"Because this mission is about a hell of a lot more than Iapetus. Should the primary mission objectives, funded by large amounts of taxpayer money, be scrapped because Richard Hoagland has a vague hunch, a hunch which may not even be testable with Cassini's instrumentation? Of course not. That would be *really* irresponsible. The mission has been very carefully planned to learn all kinds of things. There are many passes by Titan, not only because it's a primary mission object itself but also because it is far bigger than any other Saturnian moon and thus uniquely suited to shifting Cassini's orbit. Iapetus is not in a very convenient orbit for flybys by a probe that is meant to study more than just Iapetus. No, I think it would be a hideous waste to totally scrap the current mission plan and make a new one just because of a hunch. It's much more efficient to be a little patient." <br /><br />"If we want to get REALLY close to Iapetus -- before September, 2007 -- what is required is a CHANGE in the close fly-bys of Titan ... which will then adjust ALL future trajectory projections. A specificially targeted change in the current Titan fly-bys will propogate forward ... affecting ALL future trajectories ... including, possibilities for closely approaching Iapetus in the next few months!<br /><br />However, for those critics who will immediately leap on this, claiming "See! He wants to totally upset YEARS of previous mission planning ... all for his crackpot ideas ...!", the answer is that a suitable SECOND fly-by of Titan -- after the early Iapetus close-encounter -- could immediately place Cassini BACK on its ORIGINAL MISSION PLAN!!! <br /><br />The repeated use of Titan's gravity, and a small amount of on-board thruster fuel, make Cassini a VERY flexible mission ..."<br />--RCH<br /><br />