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Unmanned Spaceflight.com _ Exploration Strategy _ Solar Sail Re-use

Posted by: JRehling Jul 27 2015, 05:33 PM

While reading about the Light Sail mission, I thought about an interesting property of solar sails, which is that by being opened/closed/rotated, the solar sail can be turned on/off comparatively cheaply. This resembles a theme often seen (always in error) in proposed perpetual motion machines, in which one part of a cycle drives the motion and the other part of the cycle gives you a free return.

So I was contemplating a reusable solar sail concept that works like this:

1) A relatively low-mass sail package can unfold to vast surface area or re-fold into a small package (and/or rotate perpendicular to the Sun, nulling the outward propulsion).

2) A payload, roughly similar to New Horizons.

3) A return system using chemical or ion propulsion.

On the first use of the system, conventional propulsion sends the craft from Earth to the closest-possible perihelion allowed by the materials.

At perihelion, the sail opens, imparting very high acceleration on the craft.

At some point after most of the possible acceleration has taken place, the sail and payload undock, letting the payload go on its way.

Then, the sail folds up and ion propulsion begins canceling its outward velocity, eventually returning it to the vicinity of Earth's orbit.

Then, a new payload and new ion propulsion unit docks with the sail, continuing inward to the perihelion distance once again.

The cycle repeats. At perihelion, the sail opens, giving the second payload its outward impulse. And so on.

The virtues of this would be to create just one massive sail for an arbitrarily large number of missions. The downside is the need for docking procedures in solar orbit.

Posted by: HSchirmer Sep 18 2019, 11:33 PM

QUOTE (JRehling @ Jul 27 2015, 06:33 PM) *
While reading about the Light Sail mission, I thought about an interesting property of solar sails, which is that by being opened/closed/rotated, the solar sail can be turned on/off comparatively cheaply. This resembles a theme often seen (always in error) in proposed perpetual motion machines, in which one part of a cycle drives the motion and the other part of the cycle gives you a free return.

So I was contemplating a reusable solar sail concept that works like this:

1) A relatively low-mass sail package can unfold to vast surface area or re-fold into a small package (and/or rotate perpendicular to the Sun, nulling the outward propulsion).

2) A payload, roughly similar to New Horizons.

3) A return system using chemical or ion propulsion.

On the first use of the system, conventional propulsion sends the craft from Earth to the closest-possible perihelion allowed by the materials.

At perihelion, the sail opens, imparting very high acceleration on the craft.

At some point after most of the possible acceleration has taken place, the sail and payload undock, letting the payload go on its way.

Then, the sail folds up and ion propulsion begins canceling its outward velocity, eventually returning it to the vicinity of Earth's orbit.

Then, a new payload and new ion propulsion unit docks with the sail, continuing inward to the perihelion distance once again.

The cycle repeats. At perihelion, the sail opens, giving the second payload its outward impulse. And so on.

The virtues of this would be to create just one massive sail for an arbitrarily large number of missions. The downside is the need for docking procedures in solar orbit.



Just came across this - you might consider pairing this with Greason's "plasma magnet sail"
https://www.centauri-dreams.org/2017/12/29/the-plasma-magnet-drive-a-simple-cheap-drive-for-the-solar-system-and-beyond/

or perhaps Zubrin's proton-bouncer dipole drive
https://www.centauri-dreams.org/2018/06/29/the-dipole-drive-a-new-concept-for-space-propulsion/

Given the updated interest in a way to accelerate probes to deep space for interstellar asteroid-comet investigations,
these might be very interesting...



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