Planning an Interplanetary Trip to Duna with LifeSupport mods. Suggentions?

[chicobaptista]

Hi guys!

So, I've been playing KSP for 3-4 years now (that long? sheesh ) and have never left Kerbin's SOI in a consistent way.

Well, I admit, I've made a few trips to Duna and Eve using AltF12 infinite propellant cheat, but never a proper interplanetary kerballed mission.

However, I have been planning kerballed missions to other planets for years, only I play in career mode, usually miss the first windows and then I get too bored to wait for the next ones, do a lot of Mun/Minmus bases, rovering etc and there comes a new patch! Start all over again. 

This time tough, I am determined to land kerbs on Duna, Laythe and Eve, no matter what!

I wanted to share my mission planning here so that more experienced travelers could point blatant flaws in my super hypothetical blueprints and maybe do a bit of constructive criticism (MOAR boosters!, while very much in line with my design principles, is not particularly helpful in these instances)

So, without further ado:

 

I calculated the interplanetary window using alexmoon's launch window planner, and got these informations:

Timetable

Kerbin -> Duna

Departure

Year 3, day 302 at 3:50:24

Arrival

Year 4, day 153 at 2:50:24

Time of flight

276 days 5:00:00

 

Stay @ Duna

~1 year 135 days

 

Duna -> Kerbin

Departure

Year 5, day 298 at 5:26:24

Arrival

Year 6, day 161 at 4:55:12

Time of flight

288 days 5:28:48

Total Mission time:

~3 years 140 days ==  ~1418 days

Notice that this gives me more than a year to perform all the explorations I want to. Is that enough for maybe 3 Duna landings, with ISRU to refuel the lander inbetween and another 5 to 6 Ike landings, also using ISRU?

Important Mods used

USI Life Support

Pathfinder

KIS/KAS

Universal Storage

That means I can store base and rover parts on my lander and build them insitu, which s my plan. Also, planning to use ISRU and SSTO landers/ascent vehicles to explore multiple biomes on Duna & Ike

Planned hardware

I plan to bring a small flotilla consisting of:

• Eämbar (Interplanetary Crew Transfer Ship)
• Two Melians (Duna Lander/SSTO Ascender) each carrying:
  • Eärendil (Duna Science Rover)
  • Duna Surface Base
• Dailir (Nuclear-powered tugs) to haul the lander (one-way trip only)

 

So, the idea is to use the Crew transfer ship as a central hub for a space station.

After landing, the engineer assembles the Base and the Rover insitu. The Surface bases works on Life Support (Pathfinder Greenhouses) and drilling ore/converting fuel to replenish the Lander/Ascender while the Rover roves (hah!) around gathering much SCIENCE!

I'm playing the idea of using the same design of the Duna Lander for my Ike lander, for redundancy and safety, but also because then the Ike lander can use the extra fuel it can get to orbit to replenish the Crew Transfer's stores. Is it more work than it's worth? Also, it would be significantly heavier than a purpose built Ike lander.

Crew

Two scientists (Sa) & (Sb)

One engineer (E)

One pilot (P)

They will all be two stars, tops, since they will be the first kerbals to venture in interplanetary space ever, in my save. Not much else to elaborate here, except that for RP purposes I'll be using Final Frontier ribbons to assign them special roles. (such as exobiologist, energy engineer, etc)

Life Support calculations

So, in USI-LS, each kerb consumes 16.2 kg of supplies per day. However my Mobile Science lab onboard Eämbar, I can cut this consumption to 4.86 kg of supplies. Also, the greenhouse allows me to grow supplies using fertilizer, dividing my required mass by 8.5, leaving me with a requirement of 0.571 kg of fertilizer for each kerb per day.  In 1418 days, that's 810,7 kg of fertilizer per kerb, for a grand total of 3243 kg to suppor all 4 kerbs on the trip, which is less than a single 2.5 container. I'll bring some more as a safety buffer. Also some initial supplies are needed, not just as a safety net, but also to start the cycle. I'll bring along 500kg, which is enough for nearly 219 days for all 4 of them.

For comparison, without using the recycler on the lab and the greenhouse converter, I would need to haul along 91,886.4 kg of supplies!

Delta-V budgets

I calculated the projected deltaV costs using a deltaV map (sorry, don't remember which, but it was updated for 1.0 aero) and got the following:

• Low Kerbin Orbit (LKO) -> Low Duna Orbit (LDO) 1700 dV
• LDO -> Duna Surface (DS) (aerobraking) 500 dV
• DS -> LDO -> 1450 dV
• LDO->DS->LDO 2000 dV
• LDO <-> Low Ike Orbit (LIO) 570 dV
• LDO->LIO->LDO 1200 dV
• LIO <-> Ike Surface (IS) 390 dV
• LIO->IS->LIO 800 dV
• LDO -> LKO 1700dV

 

I understand that there are many different possible transfers, and that usually the more dV you can spend, the less time you have to wait. In a scenario with life support, do you think it is worth "kicking the door" so to speak to avoid huge amounts of supplies?

 

Mission Plan

Ah yes, now we get to the meat of it:

 

1.  Transfer from LKO to LDO a flotilla composed of:
   • InterplanetaryCrewTransferVehicle with (Sa)(Sb)(E)(P)
   • DunaLander+Tug
   • IkeScienceLander+Tug
2. Dock all the ships to create DunaScienceStation with (Sb) manning the science l ab
3. Duna Exploration
   1. Land DunaLander with (Sa)(E)(P)
   2. Establish SurfaceBase (E) and start drilling to refuel the lander
   3. Build ScienceRover (E)
   4. ScienceRover explore nearby biomes (P)(Sa)
   5. Dismantle Rover and Base and repack into DunaLander (E)
   6. Reorbit and dock with DunaScienceStation
4. Repeat #3 as needed
5. Prepare for Ike Expedition
   1. TransferCrew to IkeScienceLander (Sb)(E)(P)
   2. Transfer DunaScienceLander+Tug from LDO to LIO
6. Ike Expedition
   1. Land DunaScienceLander on IS
   2. Start refueling (E)
   3. Explore nearby biomes (Sb)(P)
   4. Reorbit and dock with Tug
7. Repeat #6 as needed
8. Transfer DunaScienceLander+Tug from LIO to LDO
9. Prepare for Kerbin return
   1. Dock with Duna Science Station
   2. Transfer crew to InterplanetaryCrewTransferVehicle
10. Transfer InterplanetaryCrewTransferVehicle from LDO to LKO
11. Dock with KhazadDûm station (that's my Kerbin Orbital Science Station, by the way) and retrieve crew+science!

 

Step 3: Profit!

So, that's about it. Thoughts? Ideas?

Thanks in advance,

 

Cheers

 

Edited June 7, 2016 by chicobaptista

[ineon]

Sounds like a cool mission. I've not tried anything quite like this, but here are some thoughts:

• Why bring a lander for Ike? Anything that can land on Duna will be able to land on Ike too. Sure you will spend a little more fuel on moving some half-empty tanks between Ike and LIO, but I bet you spend much more transferring a whole separate lander from Kerbin to Duna. (Having re-read I might have misunderstood, does lander = base? i.e. will some of the lander never get back to LDO? If so then nevermind on this point.)

• 13 hours ago, chicobaptista said:

  Build ScienceRover ... Dismantle Rover

  Are you doing this with KIS? This sound tedious (and possibly error prone), can you just dock the rover to the lander? You could use Infernal Robotics for epic loading and unloading and/or just KAS struts to make sure that it does not fall off.

• 13 hours ago, chicobaptista said:

  They will all be two stars, tops, since they will be the first kerbals to venture in interplanetary space ever

  3 stars is possible without going to another planet. IIRC: 3 stars = orbit Mun + flag on Minmus + pop your head out of Kerbin SOI for the briefest of seconds.

• Looks like scientist B is going to be a bit lonely, I assume that you are bringing along a mobile science lab in the orbiter. What about putting scientist C in there too? It seems like you get that 'for free' to me.

[chicobaptista]

All right, thanks for the thoughts! A bit of clarification is needed, it seems, so:

(I'll also edit the OP to incorporate these aspects)

On 6/6/2016 at 11:33 AM, ineon said:

Sounds like a cool mission. I've not tried anything quite like this, but here are some thoughts:

• [...] does lander = base? i.e. will some of the lander never get back to LDO?

Thanks! Well, yeah, the base will be built from parts transported by the lander. But in theory, all of it will be disassembled and packed up back on the lander. So technically yeah, I can use the same lander on Duna and Ike. I am probably going to do that, as it seems simpler and more efficient. A backup would be nice, though...

 

On 6/6/2016 at 11:33 AM, ineon said:

• Are you doing this with KIS? This sound tedious (and possibly error prone), can you just dock the rover to the lander? You could use Infernal Robotics for epic loading and unloading and/or just KAS struts to make sure that it does not fall off.

Not gonna lie, it can be kinda tedious and I made a few mistakes building my Eärendil-class rover on the Mun. It was nearly uncontrollable, until I figured out that I could plop the rover wheels in the correct place by changing attachment nodes with KIS. However, the Buffalo parts for rovers make it simpler than would be in stock and now it takes me 3 min tops to build them. and way less to dismantle them. I used Infernal Robotics for a while, but it seems to me way more complicated then assembling them on site. Of course, that means it has to be kerballed, so not doing that on Eve anytime soon. Docking the rover does seem simpler, and I'll look into that! Aerodynamics might become a challenge tough. Or is Duna atmosphere thin enough that I could ignore the drag of the rover dangling below the lander?

On 6/6/2016 at 11:33 AM, ineon said:

• [...] What about putting scientist C in there too? It seems like you get that 'for free' to me.

Well, I have the crew space, but Life Support would become an issue. You see, the whole mission is planned to take around 1400 days, and in USI Life Support each kerb needs 16.2 kg of supplies each day. An extra kerbonaut would cost me another 22 tons of supplies. It would be reduced by using recyclers and converters, but still, not exactly cheap, mass-wise. And for not much gain, I guess. Unless the extra scientist would significantly accelerate my research on the orbital station? If I don't bring another kerb, probably the best idea would be rotating who gets to man the fort during the expeditions, so they don't get lonely for too long.

 

Also, I guess putting some pictures of my crafts would help visualize the mission better? I'm nearly done designing them.

[Frank327]

I'll answer a few questions on the basis of what I experienced with my Duna+Ike apollo mission in career mode before 1.0, the vessel from LKO onwards looked like this:

Spoiler

First of all, it's a good idea to use the same lander for Duna and Ike. Of course the requirements are different, the dV for the Ike landing + return requires almost half as much fuel but you don't have to send your lander fully fueled to Ike of course. Whatever you'd be wasting on sending a slightly oversized lander to Ike is more than compensated by the fact that you only need one lander for two destinations. On top of that you want to add surface mining into the mix and sending two landers of the same design that can both refuel themselves is just wasteful. I don't know how doable this is with rovers and bases that you want to assemble, those seem a hassle to land and get back into orbit again. Also maybe instead of relying on mining you can take extra fuel in the main module and refuel your lander in orbit. 

Also you can save a lot of dV by not parking your "mothership" in a circular Duna orbit but in an elliptical orbit that doesn't quite reach the apoapsis for getting captured by Ike. From that orbit you can launch your lander at apoapsis, doing a slight retroburn and letting the atmosphere do the rest of the work for landing. Only downside is that you might end up in a mountainous area because you can't precisely target a landing area anymore. From there I launched my lander again and made it rendezvous with the mothership again into the elliptical orbit and the entire thing only had to make small burns to reach Ike orbit. Remember that every burn you make with the mothership spends a lot more fuel than the burns with only landers. So make the landers do most of the work and you can save weight. 

In general this seems like a hugely ambitious mission for your first real mission outside of the solar system with 3 components landing on two bodies and the entire thing being reusable because you intend to dock it in LKO again. Also am I understanding correctly that you're sending a small fleet instead of a single thing to duna? Because then you have the extra action of synchronizing everything once you're there because they'll arrive at vastly different times and locations. If your goal is to do a career landing on Duna and Ike then I would:

1. Not include mining

2. Not include a rover

3. Not include a surface base

4. Only do one landing on each body

5. Expect nothing to be reusable and only have a lander can with kerbals land back on kerbin.

Doing interplanetary apollo missions with life support is a challenge by itself, no reason to make it more complicated than that in your first real interplanetary mission.

Edited June 8, 2016 by Frank327

[chicobaptista]

Thanks for your inputs @Frank327 ! I'll try to address your points here, and also update the OP again, for you have swayed my mind on some points.

Also, your mothership looks awfully like my Melian lander! I'll update the OP soon^tm with pics of my proposed vessels, so that you may compare them.

7 hours ago, Frank327 said:

First of all, it's a good idea to use the same lander for Duna and Ike. [...] On top of that you want to add surface mining into the mix and sending two landers of the same design that can both refuel themselves is just wasteful.

Yeah, I'm totally convinced on that one. I'll send just one lander to do both Duna and Ike, for less hassle. And it's not like I'm swimming on funds yet, like some kind of Scrooge McKerbal, so that's a nice plus. It will rise the stakes, not having a backup system if the lander ends up lacking dV, crashes, or otherwise fails, but that's KSP for you eh? A good incentive for planning a rescue mission, at the very least. 

7 hours ago, Frank327 said:

Also you can save a lot of dV by not parking your "mothership" in a circular Duna orbit but in an elliptical orbit that doesn't quite reach the apoapsis for getting captured by Ike. [...]

The thing here, as I see it, is that going up again will cost more fuel for the lander, since it now has to go all the way into that elliptical orbit. And since I'll be doing at least 3 landings on Duna, that cost will be multiplied by that. Also, I was planning on transferring just the lander to Ike, not the whole mothership (It has the dV to spare for that, being capable of landing on Duna and back), so that cost of transferring it (the mothership) would probably compensate the dV costs of parking it on a Duna Low Orbit. I'll have to calculate that, tough, so fun times ahead! Hurry, to the bat-calculator! 

7 hours ago, Frank327 said:

In general this seems like a hugely ambitious mission [...]. Also am I understanding correctly that you're sending a small fleet instead of a single thing to duna? Because then you have the extra action of synchronizing everything once you're there because they'll arrive at vastly different times and locations.

I know! The scope of it is exactly what appeals to me so much. I've done Orbital Station Assembly, sky-craned surface bases on Mun and Minmus using USI-MKS and Infernal Robotics mods, played a lot with KIS/KAS on site constructions for both rovers and bases, built huge cargo freighters with ExtraplanetaryLaunchpads on Minmus, but never got to leave Kerbin's SOI. If I'm going to do it, I plan do do it with style. 

So yes, I'm planning in sending a small fleet, a flotilla, instead of a single assembled vessel. The synchronizing will be hugely assisted by Kerbal Alarm Clock, which helps me juggle all the maneuver nodes, SOI transitions etc. I've done it before, to Minmus. Not to the Mun though, for it is far too close, and it gets too hectic for me, even with the assistance of KAC. I've also practiced the interplanetary transfers by going from the Mun to Minmus, sending two or three ships at roughly the same time and juggling their capture nodes with KAC. It can be a bit nail-biting, but works.

7 hours ago, Frank327 said:

If your goal is to do a career landing on Duna and Ike then I would:

[...]

Doing interplanetary apollo missions with life support is a challenge by itself, no reason to make it more complicated than that in your first real interplanetary mission.

I agree, these are all good points. However, I'm not sure I'll have the patience to do this the simple way first and then await for the next transfer window to do a more complex mission later.

I'll try to do things in a way that I can RP that the pilot will "simulate" the Duna and Ike landings once each before the real deal, so that if things go awry, I can simplify the mission plan or simply scrub the mission and get everybody back in one piece. It'll be a bit frustrating, but better than losing someone or having to leave them behind. That would be a huge morale breaker for the guys, and no fancy astronavigation using continual thrust maneuvers like in "some pieces of fiction" (sorry, spoiler alert!) to swing them back just in time for a rescue.

Nevertheless, I'll take your points into consideration. I'm planning on redesigning the lander so that it can, if necessary, land, leave the equipment (base and rover) behind and rendezvous with the mothership at least once with it's own fuel stores, so as to not rely so heavily on mining and ISRU, and bringing extra fuel stores on the mothership as a safety net.

Again, thanks for your thoughts!

 

Edited June 8, 2016 by chicobaptista