[0.17] [Erkle+ORDA] Orbital Propellant Depot Olympus

[Temstar]

Imagine a world without gas stations, how far could you drive your car before you have to turn around and head for home? Until now, space exploration lives in just such a world. We got to the Mun and back only by kicking everyone out of the backseat and piling jerry cans full of fuel inside.

A gas station in space – an orbital propellant depot allows us to reach deep into space in ways previously thought impossible. Research have shown that the majority of cost associated with spacecraft development is not in the spacecraft but in the development of the launch vehicle. And as we build larger and more capable spacecrafts the size of the launcher vehicle underneath must increase exponentially. A spacecraft, fully fuelled and capable of interplanetary landing and return will require a rocket at launch so massive it will border on the impossible.

But what if we could launch this spacecraft without its fuel? Fuel often takes up as much as 90% of the laden weight of spacecrafts, if we were to launch a spacecraft ‘dry’ knowing its fuel is waiting for it in orbit then you would only need a rocket 1/10 or less the size of the original, or alternatively the same heavy lift launch vehicle could be used to launch a dry spacecraft ten times the size of a fuelled one, putting return trips to the outer planets within reach.

To becoming a space faring civilisation we need orbital propellant depots, and now we have one.

Orbital Propellant Depot Olympus features:

• 6400L of bipropellant and 2200L of RCS monopropellant storage capacity in orbit
  
• Six hybrid ORDA/Erkle docking ports for easy docking and fuel transfer
  
• Easy to fly HLLV, capable of reliably putting depot and about 3600L of bipropellant in orbit at launch
  
• Powerful on board manoeuvring engine, easily capable of transmunar injection
  
• Easy accessibility features, allowing anywhere-to-anywhere EVA for refueling ships without using EVA suit jetpack.
  

T - 5: Turn on ASAS and throttle up

T: Stage for initiation and hold down arm release, let the rocket go straight up

T + 25: SRB separation

T + 1:30: Outer liquid booster separation, rocket should be at about 9000m

At 15000m, begin pitching down till you’re at 45 degree to horizon

T + 3:14: inner liquid booster separation, depot manoeuvring engine ignition, begin pitching down to about 10 degree to horizon

T + 3:53: core sustainer engine jettison, keep the depot’s own engine burning and pitch down to horizon

Continue until orbit is achieved. Recommended LKO orbit for depot is 75000m (I choose this because this was the performance ceiling of my SSTO)

After testing prototype with either Erkle's or ORDA's docking mod I came to the conclusion that neither were mature enough for a propellant deport. They each had their strength’s and weakness. The solution was simple: use both!

The hybrid docking system that uses both mod takes advantage of strength of each and avoid the weaknesses. ORDA provides a very powerful guidance and navigation computer and RCS fuel transfer capabilities while Erkle’s system provides solid hard docking. The hybrid allows a semi-automated docking process:

Fly the docking ship and make a rendezvous with Olympus using hohmann transfer orbit like usual

Once you’re within 1km, jump to Olympus with [ ] key and turn on ORDA computer. Go to Rendezvous & Docking > ATT > VP, this keeps the nose of Olympus in the direction it’s travelling. Toggle ATT to OFF and roll the ship to orientate the navball to level with horizon and toggle ATT > VP back on, make sure your ASAS is off

Jump back to the docking ship, turn on its ORDA computer and go to the Tgt tab. Select the vessel port and pick an Olympus docking port you want, the port numbers are:

1 fore (front)

2 starboard (right)

3 nadir (below)

4 port (left)

5 aft (behind)

6 zenith (above)

With port selected, go to Rendezvous & Docking > DOCK > AUTO and hit Engage, turn off ASAS if on and turn on RCS

The computer will start in ENTRY mode and fire RCS engine until Olympus is about 50m away

The computer will then go into ORIENT mode and turn so the docking system on your ship is lined up with Olympus docking target, while this is happening right click on your Erkle docking port and turn on warp claw

