Defining Electrodynamic Braking in Spacecraft

Some references would be useful! Unfortunately, I'm not aware of 'torque rods'.

It is indeed clear (or should be) that gravitational forces are not the only ones acting on extraterrestrial objects.

I am aware of the torque rods. You mentioned the tether experiments. As I recall, they produced hefty amounts of power. Still, they are not use. You have an idea, why?

"As I recall, they produced hefty amounts of power. Still, they are not use. You have an idea, why?"

Why? Perhaps the law of conservation of energy as translated through Lentz's Law.

Perhaps the Power produced would approximate the braking force * velocity. The Lentz Braking force would translate to reduced orbital energy and reentry.

Power * time = delta (.5mv^2)

Pt/.5m = V^2

sqrt(pt/.5m) = delta V

The force vector generated by the induction process would be opposite the velocity vector.

The work will be limited to the circuit acceptance of the induction circuit. In the case of a solid object the "circuit inductance" would be quite low. Is it possible that as the asteroid cuts the excitation field lines (Geo-field) it actually induces a field that is of opposite polarity to the dipolar geo-field and cancels any purely magnetic attraction that would be expected between a ferromagnetic material and a dipolar magnetic field?

There must be some type of electro-dynamic effect; the three components of induction are present - a conductor (the asteroid body), an excitation field (Geo-field), and rate of change (the asteroid velocity relative to Geo-field.) The question is scale.

At this link - http://www.bestsyndication.com/?q=072407_solar-power-sailing-in-outer-space-extend-long-distance-travel.htm , in the section dealing with Electro-dynamic Braking, I propose that it may be possible, because of the enabling technology of super-conductivity, to use the orbital energy of an asteroid, along with Sol-field, as a source of power for a number of different deflection strategies.

It may only be the wishful thinking of a dreamer; but I believe two effective components for an induction process are present, I propose we make a third available. The question is scalability and the ability to dissipate or use the produced power. The ability to use or dissipate power will define the "acceptance" of the induction circuit; and therefor the feasibility of the overall process.

Yes, it is quite interesting.

The tether generator converts delta v into electricity. At the same time the solar panels have the same basic dilemma. Assuming 30% of the photon's energy converted into electricity, while the rest pushes agains the solar sails. Hence, periodic reorientation might cancel some vectors, but not the straight component away from the Sun. Well, there is no free lunch...

On a different vector.... It is a fact, that most quasistationary commnication satellites and weather satellites die on fuel starvation. Well, some 20 years ago it was learned, that due mostly the Moon, the satellite describes a vertical figure 8, if its stationkeeping is a bit relaxed. It readily doubled their life.

NASA has for some time a refueling programm in development. It makes sense. The monpropellant is loaded into the satellite before takeoff. The same nipple can be used for refueling, as soon as the necessary robotics are refined. On the other hand, such a move upsets everybody's design / scientific / business plans. As today everybody knows, when the next set of instruments will be introduced. But with refueling???

The passive admittance concept is an impressive next step. Kudos for trying.

"The tether generator converts delta v into electricity." - more accurately - converts the orbital energy of the tethered package to electrical energy. I worked an KE equality when I should have worked an orbital energy equality; but I don't know how.

Since orbital energy is joules per kg I guess it might look something like this?

Pt/m = delta (u/2a) ???

(Pt/m)2a= u

delta a = u/(2Pt/m) ???? where delta a is the change in semi-major axis as a result of the electrical energy generation - Power * time (Pt); m is tether package mass and u is the gravitational parameter of the prime focus body.

Now we stepped down the orbit - how do we step it up? Put power into the system by generating a magnetic field that opposes the field of the prime focus body? Thus generating a force perpendicular to the velocity vector opposite the direction of prime focus mass.

BUT

From a stable orbit if you increase the orbital radius without changing the magnitude of the velocity you will now have excess hyperbolic speed - that is - escape velocity - where that excess hyperbolic speed will approximate Sqrt (2Pt/m)? If you reverse polarity and reduce orbital radius without changing the magnitude of the velocity you will change eccentricity?

These things would be good - Now you don't NEED onboard fuel for orbital maintenance - you can do it with parasitic power from the solar panels and field coils? ________________________________________________________________

I believe the refueling experiments you are referring to was the "Orbital Express Program."

Refueling technology allows for the on orbit fuel depots required for really grand Newtonian Propulsion schemes. The Neanderthals would be proud?

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"At the same time the solar panels have the same basic dilemma. Assuming 30% of the photon's energy converted into electricity, while the rest pushes against the solar sails."

I have always wanted to see the energy conservation math of a Solar Sail.

Your comment also makes me curious as to the energy conservation math of a photovoltaic cell.