Project HASDA - Reusable Crew Vehicle (lifting-body spaceplane)

[PhantomCruiser]

I'm not sure enough people know about it, yet.

 

[Pipcard]

edit: please ignore, I realized that the flight model at this time was actually like a Delta-glider

I found a method of re-entering my vehicle; it is by no means realistic, but it is relatively easy to accomplish. This method is inspired by blixel's (David Courtney) method of landing the default Delta-glider, but is not quite the same. It also doesn't waste RCS fuel, and you do not have to wrestle with the controls.

1. Use BaseSyncMFD to determine when your orbit's path will pass closest to the target base.
2. On that orbit, perform a de-orbit burn half-an-orbit away from the target until your periapsis is 0 km.
3. As you're nearing 120 km altitude (where the simulated atmosphere starts to act on your craft), turn prograde and level horizon (yaw to point yourself near the prograde vector).
4. Somewhere below the Karman line (<100 km) in which the atmosphere becomes slightly more dense, use the roll (numpad 4 and 6) as well as trim (insert and delete keys) to make it so that the projected flightpath in AerobrakeMFD reaches the base.

It is important that you use x0.1 (10 times slower) time acceleration and quickly tap (not hold) the insert or delete keys in order to have more precise control over trim and the projected landing distance from the base (which is actually very stable and does not jitter around if you leave it alone).

As you can see it is pointed close to the prograde vector. The "animation trick" will make the craft look like it is pointed 40 degrees upward when viewed from the outside.

5. Don't aim directly at the base, aim for a spot a few dozen kilometers out so you can prepare your runway approach better. (Also you can bleed off more speed by banking and turning)

6. Line up with the runway and land.

 

[Cizurator]

Well, you'll probably be the first to test this animation trick on your vehicle. I have a feeling that local magicians of aerodynamics will put many curses on us for this good looking, yet somewhat unpure solution. :uhh:

 

[Urwumpe]

Well, you'll probably be the first to test this animation trick on your vehicle. I have a feeling that local magicians of aerodynamics will put many curses on us for this good looking, yet somewhat unpure solution. :uhh:

Only looks good in external view.... Also the curses will come anyway, too low drag. :lol:

 

[Pipcard]

For some reason, I cannot get the control surface animations to work.

When I create an animation component for my elevons and tie it to the landing gear animation sequence, the elevons move (so it is not a problem with mesh groups).

But when I tie them to a control surface animation (such as pitch or roll), they don't move at all when holding the numpad keys for rotation.

Control surfaces work (but the animations don't) within the atmosphere despite not having specific definitions in the aerodynamics section of the .ini.

Problem solved. See post below.

 

[Pipcard]

I forgot something extremely crucial:

In the .ini, there is supposed to be a line saying "[AERODYNAMICS]" (without quotes) before all the lines defining the aerodynamic parameters.

All this time, my craft had been flying like a Delta-glider, and the control surface animations wouldn't work.

But now that I put that line, it is now possible for me to have a craft that can hold at a 40 degree angle of attack using AerobrakeMFD's AoA hold autopilot. (because the moment coefficient works)

---------- Post added 12-23-14 at 01:34 AM ---------- Previous post was 12-22-14 at 01:49 AM ----------

I am currently testing out drag coefficients for re-entry and landing. Sometimes, the drag had been too high and the craft slowed down too much prior to landing, so I had to lower it.

 

[Urwumpe]

In the .ini, there is supposed to be a line saying "[AERODYNAMICS]" (without quotes) before all the lines defining the aerodynamic parameters.

:hmm:

:blink:

:rofl:

OK, and I wondered what the hell I have been missing there, but since I am no Spacecraft3 or GenericVessel guy, it is easily possible for me to be wrong there. :thumbup:

Good to read that aerodynamics are now working.

 

[Pipcard]

I think I'm getting close to a desired flight model. I probably just need to add an airbrake function (if the speed is too high for landing).

One thing I've learned is that the VAIRFOIL_AREA setting in the spacecraft3 .ini affects your craft's lift and drag coefficients (see S*Cl and S*Cd in AerobrakeMFD). I've set mine to 13.9.

The [y] value in VAIRFOIL_LIFT_[n]=([x],[y],[z]) equals a value that is multiplied by the VAIRFOIL_AREA to get the S*Cl (lift coefficient) at the angle of attack [x]. For example, if you set [y] to 0.7914, it gets multiplied by 13.9 to get an S*Cl of about 11.

11 is a good S*Cl value for landing a craft of this mass at low enough speeds, but if the VAIRFOIL_AREA is too low or too high, the drag might be too low or too high.

Also, I've recently found out that the XR2 has a L/D ratio of 0.5 during re-entry, which is why it doesn't need to perform roll reversals/s-turns.

 

[Pipcard]

edit: I just added MFDs to my spacecraft (the MFD texture uses its own material), but I'm currently trying to get the HUD to work.

 

[Pipcard]

I was planning on adding parachutes for emergency water landings, but apparently spacecraft3 only supports one drag-increasing animation, and that's taken up by the elevon speedbrake. Sorry, but I just don't have the time to make a .dll at the moment.

 

[Pipcard]

This is the problem with the HUD. I placed it closer to the middle (it's supposed to be over the left MFD, if there's a CameraMFD) in order to show how it seems to ignore the mesh in front of it. Note that the HUD currently has a transparent texture. (also it isn't properly aligned yet)

---------- Post added 01-10-15 at 11:00 AM ---------- Previous post was 01-09-15 at 08:52 PM ----------

But on liber's Dream Chaser, the HUD doesn't do that. How can I do this?

 

[Pipcard]

No matter what I do, no matter what set the material to (texture or no texture), no matter how the mesh is grouped, it seems that I cannot get the HUD to show properly.

So it looks like I'm going to have to skip out on having a HUD in the virtual cockpit.

 

[Pipcard]

I finally figured it out. This person was having the same problem as me, so I moved the HUD and MFD mesh groups to the end of the .msh file, and named the HUD and MFD materials so that it would be at the bottom.

Remember: Ctrl+H completely toggles the HUD on and off.

(Note: the .msh file shown below is before I took it through *\Orbitersdk\utils\Shipedit.exe to make the file size slightly smaller, which is why the mesh groups still have actual names instead of generic ones)

 

[Pipcard]

The RCV fleet:

 

[Pipcard]

APAS docking adapter (connects to 80 cm hatch)

 

[ISProgram]

I totally forgot that the RCV even has a docking adapter. :facepalm:

 

[Pipcard]

Docked to the ISS:

 

[Pipcard]

Crew access tower is complete!

All that's left in the current development itinerary are the scenarios and documentation.

 

[K_Jameson]

That payload interface is very thin at top; seems to me a little weak...

 

[Pipcard]

That payload interface is very thin at top; seems to me a little weak...

As shown here, this is the precedent:

I couldn't have a Dream Chaser/Atlas V-style payload interface either because the APAS docking adapter wouldn't be able to fit through when moving forward from the second stage. So the docking adapter and the launch vehicle adapter has to be conical. I had some doubts about it, too.

edit: here's another one, but it's from the 60s