Going to the moon and back 2011 [DGIV realistic settings]

[PriestLizard]

Hi there.

I'd like to present to you my first real challenge in orbiter. Actually I don't only post it because I think its kind of interesting - but also because I might need your help in solving the last stage of this challenge (haven't figured out a solution yet). Its not an hard challenge for experienced Orbiters I believe... but it might be interesting for starters like me.

This challenge is about mission SEP-3, my little Space Exploration Program, where I wanted to gain some more experience with more advanced missions (which means: more than going to ISS and back ).

The objective for SEP-3 was to go to the moon. Thats basically it. With SEP-1 I reached lunar orbit but didn't touch down. So SEP-3 was/is supposed to land on the moon. The restrictions were:

- The year is 2011 and NASA has just started to use its new DeltaGlider IV. No other advanced spacecrafts are available (no XR-x etc.).
- Of course any real spacecrafts from these days may be used. Personally I have some "launchers" like Vega or Ariane, but I don't know enough about scenario editing to use them... that's why I sticked to DGIV only.
- Settings for DGIV: Realistic fuel settings, which means DGIV is only capable of reaching LEO w/o help. This is the most important part which makes this mission a challenge after all.
- Payload! One payload of fuel (for DGIV) has a weight of 2232kg... so the maximum fuel you could get out of these would be ~2000kg.
- Think of reasonable cost calculations! Launching a DGIV might cost several million dollars so be careful to use more spacecrafts than essentially needed.

Objective: Land on the moon and come back.

---

Now my approach to this scenario. I already figured out I haven't done everything right, which might be the reason why I'm in trouble late into the scenario. But more about that later.

I used two vessels. The first one, Columbia II (actually performing SEP-2), was intended to reach LEO with suitable Inc for fuel transfer. The second, Serenity (SEP-3), would take-off, meet the Columbia II in orbit, refuel, then start its journey to the moon.

Both vessels had an extra fuel-tank as payload with ~2000kg of extra fuel. When I started the mission I didn't have the island airport yet, so I started at KSC which is bad for moon trips. But OK. Both vessels started with AP heading for 90°. The rendevouz in LEO was actually fun... I already docked to ISS many times but meeting another "small" vessel in orbit was really cool.

I performed an EVA to dock Serenity to the extra fuel pod launched by Columbia II which brought some extra 2000kg of fuel. I did the trans-lunar burn with Serenity (using LunarMFD) and then landed the other ship at KSC (actually the first time I ever hit the perfect center of the runway ^^). After deorbit burn, the Columbia II had about 25% of fuel left! This was a mistake by myself. These 25% would have helped the Serenity a lot!! I had to use the fuel with Columbia II though as I came down a little bit short to KSC but thats another mistake by myself. These things should have done a lot better.

Anyway Serenity reached a low lunar orbit on FD7. Before that, I did a maneuver to use the second fuel pod: Releasing the payload, rotate and dock - another fun maneuver. Still fuel was already very low after lunar orbit insertion so I thought about quitting the mission and heading back to earth again but hmmm... I pushed myself to try it. I began the landing sequence, retro burn and hover AP, smooth touchdown on 8:31:18 of May 4th

Launching from lunar surface at the end of the same day and letting LunarMFD do the TEI on 20:39:44. Thats the situation now and I haven't continued with the mission since then (actually yesterday).

Some orbit parameters with reference to Earth:
PeR 5.850M
ApR 0.009AU
Fuel: 651kg left (main + RCS!)

---

Now the question is: the fuel will probably not be enough to do a earth orbit burn AND a reentry burn. If I could reach earth orbit, its OK, I could do another rendevouz, refuel, and land. But I doubt that the fuel will be enough to reach a stable earth orbit (look at the high eccentrity of the orbit parameters).

I already know some mistakes during my mission. LunarMFD also did a very fuel-consuming transfer burn (the interception was not in the highest point of orbit, but rather right in the middle, so a lot of energy was wasted). However I want to finish this mission so the sub-challenge of this mission is to now bring Serenity back home safely.

