Launch windows with life support.

[Motokid600]

How do you do it? TAC really adds in an interesting perspective to the game. An easy manned mission to Duna now needs much more planning. And it gives you a reason to keep kerbals on the ground for more then five minutes because of launch windows. What is the best way to go about this? With the launch window planner I can find out perfectly how much life support is needed during the maximum duration of a mission. But waiting for the ideal launch window to go home takes far too long. The travel time is no problem. An extra thousand or so dV and I can get to Duna under a 160 days. Its the wait at Duna ive been scratching my head over. Over what the best way is to go about it.. a big, heavy habitation module with enough LS to last to the next ejection window? Ill be burning extra dV in order to shorten that time, but what I really wonder is.. can I really just spend a few minutes on the surface and return? Lol.. It would be far more simple(*cough*cheaper!). Or would the return dV needed after just arriving be too excessive? Making that vacation on Duna practical...

Edited January 1, 2015 by Motokid600

[CalculusWarrior]

Life support definitely adds an entirely new dimension to KSP, and is primarily the reason NASA hasn't been to Mars yet. While I don't have TAC installed, I prefer to design my missions as if I do have it. I just can't bear to send a single kerbal interplanetary in a 1-kerballed pod!

I prefer to go with the 'drop the base' (heh heh) method, bring along a big Duna base as your payload (fun exploration rovers and/or planes are optional) with enough life support for the kerbals to live on the surface for however long the transfer window will last. The problem with your idea to keep the time on the surface of Duna short is that you're still going to lose time during your Hohmann Transfer.

If you had an insane amount of delta-v (such as >100 km/s), you could ditch the Hohmann, and go for a brachiostone trajectory, but that's not feasible in KSP without mods like KSP Interstellar or the like. Hibernation mods could also be a solution: simply deep-freeze your kerbals until the correct transfer window pops up.

However, if you like to keep things stockalike/realistic, then your best bet would be to check out the Transfer Window Planners. The original is an excellent webapp by alexmoon, which generates a porkchop plot similar to those NASA uses to plan their own missions. You can analyze the best times to launch, and are able to see how and where increased delta-v expenditure lets you decrease time of flight. TriggerAu of Kerbal Alarm Clock fame has also made an in-game version which can automatically add KAC alarms for the transfers you choose.

Hope this helps!

[Motokid600]

The transfer planner is what im using to plan out the mission. With it I can tell the perfect time needed for the transfers too and from and the stay. TL;DR of my op now that I think about it is the hab module. With TAC is a hab module loaded with a large amount of LS necessary to wait until the next optimal window? And to what extent can I minimalize the time spent on the surface within practical dV amounts for the trip home?

[Empiro]

With the default settings, TAC doesn't add too much to your launch window considerations. I haven't played with TAC LS in a few versions, but when I played, the large 2.5m life-support container could sustain a crew of three for several (Kerbin) years, and it didn't weigh that much either. For my Duna mission with a crew of 3, I think I only needed two of those modules (and no water or CO2 filters), and had plenty of life-support remaining when I got back.

Both ways, I just did a minimal delta-v Hohmann transfer at the standard launch windows, and I think the total trip was under 3 Kerbin years. One extra consideration for me was that I played with Deadly Re-entry, so I couldn't do too aggressive of an aero-capture, which would be necessary with faster transfers (I still had to expend about 100 m/s back at Kerbin to get into a capture without burning up).

[PB666]

Life support definitely adds an entirely new dimension to KSP, and is primarily the reason NASA hasn't been to Mars yet.

The word I heard was that the 'risk' exceeds the technology. If you do the calculation and compare risk for mercury/apollo phase and risk in the shuttle program, both for launch and reentry, the known risk have always been present, and despite disasters, ultimately acceptable. An unacceptable risk falls into the category that is probably best described as a suicide mission. So that the second aspect, the technology, needs to be probed. Guessing I would say that if you probed the NASA planners they would confide that there is not a complete set of technologies that gets healthy nauts to mars, more importantly safely and relyably lands into a high-g surface with low atmospheric breaking. The problem gets more 'suicidal' when one figures in the fact there is no known method to return living animals from the surface of Mars. If you can't return nauts from a landed mission, then overtime it becomes linearly more difficult to keep them alive, at such a point where it is either financially or technically impossible, the suicide mission is complete. There is no 'earth-like' planet, and even in the closest approximation Mars falls short of the light, pressure, and gravity needed to sustain life. As each of these deviate from Earth's the cost of technology needed to support life increases.

Whereas you want to keep your nova-martians alive you need a space-station in orbit, low cost supply ships, something that can target the base, land successfully at 100 m/s (therefore not needing to burn) and some means of cheaply deorbiting it. Grow the food in orbit and supply the base nutrients either from comet mining or from Earth, but also bank reserves for the half decadal period where Mars is not in a launch window. On that station lots of plant growth bays with LEDs and Large array of solar panels that can supply electricity, and of course the station needs to be manned.

When we get into the reality discussion, we quaintly have to deal with the fact that the kerbals start their program with no known metropolii, in a junk-yard with a sodded launchpad and a compressed aggregate runway, neither of which are capable of supporting an inter-whereever manned rocket, with a budget a millionth that of NASA. There is no reality to a Duna mission when compared to NASA.

The grand solution here is to mod KSC, mod parts, create reality by breaking the realities-that-be, since real reality does not suffice, and fake reality does not suffice, therefore any other reality is just as good.