downloaderfan
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Greetings orbiter-forum community,
First, some backstory:
During my free time, I occasionally launch orbiter to find some cool 'launch windows' to perform slingshot maneuvers mostly to outer planets using assists from inner planets. I've posted one scenario titled 'The ultimate great grand tour' in the tutorials section of this forum and have many other scenarios which are just on my PC yet.
I very recently came across the Trajectory optimization tool after reading some posts, so I immediately downloaded the tool to find out whether it can simplify the process of finding launch windows for complex slingshot maneuvers. After reading the manual once, I went ahead to find some launch windows with some constrains that I've applied. I typically try to keep the fuel used as well as the TOF to a minimum, the fuel utilized is normally what it would take to get to venus, then I would sling around wherever else I wanted to go.
After coming up with a few trajectories in Trajectory optimization tool, I tried to plan the same in TransX but I was unable to do so due to a couple of reasons, that's why I'm writing this post in hopes of solving these issues.
So, the first trajectory I tried to find is a launch date for EVVEJ.
Zoomed in image
So you can see that, the transfer first from earth to venus looks fine, but after that, TOT doesn't display any orbit for venus to venus, then it again shows an orbit for venus to earth then jupiter. Is this some kind of limitation that TOT has? That it can't plan slingshots to the same planet again for gravity assists? While trying to plan this in orbiter, I was able to get from earth to venus with arrival at the specified date(as per TOT), also venus to venus at the specified date(although, I had to lose energy relative to the sun instead of gaining which is absurd), then got stuck when I tried to get to earth.
I would have shared the text data but it got lost due to a TOT crash so the image is all I have as of now, but if it's absolutely necessary, I don't mind planning the same trajectory again to post the text data. This just seems to be a general issue(getting to the same planet back) since some other trajectories I planned also had this issue of no orbit shown by TOT.
Problem 2:
Ok, so to avoid getting back to the same planet, this time I decided to plan EVMEJ.
So, again I was able to find a trajectory using TOT, but was not able to plan the same using transX in orbiter.
Here is an image of the TOT plan,
Zoomed in
Text data:
Starting optimization...
Optimization finished in 504.2767 seconds with message: Average change in trajectory
fitness function less than tolerance.
Results of the analysis are as follows:
The optimal departure from EARTH occurs at 6/12/2015 19:11:52 (C3=15.7723 km^2/s^2)
The optimal flyby of VENUS occurs at 9/14/2015 11:34:6 (deltaV=82.9022 km/s, pass
radius=26643.9676 km)
The optimal flyby of MARS occurs at 3/25/2016 2:55:36 (deltaV=154.3439 km/s, pass
radius=758.2502 km)
The optimal flyby of EARTH occurs at 1/28/2019 10:54:45 (deltaV=47.7631 km/s, pass
radius=7015.9559 km)
The optimal arrival at JUPITER BARYCENTER occurs at 7/3/2021 5:16:30 (arrival
velocity=6.1866 km/s)
The optimal trip duration is 2212.4199 days.
Again, while trying to plan this using TransX, I wasn't able to succeed. I was able to plan Earth to Venus very accurately.
But again, getting to mars from venus was not possible using transX as depicted by TOT.
Here is the scenario where I have planned the trajectory from earth to venus, but getting to mars doesn't seem to be possible.
So I wanted to know if there's some mistake I'm doing as of now because I'm not able to find one from the manual. Thank you for your time.
First, some backstory:
During my free time, I occasionally launch orbiter to find some cool 'launch windows' to perform slingshot maneuvers mostly to outer planets using assists from inner planets. I've posted one scenario titled 'The ultimate great grand tour' in the tutorials section of this forum and have many other scenarios which are just on my PC yet.
I very recently came across the Trajectory optimization tool after reading some posts, so I immediately downloaded the tool to find out whether it can simplify the process of finding launch windows for complex slingshot maneuvers. After reading the manual once, I went ahead to find some launch windows with some constrains that I've applied. I typically try to keep the fuel used as well as the TOF to a minimum, the fuel utilized is normally what it would take to get to venus, then I would sling around wherever else I wanted to go.