I have to think about a possibility to launch another DGIV again and somehow meet the Serenity BEFORE it reaches the earth, do a refuel-rendevouz and then bring Serenity to a stable orbit. I don't know how complicated this will be.

Ideas? If you're interested in a scenario file, I can post it here.

See you

P.S.: Some pictures will be uploaded later!

 

[dougkeenan]

What is "LunarMFD" ?

 

[PriestLizard]

Ah sorry, I was talking about LunarTransferMFD of course: http://koti.mbnet.fi/jarmonik/Orbiter.html

 

[agentgonzo]

When coming back from the moon, you don't need to perform an Earth Orbit Insertion burn, or a reentry burn. You can come directly back in from the moon to a reentry. You will need to performa reentry 'inverted' at around 65km altitude. This will allow you to use the aerodynamic surfaces of the DGIV to pull you down into the Earth as you gradually aerobrake instead of flying through the atmosphere and back out to a large perigee.

There is a tutorial of how to do this with the XR2 that Tommy made using my technique [ame="http://www.orbithangar.com/searchid.php?ID=3660"]here[/ame]. That should save you a lot of fuel on the return leg.

If done correctly (and doing your TEI so that you reentre the Earth's atmosphere about 1/2-1/4 of the way away from your target base) you can perform an Apollo-stlye direct reentry and then turn heads-up once you've done most of the reentry to be able to glide deadstick to a runway landing.

I tried this method (with the XR2 I think) and found that you could do it with large payloads as long as you made your reentry slow enough to not burn up. I think that I did it on a reentry from Mars with a full load of fuel, but had to essentially perform one entire orbit of the Earth aerobraking to be able to aerobrake enough without burning up.

Edit: Here's the thread talking about direct reentry (with the XR2, but is possible with the DGIV as I mentioned in one of my posts)

 

[PriestLizard]

When coming back from the moon, you don't need to perform an Earth Orbit Insertion burn, or a reentry burn. You can come directly back in from the moon to a reentry. You will need to performa reentry 'inverted' at around 65km altitude. This will allow you to use the aerodynamic surfaces of the DGIV to pull you down into the Earth as you gradually aerobrake instead of flying through the atmosphere and back out to a large perigee.

There is a tutorial of how to do this with the XR2 that Tommy made using my technique here. That should save you a lot of fuel on the return leg.

If done correctly (and doing your TEI so that you reentre the Earth's atmosphere about 1/2-1/4 of the way away from your target base) you can perform an Apollo-stlye direct reentry and then turn heads-up once you've done most of the reentry to be able to glide deadstick to a runway landing.

I tried this method (with the XR2 I think) and found that you could do it with large payloads as long as you made your reentry slow enough to not burn up. I think that I did it on a reentry from Mars with a full load of fuel, but had to essentially perform one entire orbit of the Earth aerobraking to be able to aerobrake enough without burning up.

Edit: Here's the thread talking about direct reentry (with the XR2, but is possible with the DGIV as I mentioned in one of my posts)

Hi Gonzo!

I checked the thread about direct reentry and I tried your methods. Although your idea seems promising and I understand the concept behind it, I wasn't able to perform it good enough.

I tried to do the maneuver with an angle of about 3.5° (shown in the DGIV computer display D2) and a approx. speed of about 11m/s. Perigee was about 65km (before aerobreaking). I tried several AoAs, from 30°-50°, and I also tried your "inverted-reentry" as well as normal reentry. The result is always the same: Shortly before perigee and at a nose-temperature of about 1800° my nose goes up to an AoA of 0°, causing the temperature to rise exponentially and finally I see DESTROYED!

I managed to survive this maneuver if I decrease my reentry angle to about 3° (I also remember that in the DGIV manual it says that the DGIV can stand up to 3° angles), but then my orbit is still highly eccentric with an apogee waaaay deep into space (cant remember any numbers, but it extends lunar orbit). I'm not sure if this can't be a solution for my scenario because even though there is plenty of oxygen left (for about 8 days), I don't think it will be enough for another full "orbit".

I will try again later... now I gotta finish my seminar about Navier-Stokes-equations first :O

 

[the.punk]

And when you manage the burns (TLI, TOI) with LunarTransferMFD you could also try it with other MFD like (IMFD, TransX).
With lunartransferMFD it is very easy. But with transx or maybe IMFD it is more challenging for you you must DO something.
This is just an suggestion. Try it.

 

[MeDiCS]

Nice, I'm doing something like that with the DGIV: realistic O2 and fuel and one passenger (the pilot), but with a Mark II engine and no extra fuel. My DGIV is currently docked with the ISS after lift-off from Cape.

I have two possible 'missions', both involving the Moon:
1. Performing a flyby and returning to Earth without entering Moon's orbit, with a possible 'direct reentry'. TransX is possibly the best tool for this, but I've only used it once.
2. Actually landing on the Moon's surface, but ignoring Beach base completely, so no refuels. I actually don't know if I can do this...


Oh, and it seems that when performing direct reentry you need to be way too precise. Maybe you could use the ship's engines to help you slow down a bit before reentry?

 

[PriestLizard]

@the.punk: Yes of course. I'm still learning though so I will do that later. Right now I'm using TransX for LEO maneuvers (rendevouz) - I tried it once for TLI but I was way off

@MeDiCS: MarkII is an interesting option. I was a little bit foolish when I picked the MarkV (the strongest one) for my lunar vessel... probably this was a bad idea.
About your suggestion: The problem is that slowing myself down in this situation will not only reduce my speed, but also reduce my perigee - which will make my ship burn. Actually I think I have to increase my speed a little to increase my perigee. I'm not sure... gotta figure something out.

 

[MeDiCS]

When you do your burn to leave Moon's orbit, go for a bit higher perigee, then do another burn to reduce speed at like, minutes before reentry. Never tried this though.

 

[PriestLizard]

Ok, I made it. Thats how I've done it:

I burned prograde to decrease my reentry angle to 3°. Then I flipped backside to perform a gonzo-style inverted-entrance maneuver - pointing at an AoA of -50°. Without correction, this would have slowed me down enough to bring me into an earth orbit - but with a rather high apogee.
So what I did was using the rest of my main engine fuel to do correction burns (still pointing at ~50° inverted). I tried to keep my PeT arround zero, so I wouldn't rise too high while still keep control of my hull temperature.

I ended up with an apogee of 450k which is good enough. I flipped again to a normal heads-up position and when I reached my apogee I did another very short burn to raise my perigee from 65k to 400k which brought me to a stable LEO. I will launch my second vessel another time, refuel and do a nominal reentry - ultimately ending this mission successfully. Things would be better if I would be able to launch a rocket with a fuel pod..... but I don't know how to do that with the scenario editor yet. :/

This aerobreaking maneuver was probably the most hardest thing I did so far in Orbiter - and one of the most fun things. Thank you guys for your help too! I believe its possible to do a direct entry without going back to LEO... but I will wait for that untill my joystick arrives. Its a pain in the *** to keep your AoA with keyboard while doing correction burns etc.

Anyway... fun mission, fun solution... thanks guys.

 

[HiPotOk1978]

Interesting challenge you presented. I am gonna give it a try here.

My mission plan is going to be as follows...

1) Energia HLLV launch vehicle to get the spacecraft into LEO
[ame="http://www.orbithangar.com/searchid.php?ID=1036"]ENERGY project, release 3[/ame]

2) Delta Tug for most of the TLI burn
[ame="http://www.orbithangar.com/searchid.php?ID=1127"]Delta Tug, release 3[/ame]

3) Sputnik's Velcro Rockets to place 4x 1500kg drop tanks on the wings
[ame="http://www.orbithangar.com/searchid.php?ID=3388"]Velcro Rockets v1.1[/ame]

4) Delta Glider IV set to Mark I engines and the lowest fuel range setting

Yury's Delta Tug is a great little booster. For those are not familiar with it, it is designed to work with any DG craft (stock DG, XR1, and DGIV) and makes it look like the Dynasoar, the original Delta Glider

http://www.daviddarling.info/encyclopedia/D/Dyna-Soar.html

 

[PriestLizard]

Wow HiPotOk ... these are some awesome add-ons Thx for the hint! I will use these for future missions now! I guess a lunar mission will be much easier with this setup though - the Energia will launch the DG so no fuel is used for lift-off, and then you got those drop tanks on your DG ... you can even use the DG payload bay for something more useful like equipment or scientific material.

 

[the.punk]

The [ame="http://www.orbithangar.com/searchid.php?ID=421"]TX winged launcher[/ame] is also good for going into orbit with dg.

 

[HiPotOk1978]

here is the scn file that I created. Besides the Energia HLLV and the Delta Tug, your also need the DGIV space shuttle skin. You could always edit it to load any DGIV skin you wanted.

For me the DGIV is an awesome craft when I am doing futuristic flights. I use them for everything from CEVs to the main craft of missions depending on the length. Here is my scn I created. The DGIV has 4x 1500kg drop tanks

Addon's used:
[ame="http://www.orbithangar.com/searchid.php?ID=1036"]ENERGY project, release 3[/ame]

[ame="http://www.orbithangar.com/searchid.php?ID=1127"]Delta Tug, release 3[/ame]

DGIV NASA skin
http://orbiter.dansteph.com/index.php?disp=dgIVMore&DId=28
Inflatable Rescue Module (to give the 5 astronauts more room on their 3 day journey to the Moon

http://orbiter.dansteph.com/index.php?disp=dgIVMore&DId=145

You might also want to get WHAP's beautiful Ascension Island since the Energia is sitting on one of the vertical launch towers
[ame="http://www.orbithangar.com/searchid.php?ID=3666"]Wideawake International[/ame]


I can't think of any other

BEGIN_DESC
Using an Energia HLLV, a Delta Tug Model 70, and an extra 6t of fuel on external stores, your mission is to go land on the moon and return safely to earth
END_DESC

BEGIN_ENVIRONMENT
  System Sol
  Date MJD 55563.2608550231
END_ENVIRONMENT

BEGIN_FOCUS
  Ship GL-01
END_FOCUS

BEGIN_CAMERA
  TARGET GL-01
  MODE Extern
  POS 2.31 -1.56 -9.16
  TRACKMODE TargetRelative
  FOV 50.00
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_MFD Left
  TYPE Surface
  SPDMODE 1
END_MFD

BEGIN_MFD Right
  TYPE Map
  REF Earth
  OTARGET Moon
  ZOOM
  TRACK ON
END_MFD

BEGIN_PANEL
END_PANEL


BEGIN_SHIPS
GL-01:DeltaGliderIV
  STATUS Landed Earth
  POS -14.4330000 -7.9708900
  HEADING 118.00
  ATTACHED 0:0,DT
  RCSMODE 0
  PRPLEVEL 0:1.000 1:1.000 2:0.983 3:1.000 4:1.000 5:1.000 6:1.000
  IDS 0:45 100
  NAVFREQ 94 524
  XPDR 0
  ;-------------------------- Skin parameters must contain directory name of skin (without space) 
  MeshSkin space_shuttle
  ;-------------------------- Cargo payload must contain name of config file or "none".(see doc) 
  CargoPayload DGIVinfMod
  NOSECONE 0 0.00
  GEAR 0 0.00
  AllDoorsState 0 0.00 0 0.00 0 0.00 0 0.00 0 0.00 0 0.00 0 0 0.00
  But1Cockpit 0 0 0 2 2 2 0 2 2 2 2 2 2 2 2 1 1 2 0 1 1 2
  But2Cockpit 0 0 0 0 1 0 0 0 0 0 0 0 0 0 98 0 0 1 0 0 0 0
  TransEffect 0
  LifeBut1State 1 2 1 2 1 2 2 2 2 2 2 2 2 0 4
  LevelBatt 100.0002
  Emergency_power 10000.0000
  VoltageStartBus 0.0000
  VoltageGen1 96.2820
  VoltageGen2 96.2819
  VoltageGenBus 96.0000
  O2tankALevel 87.4077
  N2tankALevel 100.0000
  O2tankBLevel 100.0000
  N2tankBLevel 100.0000
  CabinO2Level 21.3868
  CabinCO2Level 600.0000
  CabinTempLevel 21.2000
  CabinPressure 14.7000
  CabinMoistLevel 36.0000
  CabinDustLevel -0.0000
  CabinO2Setting 21.4000
  CabinTempSetting 21.2000
  CabinPressSetting 14.7000
  AntennaTarget no_target
  O2ConsumptionSetting 1
  FuelConsumptionSetting 0
  MainenginePower -1
  ;------------------Crew parameters  UMMUCREW Function-Name-Age-CardiacPulse-WeightKg (fonction of Pilot must be: Capt) 
  NoOneOnBoard 0
  NoPilotOnBoard 0
  UMMUCREW Capt-Christopher_Coles-47-73-77
  UMMUCREW Ast-Will_Gilliam-30-77-69
  UMMUCREW Ast-Neil_Simon-35-73-78
  UMMUCREW Ast-Frank_Jones-44-71-69
  UMMUCREW Ast-Steve_Meyers-32-75-72
  FailGearFailure 0
  FailGearCollapse 0
  FailLeftMainEngine 0
  FailRightMainEngine 0
  FailHoverEngine 0
  FailRcs 0
  FailSurfaceControl 0
  FailComputer 0
  FailComputerBlueScreen 0
  FailAutopilot 0
  FailExtRadiator 0
  FailAirbrake 0
  FailNoseCone 0
  FailCanopy 0
  FailAntenna 0
  FailLeftTurbo 0
  FailRightTurbo 0
  FailCargoDoor 0
  SpacesuitTimer 0
END
Tank1:Velcro/DropTank500gal
  STATUS Orbiting Earth
  RPOS -6308472.64 -764204.81 -457742.58
  RVEL 10.426 183.303 -421.880
  AROT -120.92 81.96 82.46
  NAVFREQ 21 50
  CONFIGURATION 0
  PRIMEBOOSTER 0
  CENTERTHRUST 0
  IGNITENEXT 0
  JETT_ON_MECO 0
  PADBIAS 1.00
  TGT_HEADING 90.00
  CROSSFEED 1 GL-01 0.5000 0 5.5000 -0.3500 -0.6000 0.0000 0.0000 -1.0000 0.0000 -1.0000 0.0000
  PAYLOAD pylon1 velcro/parts/pylon velcro/parts/pylon 0.00 0.00 0.00 0.10 0.00 1.00
END
Tank2:Velcro/DropTank500gal
  STATUS Orbiting Earth
  RPOS -6308472.85 -764209.19 -457732.49
  RVEL 10.426 183.303 -421.880
  AROT -120.92 81.96 82.46
  NAVFREQ 21 50
  CONFIGURATION 0
  PRIMEBOOSTER 0
  CENTERTHRUST 0
  IGNITENEXT 0
  JETT_ON_MECO 0
  PADBIAS 1.00
  TGT_HEADING 90.00
  CROSSFEED 1 GL-01 1.0000 0 -5.5000 -0.3500 -0.6000 0.0000 0.0000 -1.0000 0.0000 -1.0000 0.0000
  PAYLOAD pylon2 velcro/parts/pylon velcro/parts/pylon 0.00 0.00 0.00 0.10 0.00 1.00
END
Tank3:Velcro/DropTank500gal
  STATUS Orbiting Earth
  RPOS -6308470.61 -764204.16 -457743.89
  RVEL 10.426 183.303 -421.880
  AROT -120.92 81.96 82.46
  NAVFREQ 21 50
  CONFIGURATION 0
  PRIMEBOOSTER 0
  CENTERTHRUST 0
  IGNITENEXT 0
  JETT_ON_MECO 0
  PADBIAS 1.00
  TGT_HEADING 90.00
  CROSSFEED 1 GL-01 0.5000 0 7.0000 -0.1500 -2.6000 0.0000 0.0000 -1.0000 0.0000 -1.0000 0.0000
  PAYLOAD pylon3 velcro/parts/pylon velcro/parts/pylon 0.00 0.00 0.00 0.10 0.00 1.00
END
Tank4:Velcro/DropTank500gal
  STATUS Orbiting Earth
  RPOS -6308470.87 -764209.73 -457731.05
  RVEL 10.426 183.303 -421.880
  AROT -120.92 81.96 82.46
  NAVFREQ 21 50
  CONFIGURATION 0
  PRIMEBOOSTER 0
  CENTERTHRUST 0
  IGNITENEXT 0
  JETT_ON_MECO 0
  PADBIAS 1.00
  TGT_HEADING 90.00
  CROSSFEED 1 GL-01 1.0000 0 -7.0000 -0.1500 -2.6000 0.0000 0.0000 -1.0000 0.0000 -1.0000 0.0000
  PAYLOAD pylon4 velcro/parts/pylon velcro/parts/pylon 0.00 0.00 0.00 0.10 0.00 1.00
END
ISS:ProjectAlpha_ISS
  STATUS Orbiting Earth
  RPOS -783393.92 6463333.61 -1700510.01
  RVEL 7403.370 353.124 -2049.524
  AROT 151.86 -33.52 0.84
  VROT -0.01 -0.08 -0.07
  PRPLEVEL 0:1.000
  IDS 0:588 100 1:586 100 2:584 100 3:582 100 4:580 100
  NAVFREQ 0 0
  XPDR 466
END
Mir
  STATUS Orbiting Earth
  RPOS 6633618.70 389872.39 484757.44
  RVEL -592.944 417.110 7697.848
  AROT 52.81 18.62 -109.51
  VROT 0.07 -0.08 0.07
  IDS 0:540 100 1:542 100 2:544 100
  XPDR 482
END
Luna-OB1:Wheel
  STATUS Orbiting Moon
  RPOS -1730792.38 1422196.52 -4700.86
  RVEL -939.069 -1143.411 -1.165
  AROT 0.15 0.23 91.56
  VROT -0.00 0.00 10.00
  IDS 0:560 100 1:564 100
  XPDR 494
END
EnergyZ_Energia:\Energy\EnergyZ
  STATUS Landed Earth
  POS -14.4432454 -7.9687597
  HEADING 360.00
  ATTACHED 0:0,Energia
  FERM 0 0.0000
  G_ELEVATION 17.70
  TIMER_C -1.00
  TIMER_A -1.00
END
EnergyA1_Energia:\Energy\EnergyA
  STATUS Landed Earth
  POS -14.4431929 -7.9687722
  HEADING 103.50
  ATTACHED 0:1,Energia
  PRPLEVEL 0:1.000 3:1.000 4:1.000 5:1.000
  BOOSTER 1
  MAINSTATUS 0
  APSTATUS 0
  DUMPON 0
  T_MARKER 76108.935
  ALLOW_AUTO_DELETE 0
  C_TRUSS 0 0.0000
  PARA_TRUSS 0 0.0000
  CORE_NAME Energia
  GEARS 0 0.0000
  RDTT 0 0.0000 0
  BRCHUTE 0 0.0000 0.5000 0.5000
  CHUTESTATUS 0
  REUSABLE_BOOSTERS 1
END
EnergyA2_Energia:\Energy\EnergyA
  STATUS Landed Earth
  POS -14.4432979 -7.9687722
  HEADING 256.50
  ATTACHED 0:2,Energia
  PRPLEVEL 0:1.000 3:1.000 4:1.000 5:1.000
  BOOSTER 2
  MAINSTATUS 0
  APSTATUS 0
  DUMPON 0
  T_MARKER 76108.935
  ALLOW_AUTO_DELETE 0
  C_TRUSS 0 0.0000
  PARA_TRUSS 0 0.0000
  CORE_NAME Energia
  GEARS 0 0.0000
  RDTT 0 0.0000 0
  BRCHUTE 0 0.0000 0.5000 0.5000
  CHUTESTATUS 0
  REUSABLE_BOOSTERS 1
END
EnergyA3_Energia:\Energy\EnergyA
  STATUS Landed Earth
  POS -14.4431986 -7.9687330
  HEADING 60.00
  ATTACHED 0:3,Energia
  PRPLEVEL 0:1.000 1:1.000 2:1.000 3:1.000 4:1.000 5:1.000
  BOOSTER 3
  MAINSTATUS 0
  APSTATUS 0
  DUMPON 0
  T_MARKER 76108.935
  ALLOW_AUTO_DELETE 0
  C_TRUSS 0 0.0000
  PARA_TRUSS 0 0.0000
  CORE_NAME Energia
  GEARS 0 0.0000
  RDTT 0 0.0000 0
  BRCHUTE 0 0.0000 0.5000 0.5000
  CHUTESTATUS 0
  REUSABLE_BOOSTERS 1
END
EnergyA4_Energia:\Energy\EnergyA
  STATUS Landed Earth
  POS -14.4432922 -7.9687330
  HEADING 300.00
  ATTACHED 0:4,Energia
  PRPLEVEL 0:1.000 1:1.000 2:1.000 3:1.000 4:1.000 5:1.000
  BOOSTER 4
  MAINSTATUS 0
  APSTATUS 0
  DUMPON 0
  T_MARKER 76108.935
  ALLOW_AUTO_DELETE 0
  C_TRUSS 0 0.0000
  PARA_TRUSS 0 0.0000
  CORE_NAME Energia
  GEARS 0 0.0000
  RDTT 0 0.0000 0
  BRCHUTE 0 0.0000 0.5000 0.5000
  CHUTESTATUS 0
  REUSABLE_BOOSTERS 1
END
Energia:Energia (ENERGY project)
  STATUS Landed Earth
  POS -14.4432454 -7.9687597
  HEADING 360.00
  PRPLEVEL 0:1.000
  NAVFREQ 0 0
  HATCH 0 1.0000
  MAINSTATUS 0
  FLIGHTSTATUS 0
  PLSTATUS 1
  STAGESTATUS 1
  APSTATUS 1
  PRESTARTSTATUS 0
  ENGINESSTATUS 0
  BOOSTERSSTATUS 0
  DUMPLEVEL 0.000
  G_ELEVATION 17.700
  T_COUNTER 76108.935
  T_MARKER 76108.93 76108.93
  JETTISONSPEED 1.000
  JETTISONINT 5.000
  CUR_AP_MSG Ready
  REUSABLE_BOOSTERS 1
  ALLOW_AUTO_DELETE 0
  ALLOW_SEND_FOCUS 1
  PITCH_ANGLE 0.0000 0.0000 0.0000 0.0000
  YAW_ANGLE 0.0000 0.0000 0.0000 0.0000
  PITCH_PROC 0.3000 0.3500 0.3200 0.4000
  YAW_PROC 0.6500 0.3500 0.6500 0.3500
  SERVICEDATA 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.00
  PL_ARMS -8.0900 -18.0000
  PL_DESCRIPTION DT 0.000 7.020 -10.630 0.000 -1.000 0.000 0.000 0.000 1.000
  IN_JETTISON 0 0
  J_MARKER 0.000
  LAUNCHAP_DATA 0 165000.00 24.2400 0.0000000 0.0000000 0.00000 200.00 8000.00 0.00 5.00 0.00 5.43 0.99 6
  MESSAGER_DATA 0 -1.00 3.00
END
DT:DeltaTug
  STATUS Landed Earth
  POS 133.4351742 0.6020974
  HEADING 66.56
  ATTACHED 1:5,Energia
  PRPLEVEL 0:1.000 1:1.000
  NAVFREQ 0 0
  ADAPTER 0 0.0000
  DT_MODEL 1
  MAINSTATUS 0
  SHELLSTATUS 0
  T_MARKER 75987.786
  PL_NAME GL-01
  ALLOW_AUTO_DELETE 0
END
DTAeroshell_DT:DTAeroshell
  STATUS Landed Earth
  POS 133.4351742 0.6020974
  HEADING 66.56
  ATTACHED 0:1,DT
  PRPLEVEL 0:1.000
  MAINSTATUS 0
  T_MARKER 75849.357
  ALLOW_AUTO_DELETE 0
END
END_SHIPS

BEGIN_ExtMFD
END

 

[agentgonzo]

The result is always the same: Shortly before perigee and at a nose-temperature of about 1800° my nose goes up to an AoA of 0°, causing the temperature to rise exponentially and finally I see DESTROYED!

Now you mention this, I remember this happening in the DGIV too. If you go too far into the atmosphere with the AOA below about 30-35° you will end up with the nose dropping and eventual distruction. You need to prevent this from happening. If you are dropping to about 65km altitude, keep the AOA at/above 50° and the nose won't drop, but you will begin to climb back out of the altitude as the wings down provide much lift (downwards as you are inverted). At higher altitudes (67-70km) you can get a lower AOA, more lift and stop your climb out of the atmosphere without the nose dropping. As I said, it is possible, but very hard and takes a lot of practice. The autopilots don't help as they don't realise you want to fly inverted.

 

[PriestLizard]

@Gonzo: Yes, its really challenging but its also very exciting - like I said - probably the most fun maneuver I did so far. Next time I will try to control my climb with a lower AoA (inverted)... this time I just used my main engines to control the climb and to keep my altitude arround 65km untill my speed was low enough.

@Topic: I now finished this mission completely. I launched my second DG, performed another docking maneuver (actually the first time I docked two DGs together), transfered some RCS fuel via FuelMFD, released the fuel payload which I launched with the second vessel and docked with the Serenity. Then nominal reentry with both ships to SRC Sumatra, Indonesia.

This mission was the most complex I did so far (as I said untill now I mostly did launch-ISS-reentry missions, sometimes only one part). I can only suggest everyone to try something like that - its a very fun way to improve your skills with Orbiter.

Maneuvers I had to do:
- Three launches w.r.t. correct heading for plane alignment
- Two TransX intercept maneuvers
- Total of four close-range dockings (fuel pods, DGs)
- TLI, TLO, TEI
- First lunar/hover/no-atmo landing ever
- First lunard/hover/no-atmo take-off
- That freakin' gonzo-style aerobreaking inverted
- Three deorbits/reentries and landings (still the most hardest thing for me I guess)

Here are some pictures:

Next plan: using a better and more advanced approach to a lunar mission by using the add-ons you guys suggested!

 

[Tommy]

The inverted re-entry technique needs to be modified a bit for the DG-IV. The XR-2 can hold high AoA's while inverted by shifting the COG, which the DG-IV can't. For a DG-IV is far easier to use a low AoA (15 degrees or less) inverted re-entry. Set your PeA to 70k, and come in inverted with a zero AoA. Once you hit Pe, use elevator trim to increase the AoA to maintain altitude, and aim for a descent rate of 50 to 20 m/s (and watch the hull temps). At the low AoA you don't get much drag so it will take a while (around 1/2 orbit) to get down to suborbital velocity. When you velocity drops below 7.5k, you'll want to be back up to about 70k alt and zero VS. Roll upright, and trim down to get about -100 m/s VS. Then engage the manual re-entry AP with an initial AOA of 45, and finish the re-entry as normal. AerobrakeMFD is recommended after you turn upright to help you get to the base accurately.

Also, you can increase the strenght of the DG-IV's controls by using a simple "trick". While in 2-d panel view, set the controls to Elevon & Gear (NOT ATM Auto). Then use <f8> to switch to "glass cockpit" view, and click on the [ROT] button in the upper left of the screen. This way both aerodynamic and RCS controls are active, giving a bit of extra strenght that can help hold the intermediate AoA's (15 - 30 degrees).

 

[the.punk]

Congratulations.

 

[agentgonzo]

Also, you can increase the strenght of the DG-IV's controls by using a simple "trick"...

Interesting! Thanks Tommy. I've heard people doing this with a joystick (to control the flight surfaces) and the keypad to do the RCS before, but not having a joystick I couldn't do that. Worth knowing!

 

[Oceanic]

HiPotOk1978 thank for that nice scenario!

i have a small question, after LOI i left the rescue module in space and landed safely at Aurora lunar base, two of the droptanks where empty and jettisoned on there own. the remaining tanks had both 12% fuel left right before touchdown. i quit orbiter to do my return to earth another day. after i docked with the rescue module i noticed that the droptanks where still attached, i opened the scenario editor just to see that the tanks where full again. is there a way to prevent this from happening?