Reusable Vessels

[LordKael]

So, I know there are tons of threads on all sorts of variations on the idea of reusable, including Scott Manley's Youtube series, and EJ_SA's Twitch stream with Condor 9 (Space X Falcon 9). My question is about the practicality of using a full reusable space program such that I can send infrastructure to a Joolian Orbital Station and be able to run missions on every moon without needing to keep shipping vessels and fuel and supplies from Kerbin. I'm playing fully stock atm, save for a handful of engines I modded myself. Any advice or building tips for reusable landers (for Tylo especially) would be greatly appreciated!

[suicidejunkie]

Well, for one, even if you have a permanent surface base for Tylo ISRU, your surface-orbit shuttle must either get fuel shipped in from other moons, or be capable of both landing & return (or return then land, then refuel which is the same difference).

I'd plan for both a surface base and a fuel depot in orbit to halve your dV requirement and allow much more reasonable size and payload.

 

Spaceplanes should be fun for Laythe.  Perhaps with pontoons so you can land in more places.

 

[cy4n]

A few tips for building reusable landers:

• Get rid of any mass you possibly can, and use the most efficient engine possible.
• The best way to land is to keep your vertical velocity at 0 while burning horizontal; when all your horizontal velocity is gone, land vertically with a suicide burn.
• Only about 5500 Δv is required to land on Tylo, spare no excess.
• Start in the lowest orbit you can; while this may sound counterintuitive, it actually decreases landing speed.

[LordKael]

6 minutes ago, suicidejunkie said:

I'd plan for both a surface base and a fuel depot in orbit to halve your dV requirement and allow much more reasonable size and payload.

I'm planning to have orbital stations around Tylo, Laythe, and Jool. 

1 minute ago, cy4n said:

• Only about 5500 Δv is required to land on Tylo, spare no excess.
•  

Is that for landing and returning to an orbit, or just to land??? Also, from what orbit does that number assume the vessel is starting?

[Aegolius13]

Jool is a tough destination for fully-reusable.  A few thoughts:

-Very large cargo SSTOs might help get stuff to orbit.  Or you could look at a Stratolaunch style airplane first stage, though this might take a mod to preserve the launcher.

-You'll probably want to refuel your craft before they leave Kerbin's SOI, either by going directly to the Mun or Minmus, or using a dedicated refueling system.  That way, you can either launch them empty, or (better still) use their fuel stores to get them into Kerbin orbit.  

-For the ejection burn, nukes nukes nukes

-Ion engines are great for puttering around Pol and Bop, but you can't resupply in situ.  

-With proper use of gravity assists on the way into Jool, you can get your injection burn down to almost nothing.  This can save a lot of mass.  

-Agree with @suicidejunkie that refueling on Tylo surface will save you a lot of trouble.  But landing in just the right spot would be pretty tricky on Tylo.  

-I think the 5500 delta-v quoted is to both land on Tylo and get back to orbit.  

-Vall, Pol and Bop are all viable sites for a Jool system mining operation.  Vall obviously takes more fuel to get on and off of, but the location is a lot more convenient.  Solar power will be limited so you may want to use a bunch of fuel cells to provide most of the power.  

Edited November 4, 2016 by Aegolius13

[natsirt721]

I would not set up a large-scale ISRU plant on Tylo or on Laythe, as the higher gravity means you're going to waste a lot of fuel just moving your fuel around.  Maybe a small plant used for refiling landers, or a lander with integrated ISRU.  Bop and Pol are attractive locations, as their low surface gravity and high orbits allow your tanker to aero- or gravity-brake down to the inner bodies with minimal fuel expenditure.  If Laythe is where your base of operations is, you can directly aerobrake there and save some time as well.  You are almost certainly going to need some large propellant storage on-orbit, unless your lander can handle a landing and takeoff from Tylo and Laythe with wetmass to spare for maneuvers.

