Astarael III: A Jool 5 Mission

[septemberWaves]

After a few weeks away due to studying, I return to the forums with a Jool 5 attempt. I've analyzed the reasons why I've failed in the past, most of which can be summed up as being too ambitious with vehicle designs (too much unneeded mass), but now I think I've found a way to do it whilst maintaining a good aesthetic.

Mod List:

Spoiler

I'm not absolutely sure that all of these mods are used, but they're all installed because I thought I might use them.

• B9 Part Switch
• Color Coded Cannisters
• Colorful Fuel Lines
• Community Resource Pack
• DMagic Orbital Science
• Editor Extensions Redux
• Final Frontier
• Firespitter Fuel Switch
• Fuel Tanks Plus
• GPO Speed Fuel Pump
• Interstellar Fuel Switch
• Kerbal Alarm Clock
• Kerbal Joint Reinforcement
• Lithobraking Exploration Technologies
• MechJeb 2
• Modular Rocket Systems
• Near Future (Construction, Solar, Spacecraft)
• RLA Stockalike
• SCANsat
• SpaceY Expanded
• SpaceY Heavy Lifters
• Stockalike Station Parts Expansion
• Trajectories
• TRP Hire
• Vx Series II Engine Pack

Now, I present Astarael III, the mothership that will undertake this Jool expedition.

Here is its launch and orbital assembly:

Spoiler

Astarael III propulsion module on the launch pad.

With UI visible.

Liftoff is successful.

Control is a bit iffy at first, but the rocket soon returns to its optimal trajectory.

Here I changed an autopilot setting to avoid staging the fairing.

Acceleration is limited to 30m/s to ensure that control is maintained.

First stage cutoff.

First stage separation.

Fairing separation.

The nuclear thermal propulsion module is equivalent to 20 stock nuclear engines, clustered in fours by Modular Rocket Systems to reduce part count.

Circularization burn takes a long time. I should've aimed for a higher apoapsis.

After several minutes of burning, it appears that the vehicle is going to dip back into the atmosphere briefly.

A final periapsis of 67km is tolerable (I don't know what's going on with the trajectories mod here).

Once back in space, a series of maneuvers are executed to move to a stable 150km parking orbit.

Back on Kerbin, the command module of Astarael III is prepared for launch. The Tylo lander is launched connected to this part of the mothership, as it is inconvenient to launch independently. This launch is crewed by Sigline Kerman, Kerlinne Kerman, Kimberta Kerman, and Jentrice Kerman. Valentina will join them in orbit later.

The Astarael III command module on the launch pad.

With UI visible.

Ignition.

Liftoff is successful.

Ascent is nominal.

Main engine cutoff, first stage separation.

Upper stage ignition.

Engine cutoff as intended apoapsis is reached.

Fairing separation.

Solar panels extend and the circularization maneuver is plotted.

Circularizing.

Circularization complete.

A series of maneuvers are executed to rendezvous with the propulsion module.

The upper stage of the launch vehicle is separated and de-orbited.

Targeting the propulsion module docking port.

Preparing to dock.

I adjusted the docking angle to ensure that the solar panels are not at risk.

Docking is successful.

Upper stage of the propulsion module launch vehicle is detached and de-orbited.

Astarael III in orbit of Kerbin. Attached in front of the cupola is the Tylo lander. Behind the crew module (which is also the Kerbin return capsule) is the cargo truss. This is where the Laythe plane and the lander for Vall, Bop, and Pol will be attached. There is also a small fuel tank for refuelling the Vall/Bop/Pol lander.

 

[Mikki]

Lots of pics to dig through, but your craft looks really reasonable, a tenth or less of docs is sure sufficient for a viable entry.
Good luck, give Tylo a kick! Don`t hit the mountain tops... I just gave your 666. like. Yes.

Edited January 9, 2017 by Mikki
spell

[septemberWaves]

@Mikki My Tylo lander is actually the one I'm most confident with. It has I think about 800m/s more delta-v than it needs, it's wide enough that it's not going to topple even on relatively steep inclinations, and there's no need to worry about a ladder because the seat is so close to the ground that a kerbal can board it without having to climb up.

I have a similar degree of confidence in my Laythe plane, considering the fact that in testing I was able to fly it all the way to Kerbin orbit with some delta-v to spare. Landing it on Laythe could be an issue though depending on whether I can find a flat enough space, but it has drogue chutes to help it slow down.

The lander that I'm least confident with is the reusable one for Vall, Bop, and Pol. It has plenty of delta-v for the job, I just haven't tested it much.

[septemberWaves]

Launch of the Laythe plane

I decided to take the spaceplane approach for Laythe. However, it can't quite reach Kerbin orbit with enough delta-v to rendezvous with Astarael III, so I had to use a different approach. Valentina pilots this launch, and is the fifth and final kerbal to embark on this Jool 5 mission.