Wait till Approach Deviation is small (<1 degree on all three axis) and switch to Rendezvous & Docking > DOCK > ATTITUDE. This keeps your ship on the correct orientation to line up with Olympus docking port. Use RCS translate control to bring your ship in

Once you close enough (about 7m from docking target) the warp claw tractor beam will turn blue and exert a slight pull on your ship. Turn RCS off and let the beam pull you in

Congratulations! You have docked with Olympus

Of course computer assisted docking is just the start. The ORDA computer uses a lot of RCS fuel during ENTRY mode that should really be done using the spacecraft's main engines. Once you become confident at docking recommended you do it manually to save RCS fuel. It's even possible to dock an Erkle-only ship to Olympus without ORDA assist at all.

Using both Erkle and ORDA allows transfer of both fuel and RCS fuel. Olympus is fully rigged with handholds for easy EVA refuelling access. The refuelling process goes:

To refuel main engine bipropellant, simply right click on the Erkle docking claw of the ship to be refuelled (this can be Olympus! That’s how it takes on fuel from tanker rockets) and click Refuel

To refuel RCS monopropellant requires EVA. Do not EVA in a way so that any docked ship becomes un-crewed. For safety always use Olympus crew for EVA

Take your kerbonaut and climb down to one of the two RCS tanks. Press G for grapple and you will notice a white line coming out of one of the machines labelled FT. This means you have taken hold of the fuel line. Press G repeatedly if you are near

multiple fuel transfer system to cycle through to the one you want

Climb down to the refuelling ship and go next to the target RCS tank that you want to fill up and press G again. This will connect the fuel line to target fuel tank.

Switch back to Olympus with [ ] key and you’ll notice a new Fuel Transfer menu. Hit Transfer to being RCS fuel transfer

Once RCS fuel transfer is complete, go back to your kerbonaut and go to the RCS tank that was just filled and press G to pick back up the fuel line. Connect fuel line to any other RCS tank that needs refuelling

Once refuelling is complete, pick up the fuel line again and climb back to the RCS tank. Hit G (might need to do a few times) to place the fuel line back

Climb back and reboard Olympus. Don’t worry about the bipropellant fuel transfer, the fuel flow will stop once it’s filled. Alternatively you can cut off early by go to the docked ship, right click on docking claw and stop the refuelling

The SSTO in this example took on nearly 3000L of bipropellant and about 120L of RCS monopropellant. It went from running on fumes to having more than enough fuel to go to the Mun and back. After a big refuelling operation like this you will want to launch a tanker rocket to meet up with the depot to refill the depot tanks. The refuelling process is the exact same as this only in reverse with Olympus as the fuel recipient.

Note that Olympus is equipped with ORDA Fuel Transfer System for both RCS and bipropellant fuel. Instead of using docking claw’s fuel transfer system you may wish to use ORDA system for bipropellant fuel transfer if you want to fill one tank at a time for spacecraft trimming. The fact that ORDA fuel transfer doesn’t require docking means that Olympus can actually refuel spacecraft without any docking ports if they can perform stationkeeping within 50m of the depot. Bipropellant fuel transfer using the ORDA system work the same way as RCS fuel transfer.

There's very little point to have a propellant depot if you have no way of refuelling it once its tanks are empty. To support depot operation tanker rockets have to be regularly launched for top ups. Here's one I've designed:

Exotanker tanker rocket

Capable of offloading 3200L+ of bipropellant and 1600L of monopropellant to Olympus on a good trip, Exotanker is an expandable and reliable tanker rocket perfect for lifting fuel to LKO. Equipped with male version of Olympus's hybrid docking system to allow semi-automated docking it's also perfect for refueling spacecraft big enough to call for dedicated tanker runs. ORDA fuel transfer system allows refuelling ships without docking ports.

Apokee II Crew Exploration Vehicle

Small multiple purpose spacecraft perfect for crew transfer and rescuing stranded spacecrafts by bringing fuel to them. Apokee II is equipped with male hybrid docking system and ORDA fuel transfer system. Also useful to keep one docked to your Olympus class as a cheap way to increase depot fuel capacity.

Dreamchaser II HTHL SSTO

Fully reusable HTHL SSTO with male hybrid docking sytem, perfect for rapid crew transfer within cismunar space on the cheap.

If you would like to design your own depot compatible ship remember to use ORDA Docking System (the male version) instead of ORDA Docking Target or Decoupler as Olympus itself is equipped with 6 docking targets.

Aside from the .craft files, you will need to install these two mods for the two docking/refuelling systems to work:

Erkle Mods - Warp Capable Docking Clamp - v0.5 x1

http://www.boxtin.co.nz/downloads/ErkleWarpClamp_v5x1.zip

Orbital Rendezvous and Docking Assistant

http://dl.dropbox.com/u/105710304/ORDA%20beta1.zip

Edited October 13, 2012 by sal_vager

[Aescwulf]

Kudos to you !

This looks amazing. And I'm guessing the depot runs out of fuel then you launch another one up?

[Cydonia]

Sweeet.

I've been wondering about doing something like this, but with the Kethane mod. My setup at moment means landing to refuel at my Minmus and Ike depot's, I don't have any orbital ones yet.

[Temstar]

This looks amazing. And I'm guessing the depot runs out of fuel then you launch another one up?

I've also attached a tanker rocket design. I use it to refuel the depot when it runs low. Each tanker refuel adds about 50% of the max capacity back to the depot (not included attached Apokee II tank capacity).

That said if you have a really big spacecraft waiting in orbit that needs 3200L+ of fuel then it's probably not worth it to dock with the depot. For that kind of fuel requirement you're better off launching a dedicated tanker rocket specifically for that spacecraft.

I actually have a 4800L to LKO tanker design as well. But it only carries 1100L of RCS fuel and it's pretty unwieldy. You'll have to be very good at docking to get that fatboy to link up to the target. If you run out of RCS fuel before you could dock that's 4800L of fuel in orbit wasted.

Edited October 1, 2012 by Temstar

[Angelmoon]

That things insane!!!! Ok, im now convinced this docking mod may work.

[lazarus2405]

I'm really pleased with the work you've done. I really appreciate the best-of-both-worlds approach to docking you're using.

My only complaint is that the part count is enormous. All the ladders and mobility enhancers really do add up. My computer's not new, but it's no slouch (C2Quad 9400 OC'd to 3.6ghz, 8gb ram, Radeon 4850). Rendezvous was a slideshow for me. I'm willing to use the jetpack if it means I can drop that part count, so I stripped the depot of its mobility enhancers.

So I'm starting to dock engines, tanks, and landers to it for use as the core node of an interplanetary mission.

[Temstar]

Yes unfortunately mobility enhancer is a double edged sword. In the early prototypes the part count was even higher because I didn't use any ladders and it was all hand hold. I recently got myself a pretty powerful new desktop (i7-3820 3.6GHz, 16GB ram, GeForce GTX 660 Ti) and even then all hand hold prototype was a slide show at lift off. Swapping out as many handhold as possible for ladders and trimming the mobility enhancers to a minimum got the part count down by about 150 and made it quite useable on this computer but I would recommend users take off mobility enhancers if they prefer performance to convenience.

Aside from mobility enhancers you could also take off ORDA fuel transfer system on the fuel tanks if you feel you are only ever going to do fuel transfer via Erkle system. You lose the ability to trim spacecraft by selectively filling fuel tanks and the ability to fuel transfer to stationkeeping but not docked spacecrafts. But these two capabilities would be pretty rarely used I imagine.

[Temstar]

By popular request, Olympus - M: now without mobility enhancers.

I've also switched first stage to the new large SRB (all other stage same). This ends up putting about 600L more fuel into orbit at launch.

Edited October 3, 2012 by Temstar

[Commander Zoom]

Outstanding! *downloads*

[Temstar]

So I'm starting to dock engines, tanks, and landers to it for use as the core node of an interplanetary mission.

If it's interplanetary travel you're looking for, I've been working on something too.

In my oppinion though neither docking mods are stable enough to make interplanetary carrrier vessels like this practical, more so when you want to dock more than one ship to the carrier.

Edited October 3, 2012 by Temstar

[ri00t]

I need a little help with it...

First I build my own home station. I used: ORDA SAS module & ORDA Docking Target. Ship are contain a more than one ORDA Docking target parts. Computer and two parts to fuel transfer.

Second I build little ship with simmilar configuration but with ORDA Docking System.

When i used a AUTO docking with ORDA somethigng goes wrong and two ships now are trajectory to run away from Sun.

So my question is: What parts are recomended within ship from ORDA to use a AUTO mode? I mean ORDA SAS, ORDA controlable pod and ORDA decoupler.

[segaprophet]

Make a kethane version please!

[penguin405]

Fantastic!!! I can't wait to download and try.

[Hiatsu2k8]

I downloaded the olympus launcher refuel station and even at stage 5 my laptop is lagging so bad I can't control it.

[Temstar]

I downloaded the olympus launcher refuel station and even at stage 5 my laptop is lagging so bad I can't control it.

You might want to try the version without mobility enhancers, it's towards the bottom of page 1. It's got something like 150 less parts.

[Festivefire]

for a sec i thought you ment 75000 km in your flight plan and i was like "single stage to the mun dafuq?" but im downloading this now and im putting them everywere!

[Temstar]

Kethane and propellant depot like this go hand in hand. Without locally produced propellant all depots must be refilled with Kerbin launched tanker rockets. It's hard enough to keep a munar depot fuelled given that tankers must do at the minimum a TMI to bring that fuel to the depot, which means something like for every litre of fuel delivered to munar orbit six litres were burnt just to lift that one litre out there. If you want to keep a depot even further from home, say in orbit around another planet then astronomical amount of fuel and rocket hardware will have to be expanded to deliever a tiny amount of fuel.

However, if you didn't have to lift fuel from deep gravity well of Kerbin surface then the equation changes. At 1/6G fuel produced on Mun could be very cheaply lifted into orbit, even Kerbin orbit by reusable nuclear tankers launched from the Mun's surface. Seen as Kethane engines don't exist yet I think the best place to put the Kethane refinary would be right at the mining site on the surface. So you have a fleet of rovers on the surface. Some drilling for kethane. The extracted kethane gets pumped to a mobile refinary to be turned into bipropellant or monopropellant and then the product is stored in tanker trucks until enough is accumulated for a tanker rocket load. Then you land the nuclear Mun tanker nearby. Have the tanker rovers drive up and fill up the rocket and off it goes to a depot.

Alternatively you could build a orbital kethane refinary with pump, converter, ORDA fuel transfer systems and all three tank types. Equipe the kethane refinary with this ORDA/Erkle docking system on the nose and dock with the propellant depot and use it as an add on module to the depot. I don't want to add kethane refinary capabilities to the depot itself as that's another mod you have to install to get it to work and it kind of dilutes the purpose of the depot. I'll rather we keep different capabilities in different ships and dock them together as required.

[Festivefire]

That is a very well thought out statement, and I agree. The only way to have sustainable interplanetary fuel depots is to ship the fuel from the planet they are orbiting, making kethane vital.

[Cydonia]

Kethane = Helium-3/Tralphium. Or is it Deuterium?

Edited October 4, 2012 by Cydonia

[Bigred2989]

Any recommended graphics settings that we should use for this? I have a pretty high end PC and this ship killed my framerate.

[Munstation]

Hey, pretty nice ship.

[mcirish3]

Bigred2989 probably not your PC make sure you have installed in non windows directory. (only a fresh install will work, dont copy and paste) I saw a 50% improvement when I did this.

[Temstar]

So in a testing for docking and planned interplanetary travel, I decided to undertake an Apollo style mission using an Olympus class and a nuclear powered reusable Apokee lander:

At the start of the mission, an Olympus class is already waiting on orbit with one crewmen. The other ship involved in the mission is the lander, here it's taking off with the two remaining crew to join with the depot.

At LKO, the two ships join up. For this occasion I picked the aft docking port of the Olympus to dock the lander, you will see in a moment why.

Time for trans-munar injection. While Olympus has plenty of fuel and thrust for TMI it's radial engines have awful Isp. So instead I elected to use the lander's highly efficient nuclear thermals rockets for the TMI burn to push the entire combined spacecraft into munar orbit. There's a trick to this: the two spacecraft's navigation must be in agreement with each other, otherwise they will fight each other for steering and cause the combination to spin out of control.. For this burn I set both spacecraft to R&D > ATT> HOLD. This makes both ships try to keep their heading at the moment the HOLD command was switched on.

Although efficient, the low thrust of the nuclear thermals rockets ment an unusually long burn. During the burn I did some fuel transfer test - turns out the fuel transfer rate between Erkle docking claw is quite high. Here we can see it's way higher than the burn rate of three nuclear rockets. Also interesting is the fact that fuel feed will continue after the receiving ship's tanks are filled if it's burning fuel - the transfer will just drop to equal to the burn rate.

8 hours later, the two ships arrive above Mun. The crew turn the combined spacecraft around and fire the nuclear thermals rockets again to slow down and settle down into a munar orbit.

While orbiting the moon, the lander crew fully fuel the lander and wait for the go for PDI.

Word from KSC is a go and Apokee Lander undocks from Olympus and begins powered descent initiate.

Apokee Lander successfully lands on the Mun! Commander Tombree climbs down first with lander pilot Gilfurt right behind him.

Tombree does his Peter Pan thing with his MMU

EVA is over and the crew gets back inside and lifts off and head back meet up with Olympus

Having linked back up again. Gilfurt gets out to work the RCS fuel lines to refuel the lander. Much like the ISS and its docked Soyuz the Apokee Lander function as a lifeboat for Olympus. Should it be necessary the crew can evacuate from the depot using the lander and escape to either a different orbit or Munar surface to wait for rescue. Thus it's a safety requirement that the lander is loaded with full fuel when docked.

Neither Olympus or Apokee Lander are intended for re-entry for this mission (though Olympus have the capability). Instead they are intended as a permanent Mun presence. To get our heroes back a new crew is launched from KSC in an Apokee II cis-munar spacecraft and heads for the Mun

The three ships join together above the Mun while the two crews exchange greetings and conduct handover. Apokee II arrives with more fuel and RCS fuel than required to get back so the additional fuel are pumped into Olympus's hold.

With the crew exchange complete the original crew undocks Apokee II from Olympus and fires its engine for TKI to take them back home.

Apokee II successfully re-enters atmosphere. Since the nose of the spacecraft is taken up by the docking port Apokee II does not have an XL parachute. Instead it mounts three regular Mk16 parachutes.

Splash down and a heroes welcome for the crew!

Apokee Lander craft file attached for those interested.

Edited October 6, 2012 by Temstar

[Bigred2989]

Bigred2989 probably not your PC make sure you have installed in non windows directory. (only a fresh install will work, dont copy and paste) I saw a 50% improvement when I did this.

What is that exactly and how do I do it? I usually just unzip all of KSP into it's own file and just play it from there. It works fine until I get ships with tons of parts on them apparently.

[mcirish3]

Bigred2989 make a folder like c:\ksp17 and unzip there instead of the unzip default folder.