Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Space Travel News .




LAUNCH PAD
Electric Propulsion
by Launchspace Staff
Bethesda MD (SPX) May 27, 2013


Do not confuse space electric thrusters with electric devices used on ground vehicles. Electrically-propelled cars use batteries for power and expel no exhaust products. In space, electric thrusters can derive power in one of two ways, from solar arrays or from nuclear power generators. To date, we have used only solar power sources for these applications.

Electric propulsion has been around for several decades. In fact, the idea dates back to 1906, when Robert Goddard made an entry in his personal notebook. Five years later, Konstantin Tsiolkovsky published the idea.

The late 1950s and early 1960s saw a flurry of research on electric propulsion devices. By 1962, technical papers that addressed the use of these new gadgets for controlling the orbits of geostationary satellites started to appear. The first in-space demonstration of an ion engine was carried on board the SERT-1 (Space Electric Rocket Test) spacecraft, launched in 1964.

Advances have continued through the last several decades, and as a result, we now see many spacecraft applications for electric thrust devices. For example, many of the latest geostationary communications satellites use some form of electric propulsion for station keeping and orbit adjustment functions.

Large electric device are being considered for planetary probes and other applications. One might go so far as to claim this technology is mature and ready for many missions.

How do these devices work? Electrically powered spacecraft use electrical energy to change the velocity of a space vehicle. Most of these propulsive devices create thrust by electrically expelling propellant mass at high speed.

When compared to chemical thrusters, electric propulsion devices offer much higher propellant exhaust velocities, i.e., higher specific impulse. This leads to much more efficient use of propellants for space missions.

However, thrust levels are much lower than for chemical rockets, preventing their use on launch vehicles. Thus, applications of electric devices are limited to in-space maneuvering.

There is one electric thrust device that does not use propellant, the electrodynamic tether. This works by interacting with the Earth's magnetic field. Such devices have not yet been widely used and will be limited to near-Earth missions.

Do not confuse space electric thrusters with electric devices used on ground vehicles. Electrically-propelled cars use batteries for power and expel no exhaust products. In space, electric thrusters can derive power in one of two ways, from solar arrays or from nuclear power generators. To date, we have used only solar power sources for these applications.

Today, electric thrusters are used on geostationary satellites and a number of exploration missions. There is talk of using these devices in connection with future human planetary missions.

For example, earlier this month, Mars mission advocates suggested the use of both chemical and electric propulsion devices for a human mission.

Since chemical rockets can provide rapid flights to Mars, these would be used to propel a crew vehicle to the red planet. A habitat, supplies and equipment would be sent ahead of the crew on electrically propelled vehicles. Robotic cargo ships would leave Earth about 2.5 years ahead of the human explorers.

Clearly, electric thrust devices have found important space applications and will continue to be used in increasing numbers and applications.

.


Related Links
Launchspace
Launch Pad at Space-Travel.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





LAUNCH PAD
Russia's Proton-M Spacecraft Set to Orbit French Satellite
Moscow (RIA Novosti) May 16, 2013
Russia's Proton-M carrier rocket will blast off on Tuesday from the Baikonur space center in Kazakhstan to put a French telecommunications satellite into orbit, a spokesman for the Russian space agency Roscosmos said. "The launch of the Proton-M carrier rocket with W3D satellite is scheduled for 20:02 [4:02 p.m. GMT] on Tuesday," the spokesman said. He added that the separation of th ... read more


LAUNCH PAD
Russian Spacecraft Manufacturer to Make Four Launches in 2014

Electric Propulsion

O3b Networks Launcher and payload integration are underway at Kourou

Arianespace underscores strong partnership with Japan during Tokyo meetings

LAUNCH PAD
Opportunity Departing 'Cape York'

Bacterium from Canadian High Arctic and life on Mars

Curiosity Drills Second Rock Target

Mars Rover Opportunity Examines Clay Clues in Rock

LAUNCH PAD
Moon being pushed away from Earth faster than ever

Bright Explosion on the Moon

NASA says meteor impact on the moon glowed like a star

Where on Earth did the moon's water come from

LAUNCH PAD
Planning Accelerates For Pluto Encounter

'Vulcan' wins Pluto moon name vote

Public to vote on names for Pluto moons

The PI's Perspective: The Seven-Year Itch

LAUNCH PAD
Critical Kepler Reaction Wheel Fails: Mission End In Sight

Sifting Through the Atmosphere's of Far-Off Worlds

New Method of Finding Planets Scores its First Discovery

Team Takes Part in Discovering New Planet

LAUNCH PAD
Girl expelled from school for exploding experiment going to space camp

New method for producing clean hydrogen

Adapter 'Flips' for Progress Toward 2014 Exploration Flight Test

ATK Hoping Tp Clean Up Rocketscience

LAUNCH PAD
Waiting for Shenzhou 10

China launches communications satellite

On Course for Shenzhou 10

Yuanwang III, VI depart for space-tracking missions

LAUNCH PAD
Asteroid Sample Return Mission Moves into Development

Asteroid 1998 QE2 To Sail Past Earth Nine Times Larger Than Cruise Ship

NASA's Asteroid Sample Return Mission Moves into Development

Dawn On Route From Vesta to Ceres




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement