Anomalies in spacecraft velocities Options

[As old as Voyage...]

Very interesting story on SPACE.com regarding currently unexplained anomalies in the velocities of spacecraft after their Earth flybys.

http://www.space.com/scienceastronomy/0802...ft-anomaly.html

Perhaps the twisting of spacetime induced by Earth's rotation could be gently altering the spacecraft's velocity.

http://www.voanews.com/english/archive/200...FTOKEN=51791561

In any case its pretty cool to have an unexplained force meddling with our best laid plans.

[nprev]

Mmm...don't forget that the gravitational constant G is the least precisely known of all the physical constants, and it's a direct coefficient for many trajectory calculations. I suspect that part of the answer lies in this uncertainty.

If anyone were to undertake a serious investigation of these anomalies, I'd suggest a very precisely balanced spin-stabilized vehicle (with operational mass known to the highest degree possible), minimal outgassing, and almost nothing ancillary but the basic bus functions needed to keep it stable & relay data that would do a high-perigee (to negate drag effects) Molinya style Earth orbit with supporting tracking.

Think we're really getting very deep into the weeds here; statistical uncertainties seem like the most probable causes for these observed effects.

[Floyd]

...would do a high-perigee (to negate drag effects) Molinya style Earth orbit with supporting tracking.

The effect seemed to be associated with unbound orbits. Did not seem to show up in simple orbit orbits--only fly by's or for craft unbound to the sun--ie leaving the solar system.

[Greg Hullender]

The effect seemed to be associated with unbound orbits. Did not seem to show up in simple orbit orbits--only fly by's or for craft unbound to the sun--ie leaving the solar system.

Not qute. Galileo was in elliptical solar orbit at each of its Earth flybys. It was hyperbolic with respect to Earth, but not the Sun.

Remains to be seen what that should make any difference, of course.

--Greg