Request Tianwen Mars Mission

[N_Molson]

@gattispilot : I'm Google-translating some chinese content...

They say that the "middle" solar panels can move up and down to adjust the angle. So when the rover is parked, it can lower the panels on the side to catch a bit more sunlight, then rise them before it resumes roving.

... and there's a flap on the shell, that can be used to adjust the descent angle. So it is some kind of lifting body. Things are getting more and more complex.

... also the lander hovers just 100 meters above ground, and looks for a spot clean of rocks.

 

[N_Molson]

Here's the lander platform hovering 100 meters above the surface, with landing gear retracted (and without the rover mesh). I now have to figure out a "negative" Flight Control System for attitude, and also make some kind of guidance program so that it can land safely on its own. Then the fancy stuff like particle exhausts, lights, animations...

 

[BrianJ]

........Things are getting more and more complex........

Funny how that always happens with Orbiter projects
Looks good

 

[N_Molson]

Progress on the descent program, now the lander correctly fires its main and auxiliary engines to hold altitude at 100 meters above the terrain (radar altitude). Right now the program stabilizes the lander so that it won't tilt in any direction, it remains stable. Also implement the 8x25N thrusters for fine horizontal speed tuning.

I have to add a "helicopter mode" that tilts a bit the lander to cancel most of the horizontal velocity, because the 25N thrusters are meant only for avoiding rocks, little more.

Then, once stabilized and the horizontal velocity canceled, the lander will proceed to the final descent.

From an aerodynamics and physics standpoint, we're good, it works in Orbiter. There's little margin (which seems realistic to me) but the numbers match. There's room for refining the initial orbit - I'm still short 500 km from the landing target -. Also have to add that body flap, which - I think - is intended to increase drag by tilting a bit the capsule, so the idea would be to overshoot slightly and use the flap to fine-tune.

Also I have of course to write instructions for the orbiter, which has to raise its periapsis to 265km once the lander is detached and on its way for entry. At this point the player should be focused on the entry vehicle, watching Mars getting bigger, so the orbiter has to manage itself.

 

[gattispilot]

Here is your lander with the details. Not sure if lost in conversation but it seems a box might have moved around the thrusters. I placed a lander DG at the same location so it was sunk down.
I found a better model to view so redoing the rover

 

[N_Molson]

OK thanks, don't worry I'll fix that !

 

[N_Molson]

Re-wrote the autopilot so that it now relies on vector components, tedious work but in the end will provide a reliable system, mostly done !

 

[gattispilot]

I redid the rover. CTRL + space opens window to control the dish,mast,...

2 antenna, 3 panels, 4 stows camera

 

[N_Molson]

Looks good ! I'll start integration of the meshes as soon as I get a good autopilot landing.

 

[N_Molson]

So after hours of debbuging my own creation (and there's still one thing to fix), I manage to have the probe hovering 100 meter above the ground (radar), with less than 0.2 m/s of horizontal speed.

Once the bug fixed (wild tiliting right after drop, that the autopilot still manages to recover from, lol), I'll start the "final descent" part, should be easy, only have to control the vertical velocity.

 

[N_Molson]

Good stuff there :

 

[N_Molson]

Good news ! I was able to find and use the DG Hover AAP (Vertical Speed Mode) ! That will help a lot. Now only a bit of still tuning to do.

Done ! I'm on the ground safely !

Tomorrow I'll work on putting the meshes together.

 

[N_Molson]

@gattispilot : Hmm... it won't fit (well, that's mostly because of the forward "turrets"). What do you think ? I'd say it could be scaled down a bit, looks a bit big on the platform. We can make the platform rails a bit narrower if necessary.

 

[N_Molson]

Looks a bit smaller, definitively, but I can also make the platform "lower" in the shell by a few centimeters, could help.

 

[gattispilot]

Oh. So I wonder if I can make the whole rover small or make the wheel fold up so the over all height is shorter. I made the rover a bit larger to fit the width of the ramps.

 

[N_Molson]

I made the rover a bit larger to fit the width of the ramps.

I'd say don't worry about them. I can scale them, not a big issue.

And yeah in that last animation (seems to be real CNSA stuff, which is quite precious in our case) the wheels are "up". They definitively fold, which would help a lot the rover to fit in the shell.

So I think a little bit of scaling down on the whole rover (not too much), and have the wheels by default in the "retracted" position. I'm pretty sure it will work that way.

Seems the very first thing the rover does once landed is to "raise" on its wheels, then it goes down the ramp (I'll have to do all that through animations I think, when the "down the ramp" animation will be over, it will spawn the rover vessel, transition should be nearly unnoticeable if I position everything correctly).

 

[gattispilot]

Just let me know what I need to do

 

[N_Molson]

@gattispilot "Just let me know what I need to do"

Can you send me the mesh a little bit scaled down, like x0.95 or something like that, and the wheels in the "retracted" position ? Thanks.

 

[gattispilot]

Do u need a working Rover scaled down and a static model scaled down with retracted wheels

 

[gattispilot]

.951 scaled and wheel rotated up