After coming up with a few trajectories in Trajectory optimization tool, I tried to plan the same in TransX but I was unable to do so due to a couple of reasons, that's why I'm writing this post in hopes of solving these issues.
So, the first trajectory I tried to find is a launch date for EVVEJ.
Zoomed in image
So you can see that, the transfer first from earth to venus looks fine, but after that, TOT doesn't display any orbit for venus to venus, then it again shows an orbit for venus to earth then jupiter. Is this some kind of limitation that TOT has? That it can't plan slingshots to the same planet again for gravity assists? While trying to plan this in orbiter, I was able to get from earth to venus with arrival at the specified date(as per TOT), also venus to venus at the specified date(although, I had to lose energy relative to the sun instead of gaining which is absurd), then got stuck when I tried to get to earth.
I would have shared the text data but it got lost due to a TOT crash so the image is all I have as of now, but if it's absolutely necessary, I don't mind planning the same trajectory again to post the text data. This just seems to be a general issue(getting to the same planet back) since some other trajectories I planned also had this issue of no orbit shown by TOT.
Problem 2:
Ok, so to avoid getting back to the same planet, this time I decided to plan EVMEJ.
So, again I was able to find a trajectory using TOT, but was not able to plan the same using transX in orbiter.
Here is an image of the TOT plan,
Zoomed in
Text data:
Starting optimization...
Optimization finished in 504.2767 seconds with message: Average change in trajectory
fitness function less than tolerance.
Results of the analysis are as follows:
The optimal departure from EARTH occurs at 6/12/2015 19:11:52 (C3=15.7723 km^2/s^2)
The optimal flyby of VENUS occurs at 9/14/2015 11:34:6 (deltaV=82.9022 km/s, pass
radius=26643.9676 km)
The optimal flyby of MARS occurs at 3/25/2016 2:55:36 (deltaV=154.3439 km/s, pass
radius=758.2502 km)
The optimal flyby of EARTH occurs at 1/28/2019 10:54:45 (deltaV=47.7631 km/s, pass
radius=7015.9559 km)
The optimal arrival at JUPITER BARYCENTER occurs at 7/3/2021 5:16:30 (arrival
velocity=6.1866 km/s)
The optimal trip duration is 2212.4199 days.
Again, while trying to plan this using TransX, I wasn't able to succeed. I was able to plan Earth to Venus very accurately.
But again, getting to mars from venus was not possible using transX as depicted by TOT.
Here is the scenario where I have planned the trajectory from earth to venus, but getting to mars doesn't seem to be possible.
Code:
BEGIN_DESC
END_DESC
BEGIN_ENVIRONMENT
System Sol
Date MJD 57185.6090907301
END_ENVIRONMENT
BEGIN_FOCUS
Ship GL-01
END_FOCUS
BEGIN_CAMERA
TARGET GL-01
MODE Cockpit
FOV 60.00
END_CAMERA
BEGIN_MFD Left
TYPE User
MODE TransX
Ship GL-01
FNumber 4
Int 1
Orbit True
Vector 4377295.24512 1395005.12175 4413960.6041
Vector -254.847096252 -126.486384635 292.705407442
Double 3.98600439969e+014
Double 57185.6090904
Handle Earth
Handle NULL
Handle NULL
Select Target
0 Escape
Autoplan
0 0
Plan type
0 0
Plan
0 1
Plan
0 0
Plan
0 0
Select Minor
0 None
Manoeuvre mode
0 0
Auto-Center™
0 0
Base Orbit
0 0
Prograde vel.
1 0
Man. date
1 57185.6090889
Outward vel.
1 0
Ch. plane vel.
1 0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
Pe Distance
1 7645212
Ej Orientation
1 0
Equatorial view
0 0
Finvars
Finish BaseFunction
Int 2
Orbit False
Handle Sun
Handle Earth
Handle Venus
Select Target
0 Venus
Autoplan
0 0
Plan type
0 2
Plan
0 0
Plan
0 0
Plan
0 1
Select Minor
0 None
Manoeuvre mode
0 0
Auto-Center™
0 0
Base Orbit
0 1
Prograde vel.
1 0
Man. date
1 57185.6086678
Outward vel.
1 0
Ch. plane vel.
1 0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
Prograde vel.
1 -2951.38117033
Eject date
1 57185.601335
Outward vel.
1 -2147.21737164
Ch. plane vel.
1 1520.28771854
Finvars
Finish BaseFunction
Int 4
Orbit True
Vector 6020403214.3 -173305917.758 -1302439487.84
Vector -5725.18527136 165.49087746 1191.97810921
Double 3.2485863e+014
Double 57267.0783594
Handle Venus
Handle NULL
Handle NULL
Select Target
0 Escape
Autoplan
0 0
Plan type
0 1
Plan
0 0
Plan
0 1
Plan
0 0
Select Minor
0 None
Manoeuvre mode
0 0
Auto-Center™
0 0
Base Orbit
0 0
Prograde vel.
1 0
Man. date
1 57185.6086708
Outward vel.
1 0
Ch. plane vel.
1 0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
View Orbit
0 0
Finvars
Finish BaseFunction
Int 3
Orbit True
Vector 106940198834 -5938074268.09 17048642654.4
Vector -10507.1821977 905.806012452 37703.0700697
Double 1.32712764814e+020
Double 57279.2023186
Handle Sun
Handle Venus
Handle Mars
Select Target
0 Mars
Autoplan
0 0
Plan type
0 2
Plan
0 0
Plan
0 0
Plan
0 2
Select Minor
0 None
Manoeuvre mode
0 0
Auto-Center™
0 0
Base Orbit
0 0
Prograde vel.
1 0
Man. date
1 57185.6090889
Outward vel.
1 0
Ch. plane vel.
1 0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
Velocity.
1 0
Outward angle
1 0.0383972435443
Inc. angle
1 0
Inherit Vel.
0 0
Eject date
1 57279.2023186
Finvars
Finish BaseFunction
END_MFD
BEGIN_MFD Right
TYPE User
MODE TransX
END_MFD
BEGIN_SHIPS
ISS:ProjectAlpha_ISS
STATUS Orbiting Earth
RPOS 6481270.69 -1617261.61 -800244.29
RVEL -1508.387 -7186.677 2320.934
AROT 28.00 0.94 40.81
AFCMODE 7
IDS 0:588 100 1:586 100 2:584 100 3:582 100 4:580 100
NAVFREQ 0 0
XPDR 466
END
Mir:Mir
STATUS Orbiting Earth
RPOS 6329443.03 -125089.84 -2082000.96
RVEL 2416.566 452.870 7338.343
AROT 0.53 -44.47 89.92
AFCMODE 7
IDS 0:540 100 1:542 100 2:544 100
XPDR 482
END
Luna-OB1:Wheel
STATUS Orbiting Moon
RPOS -44004.14 -2237543.73 -18.02
RVEL 1479.820 -29.087 -0.002
AROT 0.00 0.00 -167.96
VROT -0.00 -0.00 10.00
AFCMODE 7
IDS 0:560 100 1:564 100
XPDR 494
END
GL-01:DeltaGlider
STATUS Landed Earth
BASE Cape Canaveral:1
POS -80.6758964 28.5227640
HEADING 150.00
AFCMODE 7
PRPLEVEL 0:1.000000 1:1.000000
NAVFREQ 402 94 0 0
XPDR 0
GEAR 1 1.0000
AAP 0:0 0:0 0:0
END
SH-02:ShuttleA
STATUS Landed Earth
BASE Cape Canaveral:5
POS -80.6745292 28.5197208
HEADING 100.00
AFCMODE 7
PRPLEVEL 0:1.000000 1:1.000000
NAVFREQ 0 0
XPDR 0
PODANGLE 0.0000 0.0000
DOCKSTATE 0 0.0000
AIRLOCK 0 0.0000
GEAR 0 0.0000
PAYLOAD MASS 0.0 0
END
END_SHIPS
BEGIN_ExtMFD
END
So I wanted to know if there's some mistake I'm doing as of now because I'm not able to find one from the manual. Thank you for your time.