SMART-1 is currently performing the verification and calibration of its instruments, while flying in its science orbit, reaching 450 kilometres from the Moon at its closest distance.

During this calibration phase, which precedes the actual science observations phase, the SMART-1 scientists are getting acquainted with the delicate operations and the performance of their instruments in the warm environment of the lunar orbit.

Although it is still preparing for full lunar operations, D-CIXS has started already sending back high-quality data. D-CIXS is designed to measure the global composition of the Moon by observing how it glows in X-rays when the Sun shines on it. In fact, different chemical elements provide their ‘fingerprinting’, each glowing in a unique way.

On 15 January 2005, between 07:00 and about 09:00 Central European Time, a solar flare occurred, blasting a quantity of radiation that flooded the Solar System and the Moon.

“The Sun was kind to us,” said Prof. Manuel Grande of the Rutherford Appleton Laboratory, UK, leader of the D-CIXS instrument team. “It set off a large X-ray [...]

SMART-1: the first spacecraft of the future


Copyright ESA

ESA INFO 16-2003. A very efficient engine, plenty of room for instruments, accurate performance, good price. All these features characterise ESA’s SMART-1, due for launch during the night of 27-28 September.

SMART-1 is much smaller, cheaper and, in many ways, ‘more powerful’ than conventional spacecraft. Its secret lies in several new technologies being tested on board, which will be essential for spacecraft of the future. But this space adventure is not only for engineers; scientists too are eagerly awaiting SMART-1 — the first European mission to the Moon.

This is the first of a series of missions designed to test key technologies for future spacecraft —SMART stands for ‘Small Missions for Advanced Research and Technology’. In the case of SMART-1, the two main new technologies to be tested are a new ‘solar-electric propulsion’ system and miniaturised spacecraft and instrumentation. Together, these technologies make up a spacecraft with revolutionary qualities: smaller, lighter, capable of carrying more scientific instruments, greater fuel efficiency. All of which also considerably reduces the cost of the mission.

So, the idea behind SMART-1 is to pioneer a futuristic philosophy, the motto of which could be: ‘more science for less money’. Even though it is the [...]

Ion drives: Science fiction or science fact?


Copyright ESA

Science fiction movie fans know that, if you want to travel short distances from your home planet, you would use a sublight ‘ion drive’. However, is such an ion drive science fiction, or science fact?

The answer lies somewhere in between. Ion engines date back to at least 1959. Two ion engines were even tested in 1964 on the American SERT 1 satellite – one was successful, the other was not.

The principle is simply conventional physics – you take a gas and you ionise it, which means that you give it an electrical charge. This creates positively charged ions of gas, along with electrons. The ionised gas passes through an electric field or screen at the back of the engine and the ions leave the engine, producing a thrust in the opposite direction.

Very fuel-efficient

Operating in the near vacuum of space, ion engines shoot out the propellant gas much faster than the jet of a chemical rocket. They therefore deliver about ten times as much thrust per kilogram of propellant used, making them very ‘fuel-efficient’.

Although they are efficient, ion engines are very low-thrust devices. The amount of push you get for the amount of propellant [...]