Contrary to my customary negative response to announcements of new space technology developments, I must say this seems like a positive one. While the electrostatic field (or solar sail) propulsion system produces weak thrust that declines with the square root of the increasing distance from the sun (twice the distance produces only 1/4 the thrust), conversely the thrust increases with the square of the proximity to the sun (1/2 the distance produces four times the thrust). Hence a mission to the asteroid belt or outer planets would begin with as close an approach to the sun as the craft could withstand. Then the electrostatic propulsion net would be deployed and electrically polarized to repel the very strong solar wind near the sun, and the thrust generated might be 50-times greater than at Earth’s orbit. The craft would cross Earth’s orbit on the way out traveling at speeds 10-times greater than achievable by any scheme of expelling reactive mass propellants carried aboard the spacecraft. (Solar wind is a very complex phenomenon, and there is no definite constant speed or density, but various studies suggest minimum speeds of 400 km/sec).

The charged thin wire net idea seems well worth testing. It doesn’t solve the fundamental problem of space flight, prohibitively high costs of boosting payload out of Earth’s deep gravity well, but for deep-space missions at least it might significantly cut the amount of payload that would have to be boosted. Practical space habitats, or commercial exploitation of space, will require exploitation of material in the asteroid belt. The electrostatic net thrust system might cut transportation costs by a factor of 10 or more.