Duna Outpost Mission Architecture Challenge

[Kerbolitto]

Chapter 11 is over, KerbinEarlyReturn is a success !

 

 

 

I had a lot of fun to fly this one, build the rescue mission and stuff .. The solar interception was a big premiere to me, first time I try it with a ship rather than an asteroid, and certainly first time at this speed !

Hope you enjoy the reading, cause I sure did .

 

 

 

[hoioh]

2 hours ago, Mad Rocket Scientist said:

There's a bunch of exponents that define how the stats scale that can only be found in cfg files, along with all the regular stats that have to be copied over. Armed with that info, you can figure out whether a scaled up spark is better than a poodle, or any number of other comparisons. I could probably just do it with a python program though...

And sometimes mod makers make mistakes in balance. I remember for this challenge, I made a lifter with that used a tantares engine that got ridiculously cheap (like less than 100 funds) when scaled down, and tanks that were free except for the cost of fuel. All in all, my rocket could deliver above average payload to LKO for the lowest cost/kg of any of the competing rockets even with markup of nearly 100%.

Of course, the challenge died before anything could fly on my rocket.  And then the reboot died too.

Must've missed that challenge, though I must say, I'm not that much of an efficiency freak. I tend to try to keep thing fair. I've used the tiny 0.09t cabin on the miner because I've got little choice if I want to stay within the payload limit and still launch a double base on the first window. I did some numbers on smaller SLV's, but it allows for too few payload options within a modular design, there simply isn't enough room to maneuver. So that's the compromise I made in order to manage within the margins. Other than that I'm just puzzling with different payloads, I just figured out I can launch another 2 surface base modules on the second window (where I expected to launch just the 1, so it appears to pay off:

I might fill up the spare NPM with some accesories or other small additions that don't neccesarily affect the mission, but do affect play/story

[Laie]

I've spent the last few days playing with the game, rather than playing the game. Building one-piece vessels using welding and typing in custom resources, combining IVAs, that kind of thing. Like, adding a few more seats to a scaled-up cockpit. Config editing can go a long way.

19 seats visible, but the lower deck stays empty: all the crew is crammed into the upper 4-seat IVA, sitting inside each other. looks eerie.

[hoioh]

Looks cool @Laie!

[Laie]

So close, yet far from what I had in mind. Maybe if I didn't come from a 60° orbit to begin with?

[Kerbolitto]

Why would you come from a 60° angle ? :p

Nice landing by the way !

Edited August 18, 2018 by Kerbolitto

[Laie]

9 minutes ago, Kerbolitto said:

Why would you come from a 60° angle ? :p

Because that's where the asteroid is:

Perspective and expectations... it probably takes some effort to see that this is an inclined orbit. Asteroid is approaching Kerbin from the south, so that' where i have to go in order to meet it. For orientation, that grey line near the top is the Mun his orbit.

Edited August 18, 2018 by Laie

[Kerbolitto]

1 minute ago, Laie said:

Because that's where the asteroid is:

Perspective and expectations... it probably takes some effort to see that this is an inclined orbit. Asteroid is approaching Kerbin from the south, so that' where i have to go in order to meet it.

Oh right I forgot about the asteroid !!

will you use the Mun to change the inclination ?

[Mad Rocket Scientist]

Well, I've been convinced about LKO asteroid mining. Especially since I realized I shouldn't combine the advanced deep space transport with the reusable transfer vehicle, and I only need ~65t of propellant for the outbound transfers.

Picture from a test of the miner and tug in the spoiler.

Spoiler

 

This C-class asteroid that was about 1/2 a year from a Kerbin intercept only had about 45t of propellant in it, I'll have to either go for a D-class or 2 C-class asteroids for the final mission:

Doing a Mun flyby on the way into Kerbin SOI to make my orbit equatorial:

Then came an environmentally friendly interplanetary nuclear aerobrake where I put the asteroid and tug on an aerobraking path, detached the tug, and put it on a trajectory above the atmosphere. Then I aerobraked the asteroid and propulsively braked the tug.

After that came a high-DV intercept to grab the asteroid before it could hit Kerbin's atmosphere again:

And there it is, ~30t of propellant in a 100x100km orbit only 146 days after "launch" (being cheated into orbit):

 

 

 

[Laie]

@MadRocketScientist I'm a bit sorry to hand this in right after your asteroid capture... here's today's issue of "anything worth doing is worth overdoing":

This was a whole day's effort, not only (not even mostly) because of the puny TWR. A longish story about my adventures in modding and mining behind the spoiler.

Spoiler

For starters, this vessel is also kind of a testbed of what I can get away with in terms of welding. Only the engines, claw and drill are individual parts. The vessel proper is two parts, the front half consist of radiators, converter, crew module and docking port, all in a single item. Plus a tank, but that's unproblematic. Lessons learned:

• Having the docking ports in the compound vessel works well, provided you only bring them together in the flight scene. When attached in VAB, they won't come apart in flight. You also cannot "control from here". No problem as long as the port doesn't face sideways.
• I had to uninstall Stockalike Station Parts because it wouldn't play nice with welding: hatches became unusable, locking the crew inside. No good if you plan to assemble things on EVA.
• welding tends to swallow part modules. The converter could only make Oxidizer, and the radiators had forgotten about core heat. Easy to fix through config file editing, but you have to notice it first.
• welded RCS nozzles lose their plumes. I wasn't aware of how much I depend on that visible clue of which nozzle is firing until I no longer had it.

