Manned, career Duna round trip

[GoSlash27]

Duna generally favors Terriers and Poodles over LV-Ns, especially if you refuel and depart from low Munar orbit. I'll knock together a design for you if I get the chance...

Best,
-Slashy

 

[GoSlash27]

Okay, so I worked out designs for 2 mission profiles.

Profile 1 departs low Kerbin orbit, retroburns at Duna, detaches a lander with a 5t payload limit and remains in orbit. Then rendezvous with the lander, recover the crew, burn for Kerbin aerobraking, and detach a recovery pod.

Profile 2 is the same as 1, except the ship first travels to low Munar orbit, tops off it's tanks, and departs for Duna from there.

The lander itself would use parachutes and a couple hundred m/sec DV for landing and 1300 m/sec for takeoff.

This makes, with the 5t payload, a 9.2t assembly with 1 LV-909.

The Profile 1 propulsion for the mothership has a few different masses/ price points to choose from .

3x LV-N.       33.0t, $33,000
1 Aerospike 36.0t, $9,400
3x LV-909     36.6t, $6,900
1 Poodle       36.7t, $5,300

The profile 2 propulsion is much simpler.

2x LV-909     19t, $3,200

HTHs,
-Slashy

 

 

[JacobJHC]

On 1/6/2017 at 11:26 PM, Squidiness said:

Can anyone post a screenshot of a minimal, Manned, and Duna-round-trip-capable rocket

There are several rockets in here that qualify as minimal but it sounds like this might not be what you're looking for. I am posting it anyway to maybe help.

[Sharpy]

1.) Should I do it Apollo style, leaving one guy in orbit with a crap ton of fuel and loading the other side onto a lander?

Up to you. Makes sense if you want a fancy lander and a fancy station in orbit, and send a lander to LKO to retrieve crew and science and leave the lander in Duna orbit. Otherwise, the same lander as for Duna can be used for Kerbin landing. Just make sure to repack the chutes

2.) I'm not good with docking, nor can I get mods, so can I do this in one launch?

You need to learn to do rendezvous. Docking can come later, but if you get the crafts close, you can transfer kerbals and science through EVA.

3.) Should I bring an ISRU converter along with me? If so, where should I have it (in the lander or in the orbiter)?

The ISRU and drills should be on the lander, and should STAY ON DUNA. You really don't want to haul all that ore to Duna orbit. In this case orbital base makes less sense. If your lander can get from Kerbin to Duna with the ISRU, it sure as heck can get from Duna to Kerbin without the ISRU.

 

[AeroGav]

On 07/01/2017 at 4:26 AM, Squidiness said:

 

. Can anyone post a screenshot of a minimal, Manned, and Duna-round-trip-capable rocket just so I can get an idea of how much fuel I need? Because ^this thing obviously didn't make the cut. I almost always overestimate the amount of fuel required to get somewhere — even if it's by a little bit — but never have I underestimated fuel the requirements of a specific mission

 

Not a rocket, but this is a self contained duna mission with no rendez vous required.   Just take off and land, take off and land , done.   I won't pretend it was easy to construct, getting the thing to handle right full tanks vs empty tanks, staged vs unstaged, took a lot of tuning.  Then again, i've never built a rocket that can do a Duna mission either, so i wouldn't really know.

 

[Squidiness]

On 1/9/2017 at 0:30 AM, Garrett Kerman said:

Yes. You might want to disable one set of engines, or else you aren't going anywhere. A couple of sugguestions:

1. Only one set of engines is needed. This is the 'propulsion module' (fancy language for a few fuel tanks and an engine). This should be launched and docked to the rest of your ship. You may want to launch a refueling mission to fill up it's tanks.

2. Get rid of that IRSU. With a ship of that size, it is absolutley pointless and only acts as a deadweight. Also, four drills is huge overkill. If you really want the IRSU, bring the 1.25 meter one, two small drills, and two radial ore tanks. Those two you're bringing are too big for your needs. Also, make sure to bring lots of power and some radiators too if you want the IRSU and the drills to work. Really, just don't bring any of that. All it is is deadweight.

3. Pack efficent engines. Get rid of those thuds. They are inefficent and not very helpful. Replace that skipper engine with a poodle engine. The poodle is more efficent, and therefore requires you to pack less fuel.

4. Pack parachutes. Duna has an atmosphere, so you should use it. Parachutes can slow down your lander quickly, meaning you use less fuel on your decent. 

5. Rid yourself of half the monoprop. If you split four tanks between the lander and the crew module, you should be in good shape. All that extra propellant won't be used and will only become deadweight.

If anything was confusing, feel free to ask me for clarification.

1. got it

2. Wait a second, there's a 1.25m ISRU? I really need to update KSP

3. I got LV-N's now, and they got me to Ike and back with only a few units of monoprop left to spare

4. got it

5. got it

Thanks for reminding me to update KSP! I don't know how to update though.... oh, well....

Edited January 19, 2017 by Squidiness
[quote name=Morgan Freeman]I can smell you[/QUOTE]

[Squidiness]

12 hours ago, AeroGav said:

Not a rocket, but this is a self contained duna mission with no rendez vous required.   Just take off and land, take off and land , done.   I won't pretend it was easy to construct, getting the thing to handle right full tanks vs empty tanks, staged vs unstaged, took a lot of tuning.  Then again, i've never built a rocket that can do a Duna mission either, so i wouldn't really know.

 

Are you kidding me? There's no way in heck I could launch a behemoth like that. I actually performed an Ike Round-Trip recently (Duna would cost too much deltaV for takeoff and orbit) with a moderately-sized lander attached to a huge "propulsion module" with 4 1.25m-wide half-sized duel tanks, an orange fuel tank, and 4 LV-N's, and apparently, the LV-N's didn't live up to their reputation of being very efficient, because they hardly got me out of Kerbin's SOI. So all the way from 100km above Kerbin, to Ike's surface, and then all the way back to Kerbin's Oceans, I was using up the fuel reserves of the lander, and I finished the final burns with monoprop, and the whole time I had a calculator out trying to find the very best transfer windows, and I returned to Kerbin from Ike with much less than 1000m/s of DeltaV left (somewhere around ~600m/s), which was, to me, nothing short of a miracle.

Quote

 

I can smell you

Edited January 19, 2017 by Squidiness
Nacho business

[AeroGav]

1 hour ago, Squidiness said:

Are you kidding me? There's no way in heck I could launch a behemoth like that. I actually performed an Ike Round-Trip recently (Duna would cost too much deltaV for takeoff and orbit) with a moderately-sized lander attached to a huge "propulsion module" with 4 1.25m-wide half-sized duel tanks, an orange fuel tank, and 4 LV-N's, and apparently, the LV-N's didn't live up to their reputation of being very efficient, because they hardly got me out of Kerbin's SOI. So all the way from 100km above Kerbin, to Ike's surface, and then all the way back to Kerbin's Oceans, I was using up the fuel reserves of the lander, and I finished the final burns with monoprop, and the whole time I had a calculator out trying to find the very best transfer windows, and I returned to Kerbin from Ike with much less than 1000m/s of DeltaV left (somewhere around ~600m/s), which was, to me, nothing short of a miracle

It's a self launching spaceplane that takes off from the runway.. it takes off with a whiplash engine that is jettisoned at flameout height, then uses the lv-n after that.  Not really for career though - the big S wings it uses are 1000 tech cost parts deep in the aviation tree

Surprisd about your duna mission struggling.  You do realise the lvn doesn't use oxidizer, so an orange tank to fuel it would be carrying loads of useless oxidizer?

Also did you use a launch window planner to get a good launch date?  I used to just eyeball it and would end up using 2 or 3 times as much delta v

Edited January 19, 2017 by AeroGav

[Squidiness]

On 1/19/2017 at 2:27 AM, AeroGav said:

It's a self launching spaceplane that takes off from the runway.. it takes off with a whiplash engine that is jettisoned at flameout height, then uses the lv-n after that.  Not really for career though - the big S wings it uses are 1000 tech cost parts deep in the aviation tree

Surprisd about your duna mission struggling.  You do realise the lvn doesn't use oxidizer, so an orange tank to fuel it would be carrying loads of useless oxidizer?

Also did you use a launch window planner to get a good launch date?  I used to just eyeball it and would end up using 2 or 3 times as much delta v

I'm actually really far in the tech tree, and I have those already. I also realized, however, that the Fuel lines in the tug were going the wrong way, which was my problem XD. The mission succeeded anyway, though. All that Fuel left over in the tug was not wasted though, because it had SAS and everything, I was able to transfer Fuel from the big tank to some smaller ones the LV-N's were attached to, and I flew REALLY close to Moho, and eventually crashed into the sun, you know, for fun, and !!SCIENCE!!

Edited January 21, 2017 by Squidiness
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