Electric Sail Invention Approaches Implementation

Helsinki - FMI: Helsinki - The electric solar wind sail developed at the Finnish Meteorological Institute has moved in a rapidly pace from invention towards implementation. Electric sail propulsion might have a large impact on space research and moving in space more generally. The electric solar wind sail developed by Dr. Pekka Janhunen at the Finnish Meteorological Institute might revolutionise moving around in deep space.

The electric sail is a Finnish invention which uses the solar wind as its thrust source and therefore needs no fuel or propellant. The solar wind is a continuous plasma stream emanating from the Sun. Changes in the properties of the solar wind cause auroral brightening and magnetic storms, among other things.

Progress without problems

Over its two-year history, the electric sail has developed rapidly from invention towards implementation and has aroused much international interest. The main parts of the device are long metallic tethers and a solar-powered electron gun which keeps the tethers positively charged.

The solar wind exerts a small but continuous thrust on the tethers and the spacecraft. The electric sail and its applications have been developed mainly at the Finnish Meteorological Institute, but component work is carried out at the University of Helsinki and in Germany, Sweden, Russia and Italy.

"We haven't encountered major problems in any of the technical fields thus far. This has already enabled us to already start planning the first test mission", says Dr. Pekka Janhunen. An important subgoal was reached when the Electronics Research Laboratory of the University of Helsinki managed to develop a method for constructing a multiline micrometeoroid-resistant tether out of very thin metal wires using ultrasonic welding.

The newly developed technique allows the bonding together of thin metal wires in any geometry; thus, the method might also have spinoff applications outside the electric sail.

Potential important applications of the electric sail

If and when realised, the electric sail could enable faster and cheaper Solar System science and exploration. It might also enable an economic utilisation of asteroid resources for, e.g. producing rocket fuel in orbit.

"The electric sail might cheapen all space activities and thereby for example help making large solar power satellites a viable option for clean electricity production. Solar power satellites orbiting in the permanent sunshine of space could transmit electric power to Earth by microwaves without interruptions. Continuous power would be a major benefit compared to e.g. ground-based solar power where storing the energy over night, cloudy weather and winter are tricky issues especially here in the far North", says Dr. Pekka Janhunen.

The electric sail was invented as a byproduct of basic research done at the Finnish Meteorological Institute of the interaction of the solar wind with planets and their atmospheres. Work of the electric sail in Finland is currently funded by the Academy of Finland and private foundations.

More information:
Dr. Pekka Janhunen, Academy Research Fellow, +358 9 1929 4635,
pekka.janhunen@fmi.fi

Read more about electronic sail

The first international electric sail meeting will be arranged at ESA ESTEC in Noordwijk, The Netherlands on May 19, 2008.
More information about ESTEC-meeting 19.5.2008

After 50 years, Oberg suggests, why not bring Vanguard back to Earth?

True pioneer Jim Oberg has articles in Astronomy, and one better on MSNBC where he discusses faithful Vanguard, which without fanfare or much notice, began it's fifty-first year in orbit, Monday.

Officially, Jim reports, Vanguard is "not space junk," and enjoys a singular place in history as easily the longest lasting spacecraft, constructed and launched before the creation of NASA.

Though it ceased functioning in 1964, Vanguard has orbited Earth almost 200,000 times and has declined in it's overall 400 to 2,400 mile orbit, circling Earth once every 133 minutes, by only an astounding 60 miles since launch, March 17, 1958.

Vanguard was the first spacecraft powered by solar cells, and contributed such previously unknown information as the actual size and shape of Earth, which turned out to be an "oblate spheroid," and slightly "pear-shaped," as we all know today, and hardly perfectly round.

As by far the oldest artificial satellite, its development began in 1955, before the Soviet Union launched Sputnik, and it outlasted even the U.S.S.R., just as it outlasted Sputnik, Explorer I and Sputnik II. Vanguard is certainly a treasure, and U.S. Air Force Space Command continues to keep track of it's location along with tens of thousands of mostly unrecognizable, true "space debris." It's official number is "00005," though it was the fourth vehicle to successfully enter orbit, the NASA designation begins, apparently, with less fortunate Buses that died along with their buggy boosters. Not so, Vanguard, however.

And, as a demonstration of robotics technology, Oberg joins others in proposing a retrieval as a museum piece, and discusses more on that possibility with Dennis Wingo, who has an actual, relatively low cost plan to make this happen.

Since Vanguard and I are almost precisely the same age, my having been a week shy of my first birthday, born before Sputnik and 53 weeks after its launch, something in me wants to see the rascal, certainly.

I would buy a ticket, and would be interested from a science standpoint to study this ultimate "long duration exposure facility," close up.

Nevertheless, however eccentric Vanguard's orbit may seem, it is obviously as "highly stable" as Oberg claims, and while it has traveled through Van Allen radiation and solar cycles swells of upper atmosphere, high and mighty and barely touching low-Earth-orbit at perigee, and then well out and away with an awesome view of the "rock from which it was hewn," a half-century ago. It isn't so high that a manned mission couldn't creep up on the speedy 1.5 kilogram wonder.

Perhaps restoring it to operation, just as anyone would any antique car from the time, and leaving it to fly on continuing to challenge the ages and as witness to a time of small beginnings, a veritable spore of the DNA from which much of our staggering, stumbling space program drew pattern.

In short, Jim. I gladly thank Nancy Atkinson, over at Universe Today, who flagged me on the wee beastie's birthday having at least been noticed by you and few others on it's happy day.

But I would just as soon pass up on a visit to the Smithsonian, and despite the hazards (more so than a trip to ISS) I'll gladly visit and examine and promise to take good pictures of this one up close, but preferably in the environment for which it was designed and then proven to be so well-suited.

See Jim Oberg's excellent article on Vanguard HERE.

And March 4, 2008 - "Why we track the trash "
by Ed White U.S. Air Force Space Command via SPACE TRAVEL