But far and away the worst gotcha was that the asteroid held barely any ore. "2800t, Resource content 95%" it said, but I couldn't refill my tanks even once. Luckily, that mission was manned and held LS resources. I noticed that my water supply was topped off. Water from asteroids? ...turns out that Community Resource Pack disperses a lot of resources on asteroids. Water up to 80%, and a host of other resources which may be present in varying amounts. Between them, there's barely any room left for boring old ore. Finding first the problem, then a workaround took the better part of the day.

...I wonder if I should keep a small fraction of water. Most of it is being reclaimed, I only need 100kg or so per person and round-trip, but as they say, every little bit helps.

Anyway, a lot to be settled before I could get on with the game, viz, redirecting that asteroid into a low equatorial Kerbin orbit. The rock was a wee bit bigger than what I had bargained for (1000t/80% should, after capture, still hold enough fuel for the whole challenge) but I'll be dammed if I let it go.

Attaching several strong reaction wheels to the asteroid made it reasonably maneuverable: I know from previous experience that weird things happen when and if you try to transmit all the torque through the pusher's claw. As it was, I could do a 180 in under five minutes and had light on the panels at almost any time.

Reaction wheels are attached with KAS ground pylons; there is noticeable flexing when they apply force, and the MJ controller has a tendency to shake them madly; due to the solar panels attached, I can only describe it as "flutter". Stock SAS is smooth, though, even at high physics warp.

Hour-long burns were bearable thanks to Better Time Warp (up to 12x was possible); using a Munar flyby I could have a cheap capture plus inclination change:

anyway

Note that the engines are running, I'm decelerating as I fly by the Mun. This helps with inclination and brings the DN closer to PE; it also lowers the Munar PE as I play past, minimum ground clearance was on the order of 2500m.

From then on, I proceeded with more conventional maneuvering until a) the rock was in a safe 7500x200km orbit,  well below the influence of the Mun and b) I was utterly fed up. I've used about 200t so far, not quite 600m/s. But that was mostly long burns where I could crank up time warp. Circularization will require another 800m/s in consecutively shorter maneuvers... I guess I'll just skip this part and edit the appropriate mass out of the asteroid.

Just btw, is anyone aware of a mod for easy and quick crew transfers? Moving a dozen people between vesels is (IMO) more tedious than many a long burn.

[sturmhauke]

50 minutes ago, Laie said:

Just btw, is anyone aware of a mod for easy and quick crew transfers? Moving a dozen people between vesels is (IMO) more tedious than many a long burn.

I haven't used it, but there's Ship Manifest. I've heard a few people say they like it.

[Death Engineering]

On 8/15/2018 at 11:36 AM, hoioh said:

I was wondering about this one, but since Kerbals in Kerbin orbit don't count towards points I'm assuming this is not a problem for mining operations in Kerbin SOI?

Right.

[Alchemist]

And here goes the second episode of my entry. To be fair, nothing really much going on here, just driving all around. And searching for the anomalies - so consider it a spoiler alert

Quick summary:

• The first expedition will bring samples from all the biomes (yup, overkill) and selfies with the anomalies
• No minable water in near-equatorial regions at all, we'll have to settle on the polar cap (and the only other biome that has has any H₂O was polar craters and with quite bad content of it)
• The base turned out to have not that great power generation (especially with half of those damn panels apparently broken during crew shuttle docking back in LKO) and battery capacity for this terrain, the first crew transfer vehicle will bring some spare parts
• Overall, I've got driving overdose even with cruise control. And I'll still have some driving to do to meet with the first crew transfer vehicle.
• Time to finally get back to some space flying

[Kerbolitto]

Chapter 12 is over !

 

Some (boring) maintenance stuff to prepare next missions.

After all the last space acrobatics which drained my brainpower a bit, I let some time go to prepare the following chapters.

They should be more interresting with the injection of WHP life support emergency ship and SLV 04 some days later !

[Laie]

My Life Support recipes, using TACLS:

• ambient moisture is collected at air condition units, filtrated (together with some of the less disgusting gray water) , and becomes clean water. I'm assuming that this applies to 2/3rds of all wastewater produced.
• larger craft process the other third in an electrolyzing unit where 75% is turned into oxygen. Remainder is waste (actually, somewhat concentrated brine).

The first reduces water demand to ~1kg per crewmember-day; the latter creates enough excess oxygen that the stations and bases that have it can provide for the shuttles and rovers that don't. Thankfully, TACLS doesn't bother with nitrogen which would presumably be hard to come by on Duna/Mars.

