RockDoctor (Slashdot reader #15,477) writes:
For over a century, the “solar sail” has been a concept in theoretical spaceflight, in science fiction, and in the last few years, actual spaceflight. Recently, the Breakthrough Starshot project has been prompting and funding a lot of work to optimise and explore the operational possibilities of flying spacecraft to nearby stars, and this has produced another (relatively) novel idea for efficient spacecraft propulsion — an electric sail.
It is well known that stars produce both radiation (light) and material outflows (“solar wind”). It is less well known that the momentum transferred by the solar wind can be considerably higher that that transferred by light. Recent calculations by the paper’s authors, Loeb and Lingam, with not-unreasonable premises, show that for many classes of star (including the most common star types) the solar wind is considerably stronger than the radiation pressure. They propose that a mesh of wires, positively charged, can drive a spacecraft more efficiently than reflecting radiation. Moreover, by using the radiation to generate electrical power, the wire grid can be kept charged and incident electrons discharged in a beam to keep the spacecraft electrically neutral. Thirdly, maintaining a charge on the grid in interstellar space can act to brake the spacecraft, or even steer it, depending on the “space weather” it encounters.
Clearly, applying these mechanisms to optimising “Breakthrough” spacecraft could considerably widen the range of trajectories and mission profiles possible.
of this story at Slashdot.
Source:: Slashdot