Challenge Expert/Realistic XR2 to the moon and back in 48 hours

[dgatsoulis]

How's this for a challenge?

Take off in a XR2 Ravenstar from Cape Canaveral (or the base of your choice), dock with Mir to refuel, land at Brighton Beach and then get back at the SAME base you took off from, in 48 hours or LESS!

The catch is that you have to use ONLY the expert/realistic settings in the XR2 Ravenstar Configuration File and NO PAYLOAD!

 

[Lucy]

Not even the CHM? That'd be a pretty cramped two days...

 

[dgatsoulis]

Not even the CHM? That'd be a pretty cramped two days...

Hehe, i guess they'd be... but if you can take the +3 tons of the CHM to the moon and back in just two days... then by all means, go for it!

Just don't take any XrMainfuel Payload with you, ok? That would be cheating!

 

[Lucy]

I'll give it a go both with and without, tomorrow when I'm sober. I have learned that flying while drunk == terrible accidents.

I mean like de-orbiting ISS. By accident. :/

 

[Arrowstar]

What would be more interesting, perhaps, would be to force the pilot to use the option that removes fuel tanks from the vessel itself and use the cargo bay fuel tanks as the sole source of fuel. There's a switch for this mode in the XR2 config file somewhere, and I've been meaning to try it. The added challenge, of course, is that you can't start with full SCRAM and main fuel tanks, not enough cargo bay space.

 

[agentgonzo]

I've made it from KSC to Brighton Beach to KSC again without refuelling along the way (but it was a much lower Delta-V trip and so probably took around a week or so to do). With refuelling in orbit, this sounds like an enteresting challenge. I'll take a go at it sometime if I can find the time...

 

[Arrowstar]

Well, did it in 6 days and 11 hours with one refueling (met up with a Tanker from Kulch's fleet) and a moon flyby with a 9 km periapsis. Sadly, I did it in 6 days and 11 hours, but there's room for improvement, particularly because I did it with *very* limited fuel (ie cargo bay tanks necessary to have anything). Obviously all settings were on expert. I'll put up pictures later tonight and will try again later!

EDIT: Pictures uploaded. See: http://orbiter-forum.com/album.php?albumid=240 Some highlights are attached to this post.

EDIT2: Didn't see the Brighton Beach requirement. Oh well.

 

[agentgonzo]

I had a quick try at this yesterday to see how easy it would be. I managed to dock with Mir within 30 minutes of launch and then used LTMFD to set up a TLI burn. I set the MET for PeA at the moon to be MET ~23hours and did the TLI burn on the first Earth orbit. It used up about 65% of my fuel and I didn't have even enough fuel left to perform the LOI burn on arrival at the moon. If it is possible to do a lunar-return mission in 48 hours, it's going to be very hard.

All these settings were with the default XR2 settings.

Can you refuel when landed on the moon?

 

[dgatsoulis]

Of course you can refuel on brighton beach, in fact there is no way to make it back since you'll have almost no fuel left when you get there.
I'm not sure what you mean "default settings"... This is what i mean:

RequirePayloadBayFuelTanks=0
MainFuelISP=0 (expert)
SCRAMFuelISP=0 (realistc)
LOXLoadout=0 (7 days) [In fact you'll need less than that since it's only a 2 day trip]
LOXConsumptionRate=4 (realistic)
MainEngineThrust=1 (realistic)
HoverEngineThrust=1 (realistic)
SCRAMfhv=1 (realistic)
APUFuelBurnRate=5 (expert)

Hint: The first half of the journey (KSC - BB) will have to be longer than the second (BB - KSC).

 

[agentgonzo]

I'm not sure what you mean "default settings"... This is what i mean:

I meant that I just installed the XR2 and loaded up any scenario without changing the settings in the config file. I'll make your changes (if required) before attempting it 'properly'. I was just doing a few test runs yesterday.

Have you managed to complete it, or was this just an idea thrown out to the community?

 

[the.punk]

Hey. This is a interesting challenge. I will give it a try. What would a be a good escape vel. I also think for 48 hours the orbiter must be hyperbolic. Or am I wrong?

 

[dgatsoulis]

Have you managed to complete it, or was this just an idea thrown out to the community?

I've done it in 1 day 22 hours 53 min, but i didn't record the flight.

Took off from a base i created in Southern Crete/Greece (35N)

I'll give it another try tonight from KSC and record it this time.

---------- Post added at 12:11 PM ---------- Previous post was at 12:10 PM ----------

Hey. This is a interesting challenge. I will give it a try. What would a be a good escape vel. I also think for 48 hours the orbiter must be hyperbolic. Or am I wrong?

Definetely hyperbolic! You should make it to the moon within 30~31 hours from take off, if you want to make it back in time (AND land at the SAME base!)

---------- Post added at 12:17 PM ---------- Previous post was at 12:11 PM ----------

What would be more interesting, perhaps, would be to force the pilot to use the option that removes fuel tanks from the vessel itself and use the cargo bay fuel tanks as the sole source of fuel. There's a switch for this mode in the XR2 config file somewhere, and I've been meaning to try it. The added challenge, of course, is that you can't start with full SCRAM and main fuel tanks, not enough cargo bay space.

Not a bad idea Arrowstar! That would definetely add to the challenge, but i think that the xr2 would be too heavy to make the trip in 48hours. Will give it a try tho!

 

[agentgonzo]

OK, that was exciting. Landed at BB at MET 15:30 with even less fuel that Neil had in '69. Refuelling and about to head back to Earth. Will try and get a playback in the next week or so... (assuming I don't die)

---------- Post added at 00:52 ---------- Previous post was at 00:24 ----------

Bother. I ended up getting to excited with the TEI and set up the TransX plan only to find out after leaving the Moon's SOI that I was flying away from the earth on a hyperbolic trajectory rather than towards it. Oh well, I'll try again next time I have a few hours to spare. Time for bed now.

 

[Arrowstar]

I have to admit, I'm not sure how you people are ending up on the Moon in 15 hours. It's taking me 30 at minimum and I'm finding that the dV required to pull that off is insane. There's no stopping. I tend to just go floating on by... very quickly.

 

[agentgonzo]

I used TransX to set up the burn (rather than LTMFD this time) and did a straight prograde burn of about 5km/s and then did a targeting/MCC burn along the way. I found that LTMFD set up a burn that used a lot of 'outward' delta-V which is very inefficient. LOI was about 8 or 9km/s Delta-V I think.

I'm thinking that I should be able to get a round-trip done in under 30 hours, with under 24 being my target.

---------- Post added at 11:07 ---------- Previous post was at 11:02 ----------

Oh, actually, looking at it I forgot to update the XR2 configs and had left them at their defaults rather than changing them for this scenario. I had left the MainFuelISP setting as 2 (normal), rather than 0 (expert)

 

[the.punk]

Definetely hyperbolic! You should make it to the moon within 30~31 hours from take off, if you want to make it back in time (AND land at the SAME base!)

Yeah. I thought so. Will give it a try soon.

 

[n122vu]

Question before I give this a go this evening. Are you guys doing a direct ascent to Mir, or are you aligning planes then doing a rendezvous normally?

 

[agentgonzo]

Direct ascent with SCRAMs and docking with Mir sometime on the first orbit (normally within about 30 minutes of wheels-up).

 

[hribek]

I have just completed this challenge in 1 day 20:02:10 (+- 5 seconds).
The trip from Wideawake to Brighton Beach took 27 hours.
I still had at least half a ton of fuel remaining on wheelstop so there's still room for improvement, I'd say at least 30 minutes.

I've been saving periodically, at every checkpoint. I plan to release all the checkpoint saves and playbacks between them as a package. It has to be split into 3 playbacks minimum, because the refueling process cannot be recorded.

For now I'll just attach my starting scenario. In case anyone gets interested, I can give them details on my delta-V budget, trajectory planning and so on, which will eventually be included in the package as well.

BEGIN_DESC
Challenge - To the Moon and back in 48 hours

--------------------------------------------------------------------------

Objective: Land at Brighton Beach on the Moon and return to your original launch site on Earth in two days.


XR2 config Requirements:

RequirePayloadBayFuelTanks=0

MainFuelISP=0 (expert)

SCRAMFuelISP=0 (realistc)

LOXLoadout=0 (7 days) [In fact you'll need less than that since it's only a 2 day trip]

LOXConsumptionRate=4 (realistic)

MainEngineThrust=1 (realistic)

HoverEngineThrust=1 (realistic)

SCRAMfhv=1 (realistic)

APUFuelBurnRate=5 (expert)


Author notes

-----------------------

This scenario was created using Space Stations\Mir.scn advanced to then-current date, superfluous vessels removed


Checkpoints:

1. Perform a direct ascent from Wideawake to Mir, rendezvous, dock, refuel.

2. Undock, depart for Brighton Beach on the Moon. (~4k delta-V)

3. course correction for periapsis & lunar orbit plane alignment.

4. lunar orbit insertion, fuel-critical descent and landing on Brighton Beach

5. quick pad refuel, return trip plan setup

6. launch & orbit eject

7. halfway to Earth, last course correction. top up RCS, use remaining main fuel to speed up.

8. inverted aerocapture entry, transition to suborbital jump to landing site (Wideawake Int.)

9. Entry, Descent, Landing


! Addons required to run scenario:

XR2 Ravenstar

Wideawake International

Interplanetary MFD

other MFDs used: TransX, AeroBrake
END_DESC

BEGIN_ENVIRONMENT
  System Sol
  Date MJD 55530.7999503881
END_ENVIRONMENT

BEGIN_FOCUS
  Ship XR2
END_FOCUS

BEGIN_CAMERA
  TARGET XR2
  MODE Cockpit
  FOV 40.00
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_MFD Left
  TYPE OAlign
  REF Earth
  TARGET Mir
END_MFD

BEGIN_MFD Right
  TYPE User
  MODE Interplanetary
  Scenario Old2
  MapMFD V5
  Reference Auto
  Target none
  Center GravityRef
  Data 0 1 1e-006 1 0 0 0 0 1 0 0 0
  MassLimit 1e+020
  CMode 0
  Config 1 1 1 1 0 0
  ExtMode 0
  Periapis none
  END 
  CorMFD V4
  Reference Earth
  Target Mir
  Source XR2
  ActiveProg 1 1
  DataA 0 3 0 1 0 0
  DataB 1.5 10 55530.79994890568 0 0 0.07629138879658548 0 55530.80651105716 0
  DVProg 0 0 0 1
  AdvConf 0 0 1 0 0
  Guidance 0
  END 
  EjectMFD V5
  Reference Auto
  Data 0 1 3 0 1 55530.79209884055 10
  Guidance 0
  END 
  BaseAprMFD V2
  Reference Auto
  Target none
  Source none
  DataA 0 0 120000 0.10821 0.366519 1 1 55530.79209884055 55530.79209884055 0
  DataB 0 3 0 1 0 1
  END 
  SlingMFD V4
  Reference Auto
  Source none
  Data 0 1 1 3 0 1 55530.79209884055 0
  END 
  LaunchMFD V4
  Target None
  Data 0 1 1 3 0 1 0
  END 
  CF1_DataA 1 0
  CF1_DataB 55530.7920114233 10 120000 2 20 150000
  CF1_SecTgt 
  mfdShare -1
  mfdProgram 2
END_MFD

BEGIN_PANEL
END_PANEL

BEGIN_SHIPS
ISS:ProjectAlpha_ISS
  STATUS Orbiting Earth
  RPOS -6616847.43 37151.03 1316740.02
  RVEL -358.768 7405.844 -2021.351
  AROT 64.10 -0.80 -32.11
  VROT -0.01 0.01 0.11
  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 5553464.32 -192137.24 -3659559.17
  RVEL 4259.966 417.986 6460.281
  AROT 3.28 21.58 94.65
  AFCMODE 7
  IDS 0:540 100 1:542 100 2:544 100
  XPDR 482
END
XR2:XR2Ravenstar
  STATUS Landed Earth
  POS -14.4300000 -7.9599500
  HEADING 118.22
  RCSMODE 0
  AFCMODE 7
  PRPLEVEL 0:1.000000 1:1.000000 2:0.700000
  IDS 0:203 100
  NAVFREQ 482 166 100 106
  XPDR 201
  SECONDARY_HUD 2
  LAST_ACTIVE_SECONDARY_HUD 0
  ADCTRL_MODE 7
  TAKEOFF_LANDING_CALLOUTS 0.000000 0.000000 0.000000 0.000000 0.000000
  APU_FUEL_QTY 0.997862
  LOX_QTY 0.999994
  CABIN_O2_LEVEL 0.209000
  CREW_STATE 0
  INTERNAL_SYSTEMS_FAILURE 0
  COGSHIFT_MODES 0 0 0
  MWS_ACTIVE 0
  COOLANT_TEMP 31.367149
  DMG_0 1.000000 Left Wing
  DMG_1 1.000000 Right Wing
  DMG_2 1.000000 Left Aileron
  DMG_3 1.000000 Right Aileron
  DMG_4 1.000000 Landing Gear
  DMG_5 1.000000 Nosecone
  DMG_6 1.000000 Retro Doors
  DMG_7 1.000000 Top Hatch
  DMG_8 1.000000 Radiator
  DMG_9 1.000000 Airbrake
  DMG_10 1.000000 Left Main Engine
  DMG_11 1.000000 Right Main Engine
  DMG_12 1.000000 Left SCRAM Engine
  DMG_13 1.000000 Right SCRAM Engine
  DMG_14 1.000000 Fore Hover Engine
  DMG_15 1.000000 Aft Hover Engine
  DMG_16 1.000000 Left Retro Engine
  DMG_17 1.000000 Right Retro Engine
  DMG_18 1.000000 Forward Lower RCS
  DMG_19 1.000000 Aft Upper RCS
  DMG_20 1.000000 Forward Upper RCS
  DMG_21 1.000000 Aft Lower RCS
  DMG_22 1.000000 Forward Star. RCS
  DMG_23 1.000000 Aft Port RCS
  DMG_24 1.000000 Forward Port RCS
  DMG_25 1.000000 Aft Star. RCS
  DMG_26 1.000000 Outboard Upper Port RCS
  DMG_27 1.000000 Outboard Lower Star. RCS
  DMG_28 1.000000 Outboard Upper Star. RCS
  DMG_29 1.000000 Outboard Lower Port RCS
  DMG_30 1.000000 Aft RCS
  DMG_31 1.000000 Forward RCS
  DMG_32 1.000000 Bay Doors
  IS_CRASHED 0
  MET_STARTING_MJD -1.000000
  INTERVAL1_ELAPSED_TIME -1.000000
  INTERVAL2_ELAPSED_TIME -1.000000
  MET_RUNNING 0
  INTERVAL1_RUNNING 0
  INTERVAL2_RUNNING 0
  ACTIVE_MDM 3
  TEMP_SCALE 2
  CUSTOM_AUTOPILOT_MODE 0
  AIRSPEED_HOLD_ENGAGED 0
  SCRAM0DIR 0.000000 0.000000 1.000000
  SCRAM1DIR 0.000000 0.000000 1.000000
  HOVER_BALANCE 0.000000
  MAIN0DIR 0.000000 0.000000 1.000000
  MAIN1DIR 0.000000 0.000000 1.000000
  GIMBAL_BUTTON_STATES 0 0 0 0 0 0
  ATTITUDE_HOLD_DATA 0.000000 0.000000 0 0 0.000000
  DESCENT_HOLD_DATA 0.000000 -3.000000 0
  AIRSPEED_HOLD_DATA 0.000000
  OVERRIDE_INTERLOCKS 0 0
  TERTIARY_HUD_ON 1
  CREW_DISPLAY_INDEX 0
  GEAR 1 1.0000
  RCOVER 0 0.0000
  NOSECONE 0 0.0000
  AIRLOCK 0 0.0000
  IAIRLOCK 0 0.0000
  CHAMBER 0 0.0000
  AIRBRAKE 0 0.0000
  RADIATOR 0 0.0000
  HATCH 0 0.0000
  SCRAM_DOORS 0 0.0000
  HOVER_DOORS 0 0.0000
  BAY_DOORS 0 0.0000
  APU_STATUS 1
  EXTCOOLING_STATUS 0
  TRIM 0.000000
  LIGHTS 1 1 1
  XRUMMU_CREW_DATA_VALID 1
  UMMUCREW XI0-Lee_Nash-39-65-78
  UMMUCREW XI1-Kara_Miller-32-65-58
  UMMUCREW XI2-Julie_Tinker-30-67-53
  UMMUCREW XI3-Frank_Dawson-36-65-77
  UMMUCREW XI4-William_Healgood-33-66-53
  PAYLOAD_SCREENS_DATA 0.2 0 1 0
END
XR2_Bay:XRPayloadBay
  STATUS Landed Earth
  POS -14.4300238 -7.9599373
  HEADING 118.22
  ATTACHED 0:3,XR2
  AFCMODE 7
END
END_SHIPS

 

[hribek]

pre-release

View attachment 48 hour Moon roundtrip.zip
Here is a pre-release of scenario files saved at some key parts of the journey and 4 playbacks that cover the entire trip. The playbacks aren't annotated, and the return trip could probably use some tiny improvements. I'lll upload the final version to OHM.