[Completed] Duna mission, planning and R&D.

[Galane]

Alan Aerospace Recycling and Packaging has sent a crew of engineers into a bubble universe (AKA another game save) to develop a mission to Duna to deliver a Kethane scanning satellite as step one in the groundwork for further missions.

Much time was saved by modifying the launcher design used for the 16,000 unit Kethane mining rover, simply named Large Rover.

The initial plan was to dock four of the launchers upper two stages to a central upper stage but they got impatient after getting two of the "sidesaddle" boosters docked and took off early. Quantum struts proved to be highly useful, requiring only four per side booster to hold on with a single Clampotron Jr.

The amount of fuel left after achieving a circular, equatorial Duna orbit had the engineers scrambling for drink coasters (much sturdier than napkins) to scribble on the backs of. Getting all four side boosters docked should provide enough go-power to get a manned lander plus four small satellites there and bring the lander back.

The old Two-Step Lander was pulled out of storage, refurbished and tested successfully in a simulated landing from and return to a 45KM Duna orbit (can that be lower and still safe?). Two-Step is already known to be capable of landing on Mun then returning to LKO under its own power.

The even older AARP Stock Lander 1 was tested first but proved to be incapable of returning to orbit around Duna. The simulated Kerbalnauts did not appear to be happy when the fuel ran out a few seconds short of reaching orbit.

Design changes have been made to the sidesaddle components to reduce a bit of weight in their discarded stages and to improve maneuverability before and after docking. For the central section, the modifications are having to be redone from scratch since someone clicked launch before clicking save. No biggie since the mission requirements have changed so much. Easier to restart from the initial Large Rover Launcher design.

What's holding things up now is figuring out a way to connect the base of the lander to the top of the launcher, then be able to dock to the same spot for the return trip and topping up the lander's fuel for landing back at KSC.

One of our engineers suggested ripping the guts out of an OKTO2 and mounting them around the inside of a Rokomax Brand Decoupler, then welding a Clampotron down inside the middle. A RockoOKTOClampo should be a very desirable and useful component for many other Kerbal aerospace companies.

Edit: Got it to work! http://forum.kerbalspaceprogram.com/threads/58406-AARP-introduces-the-RockoOKTOClampo Just need to figure out how to get rid of the fairing but it'll work fine as it is.

Edited July 23, 2014 by Galane

[Galane]

With the custom part in inventory, hand assembled one at a time by AARP's crew of stalwart, hard wor... Hey! You! The green guy! Lunch is in 30 minutes, get back to work!

*ahem* hard working Kerbals, the Duna mission is well on its way to being on its way.

Core part launching. It makes it to a 71KM orbit with just a whiff of fuel left in the second stage. Staging gets re-arranged to pop off the small engines on their short Stretchy Tanks to make room for the side boosters to dock. Second and third stages are both topped with the RockoOKTOClampo. The goal is to keep the second and third stages together then dock the landers nose to the top of the third stage for the return trip. Retaining the seperation capability and the four 3rd stage side tanks and engines is just for insurance in case the second stage fuel is expended on the way back to Kerbin. Never hurts to have enough thrust to make it into a good orbit before landing.

Side booster launching. There's a small Kethane scanning satellite on top, which also provides the remote guidance for docking. The third stage on this has a RockoOKTOClampo just in case it happens to end up in some sort of orbit in the Duna/Ike system. In such a happy circumstance, the ROC will enable it to be repurposed as a fuel depot or for moving things around.

First side booster docked to the core. Three more to go. A ship with a lighter payload and only two side boosters has already made it to Duna, but will be retconned out of existence by the quicksave. It's performance and amount of fuel left over was impressive enough I decided to try for a manned mission and return.

Instead of four Kethane scanners I'm thinking of building a pair of Kethane mining landers specifically for Duna. Getting them into orbit atop two of the side boosters will be easy. All five of these are slight modifications of one of the boosters built for heavy Kethane mining Mun rovers. That will provide the security and redundancy to ensure a fully fueled ship for the return flight. The manned lander's weight will be reduced by dropping its three side tanks and LV-909 engines.

Two-Step Lander makes it down to Duna surface with some fuel left in the side tanks. They'll be used for the liftoff then dropped when empty as the additional thrust isn't required after expending their remaining fuel.

Retaining the four top orange tanks from the side boosters all the way to Duna may be a problem for fuel use. But since they'll be carrying the scanners and mining landers, they'll have to be kept instead of dropped when empty as was done in the unmanned flight. On the other hand, they'll also provide plenty of fuel storage to get going on the way back to Kerbin, then can be cut loose when empty.

Have to assemble this the hard way in orbit. I tried making the Clampotron Jr on the side booster the root part then saving the upper stage of the side booster as a subassembly, but it wouldn't click onto the ports on the sides of the core. I could have rebuilt the side boosters out from the ports but that would be more effort than just launching five rockets to dock together. ;P Getting the four Quantum Struts on on the booster individually placed was bad enough.

No space plan survives contact with hard vacuum.

Edited November 16, 2013 by Galane

[Monkeh]

I've just been on a Duna mission so if you'd maybe like some inspiration feel free to click here.

Good work, I like seeing what others get up to in this game.

[Galane]

Today's development time went into a design for an 8,000 unit Kethane lander for Duna. The test program included descent tests, drilling capability, fully loaded ascent to 45KM orbit tests (had to stack another small tank on top to have enough fuel) and finished up with a transfer to Ike orbit. That was successful but the final test lander somehow impacted Ike (in a puff of smoke, no explosion) when the periapsis was set to 10KM and warped to for circularizing at that altitude.

MechJeb is also having issues with screwing up orbits by idling the lander's engines after passing nodes. May have to add four of the little orange radial mount engines to give just a bit more thrust. Of course that will require another round of tests. I'm certain it's not too low of thrust since AARP's much heavier 32,000 unit Kethane lander has the same four white radial engines and no issues with idling past nodes.

Self refueling tests were conducted on the KSC launchpad and the final function test was performed on Mun to ensure the small drills would penetrate deep enough on a Kethane deposit.

Refueling the ship for return from Duna will be tedious with these two small landers, but at least it'll be possible.

The final part of the test program was setting the Kethane lander atop a SideSaddle booster then launching to a 71KM orbit and docking to the Duna ship assembly. The simulation computer hit a wall when the two approached. Lag was significant and the slowdown seemed to cause much difficulty in aligning for docking with huge amounts of overshoot on every maneuver. It finally got straightened up with only a few meters left and docking was successful.

Since repeating that wouldn't add anything to the test data, the manned Two-Step Lander was decoupled and the rest of the ship deorbited, then the lander brought down safely to KSC.

Some final tweaks still need to be made, fixing a solar panel action group on the Kethane lander, adding strut guns to the top of Two-Step, making sure action groups on the five sections are properly assigned. The four Quantum Struts on each SideSaddle don't all make contact on dock, but do when toggled off then on with action group 1.

AARP's Media Relations Department produced this handout photo of the final test assembly in Kerbin orbit.

I don't know if I'll actually be able to complete this mission in the "real" game. Just launching the components gets pretty slow until the first stage drops, taking its strut spam with it. Using Quantum Struts and Kerbal Joint Reinforcement on the orbital sections helps with the part count. The boosters I'm using are "legacy" ones from before KJR, thus the strut spam to keep the first stage held together. When I opened the TAC Fuel Balancer window on the final test assembly...

I may have to try the UbioZur welding plugin to stick some of the throwaway parts together.

[Galane]

Well, there wasn't really anything I could do with UbioZur. Too many custom parts it doesn't grok.

So the busy little green guys set to with their prybars to pop off anything they didn't think was absolutely required. The five engine clusters on the side boosters got replaced with single mainsails. With Kerbal Joint Reinforcement added, a lot of standard struts went in the spares bin.

But the lightening project went a bit too far. The top end of the core got wibbling about to the point it looked like it might break off, and during the initial maneuvering to raise Kerbin apoapsis to 300KM (waiting for less than two days at 50X warp in a 71KM orbit is slooooooow) the clampotron Jr and quantum struts holding one of the side boosters on just let goduring a warp transition. Sooo, rather than reload and repeat the hours it took to dock all this stuff together, I reloaded and enabled unbreakable joints, but only during full thrust main engine burns. The ship *is* capable of getting to Duna with the fuel it has, it just needs a wee bit of help staying in one piece. The jr docking port and four quantum struts are capable of holding that much thrust, I did it with the original mission I scrubbed. The problems are the four quantum struts I should've left on the core (but the core launched with no wobble, despite being pounded into the air by four mainsails and *eight* skippers!) and lag VS warp issues causing parts to not occupy their correct relationships to one another. "Why is that decoupler in the middle of the side booster sliding sideways, KJR doesn't let that happ... oh krap! There goes a whole booster flying off." F9!

Here's the final side booster coming in to dock. Lag is getting pretty thick now but not bad enough to prevent docking autopilot from being able to control it. (Unlike with the larger number of parts on the test ship assembly.)

Note the solar panels on the kethane scanning satellite. They're the only power source keeping the battery charged on the side booster. The battery is on the satellite so when it's popped loose in Duna orbit the tank is dead debris. Those panels were folded up after docking and all power for the flight comes from the 12 RTGs. That was to reduce lag from the extra calculations of solar panel exposure.

Fully assembled, fuel topped off and ready to go! Just before I was going to raise the orbit, I realized that I had no power source at all for the core after separating the manned lander. Oops! That would make docking to it for the return trip a bit of a problem since it would be uncontrollable.

Look at the tops of the kethane landers. I'd already fitted them with the two way combo clampotrons so they could dock to the sides of the core, to the manned lander or to the front of both stages of the core. So I quickly stuck together a small RGU, a 100 unit RCS tank, four ReStock 5-Way RCS blocks and four RTGs, then launched two of those to dock to the landers.

That nailed down what the separation sequence had to be at Duna.

Kethane satellites cut loose first, then the side tanks they were on top of, undock the little birds with the RTGs and dock them to the clampotron jr's on the core. After some kethane is spotted in an equatorial area, the kethane landers can be dropped and their empty side tanks disposed of, leaving two jr ports free for the kethane landers.

Current mission status is the ship is in a 45KM equatorial orbit, one kethane satellite is in a 15 degree orbit, the other in a 25 degree orbit, angled opposite to the first. Two side tanks dropped and one RTG bird moved. That was a hard thing to get docked. Apparently if there's not enough mass to bang in hard enough, the ports don't grab hold very well. I had to back off several times and try different approach speed settings until it finally caught.

Here's the ship after completing the TDI burn. Lag is reduced a bit after shedding a few parts.

I didn't get shots of the ship as I separated the satellites. KSP crashed shortly after I moved the first RTG bird to the core, but I have it quicksaved in that state, and also have a save with the assembled ship in LKO. Would be nice if there's a way to pull that assembly out of the save so it can be worked on all together in the VAB to do the fixes it needs.

No aerobraking, no parachutes, just the pure, solid support of rocket thrust. That's how Alan Aerospace Recycling and Packaging does space flight.

Edited November 19, 2013 by Galane

[Galane]

"Hey, Jeb."

"What's up,Bill?"

"Mission Control uploaded a new patch to the guidance computer last night, 2.1 build 104."

"I think we'd better do a simulation test before we use it to send a Kethane lander down."

"Good idea! If it doesn't go right, we won't be going home any time soon."

One landing test later...

"We are sooo screwed."

"I hope we have a backup of the previous version!"

The first landing, MechJeb had the engines aimed properly retrograde but also angled upwards a bit, and ran them at a low throttle setting all the way down. It finally flipped the lander upright but not soon enough to kill horizontal velocity or slow down enough vertically. When I saw the docking port and RGU skimming along like this, it reminded me of an old 1950's UFO photo so I quickly moved the camera angle low and snapped that shot.

OK, F9 and try again. Success the second time, kept it aimed more or less the right direction but idled the engines much of the way down after beginning the second burn. It also pitched the lander up and down many times between the deorbit burn and beginning the braking burn.

"Y'know, I think if we reset the lander's computer it might work."

"Jeb, I dunno..."

"We have to get the refueling started ASAP."

"Well, we do have two landers..."

"Ok then, lets remotely light that candle!"

"Whew! It worked. Sure burned an awful lot of fuel."

"When they ran the sims on these during development, they took nearly all their fuel just to get back to orbit."

*runs some calculations*

"Jeb, I'm real glad we're very good friends. Every trip of these landers is going to bring up enough Kethane to just more than refill their main tanks. All we'll get for the return fuel is whatever extra goes into the landers' top tanks."

"Well then, we'd better land ourselves and plant that flag!"

"Huh, weirdness!"

"What's weird, Bill?"

"The old Two-Step used pretty much the same amount of fuel it did in sims on build 102 of the guidance software, even though with 104 it ran the engines most of the way down."

After the successful landing of the DunaRuna-2, the first attempt at landing the second Kethane lander went wildly worng, but in a different way from the first fail. It did the deorbit burn correctly but then got mixed up about which way was forward, flipped over prograde and tried to flee the Duna/Ike system - with the engines at idle. Reloaded from save, tried again and it worked.

Both Kethane landers are identical, same craft file, no parts stuck on upside down.

Edited November 20, 2013 by Galane

[Galane]

"Aaaaghhh! This isn't working! We're trying to fill a swimming pool with a pair of Dixie Cups!"

"Bill, WTH are you going on about?"

"The numbers on the refueling. Every time one of the Kethane landers lifts from Duna it burns nearly all its fuel, most of which it had to manufacture on the surface. Then to rendezvous with the ship it has to convert some Kethane. Then by the time it docks and converts the rest of the Kethane to fuel, there's barely a splash more than what it was sent down with. Dixie Cups! May as well get out and push the ship home!"

"So, the problem is the landers are not efficient enough to get us refueled because Duna's gravity is too strong?"

"Yes! And we're going to be here a long time waiting."

"Gravity. Gravity... I have an idea. What about Ike? It has a lot lower gravity. I bet there's Kethane on Ike!"

"Yeahhh, great idea Jeb, but we put both scanning satellites into Duna orbit. Dunno why the engineers put on two, seems to be a software issue where only one at a time will actually scan... Then we'd have to get at least one lander to Ike too."

"Well, you said we're going to be here a while, crunch the numbers and see if the satellite with the most fuel left can make it to Ike, and if a fully fueled lander can make it."

*sound of crunching numbers*

"YES! That will work! We can get one satellite to Ike and the landers can get there too. They'll be able to deliver a lot more usable Kethane. We'll be fueled long before the transfer window back to Kerbin."

*Interlude while satellite and lander fly to Ike*

Satellite transfer.

A definition of "circularize" with which I am not familiar. MJ got it round but way off center.

Lander transfer.

"Mission control, Jebediah Kerman here, we're about to initiate a transfer burn of DunaRuna-2 from LDO to LIO."

"Roger that, you are go for burn. By the way, we updated the autopilot software again. Skipped a couple of versions, including one that just flat out didn't work at all. For some reason the computer module would just fall off the ship."

"Uhhh, yeahhh. Real confidence boost there, control. Burn coming up in T-5, 4, 3, 2, 1, +1, +2, +3... Bill, check the autopilot is on."

*switch clicks off and on*

"Autopilot on and confirmed active. Engines armed. Control vector aimed the right direction."

"Try the lander engine."

*Poodle engine sound*

"That works, I'll try switching back to the Skippers... Nope, nothing. Trying manual throttle actuation... Hey! It's jammed! Can't move it. Autopilot off, throttle up. It works! AP on and <BLEEP>!"

"Well Bill, looks like we aren't leaving Duna orbit unless we fly it manually. Or wait for another update to the autopilot software. Could make it to Ike using the lander engine but that won't get us back to Kerbin."

Edited November 30, 2013 by Galane

[Galane]

"This is ground control to Major Jeb. Can you hear me, Major Jeb?"

"This is Maj... uh what? Since when are we in the army?"

"Hah! I win the bet! Nevermind that, we've uploaded a new patch to the autopilot. Set up the Duna to Ike transfer again and see if it works."

"Copy that! Node in T-3, 2, 1... YEEEHAWWWW! We are GO for Ike!"

*in Ike orbit*

"Y'know, Bill, since we're here, may as well poke a flag into Ike."

"I'm all for that! I want some gravity under my feet again."

Kethane lander on Ike.

All three landers docked.

The lag and lack of strut guns on the kethane landers made docking the second one very difficult. Had to shut off SASS on the big ship just before docking to keep kill rot from shaking it all about.

Product Testing showed that upper 64 tank and four boosters aren't needed to get back to Kerbin. With the RockoOKTOClampo I could cut that loose then dock the manned lander to the top of the four-pack of 64's.

With 124 days to go until the return window, It's cleanup time. Grabbing one of the boosters in elliptical orbit around Kerbin in order to deorbit it.

PS. The mission is named DunaRuna 2 because the test design and assembly in Product Testing was DunaRuna and there were some significant changes from test to 'real' mission. The DunaLite heavy kethane scanner satellite and its booster are still in LKO. I know it can get to Duna with plenty of fuel to spare, where else might I send it? It does have two empty clampotron jr ports I could dock some small things to. It predates the ROC so I can't pop the satellite off the nose and dock something else to repurpose the ship. Could send up a robot... (AKA editing the part name in save to swap it out.)

Edited November 30, 2013 by Galane

[Galane]

Decided to bring this home, didn't take any shots but somehow managed to get an Ike encounter leaving Duna AND a Mun encounter arriving at Kerbin, both of which royally screwed things up, requiring much fuel to be used to avoid hitting both of them.

Good thing I built the ship with lots of fuel capacity! Despite switching Target to Mun it circularized retrograde around Kerbin between the orbits of Mun and Minmus. I figured capturing into Mun orbit then transitioning from there to LKO would work.

I had to build a special tanker (hooray for Size 3 tanks!) to fly out there to get enough fuel in the ship to get it down to a lower orbit. Then I had to send out a Deorbitizer to bring the tanker down.

The Duna Runa 2 lander landed safely (as it always does) so Mission Accomplished.

Now I have to decide if I want to leave the ship core in orbit for re-use (is going to be a PITA to shift around to a prograde orbit) or crash it.

Still to do, build a Kethane miner lander for Duna that doesn't burn up almost all the fuel it makes or Kethane it extracts getting back to orbit. I might try a variant of my (still waiting to go to) Eve trio of a mining rover, converting rover and a land/return vehicle - designed for SSTO-ing a significant amount of fuel to orbit. I'm thinking airship parts like the Eve lander.