Project Mars Design Reference Mission 1

[markp]

More autopilot fun!

Have the heading correction part of the autopilot working. Can now fly to the base.

The first image shows an overshooting of Cape Canaveral due to a recent problem in the code related to calculating the distance to the target. I switched to a new target, the amazing Pictown a bit south of Cape Canaveral, to try and isolate the problem.

I managed to fix the problem and landed within a couple of km of the base just using a constant angle of attack of 50 degrees and bank modulation. I took some screenshots when I realised the autopilot problems had been fixed. The images show the vehicle targeting Pictown and then circling over (as the heading is changing very quickly close to the base).

I think I will get the autopilot to reduce the angle of attack below Mach 5, or perhaps Mach 3, for a higher lift over drag to fly a bit better close to the target, haven't figured that out yet or what's required. The last two images are with pitch and bank hold autopilots switched off and activation of Orbiter's hold level autopilot in preparation for a manual landing.

Next step will be the activation of the hover landing and targeting part of the autopilot for a precise landing and updating that to use thrust vectoring.

 

[markp]

Here's a quick movie demo of the reentry autopilot at work. The initial heading is meant for a landing a Cape Canaveral but I decided to divert to Wallops Island to give the code a good test. I used x10 time acceleration for some of the flight. Close to Wallops Island some thrust is applied manually to give a bit more speed. Other than that the reentry is totally automatic. Close to the surface I switch the autopilot off and attempt to fly it manually which I mess up a bit. Hopefully get the hover landing autopilot up and running so I don't have to worry about landing.

The Wallops Island base addon is by 4th rock, which you can find it in his thread in the Addon development section on the forum.

 

[markp]

Making progress with the new hover landing autopilot. Have figured out (and tested) how to calculate the tilt of the lander to slow it down over a specified distance, when using the hover engines, while maintaining altitude.

Just in the process of activating the other regular parts of the hover autopilots to make everything is working on the other planets.

I think I will then look into the deorbit autopilot, which needs a bit of attention, and also planning to include an ascent autopilot. I'm also interested providing a launcher for the mission. Once that is done and the return capsule has been updated I think that'll be it for the next iteration of the add-on.

 

[4throck]

Nice to see Wallops there. That's what I'm doing all those bases for.

The add-on looks interesting. The autopilots look fun, but don't make them too good, otherwise there's noting to pilot!

Personally, I'd like to have an "advisor autopilot" that would indicate what I have to do, without actually controlling the vessel. Kind of like a guided tutorial.

 

[markp]

Good point about the autopilots, I could display the numbers for a pilot to use like pitch and bank angles, thrust level, tilt angle, stuff like that.

Thanks for doing those bases, really makes a difference to the Orbiter experience!

 

[markp]

Having problems with my pitch autopilot. Needs to be more sophisticated because the nose oscillates a lot. Still needs a bit of work.

However it's working well enough for a glide into Wallops and do a hover landing. All on autopilot. The autopilot adjusts the pitch (or angle of attack) so the vehicle generates the required lift to reach the target. The heading is adjusted by monitoring the heading of the target relative to the lander. This will be needed for the capsule when it is using the paragliding for a landing. I'm actually wondering if for a landing on land the capsule could then do a hover landing, or even more exotic, be captured by some platform moving along the ground.

 

[markp]

Have started the modelling of a new capsule for the DRM. Used my artistic license somewhat and based it on the Gemini capsule. Haven't decided what kind of docking port is needed yet so the look of that might change.

 

[IronRain]

Have started the modelling of a new capsule for the DRM. Used my artistic license somewhat and based it on the Gemini capsule. Haven't decided what kind of docking port is needed yet so the look of that might change.

View attachment 11365

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Looks good! Gemini is my favorite program anyway

As for the docking port, I would go for the softdock methode of NASA, iLIDS: http://dockingstandard.nasa.gov/Documents/AIAA_ATS_NDS-IDSS_Overview_Draft1.pdf

Sent from my iPad using Tapatalk HD

 

[markp]

That's great thanks for the link IronRain, I didn't actually know about the standard docking system and all that.

I've used the drawings and numbers in the document to construct a new docking port and modified the capsule to a shape more resembling the "Visiting Vehicle" that is proposed to visit the ISS to test out the new docking system. Feels a bit more realistic now.

 

[markp]

Progress report:

1. Have added the appropriate aerodynamic properties for the capsule.
2. Programmed the animation sequence etc to deploy the parafoil.
3. Tested transition from capsule flight to parafoil and the autopilot for the glide on the parafoil to the target landing point

 

[markp]

A couple more things:

1. Capsule guidance and control during entry is working nicely using the bank modulation approach
2. Started playing around with design for capsule control panel
3. Hover landing for capsule working

With the hover landing I haven't checked the numbers (fuel and engine mass and size) to see if this is really possible. The capsule is pretty small as it is. Let's see, I might increase it's size or just stick with landing on skids with the parafoil.

Some screen captures from tests.

 

[BruceJohnJennerLawso]

A couple more things:

1. Capsule guidance and control during entry is working nicely using the bank modulation approach
2. Started playing around with design for capsule control panel
3. Hover landing for capsule working

With the hover landing I haven't checked the numbers (fuel and engine mass and size) to see if this is really possible. The capsule is pretty small as it is. Let's see, I might increase it's size or just stick with landing on skids with the parafoil.

Some screen captures from tests.

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:lol:, a school bus full of tourists happening by.

Two questions:

-Where is that exhaust texture coming from?
-Whats up with the panel? It almost looks like its made of stone.

 

[markp]

Do you mean where did I get the texture from or where is the exhaust coming from on the capsule?

It's just the normal standard Orbiter texture. The exhaust itself is coming from an engine in the side of the capsule. The centre of mass is quite far back so I figured putting an engine at the back to enable a soft and precise landing. I'm considering this approach so the crew don't get injured on landing and they can be recovered from the capsule quickly on their return if necessary.

About the panel. Trying to make it look futuristic but maybe not

About the bus ... it's for the crew, there's supposed to be six of them so I figured they'd want a big bus for themselves and all the support crew (it's actually from the Pictown addon).

 

[N_Molson]

Hehe landing right on the parking lot can be convenient, but some people will be angry to have their cars crushed by the capsule. "Hey, we found a new soft-landing method, now we aim at parking lots and cars make a nice landing cushion" :lol:

Nice work by the way ! :thumbup:

 

[markp]

Update:

1. I have more accurate aerodynamics for the capsule on the parafoil.

2. The parafoil flies quite slow now, maybe 20 m/s at touchdown so I think I may scrap the hover landing and use skids. The hover landing was kind of influenced from the landing for the Icarus test vehicle I was using to develop the autopilots and I think that type of landing will be used for the Mars landers only.

3. Updated the texture for the panel to make into a more normal straight forward kind of Orbiter panel until I see how the capsule cockpit evolves.

4. Haven't crashed into any buses or what not, although getting close!

---------- Post added 03-19-13 at 02:11 PM ---------- Previous post was 03-18-13 at 02:34 PM ----------

Here's a clip, mostly in cockpit view, of the parafoil deployment (no outside view) and then the glide to the base. It's all flown by the autopilot.

 

[markp]

Added the new capsule to the cargo lander. Looks a little unusual to me as it's a bit of a departure from the DRM1 capsule in the illustrations.

 

[BruceJohnJennerLawso]

Added the new capsule to the cargo lander. Looks a little unusual to me as it's a bit of a departure from the DRM1 capsule in the illustrations.

View attachment 11512

Maybe it would look better if it had a platform on top of the upper tanks?

I like it though.

 

[Screamer7]

You are doing a great job, Mark.
Are these MDRM landers you worked on different from what is available at OH?

 

[markp]

Bruce, that's a great idea about the platform. It would give the astronauts something to stand on before they climb into the capsule and it'll also be something for the ladder to be attached to. At the moment it's attached to the MAV and is dropped when the MAV is launched, which I'm not sure is sound from an engineering perspective.

Screamer7, yes these are the same as the ones on OH. I'm just updating the autopilots for them and redoing the visuals for the MAV capsule and stage.

Have also started building the DRM rocket launcher.

 

[BruceJohnJennerLawso]

Have also started building the DRM rocket launcher.
View attachment 11514

I would assume the launcher would need to be a HLV, unless you were planning on following the Mars For Less plan.

Why not go with this once its completed, at least as one major option for users.

http://www.orbiter-forum.com/showthread.php?t=30691

It might not really be the 100% most realistic option, but I have a feeling that combining two great Orbiter projects cant hurt :thumbup: