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ESA develops a smarter way to travel through space
European Space Agency ^ | 06.11.02 | ESA

Posted on 06/11/2002 6:07:17 AM PDT by callisto

11-Jun-2002 As scientists demand more from space missions travelling to other worlds and beyond, traditional rocket technologies are beginning to show shortcomings. In response, ESA are helping to develop a new type of rocket engine, known as solar-electric propulsion, or more commonly, an ion engine, that can mark a whole new era of space exploration.

Solar-electric propulsion is ESA's new spacecraft engine. It does not burn fuel as chemical rockets do; instead the technique converts sunlight into electricity via solar panels and uses it to electrically charge heavy gas atoms, which accelerate from the spacecraft at high velocity. This drives the spacecraft forwards. In a chemical rocket, burning the fuel creates gas that is expelled relatively slowly compared to electric thrusters. However, in an ion engine, the gas is ejected at large velocities, which makes it generally much more efficient, so less fuel is required.

Such engines have long been the subject of science fiction; now ESA has helped turn them into science fact. A small ion engine is currently lifting ESA's telecommunications satellite, Artemis, to its planned orbit around Earth and, early in 2003, SMART-1 will blast off from Kourou, French Guiana. Once in space, this small craft will use an ion engine to reach the Moon.

Ion engines are truly important because their high efficiency makes previously impossible missions achievable. In fact, SMART-1 will test a manoeuvring technique, using its ion engine and the gravitational pull of the Moon, which will be essential for ESA's BepiColombo mission to Mercury, lifting off in 2012. Giuseppe Racca, project manager for SMART-1, explains, "With chemical propulsion you can only do a fly-by or go into a very elongated orbit around the planet. If you want to achieve a low Mercury orbit and really observe the planet, then you can only do that with electric propulsion."

As well as BepiColombo, solar-electric propulsion will be used for ESA's Solar Orbiter mission, to be launched at the same time. This probe will use an ion engine to rise out of the plane of the Solar System and study the Sun at high latitudes.

Since they do not need to carry so much fuel, ion engines release room for more scientific instruments. As technology continues to get smaller, the size of instruments decreases and the overall size and mass of the spacecraft decreases, further increasing efficiency. Racca says, "Solar-electric propulsion opens up the way to explore the inner part of the Solar System because you have the Sun to power you."

Further away, however, where the Sun's light is weaker, a new electricity source, such as a nuclear generator, would be needed. This is the next logical step for the technology, according to Racca. He says, "They could take us to the Kuiper belt and even farther away." The Kuiper belt extends beyond the planet Pluto and is a dream destination for many scientists because it contains comets that have been undisturbed since the formation of the Solar System. Beyond these comets is a mysterious realm of magnetic fields and rarefied gases known as interstellar space that astronomers would love to explore. Solar-electric propulsion would make such a mission possible because an ion engine can run almost constantly, so that eventually it outperforms any chemical rocket on such long flights.

"Electric propulsion as a whole, including solar and nuclear types, will really allow us to open a new era of Solar System exploration," concludes Racca.


TOPICS: Astronomy; Science
KEYWORDS: esa; smart1; solarelecpropulsion; space

1 posted on 06/11/2002 6:07:17 AM PDT by callisto
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To: RightWhale;PatrickHenry; VadeRetro; longshadow; BikerNYC; medved;Brett66;vannrox;
ping
2 posted on 06/11/2002 6:09:46 AM PDT by callisto
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To: callisto
Sounds like a better idea...
3 posted on 06/11/2002 6:34:36 AM PDT by medved
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To: callisto
"...solar-electric propulsion, or more commonly, an ion engine..."
Wasn't this kind of engine used on a number of small probes? Indeed it seems to be a wonderful advancement of technology.
4 posted on 06/11/2002 6:50:00 AM PDT by vannrox
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To: vannrox
Deep Space 1 had NASA's experimental ion engine. I don't think we've sent any other spacecraft up with it also, but I could be wrong.
5 posted on 06/11/2002 7:04:50 AM PDT by callisto
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To: callisto
... the technique converts sunlight into electricity via solar panels and uses it to electrically charge heavy gas atoms, which accelerate from the spacecraft at high velocity.

This has always been the hangup. I don't think solar panels are anywhere near the level of efficiency they need to be yet. But they may have made some breakthroughs while I wasn't looking.

6 posted on 06/11/2002 7:14:37 AM PDT by PatrickHenry
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To: callisto
Note to self: These puppies won't work for the boost phase. Very large chemical rockets still required to get the little puppie into space.
7 posted on 06/11/2002 8:10:32 AM PDT by GingisK
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To: callisto
Ion propulsion is finally being used, what was the development time for it? About 50 years? They have got to reduce the ridiculous amount of time to implement these technologies.
8 posted on 06/11/2002 8:13:37 AM PDT by Brett66
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To: callisto
This technique, developed initially by Robert Goddard, the Tesla of rocketry, is vital to asteroid mining. No other method of propulsion comes close to profitability for such business opportunities.
9 posted on 06/11/2002 9:22:01 AM PDT by RightWhale
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