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New Kind of Orbit Could Ease Mars Communications
japan_dan writes "An interesting way to enable Earth-Mars communication when the Sun occludes the direct radio line-of-sight: ESA proposes placing a pair of continuous-thrusting relay satellites, using a solar electric propulsion system — one in front and ahead of Mars, the other behind and below — with both following non-Keplerian, so-called 'B-orbits'. This means the direction of thrust is perpendicular to the satellites' direction of flight, allowing them to 'hover' with both Earth and Mars in view. Quoting from the Q&A: 'We found that a pair of relay satellites would only have to switch on their thrusters for about 90 days out of every 2.13-year period, and this solution would only increase the one-way signal travel time by one minute, so it could be effective.'" Here is the paper describing non-Keplerian orbits (PDF).
... to park such a device at L4 or L5, where you wouldn't require *ANY* fuel to keep it in position?
File under 'M' for 'Manic ranting'
The original article was mentioning satellites following/leading mars. With the satellites in mars Lagrange points, the distance would be longer, though not entirely double.
What the hell, I'll bother to do the math this time, using your figures of 150 Gm and 25 Gm that would result in a maximum distance from earth the a mars Lagrange point at about 350 Gm, plus the 250 Gm to mars gives a distance of ~600 Gm vs the strait line of 400 Gm. so its a ~50% increase in time.
Of course I could get pedantic and claim I was talking about the difference in time. But that would be fudging to cover my my lazy ass failing to math.