
	Where results make sense

Topic: Tether propulsion

Related Topics

Magnetic sail

Space elevator

Rocket propulsion

Phantom loop

Spacecraft propulsion

Solar sail

Momentum wheel

Solar panel

Terraforming

Ion thruster

Venus Express

Power plug

Count noun

Celestial body atmosphere

In the News (Sat 28 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Tether propulsion - Wikipedia, the free encyclopedia
		Tether propulsion uses long, strong strings (known as tethers) to change the orbits of spacecraft.
		The sensors to sense tether vibrations can either be an inertial navigation system on one end of the tether, or satellite navigation systems mounted on the tether, transmitting their positions to a receiver on the end.
		A tidal stabilized tether is called a "skyhook" since it appears to be "hooked onto the sky".
	en.wikipedia.org /wiki/Tether_propulsion (1830 words)

	Spacecraft propulsion - Wikipedia, the free encyclopedia
		Spacecraft propulsion is used to change the velocity of spacecraft and artificial satellites, or in short, to provide delta-v.
		This means that for maneuvering in space, a propulsion method that produces tiny accelerations but runs for a long time can produce the same impulse as a propulsion method that produces large accelerations for a short time.
		The law of conservation of momentum means that in order for a propulsion method to change the momentum of a space craft it must change the momentum of something else as well.
	en.wikipedia.org /wiki/Spacecraft_propulsion (3368 words)

	The Terminator Tether
		Tethers Unlimited Inc. is currently developing a system called the Terminator Tether™ that will provide a low-cost, lightweight, and reliable method of removing objects from low-Earth-orbit (LEO) to mitigate the growth of orbital debris.
		While the satellite is operational, the tether is wound on a spool, and the device is dormant, waking up periodically to check the status of the spacecraft and listen for activation commands.
		This tether interacts with the ionospheric plasma and the geomagnetic field to produce currents running along the tether, and these currents in turn cause forces on the tether that lower the orbit of the tethered spacecraft.
	www.tethers.com /TT.html (285 words)

	FuturePundit: Tethers As Orbital Space Debris Cleaners
		When electrical current flows through a through a tether connected to a spacecraft, the force exerted on the tether by the magnetic field raises or lowers the orbit of the satellite, depending on the direction the current is flowing.
		His plan is to equip the tether with a roving sheepdog, a small vehicle that is released near a piece of debris to fly around it looking for a suitable point to latch onto.
		The tether is necessary because parking old satellites in "graveyard" orbits eventually results in the generation of smaller and more dangerous pieces of space debris as micrometeorites collide with the satellites.
	www.futurepundit.com /archives/000885.html (1191 words)

	TTU MXER Research - About MXER (Site not responding. Last check: 2007-10-07)
		Momentum-exchange tether propulsion transfers momentum from one object to another by briefly linking a slow-moving object with a faster one.
		NASA's MXER tether technology development team presently includes Tennessee Technological University in Cookeville, Tenn.; Lockheed Martin Astronautics in Denver, Colo.; and Tethers Unlimited of Lynnwood, Wash. Several other organizations and businesses are expected to join in the near future.
		MXER tether technology is being developed by the In-Space Propulsion Technologies Program, which is managed by NASA's Office of Space Science in Washington and implemented by the In-Space Propulsion Technology Projects Office at Marshall Space Flight Center in Huntsville, Ala.
	mxer.tntech.edu /about (610 words)

	Cruising World - Perpetuated Motion (Site not responding. Last check: 2007-10-07)
		Tether is a big, engaging fellow with a mad scientist's air.
		Tether reckons that using the motors in regeneration mode with big fixed-bladed props in light air costs as much as a knot of boat speed in monohulls and two knots in multihulls.
		Tether says he's deliberately created the STI system in a modular way so that, for instance, nickel-metal-hydride or lithium-ion batteries--which have a significantly higher power density than lead-acid batteries do--can be introduced as soon as big enough ones are available.
	www.cruisingworld.com /article.jsp?ID=36169&typeID=396&catID=0 (2892 words)

	TUI: Engineering the Future
		In an "electrodynamic tether drag" system, such as the Terminator Tether, the tether can be used to reduce the orbit of the spacecraft to which it is attached.
		Essentially, the tether converts the orbital energy of the host spacecraft into electrical power, which is dissipated as ohmic heating in the tether.
		Tethers Unlimited, Inc. has helped NASA to explore the potential for using electrodynamic tether propulsion to maintain the orbit of the ISS.
	www.tethers.com /EDTethers.html (656 words)

	[10.06] Emerging Propulsion Technologies (Site not responding. Last check: 2007-10-07)
		The MXER tether is a long, rotating cable placed in an elliptical Earth orbit, whose rapid rotation allows its tip to catch a payload in a low Earth orbit and throw that payload to a high-energy orbit.
		Electrodynamic tether propulsion is used to restore the orbital energy transferred by the MXER tether to the payload and reboost the tether's orbit.
		Tether development additionally embraces the science investigation of ionospheric physics, micrometeorite and space particulates in LEO and precise earth environment knowledge of gravity fields, solar flux,.thermal environments and magnetic fields.
	www.aas.org /publications/baas/v36n4/dps2004/529.htm (394 words)

	NASA - NASA Engineers, Tennessee College Students Successfully Demonstrate Catch Mechanism for Future Space Tether
		Tether technology, as potentially implemented in space, transfers energy and momentum -- called momentum exchange -- from the tip of a fast-moving, spinning tether to a slower-moving object, dramatically increasing the object's speed.
		As the tether -- a long cable, approximately 60 to 90 miles in length -- spins end-over-end in space, it catches a payload in low Earth orbit via a catch mechanism, carries it for a half-rotation, and throws the payload toward its final destination.
		Tether technology is being developed by the In-Space Propulsion Technology Program, managed by NASA's Science Mission Directorate and implemented by the In-Space Propulsion Technology Office at Marshall.
	www.nasa.gov /centers/marshall/news/news/releases/2005/05-108.html (766 words)

	Electrical tethers - a "propellant-free" concept - may propel spacecraft
		Although using the same principles as the ProSEDS demonstration, a propulsive tether on ISS would be powered by electricity from the ISS's solar arrays: 5 kW of electricity would produce a steady push of 0.5 Newton (about one-eighth of a pound).
		Tethers in space describes the past, present, and promising future of tether applications in space, including technical details.
		Tethers Unlimited is a Clinton, Wash., company partnering with NASA/Marshall on ProSEDS and developing advanced tethers for other space applications.
	science.nasa.gov /newhome/headlines/ast22jan99_1.htm (1204 words)

	SPACE.com -- Tether Technology: A New Spin on Space Propulsion
		Under the auspices of the In-Space Propulsion (ISP) Program, NASA is footing the bill on five research areas: aerocapture; advanced chemical propulsion; solar electric propulsion; solar sail technologies; and space-based tether propulsion.
		Propulsion costs for space missions would drop by a factor of ten or more, he said.
		Under the new In-Space Propulsion contracts, research teams will be busy over the next couple of years using simulations and ground tests to show that the technical challenges of MXER tethers can be solved, he said.
	www.space.com /businesstechnology/technology/tether_tech_030618-1.html (707 words)

	Propellant-free space propulsion using tethers
		The electrical and tether principles were first demonstrated together in space by the Tethered Satellite System on the Space Shuttle in 1992 and 1996.
		Propulsive tethers will do the job for a small cost and a weight less than 50 kg (110 lbs).
		Details of are available in the Electrodynamic Tether Propulsion and Power Generation at Jupiter (NASA TM -1998-208475, June 1998) by Johnson, Gallagher, J. Moore of SRS Technologies, and F. Bagenal of the University of Colorado at Boulder.
	science.nasa.gov /newhome/headlines/ast15oct98_1.htm (1643 words)

	ScienceDaily: Tethered Transportation In Space: Experiment Will Lasso Energy From Earth's Atmosphere
		When electrical current flows through a tether connected to a spacecraft, the force exerted on the tether by the magnetic field raises or lowers the orbit of the satellite, depending on the direction the current is flowing.
		Most of the metallic tether will be exposed to the environment of space, instead of covered with an insulating sleeve as in previous electrodynamic tether missions.
		Electrodynamic tethers used for propulsion in low-Earth orbit and beyond could significantly reduce the weight of upper stages used to boost spacecraft to higher orbit.
	www.sciencedaily.com /releases/1999/03/990326175035.htm (1206 words)

	Takeoff \| Scientific Cage ©
		Instead, electric propulsion systems are "power limited" because the rate at which energy from the external source is supplied to the propellant is proportional to the mass of the power system.
		An interesting example for electric propulsion is the advanced ion propulsion technolgy which is currently being demonstrated on the Deep Space 1 mission.
		It functions like this: when the tether is lowered down from a vehicle in orbit, such as the Space Shuttle, the end of the tether (which is now in a lower orbit/altitude) will move slower than the respective orbital velocity.
	www.scientificcage.com /doc/takeoff_20001007.html (1382 words)

	Cyberpunks.Org - Technology, Privacy, Security, and the Future (Site not responding. Last check: 2007-10-07)
		The force exerted on the tether by the magnetic field can be used to raise or lower a satellite`s orbit, depending on the direction of the current`s flow.
		This propellant-free propulsion idea not only draws power from the space environment, it could open up the possibility of using orbiting in-space tethers as "space tugboats", or enabling fuel-free raising and lowering of satellite orbits.
		Tether advocate, Jerome Pearson is president of Star Technology and Research, Inc., of Mount Pleasant, South Carolina.
	www.cyberpunks.org /display/601/display/616/article (1121 words)

	TSS-1R: Page 29 (Site not responding. Last check: 2007-10-07)
		If the direction of the current in the tether is reversed, the force caused by its interaction with Earth's magnetic field changes from drag to propulsion.
		The electrical energy flowing into the tether is transformed into motional energy for the spacecraft, causing it to gain altitude; thus, the spacecraft's orbit is boosted without the use of precious fuel.
		With the Tethered Satellite System, the region of Earth's atmosphere at 130 km can be surveyed for long periods because the large inertial mass of the orbiter overcomes the satellite's relatively small drag.
	liftoff.msfc.nasa.gov /Shuttle/sts-75/tss-1r/brochure/page_29.html (528 words)

	[No title]
		At best, the current carrying tether is a novel form of reaction engine, that imparts a small velocity increment to a relatively large mass of plasma in the region that its orbit passes through.
		In essence, each end (plasma contactor) of the tether spews a "sheet" of charged plasma (see figure 1 below), which follows the curvature of the magnetic field lines toward the magnetic pole, to the E region of the lower ionosphere, where collisional diffusion of charge completes the circuit between the upper and lower field lines.
		The Tethered Satellite System (TSS) is a joint project between the United States and Italy, and TSS-1, an electrodynamic mission, is scheduled for flight on STS-45 (31 Jan 1991).
	www.cs.cmu.edu /afs/cs.cmu.edu/user/mnr/st/std010 (4400 words)

	Preprints Sep/Oct 99 (Site not responding. Last check: 2007-10-07)
		Electrodynamic tether thrusters can use the power provided by solar panels to drive a current in the tether and then the Lorentz force to ``push'' against the Earth's magnetic field, thereby achieving propulsion without the expenditure of on-board energy sources or propellant.
		Practical tether propulsion depends critically upon being able to extract multiamp electron currents from the ionosphere with relatively short tethers (10 km or less) and reasonably low power.
		The Propulsive Small Expendable Deployer System experiment is planned to test the ``bare tether'' design in space in the year 2000 by deploying a 5 km bare aluminum tether from a Delta II upper stage to achieve up to 0.5 N drag thrust, thus deorbiting the stage.
	cfa-www.harvard.edu /ep/preprint/sepoct99/4825.html (247 words)

	[No title]
		He is in the forefront of efforts to develop space tether technology for scientific and technological applications which include exploration of the ionosphere/thermosphere as well as developing electrodynamic tethers for propulsion applications.
		As a Co-I for NASA's ProSEDS electrodynamic tether propulsion mission which is to fly on a Delta-II in August, 2000, Professor Gilchrist is responsible for providing both plasma diagnostics and high-voltage control instrumentation.
		He was PI for a NASA funded study of space tether application to ionospheric/thermospheric research and was organizer for a 1994 international workshop on the subject with over 50 participants from five countries.
	www.eecs.umich.edu /RADLAB/bio/gilchrist.dir/experience.html (1177 words)

	Tether Technology: A New Spin on Space Propulsion [space elevator] (Site not responding. Last check: 2007-10-07)
		MXER tethers are considered by NASA to be "high risk with high payoff," said Les Johnson, Manager, In-Space Propulsion Technology Projects at the NASA Marshall Space Flight Center in Huntsville, Alabama.
		Johnson said that MXER contract awards are focused on rendezvous and capture techniques, stability of the tether, as well as strength and survivability of the cable as it speeds through space.
		The way in which you boost the tether to a higher orbit is by using the earth's magnetic field and the tether itself as a sort of electric motor.
	www.freerepublic.com /focus/f-news/931210/posts (2270 words)

	Space Transfer Technologies (Site not responding. Last check: 2007-10-07)
		Electrodynamic tether propulsion also shows promise for propellantless Earth orbit transfer as well as orbiting space science missions at Jupiter.
		STT plans to test this concept on the propulsive small expendable deployer system (ProSEDS) as a precursor to multiple applications of tether propulsion.
		Ion propulsion offers 3,000 seconds of specific impulse, reducing the mass of the propulsion system and enabling shorter mission times.
	www.allstar.fiu.edu /prime-tech/stt.htm (268 words)

	[No title]
		Put the solar cell array and CCD (with filters to remove a lot of extraneous radiation that isn't close to the wavelength of the laser/maser chosen) at the center of the "sphere"; sunlight is focused onto the solar cells.
		The area enclosed by the current-carrying tether would have to be pretty extensive in order to generate enough of a magnetic moment to interact with Earth's relatively weak magnetic field.
		I'm working on a control system stability analysis for the Tethered Satellite System program, and have access to tools and documentation that would be useful to an amateur group trying trying to build a probe using this technology.
	www.cs.cmu.edu /afs/cs.cmu.edu/user/mnr/st/std009 (3677 words)

	PMG (Site not responding. Last check: 2007-10-07)
		NASA-sponsored PMG (Plasma Motor Generator) was a 500 m long electrodynamic tethered system deployed from the Delta-7925 second stage with the primary goal of testing power generation and thrust by means of an electrodynamic tether system.
		This mission was the first example of a propulsion system for space transportation that did not utilize any propellant (and mass ejecta) but rather achieved propulsion by converting orbital energy into electrical energy (deorbit) or electrical energy into orbital energy (orbit raising).
		In summary, an electrodynamic tether can operate as a magnetic thrusters around planets with a magnetic field and a ionosphere.
	www.skyrocket.de /space/doc_sdat/pmg.htm (110 words)

	ProSEDS - Summary
		The Propulsive Small Expendable Deployer system (ProSEDS) is a tether-based propulsion experiment that draws power from the space environment around Earth, allowing the transfer of energy from the Earth to the spacecraft.
		An electrodynamic tether upper stage could be built using the propulsive tether technology to transfer satellites from a launch vehicle in low orbit to orbits of about 1,500 km (810 nmi).
		Atmospheric drag on the station will be about 0.3 to 1.1 newton (depending on time of year), and the tether could produce 0.5 to 0.8 newton of thrust.
	www.spaceandtech.com /spacedata/logs/2002/proseds_sumpub.shtml (379 words)

Try your search on: Qwika (all wikis)