My first Duna-Return Mission finally completed

[Kuldan]

Hey guys,

I usually don't post about my flying since a lot of people here have more interesting stories to tell, but I recently flew a very nice mission:

Three launches, all timed so they would arrive around the same time at Duna using a 100% stock interplanetary stage using NERVA (plus NovaPunch 5M stuff for launching):

1x Duna Lander Vehicle, dropping a 3-Kerbal Pod Lander to the Surface (Only launching with 2 Kerbals, one got left at the launchpad..)

1x Duna Rover Vehicle, dropping a 1-Kerbal Pod Rover to the Surface

1x Duna Crew Return Vehicle, 3-Kerbal Pod + 5-Crew tank for the return trip (waiting in Orbit)

Using my favorite Mods, I used the Protractor to time my launch window for Kerbal parking Orbit (about 0.10° off to allow for all three launches to happen),

had Mechjeb do the Ascent to Orbit (Would lag out my machine if doing manual..), then did the transfer burns manually (well, what is it - point prograde and burn until there

Had three nice orbital insertions about 3 days apart, which gave me enough time to do the orbital insertions for each ship..

Landed the lander, landed the rover about 500m from it (well, close enough and did my thing, until a nice launch window showed itself for a return to Kerbin - left the Rover on the planet, it's

Pilot transferred to the Lander Capsule for Ascent .. went back to Orbit, and had about half a tank of fuel left.. so we did a neccessary plane change to accomodate the orbit of our return vehicle,

and then I played catchup using the (much better fuelled) return vehicle employing the ORDA computer for measurements (but doing the RDV manually), and finally docked both ships using ERKLE (works better

than ORDA right now) just relying on ORDA Attitude control. then did an EVA-Personell transfer to the crewtank (will be possible with menus in the new ORDA..can't wait!), dropped the Lander in Orbit (could theoretically be re-used if refilled using ORDA refuel Mod), and went on my way home.. and safely landed my six Kerbals using four radially mounted parachutes and a small Lander Engine for the extra smoothness on Landing.

No pictures yet, since I didn't think the mission would actually work, and therefore didn't take any.. but I will add pictures of my launchers later today when I return home.

Edited October 9, 2012 by Kuldan

[Tom K.]

I'm trying to do a Duna and return mission myself, The rocket is completly done and tested but I haven't really got time to do the mission.

Its a big rocket with four parachutes a the top, my plan is to use the little atmosphere on Duna as effecient as possible, when the parachutes slow me down enough I will start a powered descent.

Then I hope I will have enough fuel to get it back in orbit and I will probably have another resque rocket in orbit already to bring them back.

A little question though, can four large parachutes resist slowing down a heavylander, in Duna atmosphere?

[Kuldan]

Hmm, good question.. in my trials, I actually figured that I do a 100% powered Landing on Duna since I have that D-V in my IPTS (Interplanetary Transfer Stage) to slow the Lander to about 300m/s before I have to drop it and switch over to the lander engines, which is plenty to do a 100% powered descent..so my lander actually doesn't even have a parachute at the moment.

[Kiershar]

I'm trying to do a Duna and return mission myself, The rocket is completly done and tested but I haven't really got time to do the mission.

Its a big rocket with four parachutes a the top, my plan is to use the little atmosphere on Duna as effecient as possible, when the parachutes slow me down enough I will start a powered descent.

Then I hope I will have enough fuel to get it back in orbit and I will probably have another resque rocket in orbit already to bring them back.

A little question though, can four large parachutes resist slowing down a heavylander, in Duna atmosphere?

There's really not much atmosphere on Duna. The atmosphere is very thin starting, starts at maybe 15km. I do aerobraking at like 12km... so unless you are already rather slow i doubt chutes are gonna be enough by themselves. Aerobraking at 25km does almost nothing!

I found that a 60 thrust nerva is good enough to land 20 tons of stuff on Duna. TWR above 0.40 and its pretty much safe.

[Vanamonde]

Four large chutes were not quite enough to bring down a lander

safely, so I added a 5th, and that seems to work pretty well, at least at a low-to-middle-altitude landing site. That's not going to work for anything much larger than this.

I don't know if you'll be able to use the chutes the way you're describing, though. Remember that they don't open fully until 500m before the surface, so you won't have a lot of time to use the engines after that. If you haven't shed most of your speed already, I suspect the chutes will either rip off or you won't have enough time to get much use out of the engines before you go splat. Not saying it's impssible, mind you, because I haven't tried it. But it sounds pretty tricky to pull off.

[Tom K.]

Four large chutes were not quite enough to bring down a lander

safely, so I added a 5th, and that seems to work pretty well, at least at a low-to-middle-altitude landing site. That's not going to work for anything much larger than this.

I don't know if you'll be able to use the chutes the way you're describing, though. Remember that they don't open fully until 500m before the surface, so you won't have a lot of time to use the engines after that. If you haven't shed most of your speed already, I suspect the chutes will either rip off or you won't have enough time to get much use out of the engines before you go splat. Not saying it's impssible, mind you, because I haven't tried it. But it sounds pretty tricky to pull off.

First off, my lander is WAY BIGGER ...

The way I want to use my parachutes isn't going straight down, I have a very nifty plan about how I want to enter the atmosphere.

I will first create an orbit, then I will lower my periabsis, to about 8 KM, that way I will make as much use off the atmosphere as possible, I will probably make sure the craft is going slower than 300 m/s then I will deploy the parachutes.

The half open parachutes will still help me slowing down, even if they aren't fully open, then when I see that they can't slow me down anymore I will start the powered descent, conserving AS MUCH FUEL AS POSSIBLE.

I hope that the little atmosphere will allow me to start making an orbit at about 20 KM, with the little fuel I would have left after landing.

From that point I will probably have to wait for docking to be implemented and a good tutorial for rendez-vous. (my closest I could get to something was 7 KM, so I'm still a noob at it. )

[RoboRay]

First off, my lander is WAY BIGGER ...

I landed a pretty big base on Duna's southern polar cap with parachutes. The base consists of four crewtanks mounted around a big lander engine with a 3-man pod on top. I had 9 big parachutes and 4 small ones, and did need to use the lander engine to bring my descent rate down to a gentle 1m/sec landing.

The rover crew was already on-site, to scout out a good landing zone and provide an aiming reference near the anomaly the base is being established to study.

I somehow didn't catch any screenshots of the chutes deployed, but you can see the arrangement here, during my aerocapture pass.

[Will_hynes]

When I go for Duna landings, I put myself into an orbit with a peridun of 11-12,000 m and wait until i slow down to any velocity below 200 m/s then deploy 4 chutes and use some engine power if necessary. I did this today in a lander with 3 small 50 thrust engines, the 2 attached to the side are my main lander/take off engines both with 1 fuel tank, and when they run out i drop them and throttle up the final engine. when i landed, the 2 outer engines had half empty tanks so when i muster up the courage, I'll try to bring them back. And by the way, this is done 100% vanilla, no Mech-Jeb non-sensory or any other mods.

[Tom K.]

I landed a pretty big base on Duna's southern polar cap with parachutes. The base consists of four crewtanks mounted around a big lander engine with a 3-man pod on top. I had 9 big parachutes and 4 small ones, and did need to use the lander engine to bring my descent rate down to a gentle 1m/sec landing.

The rover crew was already on-site, to scout out a good landing zone and provide an aiming reference near the anomaly the base is being established to study.

I somehow didn't catch any screenshots of the chutes deployed, but you can see the arrangement here, during my aerocapture pass.

My lander is still WAY BIGGER!