Sleepy_Steve

Why in god's name do you need to take 107 tons on a Duna mission?

Yeah, the mono prop is there from docking requirements on the Jool mission I'm doing... It's basically a flotilla of 7 different vessels sent on a large single ship. The idea is that when the mission's landings are finished, that I'll consolidate all remaining fuel and RCS into the return ship and see how far it can make it home. Would it make more sense to burn off the extra RCS first and ditch those tanks before using the last of my fuel? Even though I'd be pushing a much larger mass with the RCS?

The full parts list is: Mk1-2 Pod, 2 radial parachutes, 1 smallest solar panel, 4 FL-R25 RCS Tank, and 3 docking ports. Engines are the 0-10's. So I'm seeing a full mass of 6.77 and a dry mass of 5.15 at an ISP of 290.... 777.3 m/s. This is basically my emergency stage. I won't know how much of it I need to use till I'm done with the visit all the moons portion of the jool mission. But I do fully expect to run out of traditional fuel before I make it back to Kerbin. How much of the ship I use to come back might be pretty minimal since there are a bunch of options with the way I designed the ship's different modules. My plan is to use whatever is the minimum possible to fit the remaining fuel into, but even that I expect to run out.

Lets say I have a ship with a 3 man capsule, it's got its own supply of RCS, and then 4 of those medium RCS tanks on it with 100 RCS each. And now lets put on two or three of those RCS engines.... How far could it go? Hypothetically, if this ship were to run out of fuel coming back from say... Jool; how screwed are the occupants?

Mission Update: ^ Ejection burn was not as smooth as I'd hoped. ~300m/s for plane change. Then I needed about 1500 m/s of burning negative radial to get an encounter with a 500km periaps at Jool. More burns are needed later to tweak into aerobreaking. So... burning radial on ejection + massive radial correction = I goofed the pre-burns and possibly missed the ideal point in my transfer window... I've noticed Alarm Clock and MechJeb have different estimations of transfer windows. MechJeb normally coming before alarm clock. Cross feed in the docking ports caused me to drain all my landers without realizing it. Now my center core is down to about a third of a jumbo-64 tank. I'm not sure how much deltaV the thing has left any more. I will not scrap any mission objectives.

Well, I think I made it... at least the main burn was done. I increased my apoapsis in the wrong angle, and had to do some odd radial stuff to get the ejection angle right. Hopefully a plane change at the AN and an encounter tweak can get me an encounter. This is a lot harder than my probes or the ship I sent to duna. Maybe it's the low TWR?

ok, so to update this... how do I estimate my burn time needed for my 1900m/s transfer burn? 190 tons, 240 thrust from the four nukes... My rough guesstimate is somewhere between a 20 and 30 minute burn. If I raise the apoapsis of the orbit to near the mun that reduces the required burn length by 42%... but that still means a 10-15 minute burn, and that still seems overly long. How accurate are my estimates? And what else can I do to make it work better? Raise my periapsis higher to give more time to do the burn? Give the ship a brief kick on the final transfer burn to Jool by turning on the Skipper and two Rockomax 48-7s for a little bit?

Related question... if using mechjeb, do existing modules on craft already in flight get feature updates when they are unlocked in the science tree, or do you have to launch fresh mech-jeb parts to gain that functionality (for example, docking autopilot)

Farmed out some contracts for science and cash. Saw some contracts expiring. I'm doing fairly routine round trips to Minmus and Mun on a single launch for $44k, and taking home normally a bit over $150k in revenue by the end of the mission.

Tylo is first, it's lander is by far the most massive... This is the untested design I came up with below. I didn't have the large docking ports yet for the big interplanetary stage (not outlined in a square) to be 100% reusable, and I don't have the large RCS tanks so I expect a pretty ugly addition to the nose of the large capsule before too long. Single launch because I'm lazy. 239 parts and 109 tons so far... Now I just have to get Bill and Jeb back from other missions, slap on a bit more RCS, and add.... 7300 liquid fuel and however much oxidizer that needs.

Now just to figure out total payload mass in the landers...

That's a good point about the non low circular orbit for the main craft. And if I split off landers relatively early, I don't have to move the WHOLE monstrosity around to each moon. That's also a very pretty delta-V map. The plan is to base the mothership around the ship on the left of this image: Initial changes are less RCS, and no science module to save payload. Additionally, two of the LV-N nacelles will be detachable tugs with probe bodies and RCS to help the landers get where they need to be without moving the whole thing around. Tylo lander would dock to the back of that ship, and the configuration would allow me to drop any number of the landers once I'm done with them and up to two of the four nukes. The two other landers would attach to docking ports at the end of the detachable nacells.

So I'm planning a joolean grand tour. Woo!! I'm going to be using 3 different partially reusable landers, and a central interplanetary tug for the mission. The goal is to hit all 5 moons. But when I look at the deltaV map I get something like 14km/sec deltaV needed on the tug to go there, visit all the moons, and come back. That strikes me as a bit excessive, is that even in the right ball park?

Finally got around to my first successful Duna landing, and topped it off with a visit to Ike first. Had about 4k dV after landing for the return journey to Kerbin. Jeb's now sitting in orbit waiting for the return transfer window. With any luck he'll be back in time for the first manned Joolean mission.

Mission update, added drogue chutes to the design and a couple of struts to the outer tanks of the lander. Made it to the Duna system, landed on Ike, scienced, then landed on Duna. After landing on Duna, doing more science, and re-adjusting staging for landing I had ~4km dV to get me home in the lander. Was able to get about 1100 science from completing contracts and transmitting eva/crew reports before heading home. It's currently in orbit around duna waiting on the transfer window home.

I started messing w/ mechJeb.... Productivity of play hours vastly improved, the panic feature is interesting. All the boring stuff I hate doing is automated while I set up manuver nodes, hit go, and watch netflix / crunchyroll. Sent a probe to Moho, launched probes for Eve and Jool into LKO, launched my Duna ship into LKO, and got my first guy back from a two hop Mun mission.

Asteroid made of soup-air?

Not the most cost effective, but I've got one that I think is reasonably cheap for a single launch round trip run to Duna for one Kerbal in the 0.24.x version. Total cost is just shy of $62k, for something like 12km/s dV. Obviously the radial decouplers on the lander needs to switch places with the parachutes for staging, or you know major malfunctions will occur. I haven't flown it yet, I'm waiting to see if I can tweak the lander design a bit after I get back science from doing some Mun landings. I've already farmed out Minmus. If it's in the tech tree for you, I might replace the side chutes on the lander with drogues, or clip some drogues in with the Mk16's pictured... I'm not sure if you can re-pack them without clipping in a strut/girder of some kind. To emulate this design, note that the RT-10's are at 33% or so, if you only run six of those boosters feeding a skipper engine, that can be bumped to 42%. Picture: Rough mission profile: use the first two stages to get almost to orbit, might by tricky given the low TWR of the 2nd and 3rd stages, might drop the poodle stage to a -16 tank instead of a -32 to keep the lifter happy and not overloaded. Then use the poodle to get me to duna, and hopefully a low orbit of Ike. Drop poodle stage at the last second, land, collect science, go land at duna, collect the rest of the science, repack chutes, take off for home, drop lander's side tanks when they're dry (possibly during ascent from Duna) and then use the remaining fuel to get home and return what I hope is a giant butt-load of science for a mission to... whatever the next contract is.

Someone fired it up while a few of us were drinking at a friend's house. Felt I needed it in my life and bought it for like $25 on steam sometime the next week.

For me I've been using a core of a skipper or mainsail with between 1 and 1.75 orange tanks on top, and using between 6 and 10 BACC SRB's with T800 tanks on top feeding into the core's tanks. The SRB's are throttled back to something like 60%-65%. Handles small/medium payloads, easy to fly and relatively cheap; more so if i can start recovering the core where most of the cost lies. Eventually I want to standardize these based on payload capacity and get the core's recoverable for cost savings later on in my program. For my Duna mission, the lifter currently costs $53k and gets me ALMOST to orbit with a 30 ton payload. The transfer stage has to contribute 400m/s to circularize the orbit. It's not perfect, but it accomplishes the mission goals. It could probably be trimmed down further in cost if I made the transfer stage smaller. I don't think it's ideal but it finds the right balance I want to have as I play through this new career save.

How heavy of a payload can that handle? I've been doing onion staging with the medium SRB's and a T800 tank on top of them feeding into the center stack lately but it's not saving me that much. I think the concept needs more development in the sandbox.

Dumb question, can you remove science from the science lab after processing so you don't have to ship all 3.5 tons of it back to the surface of kerbin? Like can you stash a bunch of science in the hitchhiker cans or 3 person command pods? If I actually have to return the things I'll have to do some re-designs on many of my ships / stations.....

I've sent all mine up as single launches, because joint strength with docked ships is enough of an issue. This is all done in career mode as I get things ready for my first interplanetary tours. They're primarily fuel stations but later versions have science labs on-board. Version 1. With it's small tug and orbit insertion / first refuel load still attached. Station made it up with more fuel than expected. This quickly started to feel cramped and lacking features. Now with crew return shuttle, refueling tanker, interplanetary tug, and two hopefully successful duna landers docked. Version 2, bigger was slightly better. But I felt that it was still a bit short on fuel capacity. So far it's the only one sitting outside of LKO. And if bigger is better, and I can still lift more into orbit... Version 3, even more bigger. Slightly harder to put into orbit. Seen with my first asteroid tug. Also going to need more refuel tugs than any other station so far.