Getting a 350km/s delta V at Earth takes about a 45 minute burn. The 2nd big problem is slowing down once you get to Pluto. My first pass I ended up trying a 2 hour burn at Pluto and flew right past it still in a hyperbolic orbit out of the solar system.....
0.001C - that's quite quick! But as you rightly say, slowing down can be a problem. I'd try IMFD "Delta Velocity" for the deceleration burn, I reckon.
I'll have to learn more about iMFD, because I've also been trying to do this mission with TransX, but using the Falcon Heavy, although I have not seen the difference with the Delta IV. I recently did Eris Explorer and Deep Impact, and the first mission with slingshots I did was manned Venus flyby using a Saturn V. Although multi-sling missions with a single planet (eg Messenger or solar probe) is difficult in TransX
Cool. I haven't tried SolarProbePlus full mission using the FalconHeavy to launch, just up to the TVI burn. Worth getting to grips with IMFD, in my view - the accuracy of the "Map" view can save you a few m/s dV over TransX in certain situations. But for slingshots and multiple-orbit intercepts you need TransX.
Just one other question, do you pass Venus behind or in front of it on the first flyby? Same question for the other flybys. I'm asking because I'm simply not sure.
TBH I can't remember how all the VGAs go! It's been 9 months since I did this one.
So I continued my SolarProbePlus mission from where I left it, just after TVI with an error of ~17m/s........
1st MCC was at Launch+3days, 5m/s dV using IMFD Target Intercept(with Offset enabled) and IMFD Map/PlanView, simply targeting centre of planet.
After the burn IMFD Map shows intercept alt. -2044km (see first image sp1.gif below).
2nd MCC was at VGA1-20days, 3.6m/s dV to set up the flyby using TransX Manouevre (see sp2.gif)
3rd MCC was at VGA1-10days, 9.7m/s dV final correction for flyby using TransX Manouevre (see sp3.gif)
During VGA1, you approach from Venus nightside as Venus catches you up and overtakes. You cross Venus' orbit just ahead of the planet and periapsis is just past the day/night terminator, on the day side at about "9am local time"on the surface(if you were on Earth) (see sp4.gif)
After VGA1, I was just setting up IMFD for a Target Intercept burn in about 1.5 orbits time (looks like it will be about 15m/s) to target VGA2. However, I forgot that SolarProbePlus is temperature sensitive - didn't place it in proper attitude during first Solar periapsis - BOOM! :facepalm:
I think this may be as far as I get at the moment - hope this helps get you through the VGA1 anyway. I do seem to remember that the VGAs don't always happen at the same intersection node of the spacecraft trajectory and Venus orbit(it might switch from the "inbound" node to the "outbound" node) - should be obvious from the dates though.
Good luck!
1st MCC(sp1.gif)
http://postimg.org/image/zdfk597d9/
2nd MCC(sp2.gif)
http://postimg.org/image/dp3kzhfrv/
3rd MCC(sp3.gif)
http://postimg.org/image/hnfpjpnnl/
VGA1 just after periapsis (sp4.gif)
http://postimg.org/image/raj7tfgn5/
P.S. Apologies in advance for inflicting more Ion Engine madness :lol: