# IdeaChandrayaan-2, Vikram lander and Pragyan rover

#### Jeremyxxx

##### Active member
I love how the Pragyan rover has a deployable solar array now.

#### gattispilot

Got the rover to follow the ramp. Need to get it off. One odd thing is when I get it CTD. Closes the Orbiter Launch window

#### Jeremyxxx

##### Active member
Nice work so far! I have been waiting patiently to get this thing flying on Orbiter soon.

#### gattispilot

Thanks. I am backing to the spinning rover again

So I may just have the rover in store position and press a key and the rover is at the end of ramp ready to explore.

#### gattispilot

So using the LEM code for the lander. I placed the lander where I want it. Exit the scn and restart and now the lander is in space

Code:
// SM Stage Parameters
const VECTOR3 LEM_DescentCS = { 6.05, 15.26, 6.17 };	// Decent Stage x,y,z cross sections [m^2]
const VECTOR3 LEM_DescentPMI = { 4.08, 1.31, 4.18 };	// Decent Stage principal moments of inertia (mass-normalised) [m^2]
const VECTOR3 LEM_DescentRD		= {0.7,1.2,0.7};	// Decent Stage rotation drag coefficients
const double  LEM_DescentMASS = 626;				// Decent Stage empty mass [kg]
const double  LEM_DescentFUEL = 845;				// Decent Stage fuel capacity [kg]
const double  LEM_DescentISP	= 4398;				// Decent Engine exhuast velocity[m/s]
const double  LEM_DescentTHRUST = 10000;				// Decent Engine max thrust [n]
const VECTOR3 LEM_DescentOFFSET	= { 0.00, -0.00, 0.00};	// Offset of Descent stage CG from combined CG
//const VECTOR3 LEM_DescentTDP[3]	= {{0.0,-0.1,10.0},{-10.0,-0.1,-15.0},{10.0,-0.1,-15.0}}; // Decent Stage touchdown points [m] RODADOS em Z
//const VECTOR3 LEM_DescentTDP[3]	= {{ 0.00, 4.40,-2.29},{-3.81,-2.20,-2.29},{ 3.81,-2.20,-2.29}}; // Decent Stage touchdown points [m]

// values from Delta Glider
// point, stiffness, dampening, isotropic/lateral friction coefficient, longitudinal friction coefficient (only used for first 3 points)
const double pesototal=LEM_DescentMASS+LEM_DescentFUEL;
const double xtx_target=-0.1;
const double xtst=(-1)*(pesototal*9.80655)/(3*xtx_target);
const double xtda=0.9*(2*sqrt(pesototal*xtst));

static const DWORD ntdvtx_geardown = 4;
static TOUCHDOWNVTX tdvtx_geardown[ntdvtx_geardown] = {
{_V( -4,-1.3166,-4), xtst,  xtda, 30.0,30},
{ _V(4, -1.3166, -4), xtst, xtda, 30.0, 30 },
{ _V(4, -1.3166, 4), xtst, xtda, 30.0, 30 },
{ _V(-4, -1.3166, 4), xtst, xtda, 30.0 }
};

Quicksave:
VLANDER:VLANDER
STATUS Landed Moon
POS 22.7810780 -70.9025260
ALT 1.306
AROT -148.482 52.147 29.257
AFCMODE 7
NAVFREQ 0 0
RAMP1 0 0.0000
RAMP2 0 1.0013
RAMP3 0 0.0000
PANEL 0 0.0000
GEAR 0 0.0000
ANTENNA 0 0.0000
END
END_SHIPS

Current State:
VLANDER:VLANDER
STATUS Orbiting Moon
RPOS 13133394.375 107780739.433 -28199664.321
RVEL 940642.4179 7726032.3393 -2024516.5467
AROT 135.346 -31.022 -53.697
VROT 17788.5434 -0.3045 -2750.9497
AFCMODE 7
NAVFREQ 0 0
RAMP1 0 0.0000
RAMP2 0 1.0013
RAMP3 0 0.0000
PANEL 0 0.0000
GEAR 0 0.0000
ANTENNA 0 0.0000
END
END_SHIPS

Last edited:

#### gattispilot

So I am going to try something. On the deployment of the rover. I am going to mount a rover mesh to the lander and move the fake rover down the ramp and then disappear and have a rover made where the fake one was.

Haven't gotten thrust to work on the lander as yet

---------- Post added 09-04-19 at 04:39 AM ---------- Previous post was 09-03-19 at 07:32 AM ----------

So I added a rover mesh and moved it to the end of the ramp and spawn the rover there. BUt I get a CTD when I dettach the rover from the lander.

I am thinking it has to do with the attachment points but not sure. the rover is at the right direction

Code:
LR2 = CreateAttachment(false, _V(0, -1.0, 3.1), _V(0, -1, 0), _V(0, 0, 1), "ROVER", false);
This gives a CTD
Code:
if (key == OAPI_KEY_K)     {
DetachChild(LR2, 0);
}
Code:
void SpiderLEM::SpawnRover(void)
{
//if (EXT_status == HATCH_DOWN){
if (GetAttachmentStatus(LR2) == NULL)
{
//SetAttachmentParams(ft_pad_att, attp_pos[1], _V(0, 1, 0), _V(0, 0, -1));

//OBJHANDLE hVessel;
VESSELSTATUS vs;
GetStatus(vs);
hMMU = oapiCreateVessel("P_ROVER", "PROVER", vs);

VESSEL *v = oapiGetVesselInterface(hMMU);
ATTACHMENTHANDLE hAttWFC = v->GetAttachmentHandle(true, 0);
AttachChild(hMMU, LR2, hAttWFC);
//}
}
}
So I fired the lander hover engine and started to spin set horizon level on and end up upside down

#### Jeremyxxx

##### Active member
Bad news: the Vikram landing has crashed on the lunar surface. Mission failed.

#### Gargantua2024

##### The Desktop Orbinaut
Despite the bitter failure, the mission would still go on as the orbiting mothership is still functioning properly at this point

#### gattispilot

Maybe the rover will be saved?

#### emin2004

##### Active member
Maybe the rover will be saved?

Unfortunately the Rover did not Survive the crash

note: that's the 2nd time We Crashed on the Moon, the Last Crash was Beresheet and The Last Crash before Beresheet was 48 years ago and that was the Soviet's Luna Probes

#### Jeremyxxx

##### Active member
Despite the disaster that has happened in the lunar surface, the development of the Chandrayaan 2 addon will still be ongoing with a hypothetical scene of what could've been India's first moon landing.

#### Gargantua2024

##### The Desktop Orbinaut
Nothing will stop Orbiter in landing Vikram successfully to the surface of the Moon

#### gattispilot

Nothing will stop Orbiter in landing Vikram successfully to the surface of the Moon

My will

So I applied horizon level and applied hover and it lifted up and then started to rotate and then ended up here upside down in the moon

Code:
PROVER:PROVER
PANEL 0 0.0000
STATUS Orbiting Moon
RPOS -193674.765 -1645379.313 527992.856
RVEL -1.3765 -0.0396 -0.6300
AROT -158.465 -25.584 171.388
ATTACHED 0:0,VLANDER
AFCMODE 7
NAVFREQ 0 0
END
VLANDER:VLANDER
STATUS Orbiting Moon
RPOS -193676.107 -1645377.102 527995.417
RVEL -1.3765 -0.0396 -0.6300
AROT -158.465 -25.584 171.388
AFCMODE 7
PRPLEVEL 0:0.906814
NAVFREQ 0 0
RAMP1 0 0.0000
RAMP2 0 0.0000
GEAR 0 0.0000
END

starts here:

Code:
PROVER:PROVER
PANEL 0 0.0000
STATUS Landed Moon
POS 22.7782765 -70.9021341
ALT 0.111
AROT -13.992 49.914 152.413
ATTACHED 0:0,VLANDER
AFCMODE 7
NAVFREQ 0 0
END
VLANDER:VLANDER
STATUS Landed Moon
POS 22.7782733 -70.9021084
ALT 1.305
AROT -135.541 62.570 39.833
AFCMODE 7
PRPLEVEL 0:1.000000
NAVFREQ 0 0
RAMP1 0 0.0000
RAMP2 0 0.0000
GEAR 0 0.0000
END

Code:
/ point, stiffness, dampening, isotropic/lateral friction coefficient, longitudinal friction coefficient (only used for first 3 points)
const double pesototal=LEM_DescentMASS+LEM_DescentFUEL;
const double xtx_target=-0.1;
const double xtst=(-1)*(pesototal*9.80655)/(3*xtx_target);
const double xtda=0.9*(2*sqrt(pesototal*xtst));

static const DWORD ntdvtx_geardown = 4;
static TOUCHDOWNVTX tdvtx_geardown[ntdvtx_geardown] = {
{_V( -4,-1.3166,-4), xtst,  xtda, 30.0,30},
{ _V(4, -1.3166, -4), xtst, xtda, 30.0, 30 },
{ _V(4, -1.3166, 4), xtst, xtda, 30.0, 30 },
{ _V(-4, -1.3166, 4), xtst, xtda, 30.0 }
};

#### gattispilot

Sure but why? The rover is really done it is the flight dynamics of the lander and deployment that is left on the lander.

#### gattispilot

oh. no idea on how to do that

#### NukeET

##### Gen 1:1
Donator
Sure but why? The rover is really done it is the flight dynamics of the lander and deployment that is left on the lander.

It might be easier to simulate the wreckage. :rofl:

#### Jeremyxxx

##### Active member
Or go the AMSO route by simulating both the Hypothetical landing and the actual failure of the Vikram.

#### Gargantua2024

##### The Desktop Orbinaut
Or go the AMSO route by simulating both the Hypothetical landing and the actual failure of the Vikram.
Like BrianJ's [ame=https://www.orbithangar.com/searchid.php?ID=6958]Mars Observer[/ame] and [ame=https://www.orbithangar.com/searchid.php?ID=7243]Beresheet[/ame] addons that have alternate what-if scenarios depicting that they successfully reached their destinations intact

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