Suggestions for manned Duna/Mars Mission including landing and return to Kerbin

[steffen_anywhere]

Dear All,

I have been wondering if anyone has had an attempt or has a REASONABLE idea how to conduct a manned mission to Duna without mods or cheats (MechJeb, etc...)? The mission should include landing on Duna and returning to Kerbin (we don't want our poor Kerbonauts to be stuck on Duna for eternity, much like the planned Mars 500 project ).

From what I've seen/tried, there hasn't been any solution that worked or was even close. Tutorials I've seen used fuel cheats for infinite fuel (kinda dumb imo). I don't really see a way of getting enough fuel+crew+Duna Lander+etc. into Kerbin orbit in an efficient way (a.k.a. one launch )...

Does anyone have suggestions/was successful at this???

Best Regards

steffen_anywhere

PS: I might go for building a spaceship in Kerbin orbit, out of several modules (would be cool, but freaking hard), but I thought there would be an easier solution...

PS2: This is a goal even NASA has failed to accomplish, so it seems hard finally. Everything I've read about planned Mars missions suggested that the getting-huge-payload into orbit was one of the major problems (if we just ignore the budget for a moment as it is irrelevant to KSP )

[capi3101]

Well, I had a notion for getting there and back but my son wanted me to go to Ike instead; don't know if it's got enough juice for a return trip at this point. Haven't tried yet, either. It's unmanned in any event. Probodobodyne OKTO and 4 PB-NUKs have the same mass as a Mk-I Command Pod, incidentally; makes a good dummy mass.

The trick is that if you're not using mods, you have to eyeball it. I don't care how good you are, if you're eyeballing everything you're not going to hit Duna at the precise phase/ejection angle to get an optimal trip. So you've got to add a pretty big fudge factor. And probably the best way to handle that is to build a multi-part ship in orbit - a main thruster pack, a service module, and a lander.

Good luck.

[Akalaël]

Well, I have MJ not for so long, and all my first missions (Duna, Dress, Jool) were nanned and made by hand... But I did not try to return to Kerbin.

Why don't you send a kind of return stage, the same that drives you to duna, but drive by a probe ? Your crew there will just have to match with it and go back. It will split your need of fiuel in half, and your launches will then be reasonnable.

Of course that will oblige to make two trips to Duna, but hey, that's feasable !

For the interplanetary travel, before I was totally cheated by MJ, I just get out of Kerbin's influence, and see on the solar trajectory where could I have an encounter. That's totally inefficient, but you're going to Duna, this "just" adds about 1k of delta-v (if I remind correct).

[maltesh]

Here's a travelogue of a trip to Duna I took back in early 0.18. Yes, there's a Mechjeb on the interplanetary stage. However , Mechjeb can't make your spacecraft do anything it's not capable of. The interplanetary stage is actually a bit of overkill for Duna: As per the album, there was enough delta-V left to return to Kerbin after spending less than 24 hours on the Dunar surface.

https://plus.google.com/photos/117586430260877805957/albums/5831825488966285105

[Awaras]

You can actually get to Duna with extremely little fuel if you time your transfer burn right - just a little more than you need to get to the Mun. This ship made it to Duna with fuel to spare (it started with a full tank from LKO):

It could almost make it back to Kerbin - it needed another 300-400 dV....

Edited May 7, 2013 by Awaras

[Godot]

Not a big problem ... I usually do it (Duna, but also other planets/moons) similar to Apollo Style ...

moving to Duna moving with spaceship+lander-combination to Duna, letting 2 of my Kerbonauts get into lander cockpit via EVA,

landing and doing things, start, rendezvous with spacecraft, EVA of my kerbonauts back to spacecraft and finally flying home

(while the lander remains in orbit)

Here a short picture story of one of my former missions to Duna (made in 0.18, therefore don´t be surprised to see a starting tower on the KSP grounds )

The only mod I used in this mission (and use on every spaceship) is Kerbal engineer redux

Start from Kerbin Spaceport:

http://imgur.com/iDFW6l3

Duna-Orbit:

http://imgur.com/WyklUeY

EVA to get into Lander:

http://imgur.com/p8n2bN6

Separation:

http://imgur.com/dgtgh01

Landing on Duna:

http://imgur.com/2FJojy6

EVA on Duna:

http://imgur.com/fGciSn0

Start from Duna:

http://imgur.com/ym7BVL4

Rendezvous with Spaceship and begin of EVA:

http://imgur.com/6WlIOKd

EVA back:

http://imgur.com/Y2h9z7U

Leaving Duna system:

http://imgur.com/HABpG0K

Kerbin greets us after a long voyage:

http://imgur.com/7NHfJJC

Splashdown:

http://imgur.com/Px7Yjal

The Album link:

http://imgur.com/a/O5w9n#0

Edited May 7, 2013 by Godot

[Francesco]

Duna is actually the easiest planet to reach: with a couple of tweaks, any Mun capable rocket can be repurposed for a Duna and back mission.

You'll need less than 8 km/s of delta-v: with this in mind, you can build a 1-seat rocket which is pretty small.

this thing actually never ceases to amaze me: in this game, with the same ship, you can both go very close (Mun) or very far (Duna).

[K^2]

Yeah, it's not that hard. I have a rocket capable of makign a round trip to Duna. Three chemical stages get it to a high Kerbin orbit, a nuclear stage gets it to Duna and places it on a reasonable entry trajectory into Duna's atmosphere. What lands on Duna is a small two-stage chemical rocket capable of making ascent and the return trip to Kerbin.

[Alistone]

I did it with a single launch vessel, but a common theme is that your entire ship cannot land and take off from Duna. Instead, you'll need to leave a large part of your mass in Duna orbit while you ride down in a lander. It is relatively easy to escape Duna's surface... on the other hand, it was pretty close and I only had about 15% of my fuel left when I redocked with the tank in orbit.

Interestingly, I just had a docking port on my main fuel tanks instead of a stack seperator. Even with no command pod of any sort I was able to redock with it for the trip home.

[Anglave]

I did a Duna and back round trip (with landing and EVA for 3 Kerbals) in 0.17.1 Completely stock, no mods whatsoever. I also did the entire mission without using the nuclear engines, as my Kerbals were worried about the potential for scattering radioactive material through the atmosphere. Which meant a heavier lift than necessary.

Unfortunately, the mission report has been lost in the great forum reset. But here is the photo album!

The Duna mission is one big lift (as docking had not yet been implemented). My recent Laythe mission was done in two lifts that docked in LKO. Neither mission required docking in orbit at the target body.

I've learned quite a bit since then, I'm confident I could design a Duna mission today that would be substantially more efficient and use fewer parts.

Edited May 7, 2013 by Anglave

[Vanamonde]

This ship went to Duna, dropped off the little station, sent the lander to the surface,

and the reusable segment came back.

The lander pilot and station crew stayed in the Duna system, though the lander/station combo had enough fuel to return to the ship if I'd wanted the mission to go that way.

All stock, mission assembled from multiple launches in Kerbin orbit.

[Eric S]

I did it with a single launch vessel, but a common theme is that your entire ship cannot land and take off from Duna.

Unlike a Mun trip, doing the separate lander/orbiter for Duna makes sense, but isn't necessary. I did this for the 40th reddit KSP challenge carrying a heatshield. Fuel margins were tight, but doable. Fuel margins are wider on my next Duna mission, but I'm using atomic engines for that mission.

[Anglave]

Here, if you're still interested in a modest Duna land and return mission, I built a 0.19.1 compatible craft. That's the file, you should be able to download it (and name it Duna Trainer.craft)

The Duna Trainer is rock steady and reliable. It doesn't have a lot of extra dV, nor a fancy scientific payload, but I just manually piloted a mission to the surface of Duna and safely back to Kerbin using exactly this ship. It's only 181 parts, and that includes some extra struts and (cosmetic) nose cones.

Find your phase and ejection angles using the Interactive illustrated interplanetary guide and calculator for KSP 0.19. They're forgiving enough that I simply eyeball them. (Also, be aware that you can fast forward much more when your ship is on the launch pad. You can even return to the space center and launch a new ship in order to fast forward more efficiently).

The Duna Trainer's four outer legs will push her nearly to an 80km orbit. It takes a bit of the central core's dV to make a nice circular orbit.

The central core can push the lander from LKO to a Duna encounter with some fuel to spare. I used that fuel to clean up my approach for an aerocapture, and make my approach equatorial. I cleaned up my approach near the half-way point between Kerbin and Duna. Make sure you correct any orbital plane difference, (with a maneuver at the crossing node) as well.

After entering Duna's SoI, I used a couple more touches of the Mainsail (very gently) to get a nice clean equatorial aerocapture lined up. Then jettison it and, as you begin to slow down upon entering Duna's (sparse) atmosphere, pop the chutes. The lander came down gently on chutes alone, but there's fuel in the budget for a little power on landing if necessary. Don't forget the landing lights and gear!

Get out and stretch your legs on Duna's surface. Don't forget to re-pack the parachutes!

Lift off on a 90 degree heading for an equatorial orbit, just like you would from Kerbin. There's not a lot of extra dV in this craft for fixing orbital alignment, so it's fairly critical that you approach and leave Duna without needing a lot of plane change. That said, there's plenty of slack for a human pilot. You certainly don't need to be perfect in order to have enough fuel to get back home.

Fast forward until your return window, and plot a course from Duna orbit back to a Kerbin intercept. Sometime around here you'll likely want to jettison the "top" fuel tank. I turn off the engine and spin the craft to toss it well away.

From here, it's just a matter of making sure your orbital planes align and that you get a reasonably efficient Hohmann transfer. I cleaned up my Kerbin approach shortly before entering Kerbin's SoI (and then touched it up again just after entering). I returned to Kerbin's atmosphere with the two smallest fuel tanks (just above the 909's) almost completely full. If you're fancy, this should be enough to aerobrake and establish an equatorial orbit, allowing you to pick a suitable landing site. Personally, I just plowed into the atmosphere and trusted that the Kerbals wherever I should happen to land would be friendly.

One last note, you'll either want to make a custom action group for the radially mounted parachutes, or manually click and deploy them as you're approaching Kerbin's atmosphere (but before you're very far into it), as the same chutes are used again for landing at Kerbin.

Happy Launching!

Edited May 9, 2013 by Anglave

[Chrisd857]

Here was my first manned trip to Duna which returned to Kerbin: Album. It's a relatively compact package with fuel to spare for my currently rather poor interplanetary transfers. Includes two Kerbals (who both land) and a rover.

[Squidiness]

On 5/7/2013 at 9:19 AM, steffen_anywhere said:

Dear All,

I have been wondering if anyone has had an attempt or has a REASONABLE idea how to conduct a manned mission to Duna without mods or cheats (MechJeb, etc...)? The mission should include landing on Duna and returning to Kerbin (we don't want our poor Kerbonauts to be stuck on Duna for eternity, much like the planned Mars 500 project ).

From what I've seen/tried, there hasn't been any solution that worked or was even close. Tutorials I've seen used fuel cheats for infinite fuel (kinda dumb imo). I don't really see a way of getting enough fuel+crew+Duna Lander+etc. into Kerbin orbit in an efficient way (a.k.a. one launch )...

Does anyone have suggestions/was successful at this???

Best Regards

steffen_anywhere

PS: I might go for building a spaceship in Kerbin orbit, out of several modules (would be cool, but freaking hard), but I thought there would be an easier solution...

PS2: This is a goal even NASA has failed to accomplish, so it seems hard finally. Everything I've read about planned Mars missions suggested that the getting-huge-payload into orbit was one of the major problems (if we just ignore the budget for a moment as it is irrelevant to KSP )

I have been asking the same question, but I guess the most practical option is to assemble the vehicle in LKO (e.g. The tug, the lander, the crew and the lab all added to the vehicle in separate launches and dockings). I want to be able to do this in a single launch, however, and I'm assuming that's also what you're here for

[bigcalm]

> I have been asking the same question, but I guess the most practical option is to assemble the vehicle in LKO (e.g. The tug, the lander, the crew and the lab all added to the vehicle in separate launches and dockings). I want to be able to do this in a single launch, however, and I'm assuming that's also what you're here for

You should be able to do this with a single launch without any issue or need to assemble in orbit.  From what I can see Anglave has the solution for you above - but if you want to do it yourself, the way I would design it is as follows:

You don't have to take the whole of your interplanetary craft down to Duna's surface and back up to orbit again.  Ideally, you should leave the transfer part of your vessel in orbit whilst the lander lands, does its business, and goes back up to orbit again to rendezvous with the interplanetary craft and dock with it again.  If you include this as part of the plan for your design, your ship will be much smaller as Duna landing engines/fuel/stuff can be ejected after use.  It does mean that you will need to do a docking in Duna orbit - so plan accordingly.

Your interplanetary stage should consist of LF-only tanks (no oxidiser) and nuclear engine(s).  As you're not using MechJeb, use alexmoon's planner to know when and at what angle to launch at to get to Duna, and then do appropriate corrections.

Use a delta v chart and (possibly) kerbal engineer to work out what delta v your craft has - you could even use MechJeb to calculate it if you wanted to but not use it and design accordingly.

Honestly, if you can build a rocket that can get to the Mun, land, take off again and get back to Kerbin, Duna is a teeny step up from that - but not much more than that -- you have to wait for the launch windows though!

 

[GoSlash27]

If you transfer to low munar orbit and refuel there, the transfer to Duna is only a 467 m/sec DV. That's a total DV of 2,200 m/sec both ways even without aerobraking; not even worth using nukes.

Best,
-Slashy

*edit* D'oh! Fooled again! Hopefully this info is helpful to someone else...

Edited January 7, 2017 by GoSlash27