The grand tour is a visit to all of the planets (sorry Pluto, you don't count). This was completed using Orbiter Space Flight Simulator. At the beginning of the trip, I set a few rules.
1. I had to start from Mir.
2. I could only refuel at Mir.
3. I must orbit or flyby all of the planets in a logical and realistic timeline.
4. I had to use the default Delta Glider.
In looking at feasible timelines, I decided to follow Voyager 2's path to the outer planets with a launch date in the Summer of 1977. Such a window to the outer planets happens only every 180 years. Because there's no returning after slingshotting past the 4 biggest planets, I decided to hit all of the inner planets first. I would have liked to have stopped by Mars on my way outward, but the 1977 timeline didn't seem to allow it as Mars is well ahead of Jupiter's orbit at that time.
So, my plan was to first travel to Mars and then return to Earth for fuel, go see the visit the rest of the inner planets, and then stop by Earth again for fuel before starting out for Jupiter.
I began my trip at MJD41889 (7/29/1973) docked to Mir with a flight plan for Mars.
I somehow mistimed my prograde burn at Earth and ended up quite a ways off track, but was able to do several corrections along the way. I eventually aerocaptured into Mars orbit on 3/21/1974.
My launch window to Mars did not allow an immediate return to Earth, so I spent most of a Martian year circling the planet, doing experiments, flying by Phobos and Deimos, and watching the scenery.
On 7/18/1975, 16 months after arriving, I used nearly all of the fuel I had left in a burn towards Earth. Luckily everything went as planned and with a small aerobrake maneuver and retrograde burn, I was able to enter a nearly perfectly synchronized Earth orbit with Mir and docked with the aging tin can with just 3% fuel remaining on 2/15/1976, just 2 1/2 years after I had originally left Earth.
After doing a lot of planning, I determined that I could not visit both Venus and Mercury and still have enough fuel left to return to Earth for the 1977 launch window. Not wanting to break my rules for the trip, I decided to use two Delta Glider's to complete the trip.
The first would be sent directly to Mercury, where it would wait and then transfer it's remaining fuel to the second DG, which would visit Venus on its way to Mercury. The next launch window for Mercury opened just 3 weeks later and the first DG launched for the 3 month direct trip to Mercury on 3/6/1976. I'd be taking the other DG past Venus and would meet up with it in a year or so.
Because I had just missed the Venus launch window while returning from Mars, I was able to spend 9 months hanging out on Mir. After a little going away party I undocked and began the trip to Venus on 1/10/1977.
Because fuel usage was very critical, I had to time the burn correctly and aerocapture once I made it to Venus. The burn went well, but I knew using the VERY thick atmosphere of Venus to slow down would be dangerous. Luckily, I nailed the aerocapture at 80km altitude and entered a very nice .34 eccentricity orbit using no fuel (except a burn at my next apoapsis to raise my periapsis back out of the atmosphere). The trip had taken just four months (entered orbit on 5/16/1977).
The clouds of Venus offered lots of entertainment while I waited 2 1/2 months for the next Mercury launch window to open. On 7/31/1977, I left the planet of the Goddess of Love behind. The quick trip to Mercury lasted only 3 months and after braking into orbit on Halloween day, I docked with the Delta Glider that had been waiting patiently for me since June of the year before. After picking up it's crew, transferring it's remaining fuel (26%) to my DG (which had 14%), and then pushing it to it's death on the surface below, we launched back toward Earth on 11/30/1977, well behind my anticipated timeline. As we left, we could see some storm activity on the blistering surface of Mercury.
When we arrived back at Earth on 4/18/1978, 16 months after leaving, the 1977 launch window had closed. My only option was to wait until late in 1978 and then try to make Jupiter in enough time to execute a slingshot to Saturn. But by the time I would arrive there, Jupiter would be well ahead of Saturns orbit and a slingshot would be difficult and result in a slow trajectory toward Saturn, putting me even further behind my timeline.
I launched on 10/2/1978 and as I left, I looked out my pilot's window and waved goodbye to the good old US of A for the last time - I would not be coming back.
While on the 26 month journey to Jupiter, it became apparent that a slingshot to Saturn would not be possible (at least, I couldn't figure one out). My only option was to enter a Jovian orbit, refuel at the base that had been established on Ganymede (o.k., so I broke my rules... big deal!), and then make for Saturn as quickly as I could.
New Year's Day 1978 was celebrated by entering an orbit around Jupiter.
It took a few days to get to Ganymede, refuel, and then enter the right orbit for my Saturn burn. I launched from Jupiter just 4 days after arriving - I wish I could have stayed longer, but the radiation levels in the Jovian system are not very inviting. I used all but 10% of my fuel leaving Jupiter's enormous gravity well, but it was alright, I would only need a little bit of it to adjust my trajectories for slingshots around the three remaining outer planets (in fact, I was able to do this using only 10% of my RCS thruster fuel).
The trip to Saturn took a mere 19 months (though I was still a year behind Voyager 2's timeline). My trip past Saturn was worth the wait.
My gravity assist trajectory to Uranus led me directly through Saturn's outer rings on 9/12/1982.
The slingshot around Saturn had helped me pick up some tremendous speed, but the distances to be travelled in the outer solar system are immense. The trip to Uranus was the longest of the trip - 4 years and 2 days. But boy was it worth the wait to see this green monster that sits awkwardly on it's side. Besides, today was my (real-life) 11th birthday (9/14/1986).
The Uranus slingshot was able to give me a nice boost and I felt bad that I wouldn't be coming back to return the momentum I had stolen. The cold trip to Neptune, the last site on my trip, took exactly 3.5 years with my flyby happening on 3/14/1990, 6075 days and nearly 17 years from when I first left Earth.
As I reached my periapsis at just 100km from Neptune's surface, I fired prograde with all of my remaining fuel. If I was going nowhere, I wanted to go there fast. This last slingshot sent me on a path out of the solar system, out of the sun's influence, and eventually to some distant star system, though my space ship would long have become my coffin by the time I reached anything of note. At a speed of nearly 30km/second, I entered the dark abyss of space. As I passed outside the furthest reaches of the planets, I turned my ship retrograde to look for a last time on the 8 planets I had visited.
Many thanks to Duncan, who's TransX made this possible and all of you who have created MFD's and scenery I used. It was quite a trip and I learned A TON! If I were to do it again, I would have done my best to do Mars-Jupiter-other outer planets. I now believe this would have been possible using Jupiter's huge gravity well to slingshot to Saturn. I learned that if you stop anywhere along the way, that you won't have enough fuel to complete the trip with one tank. I plan to revisit the timeline and try to do the trip on one tank of DG fuel. I think a Venus-Mercury-Mars-Jupiter-Saturn-Uranus-Neptune trip may be possible with only one stop to realign (either Mars or Venus). It may not be possible, but it will be fun to try.
A few questions:
- Is there any alternative to the WakeUpMFD? Though it works great, it ceases to work if focus changes from the Orbiter window. This trip took about 12 hours of computer time and without the WakeUpMFD, it would have been nearly impossible, but in order to use it, I couldn't use my computer to do anything else.
- The BurnTimeMFD is great, but I saw it posted somewhere that it's calculations are not correct. Is there something better for timing burns (short of a calculator and pencil?).
Hope ya'll enjoyed the tale - it was fun to experience and write up.