I'm not so sure about farming. I guess I'll just require water and some ore, as stand-in for whatever resources taken out of the environment. Given that I can drill for both, this ultimately means that farming will "just work". Will that be alright?

[Alchemist]

15 hours ago, Laie said:

nitrogen which would presumably be hard to come by on Duna/Mars.

Actually, on Mars that wouldn't really be a problem - if you just freeze CO₂ (which is much easier than liquefying N₂ or O₂) out of the atmospheric air, you'll end up with a mixture of nitrogen and argon.
On the other hand, the only big concern for nitrogen is supplying it for plants to make protein, and only if you go for certain nitrogen-binding microorganisms (instead of making fertilizer), you'd really need a certain amount of N₂ in air, otherwise having another inert gas or even reduced pressure (just don't drop it too quickly) doesn't make too much difference as long as you have 21 kPa of O₂ in the mix and manageable amount of CO₂

[Laie]

@Alchemist Oh, that's interesting -- I thought mars was legendarily nitrogen-poor, and that you'd need to bring it all with you.

[Alchemist]

1 hour ago, Laie said:

I thought mars was legendarily nitrogen-poor, and that you'd need to bring it all with you

Well, there isn't too much nitrogen,  if you take in the account atmospheric density and that there is 95% CO₂. But N₂ is still reasonably easy to harvest from this atmosphere, water is more of a problem on Mars.

Much bigger problem is rocky bodies without atmosphere in the inner Solar system. Namely, the Moon.
Basically, nitrogen just has no tendency to form low-volatile vacuum-stable minerals. And carbon also has this kind of issue - carbonates may be relatively abundant, but they don't survive on lunar surface. Well, if you intend on mining trace isotopes put there by solar wind (namely, Helium-3), you'd probably end up extracting decent amounts of carbon, nitrogen and especially hydrogen in the same process. Otherwise, craters in polar areas are the best pick for volatile elements, but it's still a huge question if you can find any much nitrogen there

[Laie]

Baby steps... Meet my crew transfer vehicle. A bit over 24t dry, has place for 32 people and lots of supplies:

I wanted to make a nice picture of orbital assembly, with Mk2 parts drifting out of a cargo bay and several Kerbals on EVA supposedly putting it all together, but found that too difficult to set up -- before you know it, half of them have drifted off-screen. So please, just close your eyes for a moment and try to imagine how it's being put together.

Of course, in truth it's a single part (SXT) and goes up by hyperedit.

The wide, windowless part of the stem is supposed to be the larder and storm shelter; a command module in front, service module & KIS storage behind (both ModPods), the torus, all welded together. Part stats have been based on a rather utilitarian vessel made of Mk3 Crew Cabins and TACLS containers.

Remember my asteroid capture? That rock is still in a barely submunar eccentric orbit. I thought I could try aerobraking if I remove the nuke and put on the CTV as propulsion unit instead, so the nuclear tug went down to LKO to pick up the Crew Transfer Vehicle, and bring it up to meet the asteroid:

First attempt at aerobraking wasn't very convincing, though. Dipping to 50km, I only lost 10m/s... and one reaction wheel.

[Mad Rocket Scientist]

1 hour ago, Laie said:

[...]

Remember my asteroid capture? That rock is still in a barely submunar eccentric orbit. I thought I could try aerobraking if I remove the nuke and put on the CTV as propulsion unit instead, so the nuclear tug went down to LKO to pick up the Crew Transfer Vehicle, and bring it up to meet the asteroid:

[....]

First attempt at aerobraking wasn't very convincing, though. Dipping to 50km, I only lost 10m/s... and one reaction wheel.

Nice looking crew transfer vehicle!

On asteroid aerobraking: I recommend dropping the asteroid as low as you want, then disconnecting the asteroid tug and propulsively braking it above the atmosphere. Then do some fancy high-DV maneuvers to get back to the asteroid. This also lets you use the nuke on your tug, since that part never aerobrakes.

[Raptor kerman]

On 8/17/2018 at 8:28 PM, Laie said:

I've spent the last few days playing with the game, rather than playing the game. Building one-piece vessels using welding and typing in custom resources, combining IVAs, that kind of thing. Like, adding a few more seats to a scaled-up cockpit. Config editing can go a long way.

19 seats visible, but the lower deck stays empty: all the crew is crammed into the upper 4-seat IVA, sitting inside each other. looks eerie.

Can we download this?

[Kerbolitto]

So what's up here ?

You're still around @Death Engineering ?

[Death Engineering]

5 hours ago, Kerbolitto said:

So what's up here ?

You're still around @Death Engineering ?

Yep still around, well back.. partly. RL kicked in and don't have time to play but will respond to questions. Hope your mission is rocking! 

[funk]

On 9/4/2018 at 11:55 PM, Death Engineering said:

Yep still around, well back.. partly. RL kicked in and don't have time to play but will respond to questions. Hope your mission is rocking! 

Same here, just lurking from time to time. For Kerbonauts RL is a b...h.

[hoioh]

Just returned home from a 3 week trip camping in France. Might return to this very soon, but right now I'm just tired from the 2 days worth of driving home