Jool 5 on a bigger scale

[Nefrums]

It was a long time since I posted a mission report here, but this will be my most complex mission to date so I thought that it deserved it's on thread.

The Ultimate Jool 5 Challenge with KScale64

KScale64 is a mod that increases the size of the Kerbol system by x6.4.   All planets have 6.4 times the radius and ~41 times the mass. So surface gravity remained unchanged.

This is closer to our real solar system that is 10 times bigger (100 times the mass) than the default Kerbol system.

The main challenge here is the effect this has on dV requirements, they are ~2.5 times larger.  For instance geting to LKO is closer to 8000 m/s dV rather than the standard 3000 m/s dV.

I will be using any part mod allowed by The Ultimate Jool 5 Challenge.

To do list:

1. Design a Tylo lander ~13 000 m/s dV   Done
2. Design a Laythe lander  Done
3. Design a Vall Lander with a reusable last stage ~ 5000 dV  Done
4. Design Kerbal return stage  Done
5. Estimate mothership dV requirements.  Done
6. Design mothership for transfers within Jool  Done
7. Design a LKO escape stage for mothership ~5000 dV  Done
8. Figure out how to get the ship to LKO  Done
9. Fly the mission Ongoing

 

Album of the ongoing mission:   http://imgur.com/a/BiSNM

 

 

Tylo Lander:

Can land and return to orbit with a little help from EVA.  Also included is a nuclear stage with 2100 dV to get from high elliptic orbit to low Tylo orbit, and a small return craft with simmilar dV to get back up to the mother ship.  

 

Laythe lander:

Reentry on Laythe is harder when orbital velocity is close to 6000 m/s. But this is handled by the inflatable heat shield that also acts a flotation device.  The last two stages are the same as on the Tylo lander.   It has enough dV to get to a high elliptical orbit of Laythe where the mothership will be parked.

 

Edited September 9, 2016 by Nefrums

[Nefrums]

I have now designed a simple small two stage lander for Vall, the upper stage will be reused for Bob and Pol.

 

I went back and did some changes to the tylo lander in order to make it shorter to make mother-ship design easier:

Edited September 7, 2016 by Nefrums

[Nefrums]

I have done some estimates of dV requirements for the mothership based on my previous jool5 missions.

LKO -> Laythe   5000
Laythe -> Tylo   100
Tylo -> Vall     100 
Vall -> Pol      900
Pol -> Bop       800
Bop -> Kerbin   1500

This is including extensive use of gravity assists within Jool SoI, but includes a direct Kerbin -> Jool transfer.   The dV requirement for LKO -> Laythe can be cut in half if I can figure out a way to fly the K->E->K->K->J route in the scaled up kerbin system 

[Mister Dilsby]

Ambitious--and what a fantastic idea to use your Vall upper stage for Bop an Pol!

[Nefrums]

45 minutes ago, Kuzzter said:

Ambitious--and what a fantastic idea to use your Vall upper stage for Bop an Pol!

Thanks.

It saves a bit of weight and as a Bop lander only requires ~1500 m/s dV   it was very easy to do.  Every ton counts when you have the insane dV requirements to transport it.  The mother-ship alone will need 8500 m/s dV (+7500m/s dV to get to LKO), and that when dragging 60t worth of landers most of the way.

 

[septemberWaves]

Perhaps for transporting your mothership to Kerbin orbit, it may be beneficial to construct it from several modules. This is within the rules since any number of launches are allowed for constructing the vessel in Kerbin orbit, and it seems to make more sense in this case than figuring out how to construct a launch vehicle that can lift the whole vehicle and landers to orbit at once.

[Nefrums]

25 minutes ago, eloquentJane said:

Perhaps for transporting your mothership to Kerbin orbit, it may be beneficial to construct it from several modules. This is within the rules since any number of launches are allowed for constructing the vessel in Kerbin orbit, and it seems to make more sense in this case than figuring out how to construct a launch vehicle that can lift the whole vehicle and landers to orbit at once.

Yes, I think that I have to do that.  It would be very hard to lift the whole thing in one go, even with the 5m boosters parts from spaceY.

Initial plan is to launch landers and return craft in one go and then the transfer engine section.   I might even have to launch them unfueled. 

 

.

 

  

[septemberWaves]

For payloads of several hundred tonnes, I find that a 5m stack with the biggest SpaceY engine cluster usually does the trick. As for the upper stage, the Nova from Vanguard Astrodynamics provides a 1g acceleration for about 500 tonnes of stuff, and you can mount it inside a SpaceY interstage adaptor to keep the 5m width. And if the first stage engine doesn't have the thrust or delta-v you need, stick a Fenrir SRB on each side and thrust limit them until you have controllable acceleration but with enough delta-v.

Of course, asparagus staging is another option, but I personally dislike using it too much because SRBs and a taller first stage can often be more effective.

Edited September 7, 2016 by eloquentJane

[Nefrums]

We'll see,  It would not be a problem to put a 1000t ship in orbit on one go on stock Kerbin, but the dV to get to LKO is ~7500 m/s with Kscale64.

 

[septemberWaves]

SpaceY Extended is allowed right? That may help out a bit.

[Nefrums]

3 hours ago, eloquentJane said:

SpaceY Extended is allowed right? That may help out a bit.

Unfortunately it is not.

 

But it turns out that that was not a problem, 7x 5m cores in asparagus config followed by 4 of the large 3.5m nukes got the complete ship into orbit.

 

In orbit, the three outer nukes tanks are almost spent but the center one is full and will get the ship to Jool!

And it will only take 5266 m/s dV and 6 years...

Edited September 7, 2016 by Nefrums

[Nefrums]

Just realized that I forgot to add the second pair of droptanks to my Vall lander.   They where supposed to add another 1300 m/s dV that was needed to go from a high elliptic orbit and back again.  My mother ship does not have the 1300 extra m/s dV to drop of the lander in low Vall orbit.

 

[Nefrums]

I went back and redesigned the engine section for the mothership.  It now has 5 quad nukes.

 

I have started the mission and done one landing: 

Reentry on Laythe was really hard, I had to make extra pass through the atmosphere before the final descent to avoid the heat shield overheating. Reentry speed was ~6500 m/s, and that is when starting in Laythe orbit.

[Nefrums]

Full album of the mission so far including Laythe landing and ascent. http://imgur.com/a/BiSNM

[DBowman]

9 hours ago, Nefrums said:

and done one landing:

I love the inflatable solution for re-entry and launchpad. 

[Nefrums]

Yes, it turns out that a large inflatable heat shield makes for a good flotation device. 

[Nefrums]

Another landing done. Main album updated.