Path to Fast Solar Sails

This is a very simple concepts but obviously it can be effective.  however, i do think we need to be operating at least one earth orbit bicycle wheel space habitat.  The device can easily be produced folded form in the hub structure, even in sections.

We then launch it sun ward for a close orbital pass and once it has left the danger zone, we unfold the sail to drive acceleration.  This sail can also be tilted to produce a large solar orbit while doing this.

We need to do a prototype run in order to master the tech, and then scale up and also change out materials.

All this puts potential stations  out into deep space past Jupiter at least.  To start with this is the delivery system for a dozen telescopes that are also able to triangulate.  Better yet it can get out there fast and into a preset orbit.

Path to Fast Solar Sails

August 30, 2024 by Brian Wang

We need to make bigger solar sails from materials that can take high temperatures. Taking high temperatures means the solar sails could fly closer to the sun. If we got four times closer to the sun than Mercury (9 million miles or so )then we could go 20AU per year which is about 3 times faster than any spacecraft we have made. If we could go to about 2 million miles from then we could go to 50-60AU per year speeds.

NASA is testing solar sail with boom structures that could make solar sails about 20 times bigger. This means demonstration of the technologies needed to fabricate, fly, navigate and control 100 – 200 kg class missions using sails in the 1,500 to 7,000-m2 class. These are being developed and ground tested. A proposed Solar Cruiser mission was canceled in 2022.

Technologies and Materials

Close solar approach in future missions will require novel solar sail materials. New Liquid Crystal Polymer film technology appears to possess the very low absorption manufacturability and toughness required. The long-chain molecules in these nematic crystals are optically birefringent, slowing light polarized along the long axis of the molecule compared to the short axis, their properties can be tailored to affect the force, and torque response without a change is macroscopic shape with lower power requirements than other methods.

Monolayer graphene and graphene based composites offer advantages for these future systems. Graphene, for example, has low aerial density and provides much higher tensile strength and temperature capability up-to 4,000 K. Atomically thin graphene is examined as a promising stand-alone material for solar sails owing to its extremely low areal density making it ideal for extremely large sails that require close perihelion approaches.

Other light, high-temperature materials such as aerographite are also under consideration. Further, ceramics, such as silicon nitride and silicon dioxide, are naturally transparent with very low losses in the visible and ultraviolet. These materials are refractory and possess high melting points (>2000K) making them potentially applicable for close perihelion approaches (4 − 20 solar radii) with minimal degradation.

Close approach can be used to accelerate solar sails to unprecedented velocities – for example, a sail with a characteristic acceleration ≃ 3 mm/s2 performing an Oberth maneuver at 0.1AU perihelion may be accelerated to >20AU/yr cruise velocity and accelerations to 50AU/year are projected with new advance materials.