downloaderfan
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Greetings orbiter-forum community,
Since I had quite a few slingshot scenarios on my PC, I thought I should share it with the community. Most of the scenarios I'm uploading here have been planned using TransX within the past 4 days as I had a week off. These scenarios contain slings to outer planets using gravity assists from earth & venus so as to minimize the deltaV required. All the scenarios have launch dates in the near future, from the time of posting.
So here I go,
Folder 1 - Low time of flight
The scenarios contained in this folder have been optimized for a low time of flight. Since all my scenarios start with a trip to venus, they require approximately the same amount of fuel. I found out that in most cases, it is possible to rendezvous with jupiter from almost any launch date that allows a trip to venus after waiting for at most 2-3 'orbits to interception' during the earth slings after venus, so to make my task of finding launch windows a bit more challenging, I decided to only go for launch windows that have a low time of flight. These scenarios have a higher encounter velocity due to a lower TOF.
The launch windows I found are as follows:
2017 EVVEJU Sedna - A low TOF solution to get to Uranus. The orbit ejection takes place early 2017. Reaches Uranus in about 10 years. Thereafter, we can also sling Uranus to get to sedna. This adds 21 more years to the mission, due to sedna being one of the most distant solar system objects humanity has ever discovered. This scenario also has my fastest transfer to jupiter, in about 4.83 years.
2018 EVEEJ - My fastest transfer to jupiter using two earth slings unlike the previous scenario. Orbit ejection take place late 2018 and encounter with jupiter occurs 5.07 years later.
2026 EVEEJN Eris - A low TOF solution to Neptune. Orbit ejection takes place late 2026. Reaches Neptune 12 years later. Thereafter, we can sling Neptune to get to Eris, but due to Eris having a very eccentric orbit with an APA of 97.51 AU and due to it being close to it's apogee & also it's slow movement, this sling adds an additional 15 years to the mission.
2026 Fall into the sun - Yeah, why not? A direct burn to the sun's surface from earth is fuel-wise inefficient, so I decided to use jupiter to lower my periapsis below the sun's surface. But, just any transfer to jupiter won't work, you need to have a high encounter velocity relative to jupiter to achieve such a feat, much higher than a typical hohmann transfer. So I looked at all my scenarios and decided, the Neptune scenario above, was perfect for this task.In other words, this scenario is a modification of the above scenario where instead of going to neptune from jupiter, I rather take a dive towards the sun. I able to reach the sun 8 years after the launch date.
2033 EVEEJS Haumea - A low TOF solution to saturn. Orbit ejection takes place early 2033. Reaches saturn in 7.5 years. Thereafter, we can sling saturn to get to Haumea. This adds an additional 10.3 years to the mission.
Note - I haven't flown these scenarios in orbiter yet, but I don't see any reason why anyone wouldn't be able to. I've never encountered a plan in transX which I haven't been able to fly successfully, except for that one slingshot trajectory of the jovian moons, but since these scenarios have trajectories in the solar system(and not the jovian system), there shouldn't be any problem executing the flight path.
While these scenarios have a low time of flight, launch dates with lower TOF(lower by about 1.3-1.5 years) can be found, but that would require a deep space maneuver, much like Cassini did it. But since TransX doesn't allow planning deep space maneuvers in advanced, planning such trajectories using TransX alone will be a tedious process of flying our trajectories in orbiter till the deep space maneuver date & and then figuring out if we can perform additional slings to our target planet after the deep space maneuver. I decided not to go down that path, I only wish someone modified transX to allow a 'Manuever mode' along with the 'Sling direct' view so that I can input a particular date in manuever mode, transX would then show where on my orbit I would be on that particular date and then I can add prograde/outward/plane change and see it's effects. Other than that, without any deep space maneuvers, I believe these scenarios have TOF values really close to the optimum TOF you can obtain using inner planet slings to outer planets.(Exactly optimum TOF solutions can be found only if all the necessary conditions(planetary alignments) match exactly and that occurs rarely)
Folder 2 - Low encounter velocity
The scenarios in this folder have a low encounter velocity, but have a higher time of flight. In the above scenarios, I've used jupiter to obtain escape velocity & only then I sling to Saturn/Uranus/Neptune. But the scenarios in this folder have me traveling to outer planets using an elliptical orbit, with encounter velocities having 'hohmannish' or close to 'hohmannish' values.
So here are the scenarios,
2017 EVVEJ - This scenario is a modification of my '2017 EVVEJU Sedna' scenario to encounter jupiter at a much lower speed. Orbit ejection takes place early 2017 & encounter with jupiter occurs 5.5 years later.
2018 EVEEU - A single venus sling & two earth slings take me straight to Uranus. Orbit ejection takes place late 2018 and arrival to Uranus takes place 15.5 years later.
2025 EVEES - A near hohmann transfer to saturn from earth after a single venus & 2 earth slings. Orbit ejection takes place early 2025. Reaches saturn in 9 years.
Folder 3 - Other scenarios
Ok, while trying to find time optimum solutions to saturn/uranus/neptune, I found many scenarios which take me only till jupiter or take me to the target planet with TOF values significantly higher than the optimum TOF value. Nevertheless, they still are fuel efficient trips to outer planets.
Here are some of those,
2018 Fall into the sun - Another fall into the sun scenario, this one has almost the same launch date as '2018 EVEEU' scenario, where i modify the trajectory such that instead of going to Uranus, I get to jupiter to fall into the sun. While this scenario has a higher encounter velocity to jupiter compared to my previous 'Fall into the sun scenario', it also requires close passes to inner planets while slinging, which increases the TOF between slings and overall increases the TOF to jupiter. Reaches the sun in 11 years.
2020 EVVEJ - Another sling to jupiter using two venusian slings and one earth sling. Total TOF is 5.8 years, orbit ejection date is early 2020, has a low encounter velocity to jupiter.
2022 EVVEJ - Trajectory to get to jupiter starting from early 2022, takes 5.3 years to get to jupiter.
2023 EVVEJ - Yet another trajectory to get to jupiter, this time starting from mid 2023. It takes 5.2 years to get to jupiter.
2023 EVVEJN Sedna - Get to neptune & then sedna starting from mid 2023, this time it takes 19 years to get to Neptune & a total 37.7 years to get to sedna.
This finally marks the end of this post. Phew!!!
And as always,
[Extract the zip file below inside the 'Scenarios' folder of the orbiter installation directory]
[Eris, Haumea & Sedna are not packaged with the default orbiter installation and have to be added separately]
Eris - [ame="http://orbithangar.com/searchid.php?ID=1343"]Eris and Dysnomia[/ame]
Haumea - [ame="http://orbithangar.com/searchid.php?ID=3364"]Haumea (2003 EL61) v2.0[/ame]
Sedna - [ame="http://orbithangar.com/searchid.php?ID=610"]Sedna v2.0[/ame]
Since I had quite a few slingshot scenarios on my PC, I thought I should share it with the community. Most of the scenarios I'm uploading here have been planned using TransX within the past 4 days as I had a week off. These scenarios contain slings to outer planets using gravity assists from earth & venus so as to minimize the deltaV required. All the scenarios have launch dates in the near future, from the time of posting.
So here I go,
Folder 1 - Low time of flight
The scenarios contained in this folder have been optimized for a low time of flight. Since all my scenarios start with a trip to venus, they require approximately the same amount of fuel. I found out that in most cases, it is possible to rendezvous with jupiter from almost any launch date that allows a trip to venus after waiting for at most 2-3 'orbits to interception' during the earth slings after venus, so to make my task of finding launch windows a bit more challenging, I decided to only go for launch windows that have a low time of flight. These scenarios have a higher encounter velocity due to a lower TOF.
The launch windows I found are as follows:
2017 EVVEJU Sedna - A low TOF solution to get to Uranus. The orbit ejection takes place early 2017. Reaches Uranus in about 10 years. Thereafter, we can also sling Uranus to get to sedna. This adds 21 more years to the mission, due to sedna being one of the most distant solar system objects humanity has ever discovered. This scenario also has my fastest transfer to jupiter, in about 4.83 years.
2018 EVEEJ - My fastest transfer to jupiter using two earth slings unlike the previous scenario. Orbit ejection take place late 2018 and encounter with jupiter occurs 5.07 years later.
2026 EVEEJN Eris - A low TOF solution to Neptune. Orbit ejection takes place late 2026. Reaches Neptune 12 years later. Thereafter, we can sling Neptune to get to Eris, but due to Eris having a very eccentric orbit with an APA of 97.51 AU and due to it being close to it's apogee & also it's slow movement, this sling adds an additional 15 years to the mission.
2026 Fall into the sun - Yeah, why not? A direct burn to the sun's surface from earth is fuel-wise inefficient, so I decided to use jupiter to lower my periapsis below the sun's surface. But, just any transfer to jupiter won't work, you need to have a high encounter velocity relative to jupiter to achieve such a feat, much higher than a typical hohmann transfer. So I looked at all my scenarios and decided, the Neptune scenario above, was perfect for this task.In other words, this scenario is a modification of the above scenario where instead of going to neptune from jupiter, I rather take a dive towards the sun. I able to reach the sun 8 years after the launch date.
2033 EVEEJS Haumea - A low TOF solution to saturn. Orbit ejection takes place early 2033. Reaches saturn in 7.5 years. Thereafter, we can sling saturn to get to Haumea. This adds an additional 10.3 years to the mission.
Note - I haven't flown these scenarios in orbiter yet, but I don't see any reason why anyone wouldn't be able to. I've never encountered a plan in transX which I haven't been able to fly successfully, except for that one slingshot trajectory of the jovian moons, but since these scenarios have trajectories in the solar system(and not the jovian system), there shouldn't be any problem executing the flight path.
While these scenarios have a low time of flight, launch dates with lower TOF(lower by about 1.3-1.5 years) can be found, but that would require a deep space maneuver, much like Cassini did it. But since TransX doesn't allow planning deep space maneuvers in advanced, planning such trajectories using TransX alone will be a tedious process of flying our trajectories in orbiter till the deep space maneuver date & and then figuring out if we can perform additional slings to our target planet after the deep space maneuver. I decided not to go down that path, I only wish someone modified transX to allow a 'Manuever mode' along with the 'Sling direct' view so that I can input a particular date in manuever mode, transX would then show where on my orbit I would be on that particular date and then I can add prograde/outward/plane change and see it's effects. Other than that, without any deep space maneuvers, I believe these scenarios have TOF values really close to the optimum TOF you can obtain using inner planet slings to outer planets.(Exactly optimum TOF solutions can be found only if all the necessary conditions(planetary alignments) match exactly and that occurs rarely)
Folder 2 - Low encounter velocity
The scenarios in this folder have a low encounter velocity, but have a higher time of flight. In the above scenarios, I've used jupiter to obtain escape velocity & only then I sling to Saturn/Uranus/Neptune. But the scenarios in this folder have me traveling to outer planets using an elliptical orbit, with encounter velocities having 'hohmannish' or close to 'hohmannish' values.
So here are the scenarios,
2017 EVVEJ - This scenario is a modification of my '2017 EVVEJU Sedna' scenario to encounter jupiter at a much lower speed. Orbit ejection takes place early 2017 & encounter with jupiter occurs 5.5 years later.
2018 EVEEU - A single venus sling & two earth slings take me straight to Uranus. Orbit ejection takes place late 2018 and arrival to Uranus takes place 15.5 years later.
2025 EVEES - A near hohmann transfer to saturn from earth after a single venus & 2 earth slings. Orbit ejection takes place early 2025. Reaches saturn in 9 years.
Folder 3 - Other scenarios
Ok, while trying to find time optimum solutions to saturn/uranus/neptune, I found many scenarios which take me only till jupiter or take me to the target planet with TOF values significantly higher than the optimum TOF value. Nevertheless, they still are fuel efficient trips to outer planets.
Here are some of those,
2018 Fall into the sun - Another fall into the sun scenario, this one has almost the same launch date as '2018 EVEEU' scenario, where i modify the trajectory such that instead of going to Uranus, I get to jupiter to fall into the sun. While this scenario has a higher encounter velocity to jupiter compared to my previous 'Fall into the sun scenario', it also requires close passes to inner planets while slinging, which increases the TOF between slings and overall increases the TOF to jupiter. Reaches the sun in 11 years.
2020 EVVEJ - Another sling to jupiter using two venusian slings and one earth sling. Total TOF is 5.8 years, orbit ejection date is early 2020, has a low encounter velocity to jupiter.
2022 EVVEJ - Trajectory to get to jupiter starting from early 2022, takes 5.3 years to get to jupiter.
2023 EVVEJ - Yet another trajectory to get to jupiter, this time starting from mid 2023. It takes 5.2 years to get to jupiter.
2023 EVVEJN Sedna - Get to neptune & then sedna starting from mid 2023, this time it takes 19 years to get to Neptune & a total 37.7 years to get to sedna.
This finally marks the end of this post. Phew!!!
And as always,
[Extract the zip file below inside the 'Scenarios' folder of the orbiter installation directory]
[Eris, Haumea & Sedna are not packaged with the default orbiter installation and have to be added separately]
Eris - [ame="http://orbithangar.com/searchid.php?ID=1343"]Eris and Dysnomia[/ame]
Haumea - [ame="http://orbithangar.com/searchid.php?ID=3364"]Haumea (2003 EL61) v2.0[/ame]
Sedna - [ame="http://orbithangar.com/searchid.php?ID=610"]Sedna v2.0[/ame]
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