Chapman Challenge
- Thread starter Piper
- Start date
Piper
Orbiting Space Addict
Yes I did. BrianJ posted a thread a while ago (I think it was the first to talk about IEATMFD) that explains a bit of the use of it and IMFD, however it does assume you are at least somewhat familiar with it. Before I release the next challenge, I'll write up a tutorial on using it. I'll try and not take too long, as the pork-chop plot generator I've been working on has been really keeping me busy.
Thanks, I really did try to tinker with the imfd and the ieatmfd according to brianj's post, but I only got more confused. The problem is that I'm not familiar at all with imfd and don't know how to read data output from it.
flying coffin
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- Dec 7, 2007
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The Delta V mode of IMFD is actually pretty similar to transx.
You adjust the prograde, outward, and plane change velocities, and
see the effects in the other MFD using IMFD map mode with the
course-plan option.
There is a pretty good description of how to do it (I hope) in the
LRO add-on documentation.
LCROSS orbit correction 1
Switch focus back to AV020Centaur and wait until the orbit is farthest from the moon.
Select IMFD in the left MFD. Click MNU, then Map. Click TgT and type Moon, Click Cnt, and type Earth.
Select IMFD in the Right MFD. In the right MFD click MNU, then Course. Select Delta Velocity mode, then set the target to Moon.
Set the dVf parameter to 0.
In the left MFD click PG, then Plan. in the right MFD, adjust dVf to get the most deflection
of the orbit you can when LCROSS intersects the moon in 1.5 orbits.
When this is done, click on Pg, then BV, then AB.
When the burn is finished, click Plan in the left MFD to turn the orbit line green again.
You adjust the prograde, outward, and plane change velocities, and
see the effects in the other MFD using IMFD map mode with the
course-plan option.
There is a pretty good description of how to do it (I hope) in the
LRO add-on documentation.
LCROSS orbit correction 1
Switch focus back to AV020Centaur and wait until the orbit is farthest from the moon.
Select IMFD in the left MFD. Click MNU, then Map. Click TgT and type Moon, Click Cnt, and type Earth.
Select IMFD in the Right MFD. In the right MFD click MNU, then Course. Select Delta Velocity mode, then set the target to Moon.
Set the dVf parameter to 0.
In the left MFD click PG, then Plan. in the right MFD, adjust dVf to get the most deflection
of the orbit you can when LCROSS intersects the moon in 1.5 orbits.
When this is done, click on Pg, then BV, then AB.
When the burn is finished, click Plan in the left MFD to turn the orbit line green again.
flying coffin
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The documentation for the Lunar Reconaissance Orbiter add-on by Brianj.
[ame="http://www.orbithangar.com/searchid.php?ID=3687"]LRO / LCROSS v.2[/ame]
flytandem
Tutorial Publisher
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- Oct 19, 2007
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- Website
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Here's another and quite interesting trojan trip. How about an out and back?
I managed a good arrival orbit and landing on "2002 DD1" still with about 2142 m/s remaining in the Fregat and decided at that point to make a go at returning to Earth.
I ejected the asteroid and did a reverse plan by going prograde at a Jupiter node and pushing the Ap above Jupiter so after 1 orbit I would encounter it. I did a sling that had the Pe drop to touch Earth orbit with the alignment to place a node at this intersection and also with earth timed to be there. It needed a 450 m/s maneuver on the way to make it on target.
With all the MCCs I arrived at Earth still attached to the Fregat but it had a bit over 1000 m/s remaining. I started a bit ahead of the Pe doing all the engine braking I could manage first with the Fregat then I jettisoned it and switched into the Chapman probe to continue the engine braking. I managed a capture just with the engine and got the Ap down to about 150M and still with 200 m/s in the can.
After a series of aerobrakes the Ap was pulled down to a bit under 300 Km agl and with the engine I pushed the Pe up to match it. But curiousity had the best of me so I went ahead and used some fuel to drop the Pe to cause a deorbit hoping to hit the USA. It was interesting to look out the glass cockpit at the flames going straight away from me. Luck had the craft drop onto the plains about 100 miles west of Kansas City and with only about 40 m/s left in fuel I timed as best I could to use it to soften the impact. Terminal airspeed dropped to about 80 m/s in the last few seconds just from friction and I managed to nudge that down to about 50 m/s at impact with the usual crashing sounds. I recorded the deorbit and landing for posterity.
-----Post Added-----
For entertainment here are the Jupiter slings first outbound to "2002 DD1" then the (sample?) return sling toward Earth.
I managed a good arrival orbit and landing on "2002 DD1" still with about 2142 m/s remaining in the Fregat and decided at that point to make a go at returning to Earth.
I ejected the asteroid and did a reverse plan by going prograde at a Jupiter node and pushing the Ap above Jupiter so after 1 orbit I would encounter it. I did a sling that had the Pe drop to touch Earth orbit with the alignment to place a node at this intersection and also with earth timed to be there. It needed a 450 m/s maneuver on the way to make it on target.
With all the MCCs I arrived at Earth still attached to the Fregat but it had a bit over 1000 m/s remaining. I started a bit ahead of the Pe doing all the engine braking I could manage first with the Fregat then I jettisoned it and switched into the Chapman probe to continue the engine braking. I managed a capture just with the engine and got the Ap down to about 150M and still with 200 m/s in the can.
After a series of aerobrakes the Ap was pulled down to a bit under 300 Km agl and with the engine I pushed the Pe up to match it. But curiousity had the best of me so I went ahead and used some fuel to drop the Pe to cause a deorbit hoping to hit the USA. It was interesting to look out the glass cockpit at the flames going straight away from me. Luck had the craft drop onto the plains about 100 miles west of Kansas City and with only about 40 m/s left in fuel I timed as best I could to use it to soften the impact. Terminal airspeed dropped to about 80 m/s in the last few seconds just from friction and I managed to nudge that down to about 50 m/s at impact with the usual crashing sounds. I recorded the deorbit and landing for posterity.
-----Post Added-----
For entertainment here are the Jupiter slings first outbound to "2002 DD1" then the (sample?) return sling toward Earth.
Code:
BEGIN_DESC
Outbound to "2002 DD1" at the Pe of the Jupiter sling. A Pe prograde burn of 297 m/s has just been completed.
END_DESC
BEGIN_ENVIRONMENT
System Sol
Date MJD 57075.1703515959
END_ENVIRONMENT
BEGIN_FOCUS
Ship Fregat1
END_FOCUS
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FOV 50.00
END_CAMERA
BEGIN_HUD
TYPE Orbit
REF AUTO
END_HUD
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Int 0
Orbit False
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Ship Fregat1
FNumber 2
Int 1
Orbit True
Vector 1382961265.74 -1773017605.58 91468993.2377
Vector 9225.11403697 7424.19566566 4517.59883947
Double 1.26686534397e+017
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Handle Jupiter
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Int 0
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END_MFD
BEGIN_MFD Right
TYPE User
MODE TransX
END_MFD
BEGIN_SHIPS
Delta4HV:Delta4HVD4HV
STATUS Orbiting Jupiter
RPOS -6256787854.22 -2697430618.17 2335202816.78
RVEL 8372.103 636.049 2110.145
AROT -16.78 -71.13 -7.50
RCSMODE 2
PRPLEVEL 2:0.028
NAVFREQ 0 0
CONFIGURATION 2
PAF 3
MET 112394799.5
HEIGHT 25.0
UPGRADE
END
Delta4HV-STG1:Delta4HVD4HVcore
STATUS Orbiting Earth
RPOS -5738932.10 -1730322.74 2761294.79
RVEL -3742.910 2390.945 -6353.558
AROT -137.48 49.83 144.96
VROT 0.46 3.12 0.00
NAVFREQ 0 0
END
Delta4HV-LHF:Delta4HVD4HVfair3
STATUS Orbiting Earth
RPOS -82897.55 -2678754.65 6196924.89
RVEL -7599.741 -612.887 -266.563
AROT -116.82 8.27 73.12
VROT -21.58 -0.12 0.00
NAVFREQ 0 0
END
Delta4HV-RHF:Delta4HVD4HVfair3
STATUS Orbiting Earth
RPOS -5257912.11 1153819.21 -3906728.49
RVEL 4803.103 2796.877 -5395.539
AROT 74.23 25.95 109.15
VROT -21.58 -0.12 0.00
NAVFREQ 0 0
END
Fregat1:cvelfregat
STATUS Orbiting Jupiter
RPOS 1382961505.59 -1773017412.55 91469110.70
RVEL 9225.114 7424.196 4517.599
AROT 58.68 -46.71 26.38
RCSMODE 2
PRPLEVEL 0:0.814
NAVFREQ 0 0
XPDR 0
PAYLOAD ChapmanOuter ChapmanOuter SpacecraftChapmanOuter 0.00 -0.15 2.00 1365.00 0.00 1.00
END
END_SHIPS
BEGIN_ExtMFD
END
Code:
BEGIN_DESC
Return from 2002 DD1.
END_DESC
BEGIN_ENVIRONMENT
System Sol
Date MJD 67930.6780172302
END_ENVIRONMENT
BEGIN_FOCUS
Ship Fregat1
END_FOCUS
BEGIN_CAMERA
TARGET Fregat1
MODE Cockpit
FOV 10.00
END_CAMERA
BEGIN_HUD
TYPE Docking
NAV 0
END_HUD
BEGIN_MFD Left
TYPE User
MODE TransX
Ship Fregat1
FNumber 4
Int 0
Orbit True
Vector 507495511656 39678532988 -565185221352
Vector 8288.67645627 -7933.02175274 7991.49427869
Double 1.32712439955e+020
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Handle Sun
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Handle Jupiter
Select Target
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Int 4
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END_MFD
BEGIN_MFD Right
TYPE User
MODE TransX
END_MFD
BEGIN_SHIPS
Delta4HV:Delta4HVD4HV
STATUS Orbiting Sun
RPOS 498142620302.76 -16059118136.52 -427102261134.31
RVEL 13244.014 -3933.843 7435.406
AROT -16.78 -71.13 -7.50
RCSMODE 2
PRPLEVEL 2:0.028
NAVFREQ 0 0
CONFIGURATION 2
PAF 3
MET 1050310661.8
HEIGHT 25.0
UPGRADE
END
Delta4HV-STG1:Delta4HVD4HVcore
STATUS Orbiting Sun
RPOS -10157694110697.96 452833472510.93 -31641598853605.69
RVEL 7117.026 -3204.717 -21153.522
AROT 77.00 40.35 -120.57
VROT -4311.93 5566.79 -6.47
NAVFREQ 0 0
END
Delta4HV-LHF:Delta4HVD4HVfair3
STATUS Orbiting Sun
RPOS -12111956727.05 3189372486.32 -156208760567.47
RVEL 29857.592 358.814 -5215.212
AROT -102.87 -32.89 69.93
VROT -21.58 -0.12 0.00
NAVFREQ 0 0
END
Delta4HV-RHF:Delta4HVD4HVfair3
STATUS Orbiting Sun
RPOS 22184769518.70 -6709112050.64 -125140963383.51
RVEL 33213.803 -3050.830 -1059.202
AROT 7.73 -70.33 149.85
VROT -21.56 -0.12 0.00
NAVFREQ 0 0
END
Fregat1:cvelfregat
STATUS Orbiting Sun
RPOS 507495511655.56 39678532988.04 -565185221351.61
RVEL 8288.676 -7933.022 7991.494
AROT -102.74 8.06 -53.10
PRPLEVEL 0:0.260
NAVFREQ 0 0
XPDR 0
PAYLOAD ChapmanOuter ChapmanOuter SpacecraftChapmanOuter 0.00 -0.15 2.00 1365.00 0.00 1.00
END
END_SHIPS
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Cmon fly, you got to do a youtube type audio/video all encompassing transx tutorial focusing on slings. It is positively criminal for one person to have such an overwhelming mastery of transx while the rest of us (me) have bupkus.:compbash2:
flytandem
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I have only done the planning for the following Trojan flight for anyone wanting to fly it.
The planning actually allowed to plan the maneuver located between the Jupiter sling and the Trojan. The way it's done is to first set up the sling plan and use the sling view at Jupiter as a guide to fine tune the Earth eject velocities to arrive exactly on the sling position. Then turn off the sling in the Jupiter to Trojan stage by going to setup and choosing autoplan=off then plan=none. Now all that's showing is your flight path in green. Then get the maneuver view showing in stage 1 and toggle through all the stages to the stage showing the trip from Jupiter to the Trojan. You can now set up the maneuver to make an arrival exactly at the Trojan. But I warn you that it takes a long time to advance the date such a long way. Date starts at the current date which in my case was Jan 1 2011 and the maneuver date was something like 18 years of advancing the date which took nearly 10 minutes of holding the + key.
. Maybe TransX needs an EXTRA-COARSE date increment? I suggest to just set up the sling and don't plan the maneuver to hit the Trojan until you are in that stage and need it.
Planning Details for "2005 MG24"
Depart Earth MJD 56968.4312
Pro= 8.966 Km/s
Out= 0
PlCh=1.42 Km/s
Encounter Jupiter on MJD 58375.0
Set up manual sling to target "2005 MG24"
sling velocity = 6711 m/s
sling date= MJD 58375.0
outward= 0 degrees
inclination= -112.8 degrees
Note: arrival at Jupiter is a bit slow so a prograde burn at the Pe of about 258 m/s (according to this rough plan) is needed but the actual value you need will be shown in the sling view during the sling.
Possible maneuver to hit the Trojan is about 785 m/s with encounter speed of 541 m/s. These are also quite rough so your mileage will vary.
Total dv after the Earth eject is therefore in theory about 1584. But likely there will be 200 m/s in MCC going to Jupiter and another 100 m/s in MCC going to the Trojan so total dv would be in the order of 1900 m/s.
All that's left is to fly it.
The planning actually allowed to plan the maneuver located between the Jupiter sling and the Trojan. The way it's done is to first set up the sling plan and use the sling view at Jupiter as a guide to fine tune the Earth eject velocities to arrive exactly on the sling position. Then turn off the sling in the Jupiter to Trojan stage by going to setup and choosing autoplan=off then plan=none. Now all that's showing is your flight path in green. Then get the maneuver view showing in stage 1 and toggle through all the stages to the stage showing the trip from Jupiter to the Trojan. You can now set up the maneuver to make an arrival exactly at the Trojan. But I warn you that it takes a long time to advance the date such a long way. Date starts at the current date which in my case was Jan 1 2011 and the maneuver date was something like 18 years of advancing the date which took nearly 10 minutes of holding the + key.
. Maybe TransX needs an EXTRA-COARSE date increment? I suggest to just set up the sling and don't plan the maneuver to hit the Trojan until you are in that stage and need it. Planning Details for "2005 MG24"
Depart Earth MJD 56968.4312
Pro= 8.966 Km/s
Out= 0
PlCh=1.42 Km/s
Encounter Jupiter on MJD 58375.0
Set up manual sling to target "2005 MG24"
sling velocity = 6711 m/s
sling date= MJD 58375.0
outward= 0 degrees
inclination= -112.8 degrees
Note: arrival at Jupiter is a bit slow so a prograde burn at the Pe of about 258 m/s (according to this rough plan) is needed but the actual value you need will be shown in the sling view during the sling.
Possible maneuver to hit the Trojan is about 785 m/s with encounter speed of 541 m/s. These are also quite rough so your mileage will vary.
Total dv after the Earth eject is therefore in theory about 1584. But likely there will be 200 m/s in MCC going to Jupiter and another 100 m/s in MCC going to the Trojan so total dv would be in the order of 1900 m/s.
All that's left is to fly it.
BrianJ
Addon Developer
@Piper - I'm glad the IEATMFD came in handy for you. I've put it up on OrbitHangar. Probably better if you link to it there, as it may get cleared off my little "utility" website in due course.
Incidentally, I'm just finishing up an epic and interesting journey with one of your "Chapman Ion 2" probes. Launched in Nov.2011 on a DeltaII 7925 to 160km x 83000km Earth orbit, took 14 months to push the apogee out to the Moon for a sling-shot into heliocentric orbit of 1AU x 1.13AU. From there, I went for a sling-shot around Mars and on to 90 Antiope, arriving in May 2019 with 10km/s dV still remaining. (Note: 90 Antiope is not a good place to get too close to if you only have an Ion engine to keep yourself out of harm's way. That's got to be the swirliest gravity field in the solar system! see pic)
From there I was going to try to make it to one of the Jupiter Trojans, but I found that IMFD "Map" just won't give you a long enough trajectory prediction to plan it out properly. So, I went for 4 Vesta instead. Arrived at Vesta in Feb.2023 with about 5km/s dV left. Now I'm trying to get back to Earth via another Mars sling-shot, but only 2km/s dV left...don't know if I'm going to make it. Damn good fun though - thanks for the "Chapmans" and the inspiration for another outing with Ion drive
All the best,
Brian
Incidentally, I'm just finishing up an epic and interesting journey with one of your "Chapman Ion 2" probes. Launched in Nov.2011 on a DeltaII 7925 to 160km x 83000km Earth orbit, took 14 months to push the apogee out to the Moon for a sling-shot into heliocentric orbit of 1AU x 1.13AU. From there, I went for a sling-shot around Mars and on to 90 Antiope, arriving in May 2019 with 10km/s dV still remaining. (Note: 90 Antiope is not a good place to get too close to if you only have an Ion engine to keep yourself out of harm's way. That's got to be the swirliest gravity field in the solar system! see pic)
From there I was going to try to make it to one of the Jupiter Trojans, but I found that IMFD "Map" just won't give you a long enough trajectory prediction to plan it out properly. So, I went for 4 Vesta instead. Arrived at Vesta in Feb.2023 with about 5km/s dV left. Now I'm trying to get back to Earth via another Mars sling-shot, but only 2km/s dV left...don't know if I'm going to make it. Damn good fun though - thanks for the "Chapmans" and the inspiration for another outing with Ion drive
All the best,
Brian
flytandem
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Wow Brian. When I get up the nerve I'll have to try to get the ion engine Chapman and the IEATMFD to drive it. It sounds like more of an art form than the strong thrust but short duration burns I am used to.
I did finish up the flight of the plan (2 posts above) to "2005 MG24". Very much as planned with 2277 m/s remaining in the Fregat on landing at the Trojan. So I set up a plan to go for Saturn with a gravity well, low Pe, capture and then at the subsequent very high Ap I raised the Pe and aligned with "Siarnaq". It also was very weird. It danced all over the place. Both TransX and IMFD were agreeing with each other but showing a constant rapid change as to where Siarnaq was going to be. I suspect there is something wrong with its trajectory. But what do I know. It definitely seemed to dance to the beat of a different source of gravity than the one the ship was moving to. But eventually, I had a landing there with 1650 m/s left in the Chapman. However looking around there just isn't quite enough fuel to go elsewhere. I am a couple hundred m/s short of being able to go splat into the atmosphere of Titan.
Ohhh so close....
-----Post Added-----
rethought about how to get to Titan and managed to find a more efficient combination of maneuvers and arrived with a nice soft aerobrake at Titan's lofty atmosphere with an average of a fraction of a G deceleration (max was 1G) to a soft .2 m/s vertical speed on landing with 185 m/s dv left in the can. Too bad Chapman doesn't have legs to stand on.
-----Post Added-----
I think I figured out the download of the ion. Ran the ion 1 scenario. Will start a tour of outer planets with a sling off the moon. That Atlas upper stage sure has weak thrust. :rofl: It's funny because I am about to find out what "weak thrust" really means. Image of just after the sling at the moon, used the remaining fuel in the atlas for a gravity well burn, then jettisoned the probe.
I did finish up the flight of the plan (2 posts above) to "2005 MG24". Very much as planned with 2277 m/s remaining in the Fregat on landing at the Trojan. So I set up a plan to go for Saturn with a gravity well, low Pe, capture and then at the subsequent very high Ap I raised the Pe and aligned with "Siarnaq". It also was very weird. It danced all over the place. Both TransX and IMFD were agreeing with each other but showing a constant rapid change as to where Siarnaq was going to be. I suspect there is something wrong with its trajectory. But what do I know. It definitely seemed to dance to the beat of a different source of gravity than the one the ship was moving to. But eventually, I had a landing there with 1650 m/s left in the Chapman. However looking around there just isn't quite enough fuel to go elsewhere. I am a couple hundred m/s short of being able to go splat into the atmosphere of Titan.
Ohhh so close....-----Post Added-----
rethought about how to get to Titan and managed to find a more efficient combination of maneuvers and arrived with a nice soft aerobrake at Titan's lofty atmosphere with an average of a fraction of a G deceleration (max was 1G) to a soft .2 m/s vertical speed on landing with 185 m/s dv left in the can. Too bad Chapman doesn't have legs to stand on.
-----Post Added-----
I think I figured out the download of the ion. Ran the ion 1 scenario. Will start a tour of outer planets with a sling off the moon. That Atlas upper stage sure has weak thrust. :rofl: It's funny because I am about to find out what "weak thrust" really means. Image of just after the sling at the moon, used the remaining fuel in the atlas for a gravity well burn, then jettisoned the probe.
Piper, I was testing out some things with the latest Chapman probes and noticed something in the configs for the AtlasV launchers. The thrust for stage 2 (in this case the Centaur) in the dual engine centaur configurations (for example AtlasV 4x2) seem to have the same thrust as the single engine centaur -- 99.2 kN.
I was wondering if that's just a typo or if I'm just reading things incorrectly.
The other changes to the probes are great - no more tumbling during aerobraking.
-- Mike
I was wondering if that's just a typo or if I'm just reading things incorrectly.
The other changes to the probes are great - no more tumbling during aerobraking.
-- Mike
flytandem
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It's interesting flying with such low thrust. Tough when it comes to gravity well burns where the thrust is really supposed to be at a specific time. But once out between the planets it's really just like any other ship. One simply gets used to holding down the thrust and toggling up the time warp to 100K for a few seconds.
My trip this morning took me from the sling of the moon out to a long prograde acceleration to allow a Jupiter intercept at whatever date it happened to be. From there I looked at what Trojan had a node about that sling date and I set up the sling as usual with all burns at a specific attitude. I knew arriving fast would be an issue so I planned a couple of softening burns first about 6 months ahead and the second 2 weeks ahead that allowed an arrival of about 15 m/s which meant I had to start the final braking burn a bit under 1 day before the Pe. Here's a pic of Chapman Ion1 in orbit around "1999 XJ55". About 9900 m/s remaining in the ship.
My trip this morning took me from the sling of the moon out to a long prograde acceleration to allow a Jupiter intercept at whatever date it happened to be. From there I looked at what Trojan had a node about that sling date and I set up the sling as usual with all burns at a specific attitude. I knew arriving fast would be an issue so I planned a couple of softening burns first about 6 months ahead and the second 2 weeks ahead that allowed an arrival of about 15 m/s which meant I had to start the final braking burn a bit under 1 day before the Pe. Here's a pic of Chapman Ion1 in orbit around "1999 XJ55". About 9900 m/s remaining in the ship.
flytandem
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LOL and a big "duh".
I had done a pretty clean climb to orbit on that flight the other day with the Ion on the Atlas and just squeaked to the moon with about 10 m/s to spare which I mentioned above that I used to give an extra push in the moon gravity well. This morning I did several more practice launches and I was on average about 5 m/s short of being able to make it to the moon. The ion wouldn't give much in the 3 day trip so I opted to abort each flight.
Then I tried something.... tossing the nose fairing once in Earth parking orbit, and what a difference. The available deltaV changed from 3120 m/s to over 5400 m/s. Duh! It also explains why I have been having such weak thrust from the upper stage. It improved by 60 or 80% by dropping the nose fairing.
So I did another flight and this time dropped the fairing at the start of the upper stage. And once in orbit, it showed I had enough deltaV (5846m/s) to nearly make it to Jupiter just from the upper stage. What a fuel savings. This means a LOT LESS burning of fuel with the ion.
I suppose the question is... what's the soonest that one can drop the fairing and still be realistic? When the first stage is dropped and the upper stage ignites?
I had done a pretty clean climb to orbit on that flight the other day with the Ion on the Atlas and just squeaked to the moon with about 10 m/s to spare which I mentioned above that I used to give an extra push in the moon gravity well. This morning I did several more practice launches and I was on average about 5 m/s short of being able to make it to the moon. The ion wouldn't give much in the 3 day trip so I opted to abort each flight.
Then I tried something.... tossing the nose fairing once in Earth parking orbit, and what a difference. The available deltaV changed from 3120 m/s to over 5400 m/s. Duh! It also explains why I have been having such weak thrust from the upper stage. It improved by 60 or 80% by dropping the nose fairing.
So I did another flight and this time dropped the fairing at the start of the upper stage. And once in orbit, it showed I had enough deltaV (5846m/s) to nearly make it to Jupiter just from the upper stage. What a fuel savings. This means a LOT LESS burning of fuel with the ion.
I suppose the question is... what's the soonest that one can drop the fairing and still be realistic? When the first stage is dropped and the upper stage ignites?
The fairing is dropped far before orbit.
I'm not sure exactly when it is dropped, but I'm guessing it is just after stage 1 seperation.
Drop the fairing then and you'll probably get even more Dv.
EDIT:
I thought you dropped the fairing on-orbit. In that case, yes. Around then should do fine.
I'm not sure exactly when it is dropped, but I'm guessing it is just after stage 1 seperation.
Drop the fairing then and you'll probably get even more Dv.
EDIT:
I thought you dropped the fairing on-orbit. In that case, yes. Around then should do fine.
flytandem
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The CD I got from atuhalpa had the fairing drop automatically. The downloaded scenarios for the Chapman Ion require it to be done manually I suppose. Is there a way to make it automatic?
....There I was at the Pe of the moon, still attached to the upper stage, enclosed in the fairing and the "J" for jettison wasn't working. I sat there using external camera, touching every key in order Q W E R T Y ... etc until finally touching "F" had the fairing pop off. I knew I would easily find my way to Jupiter if only I could get the Ion out of its cage.
....There I was at the Pe of the moon, still attached to the upper stage, enclosed in the fairing and the "J" for jettison wasn't working. I sat there using external camera, touching every key in order Q W E R T Y ... etc until finally touching "F" had the fairing pop off. I knew I would easily find my way to Jupiter if only I could get the Ion out of its cage.
flytandem
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I just flew the Chapman Ion 2 launched from Atlas V-422 and discovered something about TransX I had not known before. A previous post I made mentioned that it's a bummer that after separating from the launch vehicle, the Chapman probe needs to have the TransX plan reinstalled from scratch. Well it turns out that's not really true. But with a caveat. By going back to stage 1 and then back one more time there is a display to state where the plan is inherited from. Click the + to choose the Atlas or whatever craft had the plan you want and then click EXE. Voila the plan is brought into the Chapman.
But there is a problem that makes this not a wise thing to do. I suspect a bug that some day Steve may fix in a future version of TransX. Seems (I could be wrong) that the plan details are not full inherited. Some details are left behind. Any maneuver that's set up is left behind and also the orbits to icept is left behind. And the loss of orbits to icept may be causing a lockup of the sim when it advances to where this value is supposed to toggle down in value.
This morning I flew a fun flight where the Chapman Ion 2 left Earth to sling Venus, Mercury, Venus, Earth, Mars, and returned to Earth to aerobrake a low orbit, total Chapman fuel used was about 3% of the tank. But I had a lot of crashes with the sim just locking up and I would have to start up from the previous save. After I did a save without TransX in an MFD and after restart, recreated the rest of the TransX plan from my current position in the sling cascade the sim again became stable.
Like everything I've done with orbiter so far, it's just trial and error. And there's so much more to learn.
cheers everyone.
But there is a problem that makes this not a wise thing to do. I suspect a bug that some day Steve may fix in a future version of TransX. Seems (I could be wrong) that the plan details are not full inherited. Some details are left behind. Any maneuver that's set up is left behind and also the orbits to icept is left behind. And the loss of orbits to icept may be causing a lockup of the sim when it advances to where this value is supposed to toggle down in value.
This morning I flew a fun flight where the Chapman Ion 2 left Earth to sling Venus, Mercury, Venus, Earth, Mars, and returned to Earth to aerobrake a low orbit, total Chapman fuel used was about 3% of the tank. But I had a lot of crashes with the sim just locking up and I would have to start up from the previous save. After I did a save without TransX in an MFD and after restart, recreated the rest of the TransX plan from my current position in the sling cascade the sim again became stable.
Like everything I've done with orbiter so far, it's just trial and error. And there's so much more to learn.
cheers everyone.
Piper
Orbiting Space Addict
Sorry for not posting this earlier, real-life rather came at me like a out of control freight-train, so I haven't been able to do much things Orbiter in the last few weeks. As such, the next Chapman Challenge is going to be a bit delayed until the end of March.
flytandem
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Definitely take care of real life.
Will do laps to the moon in the mean time.