If you're going reusable, I would design a 2-part lander.  The lander segment has 3.5-4kps dV with a small onboard ISRU plant.  This allows to land, refuel, and take off from any given body around Jool.  The second part would just be an NTR attached to a fuel tank.  This allows for more efficient orbit-to-orbit transfers around the system, and it can be refueled by the lander.  Keep in mind that the small drill has a minimum concentration value (2% IIRC) so you're going to want to ore-scan all the bodies before you land.  

[magnemoe]

8 hours ago, suicidejunkie said:

Well, for one, even if you have a permanent surface base for Tylo ISRU, your surface-orbit shuttle must either get fuel shipped in from other moons, or be capable of both landing & return (or return then land, then refuel which is the same difference).

I'd plan for both a surface base and a fuel depot in orbit to halve your dV requirement and allow much more reasonable size and payload.

Spaceplanes should be fun for Laythe.  Perhaps with pontoons so you can land in more places.

Has build an Tylo SSTO, yes it would need refueling in orbit and on ground, however its way easier to bring fuel from Pol than an new craft from kerbin. On Laythe you use atmospheric engines. 
Duna, Vall, Moho and the lower gravity bodies reusabliity is no huge issue if you have an small mining base. 
Eve is the only place reusablity is unpractical. 
It depend a bit on your objective, for planting an flag and going home while traveling as light as possible, you don't need reusablity, for gathering all the science you want on board isru, for moving between an ground base with isru and orbit you don't want it. 

[GoSlash27]

LordKael,

 If you want to go fully reusable (my personal preference), I recommend forgetting about Tylo. Any lander you come up with will either be too close to the DV margin to be safe or too thirsty to be practical. Single stage designs grow exponentially with DV budgets, and there is a hard limit to how much you can get out of one stage.

Assuming twice the bare minimum DV for landing (necessary for precision/ safety margin), you're looking at 13.5 tonnes total for each tonne of payload using the aerospike. This only gets you to the surface, so it requires ISRU on the surface and refueling in orbit.

Best,
-Slashy

 

[Kertech]

the rare times I do multiple missions to Eve or Tylo I tend to design a semi reusable ship. Orbital insertion and rendezvous stage with RCS, Lifesupport and coms, and an ascent stage which is expendable. It makes sense for all the extra stuff I have to make my games difficult. 

Eve and Tylo are pointless for resuable!

[cy4n]

16 hours ago, LordKael said:

I'm planning to have orbital stations around Tylo, Laythe, and Jool. 

Is that for landing and returning to an orbit, or just to land??? Also, from what orbit does that number assume the vessel is starting?

Landing and returning, in the most efficient way possible

[Starhawk]

This is my reusable Tylo lander.

It doesn't have much margin for error, so a Tylo landing can be quite harrowing.  But this craft can definitely do it.

Happy landings!

 

[Jhawk1099]

19 hours ago, LordKael said:

So, I know there are tons of threads on all sorts of variations on the idea of reusable, including Scott Manley's Youtube series, and EJ_SA's Twitch stream with Condor 9 (Space X Falcon 9). My question is about the practicality of using a full reusable space program such that I can send infrastructure to a Joolian Orbital Station and be able to run missions on every moon without needing to keep shipping vessels and fuel and supplies from Kerbin. I'm playing fully stock atm, save for a handful of engines I modded myself. Any advice or building tips for reusable landers (for Tylo especially) would be greatly appreciated!

Well this is very achievable. All you really need is a fuel resupply system. This could be achieved by a singular plant on one of the lower gravity moons (so you don't burn as much fuel getting to your station in orbit) with a bunch of engineers there so it doesn't take several years to get any substantial amount of fuel. A couple words of warning however... Watch your part count. I made a video a while back about a similar operation but in the kerbin system. My mining base on minmus quickly got into the 500's and my computer had trouble landing any craft next to it. Also a reusable tylo lander will have to have a load of delta v (I think around 7k) without being able to stage any parts and a twr>1 when full of fuel. This will be the most difficult part of your operation. I hope my input helps you out and if you want further help I'd be more than happy to lend a hand.