Spoiler

Launching the Laythe plane like the space shuttle was perhaps not the ideal approach. It did prove to be effective, however. The liquid fuel tank for atmospheric use is empty, and the entire shuttle will be refuelled by a separate vehicle once docked to Astarael III.

Ignition.

Liftoff is successful. Much like my Space Shuttle Valery, this shuttle has to pitch up immediately upon launch to counteract the off-balance thrust vector. The Vector engine means that this is not a problem.

The high thrust of the Vector engine means that acceleration is high, but conveniently MechJeb has a feature that allows for limiting acceleration to reduce drag losses.

Ascent continues nominally.

The vehicle becomes unstable once its nearly out of fuel, as the center of mass is beyond the 10° vectoring range of the engine. I deactivated the autopilot and separated the launch vehicle, and then reactivated the autopilot. The rapier engine on the plane is used to complete orbit.

Main engine cutoff as 80km apoapsis is reached.

The shuttle has some small solar panels to stop it from running out of electric charge during atmospheric flight, as the rapier engine unfortunately lacks an alternator. I had issues with the prototype where it had to glide to a landing approach whilst fully unpowered, which worked somehow but was not ideal.

Circularization maneuver is successful.

Once in orbit, the plane executes several maneuvers to rendezvous with Astarael III.

The plane approaches Astarael III.

I switch to Astarael III briefly to change the Smart A.S.S settings. I usually set my motherships to constantly point prograde (with a roll setting that's good for screenshots), but this makes docking inconvenient as it requires constant compensation for the rotation.

The docking port on the Laythe plane faces downward relative to the plane, because that was the best way to attach it to the mothership. The RCS ports are the small ones from RLA Stockalike, and there are some in front of the docking port and some on the wing tips.

After MechJeb's autopilot used far too much monopropellant to maneuver into place, I decided to dock manually.

Approaching using the rapier engine rather than the RCS thrusters. This made maneuvering into position a pain.

This docking took place at a bad angle, so I transferred some monopropellant into the plane and undocked to try again.

Docking successful, but as is clear in this screenshot it was still not optimal.

The final docking approach was successful, and the plane is about as well-aligned as I can make it with a manual docking maneuver.

Astarael III waits in orbit for the next launch.

 

[DerekL1963]

Just curious, why not use a pair of PB-NUK's on the spaceplane instead of solar panels?

[JacobJHC]

20 minutes ago, DerekL1963 said:

Just curious, why not use a pair of PB-NUK's on the spaceplane instead of solar panels?

I am not him but they are good at overheating and are expensive.

[septemberWaves]

39 minutes ago, DerekL1963 said:

Just curious, why not use a pair of PB-NUK's on the spaceplane instead of solar panels?

Solar panels look better and are cheaper.

18 minutes ago, JacobJHC said:

I am not him but they are good at overheating and are expensive.

*her. And to my knowledge the RTGs don't overheat, my main reason for not using them was appearances.

[JacobJHC]

Just now, eloquentJane said:

Solar panels look better and are cheaper.

*her. And to my knowledge the RTGs don't overheat, my main reason for not using them was appearances.

Sorry about that.. for me RTGs overheat for reentry reasons with my space-planes. 

[Thor Wotansen]

For spaceplanes, a little rule of thumb I've found is that you can get to orbit with one Mk 1 liquid fuel tank and one of those long 1.25m LFO tanks for each rapier.  Obviously for Laythe that's a little OP but a little extra fuel for rendezvous never hurt.

[septemberWaves]

Just now, Thor Wotansen said:

For spaceplanes, a little rule of thumb I've found is that you can get to orbit with one Mk 1 liquid fuel tank and one of those long 1.25m LFO tanks for each rapier.  Obviously for Laythe that's a little OP but a little extra fuel for rendezvous never hurt.

The plane was designed for Laythe rather than Kerbin. With a bit more overengineering I could've probably made it able to reach Kerbin orbit with the spare 300-ish m/s of delta-v needed to rendezvous with Astarael III in its 150km parking orbit, but then I would've had to make Astarael III itself carry more fuel to propel the more massive spaceplane to the Jool system. The plane can actually get to an 80km parking orbit around Kerbin as it is (and I spent quite a while playing around with fuel quantities in order for it to be able to do that), it just can't get any further than that. And because of its low mass it actually uses significantly less fuel than you're suggesting (it's only about 8.1 tonnes when fully fueled).

[Thor Wotansen]

Ah, make's sense.  I've been designing a Jool mission ans I have a spaceplane for Laythe that's a little bigger, but that's because I want 2 kerbals on it, so I went with a Mk 2 plane.

[septemberWaves]

15 hours ago, Thor Wotansen said:

Ah, make's sense.  I've been designing a Jool mission ans I have a spaceplane for Laythe that's a little bigger, but that's because I want 2 kerbals on it, so I went with a Mk 2 plane.

I guessed yours would be a bigger plane from that fuel amount. I'm going for a 3rd level challenge, so I only need to land one kerbal on each moon as long as they're different kerbals (hence why Astarael III has such a large crew section). At some point I'll probably send a much larger Jool 5 mission, but that won't be for a while.

[sdj64]

On 1/12/2017 at 5:38 PM, DerekL1963 said:

Just curious, why not use a pair of PB-NUK's on the spaceplane instead of solar panels?

Not to mention that for a plane this size, two RTGs would be a significant extra bit of dead weight.  As it is it looks good and the shuttle style launch was very creative!

[DerekL1963]

I'm just concerned about solar at Jool...  I had big problems with that while I was developing my landers.

[septemberWaves]

On 1/16/2017 at 2:14 PM, sdj64 said:

As it is it looks good and the shuttle style launch was very creative!

I'm glad you liked it. I was considering using a drop-tank with extra liquid fuel and oxidizer, but I figured the shuttle would be more interesting.

On 1/17/2017 at 0:01 AM, DerekL1963 said:

I'm just concerned about solar at Jool...  I had big problems with that while I was developing my landers.

My Laythe plane can ascend on just battery power (I know because it's actually capable of being a Kerbin SSTO, it just couldn't then reach the parking orbit of Astarael III), and it can land with the limited trickle of power provided by the solar panels. The mothership has a lot of power storage so it should be fine. The Tylo and Vall/Bop/Pol landers use tiny RTGs, but knowing the power consumption and the way similar landers work I would guess that they are capable of landing and returning on their own battery power. I haven't actually tested any of them at their destinations because Hyperedit seems to cause difficulties and something else installed seems to be breaking the stock cheat menu, but I'm confident enough that they'll work.

[Mister Dilsby]

6 minutes ago, eloquentJane said:

My Laythe plane can ascend on just battery power (I know because it's actually capable of being a Kerbin SSTO, it just couldn't then reach the parking orbit of Astarael III), and it can land with the limited trickle of power provided by the solar panels. 

Jane, really like the design of that little spaceplane--however I think you may have more trouble than you expect with solar power in the Jool system. Remember, insolation drops off with the square of the distance from the sun, and Jool is quite distant. In addition, nights are very long on moons which are tidally locked to Jool. Also, eclipses happen with some frequency. Fun times!

I think you can still make it down and up, though. Do you even need batteries for descent? I don't believe control surfaces use electricity--maybe enable SAS, if you need it, but turn off all the reaction wheels which do draw power. Once you get to the surface, unless you have some sort of time constraint it doesn't matter how long Val is down there recharging batteries and transmitting science. Then, ascend to orbit

All my Jool landers do have at least one RTG stashed somewhere, for this reason. The mining shuttle has six large fuel cell banks as well, and the carrier has a couple of fission reactors ( a mod) to provide power for the life support system (also a mod). I remember doing a calculation at one point for how many Gigantors I'd need if I was going to do it all on solar--the ship would have ended up looking more like a man o' war in full sail  

[septemberWaves]

Refueling the Laythe Plane

An autonomous refueling vehicle is launched to Astarael III to refill the drained tanks of the Laythe spaceplane.

Spoiler

Liftoff is successful.

Booster cutoff and separation.

Main engine cutoff as 80km apoapsis is reached.

Fairing separation. The red tank is the propellant for the refueler, whilst the tanks above contain the fuel that is to be transferred to the Laythe plane.

Circularizing. The circularization burn will be started by the launch vehicle and completed by the refueler spacecraft.

First stage cutoff and separation.

Spacecraft engine ignition.

Circularization complete.

A rendezvous with Astarael III is plotted, and the relevant maneuvers are executed.

Approaching Astarael III.

Astarael III rotates to an optimal position for the docking maneuver.

Shutting down the main engine.

Docking is successful.

Preparing for fuel transfer.

The Laythe plane's fuel tanks are fully refueled.

Undocking the refueler.

De-orbiting.

 

Astarael III with the Laythe plane now fully fueled.

 

@Kuzzter My Laythe plane can fly without the extra solar panels. I tested it without them on Kerbin, and it can reach orbit exclusively on battery power. And you're right about it not needing power for the control surfaces. The static solar panels on the Laythe plane are mainly so that the power drains slightly slower than usual on descent. They're not technically necessary, they're just an extra redundant system. They also mean that the plane will still have some way of generating power if I make a mistake and damage the extendable solar panels.

Edited January 19, 2017 by eloquentJane