Featured Research

from universities, journals, and other organizations

Getting to the moon on drops of fuel

Date:
March 29, 2012
Source:
Ecole Polytechnique Fédérale de Lausanne
Summary:
The first prototype of a new, ultra-compact motor that will allow small satellites to journey beyond Earth's orbit is just making its way out of the lab. The goal of the micro motor: to drastically reduce the cost of space exploration.

The first prototype of a new, ultra-compact motor that will allow small satellites to journey beyond Earth’s orbit is just making its way out of the EPFL laboratories where it was built. The goal of the micro motor: to drastically reduce the cost of space exploration.
Credit: EPFL news

Imagine reaching the Moon using just a fraction of a liter of fuel. With their ionic motor, MicroThrust, EPFL scientists and their European partners are making this a reality and ushering in a new era of low-cost space exploration. The complete thruster weighs just a few hundred grams and is specifically designed to propel small (1-100 kg) satellites, which it enables to change orbit around Earth and even voyage to more distant destinations -- functions typically possible only for large, expensive spacecraft. The just-released prototype is to be employed on CleanSpace One, a satellite under development at EPFL that is designed to clean up space debris, and on OLFAR, a swarm of Dutch nanosatellites that will record ultra-low radio-frequency signals on the far side of the Moon.

The motor, designed to be mounted on satellites as small as 10x10x10 cm3, is extremely compact but highly efficient. The prototype weighs only about 200 grams, including the fuel and control electronics.

"At the moment, nanosatellites are stuck in their orbits. Our goal is to set them free," explains Herbert Shea, coordinator of the European MicroThrust project and director of EPFL's Microsystems for Space Technologies Laboratory.

Small satellites are all the rage right now because their manufacturing and launch costs are relatively low -- about half a million dollars, compared to conventional satellites that run into the hundreds of millions. But nanosatellites currently lack an efficient propulsion system that would render them truly autonomous and thus able to carry out exploration or observation missions.

A motor that doesn't burn fuel

Instead of a combustible fuel, the new mini motor runs on an "ionic" liquid, in this case the chemical compound EMI-BF4, which is used as a solvent and an electrolyte. It is composed of electrically charged molecules (like ordinary table salt) called ions, except that this compound is liquid at room temperature. The ions are extracted from the liquid and then ejected by means of an electric field to generate thrust. This is the principle behind the ionic motor: fuel is not burned, it is expelled.

In the motor developed at EPFL, the flow of ions is emitted from an array of tiny silicon nozzles -- over 1,000 per square centimeter. The fuel is first guided by capillary action from a reservoir to the extremity of the micro-nozzles, where the ions are then extracted by an electrode held at 1,000 volts, accelerated, and finally emitted out the back of the satellite. The polarity of the electric field is reversed every second, so that all the ions -- positive and negative -- are ejected.

SystematIC Design, a MicroThrust project partner, designed the motor's electrical system. The ion ejection system requires a high electrical voltage, but the available energy aboard a 1-liter nanosatellite is limited to a few small solar cells -- in practice, about four watts of power. The Dutch company was able to develop a system that overcame this difficulty.

Cruising speed: 40,000 km per hour

After six months of acceleration, the microsatellite's speed increases from 24,000 km/h, its launch speed, to 42,000 km/h. The acceleration is only about a tenth of a millimeter per square second, which translates into 0-100 km/h in 77 hours. But in space, where there is no friction to impede motion, gentle but steady acceleration is the way to go.

The ionic motor will power CleanSpace One -- a nanosatellite whose mission is to tidy up space by grabbing space debris and pulling it into Earth's atmosphere to be safely incinerated. According to the Swiss Space Center, CleanSpace One will take two to three months and more than 1,000 terrestrial revolutions to reach one of its targets, the decommissioned Swisscube cubesat or Tlsat-1 cubesat. Scientists have just over a year to finalize their system.

Researchers have a bit more than a year to finalize the ionic motor. The prototype was developed in the context of a European project coordinated by EPFL and involved Queen Mary and Westfield College in the UK, the Dutch companies TNO and SystematIC Design B.V., and Nanospace AB in Sweden.


Story Source:

The above story is based on materials provided by Ecole Polytechnique Fédérale de Lausanne. Note: Materials may be edited for content and length.


Cite This Page:

Ecole Polytechnique Fédérale de Lausanne. "Getting to the moon on drops of fuel." ScienceDaily. ScienceDaily, 29 March 2012. <www.sciencedaily.com/releases/2012/03/120329101802.htm>.
Ecole Polytechnique Fédérale de Lausanne. (2012, March 29). Getting to the moon on drops of fuel. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2012/03/120329101802.htm
Ecole Polytechnique Fédérale de Lausanne. "Getting to the moon on drops of fuel." ScienceDaily. www.sciencedaily.com/releases/2012/03/120329101802.htm (accessed October 20, 2014).

Share This



More Space & Time News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) — Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) — Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
Powered by NewsLook.com
Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Newsy (Oct. 17, 2014) — The smallest of Saturn's main moons, Mimas, wobbles as it orbits. Research reveals it might be due to a global ocean underneath its icy surface. Video provided by Newsy
Powered by NewsLook.com
Comet Set for Rare Close Shave With Mars

Comet Set for Rare Close Shave With Mars

AFP (Oct. 16, 2014) — A fast-moving comet is about to shave by Mars for a once-in-a-million-years encounter that a flurry of spacecraft around the Red Planet hope to capture and photograph, NASA said. Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins