Chapman Challenge

[astrosammy]

Yes, I reentered and landed. I always wanted to use a shuttle with IUS, after seeing some cool pictures of IUS deployments:

 

[T.Neo]

:speakcool:

 

[Piper]

Wonderful job Astrosammy, those pics look fantastic!

 

[atuhalpa]

Chapman challenge basic

Atuhalpa's Chapman challenge report:

Launch vehicle: Atlas 551
Launch Date: 55993.1069
Location: Kourou
IMFD: Surface launch
Transx: Ejection and subsequent course corrections

LEO: 84% fuel 2nd stage
Post eject: 8.9% fuel 2nd stage
1st mid course @ 56027.5807 7.7% fuel 2nd stage
2 additional minor course corrections to maintain PeA @100kms~

Aerobrake positioning @ 56085.0291 7.3% fuel 2nd stage
1st aerobrake pass @ PeA 85.72kms; ApA 7.215Mms
2nd aerobrake pass @ PeA 82.88kms; ApA 1.958Mms
Orbit circularization@ .0001 Ecc; ApA 562.5kms 2.7% fuel 2nd stage
Mission complete @ 56085.3879

 

[atuhalpa]

I can't thank Piper and the rest of you dedicated people enough for the wonderful gift that Orbiter is. I used to fly online combat flight sims and play RTS games rabidly. Now I educate myself and delve into Orbiter rabidly. I had a great time piloting Deepstar, Vespucci, and even the Millenium Falcon, but attempting realistic and challenging scenarios such as the Chapman challenge has taught me and stimulated my pleasure and reward centers way more than the futuristic scenarios ever did. As we used to do in IL2 Strumovik: <S!> (Salute) to all who make Orbiter the international phenomena that it is.

Sincerely, Atuhalpa.

 

[Zachstar]

Just a note here.

The Centaur push stage uses fuel that boils away over time in space. It will be a dead hulk by the time it gets to venus much less have any fuel to do anything.

With serious modifications it may keep most of its remaining fuel to make it to the moon but no way outside of that!

 

[mjanicki]

The Centaur push stage uses fuel that boils away over time in space. It will be a dead hulk by the time it gets to venus much less have any fuel to do anything.

I knew there was a reason I shouldn't have carried the Centaur with me. Thank you for this information. It will help when planning future challenges and other voyages.

 

[atuhalpa]

MPCORB viewer problems

When I try to export anything into orbiter I get a run time error 76. Any thoughts?

Atuhalpa.

 

[astrosammy]

Maybe running this in the background helps: [ame="http://www.orbithangar.com/searchid.php?ID=1059"]Format converter[/ame].

 

[atuhalpa]

Thanks sammy. I fixed the problem by turning on some stuff I had turned off in "startup"

 

[atuhalpa]

Piper, is it kosher to use a Delta4HV upgrade with a fregat to do the advanced challenge?

I need all the help I can get......................

 

[Piper]

Piper, is it kosher to use a Delta4HV upgrade with a fregat to do the advanced challenge?

I need all the help I can get......................

Sure, but I'll tell you right now that you don't need that much dV to complete it. All you need is enough dV to get to Jupiter with a basic Hohmann transfer, find a leading trojan with an inclination between about 30 and 40 degrees, and time your depature so that when you do a fly-by Jupiter you do it at about the same time you cross the trojan's node. I posted a scenario that gets you to 2001 DZ3 that has an encounter veloctiy of about 1200m/s (iirc). Here is another scenario for Meges, a larger trojan (about 50km in diameter), and one that gave me an encounter velocity of only about 950m/s. The scenario uses an Atlas V 552, but you can of course change it to anything you like.

BEGIN_DESC
Launch Chapman 14, onboard a Atlas 552, to the Jupiter Trojan "Meges."  Swing-by Jupiter to get to it and put yourself into orbit around it.
END_DESC

BEGIN_ENVIRONMENT
  System Sol
  Date MJD 58131.7
END_ENVIRONMENT

BEGIN_FOCUS
  Ship AtlasV
END_FOCUS

BEGIN_CAMERA
  TARGET AtlasV
  MODE Extern
  POS 2.89 0.74 -110.96
  TRACKMODE TargetRelative
  FOV 50.00
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_MFD Left
  TYPE User
  MODE TransX
  Ship  AtlasV
  FNumber 5
  Int 1
  Orbit True
  Vector  396451.035217 5007999.44854 -3918269.51067
  Vector  407.451098393 -11.5045207652 26.5218550764
  Double  3.98600439969e+014
  Double  56548.006728
  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
Base Orbit
0 0
Prograde vel.
 0  0
Man. date
 0  56548.006539
Outward vel.
 0  0
Ch. plane vel.
 0  0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
Pe Distance
 0  7645212
Ej Orientation
 0  0
Equatorial view
0 0
Finvars
  Finish BaseFunction
  Int 2
  Orbit False
  Handle Sun
  Handle Earth
  Handle Jupiter
Select Target
 0 Jupiter
Autoplan
0 0
Plan type
0 2
Plan
0 0
Plan
0 0
Plan
0 1
Select Minor
 0 None
Manoeuvre mode
0 0
Base Orbit
0 1
Prograde vel.
 0  0
Man. date
 0  56548.0067283
Outward vel.
 0  0
Ch. plane vel.
 0  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  8760.57269615
Eject date
 1  58132.9502884
Outward vel.
 1  73
Ch. plane vel.
 0  -770
Finvars
  Finish BaseFunction
  Int 4
  Orbit True
  Vector  340743866703 -7890259262.32 334176971692
  Vector  -4709.35265714 162.83282363 -4633.64143142
  Double  1.26686534397e+017
  Double  58110.8118354
  Handle Jupiter
  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
Base Orbit
0 0
Prograde vel.
 0  0
Man. date
 0  56548.006704
Outward vel.
 0  0
Ch. plane vel.
 0  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  154573448826 -8025716674.09 -769844088380
  Vector  10264.5498094 -6403.91442202 2855.54194119
  Double  1.32839126489e+020
  Double  58929.7627551
  Handle Sun
  Handle Jupiter
  Handle Meges
Select Target
 0 Meges
Autoplan
0 0
Plan type
0 2
Plan
0 0
Plan
0 0
Plan
0 2
Select Minor
 0 None
Manoeuvre mode
0 0
Base Orbit
0 0
Prograde vel.
 0  0
Man. date
 0  56548.0067283
Outward vel.
 0  0
Ch. plane vel.
 0  0
Intercept with
0 0
Orbits to Icept
0 1
Graph projection
0 0
Scale to view
0 2
Advanced
0 0
Velocity.
 0  0
Outward angle
 3  -0.0284314135146
Inc. angle
 4  1.92229830777
Inherit Vel.
0 0
Eject date
 0  58929.7627551
Finvars
  Finish BaseFunction
  Int 5
  Orbit False
  Handle Meges
  Handle NULL
  Handle NULL
Select Target
 0 None
Autoplan
0 0
Plan type
0 1
Plan
0 0
Plan
0 2
Plan
0 0
Select Minor
 0 None
Manoeuvre mode
0 0
Base Orbit
0 1
Prograde vel.
 0  0
Man. date
 0  56548.0066945
Outward vel.
 0  0
Ch. plane vel.
 0  0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
Draw Base
0 0
Finvars
  Finish BaseFunction
END_MFD

BEGIN_MFD Right
  TYPE User
  MODE TransX
END_MFD

BEGIN_SHIPS
AtlasV:MultistageMultistage2
  STATUS Landed Earth
  BASE LC41:1
  HEADING 90.00
  FUEL 1.000
  CONFIG_FILE ConfigATLASV500_SeriesDual_Engine_CentaurShort_FairingAV552_Chapman.ini
  CONFIGURATION 0
  CURRENT_BOOSTER 1
  CURRENT_STAGE 1
  CURRENT_PAYLOAD 1
  FAIRING 1
END
END_SHIPS

-----Post Added-----


The advanced challenge seems to be a bit too difficult for most people, so I'm changing the advanced challenge slightly, you no longer need to orbit the Jupiter Trojan, just fly-by it (after a fly-by of Jupiter), and the bonus is to orbit it. I'm also extending the challenge until the end of February.

Modified Advanced Challenge:
HTML clipboard

• Mission Goal: Swing-by Jupiter, then fly-by any Jupiter Trojan asteroid​
  • Bonus: Orbit the Trojan instead of flying-by it​
• Spacecraft: Chapman Outer​
• Launch Location: Your Choice​
• Launch Vehicle: Your Choice​
• Launch Window: 55562.0000 and onward - Anytime after January 1st 2011​
• Required Add-ons:​
  • [ame="http://www.orbithangar.com/searchid.php?ID=1436"]MPC Database Viewer/Exporter[/ame] by Joseph Morgan​

Also to assist those searching for usable trojans to fly-by, I've created a zip file with 35 possible candidates for completing the challenge with the bonus (I've only tested Meges out of the bunch, but most of the others should be good too):

Jupiter Trojans

As for the Regular Challenge, I realized that when I tested it, the ChapmanInner1 I was using was slightly different then the one I released. Add this to the beginning of your ChapmanInner1.ini:

[AERODYNAMICS]
RUDDER_ATTACK=(0,0,0)
RUDDER_AREA=0.0001 ; no rudder
RUDDER_LIFT=0
AILERON_AREA=0.0001 ; no aileron
AILERON_LIFT=0
AILERON_ATTACK=(0,0,0)
ELEVATOR_AREA=0.0001 ; no elevator
ELEVATOR_LIFT=0
ELEVATOR_ATTACK=(0,0,0)
ELEVATOR_TRIM_AREA=0.0001
ELEVATOR_TRIM_LIFT=0
ELEVATOR_TRIM_ATTACK=(0,0,0)
RUDDER_TRIM_ATTACK=(0,0,0)
RUDDER_TRIM_AREA=0.0001 ; no rudder trim
RUDDER_TRIM_LIFT=0
FLAPS_ATTACK=(0,0,0)
FLAPS_AREA=0.0001 ; no flaps
FLAPS_LIFT=0
VAIRFOIL_ATTACK=(0,0,-0.2)
VAIRFOIL_CHORD=1.4
VAIRFOIL_AREA=4.2
VAIRFOIL_ASPECT=2.14
VAIRFOIL_WAVE_DRAG=0.2
VAIRFOIL_CD0=0.2
HAIRFOIL_ATTACK=(0,0,-0.2)
HAIRFOIL_CHORD=1.4
HAIRFOIL_AREA=4.2
HAIRFOIL_ASPECT=2.14
HAIRFOIL_WAVE_DRAG=0.2
HAIRFOIL_CD0=0.2
HAIRFOIL_LIFT_1=(-180,0)
HAIRFOIL_LIFT_2=(0,0)
HAIRFOIL_LIFT_3=(180,0)
VAIRFOIL_LIFT_1=(-180,0,0)
VAIRFOIL_LIFT_2=(0,0,0)
VAIRFOIL_LIFT_3=(180,0,0)

This should correct any chaotic tumbling when aerobraking.

 

[Whatu]

Ok, I'm approaching venus now, though my ejection burn wasnt exactly perfect...

So, for aerobraking...

What are the structural limits of the probe? How much g's and how much dynamic pressure is recommended?

Its possible to slow down enough to be captured in the first pass?

I want to finish this one and try to flybly a trojan Thanks

 

[Piper]

Ok, I'm approaching venus now, though my ejection burn wasnt exactly perfect...

So, for aerobraking...

What are the structural limits of the probe? How much g's and how much dynamic pressure is recommended?

In real-life, the probe probably wouldn't do anything more then 0.01gs, and just do dozens or hundreds of aerobrakes.

Obviously, I don't expect people to do that many, but you should limit it to no greater then 0.5gs.

Its possible to slow down enough to be captured in the first pass?

No, the probe would burn up without a heatshield.

I want to finish this one and try to flybly a trojan Thanks

Good luck!

 

[atuhalpa]

Chapman advanced

Wow! Piper I just emulated the initial transx setup and ejection burn for your Trojan Meges encounter. I believe I will be able to duplicate your feat, no doubt with many saves and "do overs", but I must commend you on your concepts. Maybe all seasoned Orbiter afficianados know what you have shown me with the meges setup, but you certainly expanded my understanding of what a flyby can accomplish depending on proximity, inclination and velocity! I will post my results, but must withdraw from formal competition in the advanced challenge. Thanks for your "puzzles".

 

[atuhalpa]

Chapman advanced completed

Piper I completed the advanced mission, but only because you posted your flight plan..............I learned a lot and enjoyed all of the concepts involved completing this challenge.

Delta 4 heavy, fregat, Kourou, Launch 58132

Thanks for the challenge................

 

[Piper]

Piper I completed the advanced mission, but only because you posted your flight plan..............I learned a lot and enjoyed all of the concepts involved completing this challenge.

Delta 4 heavy, fregat, Kourou, Launch 58132

Thanks for the challenge................

Finally! Somebody who has completed the advanced challenge! Now let's see if someone can get into orbit around a trojan.

By the way, in case anybody has been following the competition, and hasn't seen, I've released a newer version of the [ame="http://www.orbithangar.com/searchid.php?ID=789"]Chapman probes[/ame]. It fixes the problem people were having with aerobraking with a Chapman probe, and fixes the incorrect weights in the given scenario files.

 

[atuhalpa]

Piper, that is a ChapmanOuter in orbit around Meges. Here is another screen shot. I guess I didn't make it clear in my post. I must reiterate that had it not been for the posting of your Meges flight plan I would still be floundering. Once I studied your plan the light came on and the rest was basically routine.

I have archived every critical juncture in the mission if you want more specific data.

 

[Piper]

Piper, that is a ChapmanOuter in orbit around Meges. Here is another screen shot. I guess I didn't make it clear in my post. I must reiterate that had it not been for the posting of your Meges flight plan I would still be floundering. Once I studied your plan the light came on and the rest was basically routine.

I have archived every critical juncture in the mission if you want more specific data.

Sorry, I didn't realize that those were from orbit, even better!

 

[atuhalpa]

Chapman challenge postscript:

For my own edification I am going to orbit a Trojan using my own flight plan and the MPC viewer. Then and only then will I feel I have truly completed the challenge.