Flight Question Interplanetry landing without LEO

[worir1]

I have pretty much just completed my first round trip to mars. I used the XR2 and managed to land on olympus base. I am now on the way back and am around 4G from earth and i was wondering is there a way to re enter and land at a specific base without having to get into orbit first? I am coming in at about 10km/s (is that deltav?) I have basesync MFD and Aerobrake MFD. I would like to land at wideawake international. Is it possible ?

 

[boogabooga]

Yes, and no.

I would recommend IMFD, which has a great base approach feature to do exactly what you asked. You'll have to learn how to use it though; IMFD is quite complex. However, it may be difficult to impossible set up your approach, depending on your trajectory.

I say yes and no because while you may be able to set up a base approach, a direct entry from interplanetary space will FRY an XR-2. I recommend setting the anticipation angle to 90 degrees and trying an inverted reentry, which is quite challenging!

 

[ADSWNJ]

For worir1 ... the inverted reentry concept is probably the most exciting / scary way you can reenter Earth's atmosphere. The idea is that you want all of the lift component of the wing to help you to descend, so you can come in really shallow and trim off your delta-V at an angle that would skip you off the atmosphere if you were the right way up.

Keep lots of save-scenarios from a few million miles away right down to entry interface and down to landing, and please post your progress!

I've never done a fully inverted reentry, but I would love to see the glide slope and configure it as one of the defaults for Glideslope 2 !! (Another Xmas project for me in my week off work!)

 

[worir1]

So i re enter upside down?! is a PeA of 90km ok?

 

[dgatsoulis]

So i re enter upside down?! is a PeA of 90km ok?

That depends on your speed at periapsis altitude. I recommend a direct reentry from the moon first, before attempting interplanetary aerocapture maneuvers.

That said, there is nothing wrong in trying. All shorts of interesting things may happen. (Most probably, you'll either burn up, or be shot back to space, but trial and error has been the driving force of science for hundreds of years). :thumbup:

Watching the V/S (vertical speed) and V/A (vertical accelaration) on the stock Surface MFD, combined with the temperature readings of the XR2, will help you.

Watching how others have performed similar flights, will help too.

 

[boogabooga]

So i re enter upside down?! is a PeA of 90km ok?

70 km.

I've completed inverted re-entries.

Here, try this scenario for practice (you should be able to make Cape Canaveral):

BEGIN_DESC
StateSaver Autosave:


System Time:

Thu May 10 20:45:10 2012


Simulator MJD:

51989.191573


Focus Vessel:

XR2-01


Relative Body:

Earth


Altitude:

152.882k



END_DESC

BEGIN_ENVIRONMENT
  System Sol
  Date MJD 51989.1915731954
END_ENVIRONMENT

BEGIN_FOCUS
  Ship XR2-01
END_FOCUS

BEGIN_CAMERA
  TARGET XR2-01
  MODE Cockpit
  FOV 39.79
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_MFD Left
  TYPE Surface
  SPDMODE 1
END_MFD

BEGIN_MFD Right
  TYPE User
  MODE AeroBrakeMFD
  Reference Earth
  Data 0 1.000000 1 0 0 0
  Target cape_canaveral
  LonLat -1.408044 0.497782 1
  AoA 0 0.000000
  Bank 0 0.000000
END_MFD

BEGIN_PANEL
END_PANEL

BEGIN_SHIPS
ISS:ProjectAlpha_ISS
  STATUS Orbiting Earth
  RPOS -2484231.90 -4660630.53 4181164.53
  RVEL -5635.722 4823.735 2038.974
  AROT -75.70 -21.00 -71.98
  VROT 0.08 -0.01 0.05
  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
  O2_TANK 100.00
  FOOD_TANK 100.00
  CFG_MONTH_O2 6.00
  CFG_MONTH_FOOD 6.00
  UCGO @@0,1,0,0,@@1,1,0,0,@@2,1,0,0,@@3,1,0,0,@@4,1,0,0,@@5,1,0,0,@@6,1,0,0,@@7,1,0,0,
END
Mir:Mir
  STATUS Orbiting Earth
  RPOS -675981.41 365406.48 -6630510.38
  RVEL 7206.311 2724.077 -574.805
  AROT -109.04 1.41 -130.63
  VROT 0.04 0.06 -0.06
  AFCMODE 7
  IDS 0:540 100 1:542 100 2:544 100
  XPDR 482
END
Luna-OB1:Wheel
  STATUS Orbiting Moon
  RPOS -580948.84 -2163146.68 1979.89
  RVEL 1428.656 -383.869 0.475
  AROT -0.03 -0.01 -83.76
  VROT -0.00 0.00 10.00
  AFCMODE 7
  IDS 0:560 100 1:564 100
  XPDR 494
END
XR2-01:XR2Ravenstar
  STATUS Orbiting Earth
  RPOS 2345715.83 -856748.29 6027003.35
  RVEL -9730.253 4051.598 3029.223
  AROT 136.23 59.07 39.60
  PRPLEVEL 0:0.680298 1:0.995863 2:0.052000
  IDS 0:199 100
  NAVFREQ 94 524 84 114
  XPDR 193
  SECONDARY_HUD 5
  LAST_ACTIVE_SECONDARY_HUD 0
  ADCTRL_MODE 0
  TAKEOFF_LANDING_CALLOUTS 10580.444872 152.340144 152.343086 0.000000 -1232.295000
  APU_FUEL_QTY 0.796516
  LOX_QTY 0.673061
  CABIN_O2_LEVEL 0.209000
  CREW_STATE 0
  INTERNAL_SYSTEMS_FAILURE 0
  COGSHIFT_MODES 0 0 0
  MWS_ACTIVE 0
  COOLANT_TEMP 35.669334
  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 51984.608132
  INTERVAL1_ELAPSED_TIME -1.000000
  INTERVAL2_ELAPSED_TIME -1.000000
  MET_RUNNING 1
  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 42.500000 0.000000 1 1 0.207696
  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 0 0.0000
  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 0
  EXTCOOLING_STATUS 0
  TRIM 0.000000
  LIGHTS 0 0 0
  XRUMMU_CREW_DATA_VALID 1
  UMMUCREW XI0-Lee_Nash-39-65-78
  UMMUCREW XI1-Kara_Miller-32-65-58
  UMMUCREW XI2-Sharon_Valerii-26-67-54
  UMMUCREW XI3-Cameron_Mitchell-36-65-77
  UMMUCREW XI4-Samantha_Carter-33-66-53
  UMMUCREW XI5-Daniel_Jackson-35-68-75
  UMMUCREW XI6-Teal_c-31-64-104
  UMMUCREW XI7-Vala_Mal_Doran-30-67-53
  UMMUCREW XI8-Elizabeth_Weir-36-68-56
  UMMUCREW XI9-John_Sheppard-34-64-77
  UMMUCREW XI10-Rodney_McKay-35-72-90
  UMMUCREW XI11-Teyla_Emmagan-27-68-57
  UMMUCREW XI12-Ronon_Dex-32-63-97
  UMMUCREW XI13-Carson_Beckett-38-74-95
  PAYLOAD_SCREENS_DATA 0.2 0 1 1
END
SH-03:ShuttleA
  STATUS Landed Earth
  BASE Habana:4
  POS -82.3982414 23.0005396
  HEADING 70.00
  AFCMODE 7
  PRPLEVEL 0:1.000000 1:1.000000
  NAVFREQ 0 0
  XPDR 0
  PODANGLE 0.0000 0.0000
  DOCKSTATE 0 0.0000
  AIRLOCK 0 0.0000
  GEAR 0 0.0000
  PAYLOAD MASS 0.0 0
END
PB-01:ShuttlePB
  STATUS Landed Earth
  BASE Habana:1
  POS -82.4000000 22.9994604
  HEADING 22.00
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END
GL-02:DeltaGlider
  STATUS Landed Mars
  BASE Olympus:3
  POS -135.4300000 12.7366196
  HEADING 0.00
  AFCMODE 7
  PRPLEVEL 0:1.000000 1:1.000000
  NAVFREQ 0 0 0 0
  XPDR 0
  GEAR 1 1.0000
  AAP 0:0 0:0 0:0
END
SH-01:ShuttleA
  STATUS Landed Moon
  BASE Brighton Beach:1
  POS -33.4375000 41.1184067
  HEADING 0.00
  AFCMODE 7
  PRPLEVEL 0:1.000000 1:1.000000
  NAVFREQ 0 0
  XPDR 0
  PODANGLE 0.0000 0.0000
  DOCKSTATE 0 0.0000
  AIRLOCK 0 0.0000
  GEAR 0 0.0000
  PAYLOAD MASS 0.0 0
END
XR2PayloadCHM-01-1:XR2PayloadCHM
  STATUS Orbiting Moon
  RPOS -296764126.91 19782415.36 278619581.29
  RVEL -10372.925 4120.452 2306.361
  AROT 136.23 59.07 39.60
  ATTACHED 0:0,XR2-01
  AFCMODE 7
  NAVFREQ 0 0
END
XR2-01_Bay:XRPayloadBay
  STATUS Orbiting Moon
  RPOS -296764122.48 19782413.51 278619582.87
  RVEL -10372.925 4120.452 2306.361
  AROT 136.23 59.07 39.60
  ATTACHED 0:3,XR2-01
  AFCMODE 7
END
END_SHIPS

BEGIN_ExtMFD
END

BTW, I recommend learning IMFD, to pull off the alignment. Learning IMFD is not trivial, either but very rewarding.

 

[dgatsoulis]

No. Just No.

Simply because you've "completed" inverted re-entries... (with a great big smile in the end)... doesn't mean you can actually do it.

 

[worir1]

I tryed a normal re entry and burned up
I tryed a inverted one and burned up.
Im guessing when my top hull temp gets high i should flip over the right way?

 

[statickid]

:2cents:

There are lots of bases all over the Earth. you can pick on that is possible to land on direct reentry, but chances are it won't be someplace cool like Wideawake or KSC.

If you don't care about landing at a major base, here's what I do

Use Map MFD. When you are close enough to register a ground track, adjust your RInc to intersect the base. If you have a weird ground track with loops and retrograde motion in it and junk, just give it your best guess by adjusting what looks like your closes approach as being a "section" of your correct approach. Inverted reentry takes a loooong distance so pick a base thats really far away from atmosphere interface. The most difficult part in my opinion is flipping back over again with out breaking the XR. The easiest way to do this is to work your way down to an altitude of about 50 and let your self start flying out again. if you time it right, you will start out on an orbit that goes back out of the atmosphere. However, as you rise out of the air unpowered, it will continue to slow you down and your orbit will decay until it is actually a reentry orbit. In the mean time, by gaining a little bit of altitude back you get a short break in temp/pressure so you can leisurely flip back over for the second phase of landing which you manage like a normal reentry.

If you want to land at a cool scenic base then i recommend including LEO in your flight plan. Unless you're just totally out of fuel/LOX and it's an emergency, including LEO is a realistic part of the plan. you can still do the cool inverted aerocapture move, but use it to get into LEO instead, wait an orbit or two for the base to come into your path and land

---------- Post added at 08:09 AM ---------- Previous post was at 08:06 AM ----------

P.S. or just get an XR raft, and direct reenter into the ocean where you have a Sea King waiting with an aircraft carrier and tug

 

[jangofett287]

P.S. or just get an XR raft, and direct reenter into the ocean where you have a Sea King waiting with an aircraft carrier and tug

How much are these XR rafts and where can I get some? My space endeavors could make great and often use of these. :lol:

 

[ADSWNJ]

I tryed a normal re entry and burned up
I tryed a inverted one and burned up.
Im guessing when my top hull temp gets high i should flip over the right way?

It's hard to visualize what's going on here, but think about this...

When you are in a normal descent, you pitch your nose up to present the thermal tiles to the airstream, and have the plasma cone flare off the nose and wings without melting the cockpit or tail. Strictly, you are trying to achieve an angle of attack of say 40 degrees by pitching up. Think about the forces on the wing in this direction ... there will be a horizontal (backwards) component helping to slow up the spacecraft, and a vertical component lifting the spacecraft. For the real Shuttle, the idea behind doing really aggressive S-turns with roll-reversals of up to +80 to -80 degrees is exactly to remove this vertical component (i.e. roll it almost into the left-right direction).

Now turn it all upside down. Say you are in a 180 degree roll, with your head directly facing down. Note that even though you are upside down, you are still trying to hold a 40 degrees AOA, so the thermal tiles are still in the plasma stream and you are still protected. In this configuration, all the possible lift of your wing is being used to push your downwards - i.e. to stop skipping off the atmosphere.

It's a wild ride!

 

[statickid]

also, try a higher PE

or... post more information

---------- Post added at 08:34 AM ---------- Previous post was at 08:31 AM ----------

your top hull should NOT heat up at all (within reason, of course) if you are getting a hull breach on the top hull you are doing something wrong, the only reason to flip over is to help you transition into gliding to land ( kind of hard for a plane to fly backwards)

---------- Post added at 08:39 AM ---------- Previous post was at 08:34 AM ----------

oh yeah and it also helps you manage lift when you get into the lower atmosphere. I suppose i was wrong a second ago, another big reason you flip over is to help you not fall to fast once you get falling. in essence, it is the same reason to be inverted in the first place, to use lift as a counter force against your free trajectory. use inverted position to counteract a hyperbolic or highly eccentric orbit, use standard position to counteract falling to fast in reentry-type trajectory. but again, at no point should the top hull breach or you've got a major parameter or orientation wrong

 

[ADSWNJ]

your top hull should NOT heat up at all (within reason, of course) if you are getting a hull breach on the top hull you are doing something wrong, the only reason to flip over is to help you transition into gliding to land ( kind of hard for a plane to fly backwards)

I first thought of it as flipping the spacecraft over on the roll axis, which leads to the scary thought of burning the top of the spacecraft. The mental gymnastics you need are essentially picturing doing that 180 degree roll but then pitching the nose up (towards the Earth as we are inverted) by **80** degrees, so that you are inverted with the nose the lowest part on the spacecraft in this maneuver, instead of tail-low in a normal descent.

another big reason you flip over is to help you not fall to fast once you get falling. in essence, it is the same reason to be inverted in the first place, to use lift as a counter force against your free trajectory. use inverted position to counteract a hyperbolic or highly eccentric orbit, use standard position to counteract falling to fast in reentry-type trajectory.

Exactly! Think of the roll angle simply as a way to dial between -100% and +100% of your wing lift into your vertical acceleration. I.e. rolled to 90 degrees, you have zero vertical acceleration from your wing. So as you control your descent, do inverted roll reversals say 30 degrees either side of 180 roll, then gradually increase to 90 degrees from inverted, then you are back into steep "normal" upright rolls as you come to say 60 km, then the rest is normal.

 

[statickid]

 

[worir1]

Thanks for all your help. I realised what i was doing wrong. I omly had an AoA of 10°. I think i did not understand the manuver. I will give it a go and tell you what happens

---------- Post added at 08:13 PM ---------- Previous post was at 06:02 PM ----------

It worked sort off... I reentered fine but when i was ajusting my AoA during re entry i kept on pressing to wrong buttons... I landed fine but missed my base. Thanks for the help

 

[statickid]

it will only get easier! not burning up is the first step

 

[PhantomCruiser]

Like throwing yourself at the ground, and missing?

I've tried inverted re-entry, failed miserably. There was a pretty good tutorial/checklist here for it somewhere? Time to use the search function...

Here's some discussion on the matter, but not yet what I was looking for...http://www.orbiter-forum.com/showthread.php?t=11551&highlight=inverted+reentry

 

[orbekler]

Here some inverted reentry for the Altea family (back from the Moon), it could help:

https://vimeo.com/33098669

https://vimeo.com/33339062

 

[Urwumpe]

There is also a NASA guidance algoritm for controlled Aerobraking, which can be used for getting such extreme reentries controlled. It is designed for getting into orbit or for skip reentries (where you leave atmosphere on a suborbital ballistic parabola to reenter at a better place), and could be turned into a MFD. I don't remember the name anymore, but the Fortran code for it was pretty old.

 

[worir1]

thanks for the help guys