Challenge Safe Lithobraking

Tommy

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I seem to remember getting this to work in a stock DG. If memory serves, it took dozens of attempts, and was still fairly "hit-or-miss".

Method was to perform a retrograde burn over the target lowering the PeA to 10 meters. Then, at Pe, a second retrograde burn to lower the ApA until it became the Pe, at an altitude to 2.4 meters (IIRC the "altitude" of a landed DG = 2.41 meters).

Gear is lowered, orient forward and use level horizon AP. At about 3 seconds before Pe, engage retrothrust to lower the PeA to just below zero. Immediately upon ground contact engage "downward" translational RCS and engage the wheel brakes. Once speed lowers a bit retro's can be used for braking (overuse of retro thrust too soon will result in "hopping".

Since you will be performing at least one half of an orbit at less than 10 meters altitude - this obviously wouldn't work in real life!
 

squeaky024

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I should try to see if I can stop if i turn 180 and touch down even softer, maybe using rcs to keep the plane down on the surface.

This will be my first intentional lithobrake :lol: (my last unintentional one left the arrow freighter nose first into saturn, i tried to enter orbit and i switched back to another plane for too long, when i switched back, well, it stopped :rofl: )
 

N_Molson

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How's about a giant magnet thing on the ground? OK, so hitting it just right would be nigh on impossible, but it would avoid any physical contact. Kind of a railgun in reverse?

Velcro. A big field of Velcro straps and a "wool shield" under the spacecraft. Sticked for good. :rofl:

Still you would have to be ultra-accurate to hit the field from Orbital Speed.
 

Luke Skywalker

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Nevermind, I did lithobrake but at the cost of braking the DGIV's hover engines and it's gears.

This is the scenario before landing

Code:
BEGIN_DESC

END_DESC

BEGIN_ENVIRONMENT
  System Sol
  Date MJD 60246.7395462076
END_ENVIRONMENT

BEGIN_FOCUS
  Ship GL-01
END_FOCUS

BEGIN_CAMERA
  TARGET GL-01
  MODE Extern
  POS 3.04 45.54 0.64
  TRACKMODE AbsoluteDirection
  FOV 50.00
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_MFD Left
  TYPE Orbit
  PROJ Ship
  FRAME Ecliptic
  REF Moon
END_MFD

BEGIN_MFD Right
  TYPE Map
  REF Moon
  OTARGET ISS
END_MFD

BEGIN_PANEL
END_PANEL

BEGIN_SHIPS
ISS:ProjectAlpha_ISS
  STATUS Orbiting Earth
  RPOS 4801446.76 4179795.18 -2146377.24
  RVEL 5188.585 -5669.555 564.172
  AROT 110.00 -10.00 80.00
  AFCMODE 7
  PRPLEVEL 0:1.000000
  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 -6388447.15 -144293.84 -1852381.53
  RVEL 2169.478 -447.327 -7420.414
  AROT 0.00 -45.00 90.00
  AFCMODE 7
  IDS 0:540 100 1:542 100 2:544 100
  XPDR 482
END
Luna-OB1:Wheel
  STATUS Orbiting Moon
  RPOS -2136945.73 671470.50 1276.41
  RVEL -443.325 -1411.603 -1.256
  AROT 0.00 -0.00 44.11
  VROT 0.00 0.00 10.00
  AFCMODE 7
  IDS 0:560 100 1:564 100
  XPDR 494
END
GL-01:DeltaGliderIV
  STATUS Orbiting Moon
  RPOS -1406701.95 983468.79 -273197.13
  RVEL 659.951 1210.551 960.060
  AROT 66.63 -25.23 -67.49
  PRPLEVEL 0:0.060769 1:0.975526 2:0.983333
  IDS 0:45 100
  NAVFREQ 94 524
  XPDR 0
  ;-------------------------- Skin parameters must contain directory name of skin (without space) 
  MeshSkin Mining
  ;-------------------------- Cargo payload must contain name of config file or "none".(see doc) 
  CargoPayload none
  NOSECONE 0 0.00
  GEAR 1 1.00
  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 1 1 1 4
  But2Cockpit 0 0 0 0 0 0 0 0 2 2 2 2 2 0 50 0 0 0 1 1 0 0
  TransEffect 0
  LifeBut1State 0 2 1 2 1 2 2 2 2 2 2 2 2 0 3
  LevelBatt 100.0002
  Emergency_power 10000.0000
  VoltageStartBus 0.0000
  VoltageGen1 96.2820
  VoltageGen2 96.2819
  VoltageGenBus 96.0000
  O2tankALevel 99.9517
  N2tankALevel 100.0000
  O2tankBLevel 100.0000
  N2tankBLevel 100.0000
  CabinO2Level 21.3885
  CabinCO2Level 600.0000
  CabinTempLevel 21.2000
  CabinPressure 14.7000
  CabinMoistLevel 36.0000
  CabinDustLevel 0.0002
  CabinO2Setting 21.4000
  CabinTempSetting 21.2000
  CabinPressSetting 14.7000
  AntennaTarget no_target
  O2ConsumptionSetting 6
  FuelConsumptionSetting 3
  MainenginePower 2
  ;------------------Crew parameters  UMMUCREW Function-Name-Age-CardiacPulse-WeightKg (fonction of Pilot must be: Capt) 
  NoOneOnBoard 0
  NoPilotOnBoard 0
  UMMUCREW Capt-Christopher_Coles-47-60-70
  UMMUCREW Spe-Burton_Lambert-22-66-78
  UMMUCREW Ast-Daniel_Gecker-33-72-75
  UMMUCREW Eng-Bradley_Banister-55-72-79
  UMMUCREW Spe-Bradley_Banister-36-65-82
  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
  UCGO @@0,1,0,0,@@1,1,0,0,@@2,1,0,0,@@3,1,0,0,
END
END_SHIPS

AND this is AFTER the landing.

Code:
BEGIN_DESC
Well that didn't work.
END_DESC

BEGIN_ENVIRONMENT
  System Sol
  Date MJD 60246.7500500598
END_ENVIRONMENT

BEGIN_FOCUS
  Ship GL-01
END_FOCUS

BEGIN_CAMERA
  TARGET GL-01
  MODE Cockpit
  FOV 50.00
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_MFD Left
  TYPE Orbit
  PROJ Ship
  FRAME Ecliptic
  REF Moon
END_MFD

BEGIN_MFD Right
  TYPE Map
  REF Moon
  OTARGET ISS
END_MFD

BEGIN_PANEL
END_PANEL

BEGIN_SHIPS
ISS:ProjectAlpha_ISS
  STATUS Orbiting Earth
  RPOS 6329559.52 -2154238.96 -661021.75
  RVEL -2131.101 -7002.790 2409.568
  AROT 110.00 -10.00 80.00
  AFCMODE 7
  PRPLEVEL 0:1.000000
  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 -1518441.66 -402919.91 -6458026.72
  RVEL 7546.053 -67.232 -1764.221
  AROT 0.00 -45.00 90.00
  AFCMODE 7
  IDS 0:540 100 1:542 100 2:544 100
  XPDR 482
END
Luna-OB1:Wheel
  STATUS Orbiting Moon
  RPOS -2143051.64 -651318.38 -29.10
  RVEL 430.297 -1415.710 -1.535
  AROT -0.00 -0.00 99.24
  VROT 0.00 0.00 10.00
  AFCMODE 7
  IDS 0:560 100 1:564 100
  XPDR 494
END
GL-01:DeltaGliderIV
  STATUS Orbiting Moon
  RPOS -417034.67 1583345.08 582880.48
  RVEL 1238.861 79.000 671.761
  AROT -173.30 61.36 -149.97
  VROT 0.05 -0.02 -0.01
  RCSMODE 2
  PRPLEVEL 0:0.060769 1:0.945959 2:0.983333
  IDS 0:45 100
  NAVFREQ 94 524
  XPDR 0
  ;-------------------------- Skin parameters must contain directory name of skin (without space) 
  MeshSkin Mining
  ;-------------------------- Cargo payload must contain name of config file or "none".(see doc) 
  CargoPayload none
  NOSECONE 0 0.00
  GEAR 0 0.10
  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 1 1 1 3
  But2Cockpit 0 0 0 0 0 0 0 0 2 2 2 2 2 0 3 0 0 0 1 1 0 0
  TransEffect 0
  LifeBut1State 0 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 99.9502
  N2tankALevel 100.0000
  O2tankBLevel 100.0000
  N2tankBLevel 100.0000
  CabinO2Level 21.3864
  CabinCO2Level 600.0000
  CabinTempLevel 21.2000
  CabinPressure 14.7000
  CabinMoistLevel 36.0000
  CabinDustLevel 0.0001
  CabinO2Setting 21.4000
  CabinTempSetting 21.2000
  CabinPressSetting 14.7000
  AntennaTarget no_target
  O2ConsumptionSetting 6
  FuelConsumptionSetting 3
  MainenginePower 2
  ;------------------Crew parameters  UMMUCREW Function-Name-Age-CardiacPulse-WeightKg (fonction of Pilot must be: Capt) 
  NoOneOnBoard 0
  NoPilotOnBoard 0
  UMMUCREW Capt-Christopher_Coles-47-60-70
  UMMUCREW Spe-Burton_Lambert-22-66-78
  UMMUCREW Ast-Daniel_Gecker-33-72-75
  UMMUCREW Eng-Bradley_Banister-55-72-79
  UMMUCREW Spe-Bradley_Banister-36-65-82
  FailGearFailure 0
  FailGearCollapse 1
  FailLeftMainEngine 0
  FailRightMainEngine 0
  FailHoverEngine 1
  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
  UCGO @@0,1,0,0,@@1,1,0,0,@@2,1,0,0,@@3,1,0,0,
END
wreck:DGIVWreck2
  STATUS Orbiting Moon
  RPOS -374834.71 1591746.75 588769.58
  RVEL 1467.006 43.260 816.746
  AROT -64.17 -9.20 79.36
  VROT -70.83 -82.56 -22.47
  AFCMODE 7
END
wreck:DGIVWreck2
  STATUS Orbiting Moon
  RPOS -374554.49 1592137.08 589787.75
  RVEL 1467.112 43.919 817.690
  AROT 153.49 15.36 163.98
  VROT 81.74 1.61 -28.67
  AFCMODE 7
END
wreck:DGIVWreck2
  STATUS Landed Moon
  POS -73.2837636 64.7730064
  HEADING 272.87
  AFCMODE 7
END
wreck:DGIVWreck2
  STATUS Orbiting Moon
  RPOS -375119.02 1592657.18 590442.80
  RVEL 1466.379 44.929 818.397
  AROT 79.56 -53.39 150.08
  VROT 9.55 120.05 79.89
  AFCMODE 7
END
wreck:DGIVWreck2
  STATUS Orbiting Moon
  RPOS -375368.74 1591777.21 588382.15
  RVEL 1466.442 43.387 816.347
  AROT 67.52 -1.41 121.63
  VROT -61.91 -42.62 -77.32
  AFCMODE 7
END
wreck:DGIVWreck2
  STATUS Landed Moon
  POS -48.3818712 53.0287705
  HEADING 165.49
  AFCMODE 7
END
wreck:DGIVWreck1
  STATUS Landed Moon
  POS -32.1591628 38.0215772
  HEADING 225.95
  AFCMODE 7
END
wreck:DGIVWreck1
  STATUS Orbiting Moon
  RPOS -374115.01 1593038.10 588041.53
  RVEL 1467.398 44.826 816.273
  AROT -146.39 -56.50 -42.83
  VROT -124.67 -32.96 -23.16
  AFCMODE 7
END
wreck:DGIVWreck1
  STATUS Landed Moon
  POS -38.7457274 45.8273322
  HEADING 203.46
  AFCMODE 7
END
wreck:DGIVWreck2
  STATUS Orbiting Moon
  RPOS -376933.58 1592134.80 586282.65
  RVEL 1454.467 48.191 806.137
  AROT -7.35 7.42 32.66
  VROT -2.87 38.32 98.08
  AFCMODE 7
END
wreck:DGIVWreck2
  STATUS Orbiting Moon
  RPOS -374911.33 1592180.12 589872.49
  RVEL 1466.746 44.087 817.800
  AROT -171.68 45.65 91.07
  VROT -97.59 -18.56 -84.35
  AFCMODE 7
END
wreck:DGIVWreck2
  STATUS Orbiting Moon
  RPOS -375008.20 1592307.28 589223.56
  RVEL 1466.656 44.194 817.247
  AROT -21.54 -68.54 -96.69
  VROT 29.43 -1.07 95.83
  AFCMODE 7
END
END_SHIPS
 
Last edited:

Richy

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I once landed a Space Shuttle this way. Started in LEO with ET full and boosters. But the landing was in retro orientation, so I was able to fire the mains, until my orbit was below the moons surface. So the wheel brakes came to action.

But try this in real! ;)

Btw: Couldn't acutally a mass accelerator also used in this way, say reversely? A spacecrafts perapsis matches with a sled with the same speed. As soon as the spacecraft touches the sled, clamps hold it down, and the sled decreases the velocity of both. Could also be used as a recuperation for charging huge capacitors for the next launch. :)
 

N_Molson

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I wonder what the G-forces must be at landing?

Enough to re-paint the cabin front wall / HUD in red :p
 

jedidia

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I don't think this is possible unless you turn your craft 180 degrees and burn the mains.

It wouldn't be Lithobraking anymore then, would it? :p

It would still make a great stunt at any lunar "air"-show, though...

Couldn't acutally a mass accelerator also used in this way, say reversely?

The concept exists, but it would have to be a very long accelerator if you want to do it with maned craft.

Also, the needed precision is enourmous. And a failed landing would be a pretty big catastrophy, not only destroying the craft, but also large parts of the accelerator. And there's no touch-and-go if you mess up your first aproach.
 
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squeaky024

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I know theres no such thing as tire wear in orbiter, but in reality I wonder if anything would be capable of sliding or rolling across the surface of the moon for such a distance. Oh and one more thing i just remembered, what about the craters? :hmm:
 

francisdrake

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Some time ago I read a story about an instrumented impactor. It was a kind of artillery shell with instrumentation in a compartment in the rear, designed to hit planetary soil without previous slow down. I was astonished that instrumentation could be built rugged enough to survive a direct impact.

This kind of direct hit probably cannot be simulated in Orbiter, as the impactor would bounce off the targets surface.
____

Space Probe Swarms to Slam into Planets for Science:
http://www.innovationnewsdaily.com/penetrator-impact-planet-2104/
 
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RisingFury

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Some time ago I read a story about an instrumented impactor. It was a kind of artillery shell with instrumentation in a compartment in the rear, designed to hit planetary soil without previous slow down. I was astonished that instrumentation could be built rugged enough to survive a direct impact.

This kind of direct hit probably cannot be simulated in Orbiter, as the impactor would bounce off the targets surface.
____

Space Probe Swarms to Slam into Planets for Science:
http://www.innovationnewsdaily.com/penetrator-impact-planet-2104/


GPS guided artillery shell: [ame="http://en.wikipedia.org/wiki/M982_Excalibur"]M982 Excalibur - Wikipedia, the free encyclopedia[/ame]
They had a lot of trouble making sure the electronics survives being fired.

Deep Space 2 (failure):
[ame="http://en.wikipedia.org/wiki/Deep_Space_2"]Deep Space 2 - Wikipedia, the free encyclopedia[/ame]
 

MaverickSawyer

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Right, I forgot about the Excalibur. The Excalibur is subject to more than 10000 g's on firing, IIRC. They wound up making custom circut board materials and mounting them edge-on in a radial pattern.
 

n72.75

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[...]

Btw: Couldn't acutally a mass accelerator also used in this way, say reversely? A spacecrafts perapsis matches with a sled with the same speed. As soon as the spacecraft touches the sled, clamps hold it down, and the sled decreases the velocity of both. Could also be used as a recuperation for charging huge capacitors for the next launch. :)


That's actually not a half bad idea. Might be possible in real life.
 

aftercolumbia

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I've landed the Delta Glider on the moon with nothing but the RCS, but the touchdown speed was just under 1500m/s, so it is obviously not realistic. On Mars, I was a lot less dead with a 650m/s landing, but of course, heaven and hell don't care if you're a little dead or really super dead, yer still dead (or in Orbiter's case, invincible.)

If the objective is to land her without hovers, than it should be realistic to come to a nose up hover at a few meters, kill the engines, and then pitch over with the RCS. It'd be a bit rough, but by all means survivable.
 

luki1997a

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I remember one time when i used DGIV hover autopilot and I was on moon orbit with PeA 1m :lol: after touching the surface the gears just destroyed. I think the point is to get circular orbit at 1 m and then going lower and lower. Using RCS in translation mode should be necessary. BTW challenge accepted ;)

---------- Post added at 07:11 PM ---------- Previous post was at 12:07 PM ----------

:lol: I did it! I used XR5. Someone can say that's cheating, because I've used Descent Hold Autopilot, but only to reach orbit. After getting it I safely managed my RCS thrusters to reach PeA at -8 m and then after touchdown I managed to get a circular orbit(when rolling on the surface :lol:). If you don't trust me, I upload my playback :) few mins before touchdown.
Tip. Keep looking outside the ship to see Brighton Beach :)

My next challenge: land at one of lpads at Brighton using Lithobraking :lol:

:hailprobe:
Download
 

Hielor

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Keep in mind that this is only remotely possible because Orbiter's moon is a nearly perfect sphere. In reality, you couldn't even come close to the necessary shallow approach angle without hitting mountains--and even if you didn't have mountains to worry about, the tiniest micro-crater or small bump would tear your undercarriage off. If you were lucky--if you were unlucky it would just send you into the surface at 1500m/s.

Someone want to try this with Orulex enabled, or maybe in KSP? :p
 

Scruce

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or maybe in KSP? :p

It wouldn't work in KSP. There are tiny height differences between the texture seams which would jump the spacecraft into a spin. Adding to this; the texture seams are less than 50 meters apart.

Trust me, I tried. :p
 
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