Completed Vikings in Space! (Kerbal Space Programme)

[Hellraiser]

Why do you need fuel lines at all?

I sent a ship to the Mun with 1 engine and ~17 tons of fuel, your Mjodhorn uses 3 engines which require more fuel, but no fuel lines.

Asparagus staging, it's more efficient as you ditch the dry mass of the side-mounted tanks and engines sooner. So more energy goes into propelling your craft rather than on getting a part you want to jettison up as the average fuel/total mass ratio during ascent increases.

The disadvantage would be in increased atmospheric drag, but Kerbal's atmospheric model is still a gross oversimplification of things so efficiency of asparagus staging isn't hampered much. That and if you're using side-mounted tanks (rather than top mounted ones) you're still going to get drag.

Unless I misunderstood the question.

 

[Ulminati]

Polant understands. No doubt due to stolen Kerman physics textbook from elementary school!

 

[Burning Bridges]

Adding 2 liquid engines that consume fuel from the central tank is not asparagus staging, it's just a complicated way of adding dry weight.

The LVT30 is imo the best engine for takeoff. A single LVT30 can lift 9 - 13.5 tons of fuel, depending on the payload. Anything less will result in higher acceleration, but decreased payload to orbit. If you want to get the most from a small rocket like the one Ulminati builds, you can not optimize acceleration, or end up with a rocket that has not enough fuel reserves. Ulminati pointed out himself that it did not work.

It would not be hard to build a ship that optimizes vmax with the 3 engines he uses, I reckon it should be pretty much in the 5000 m/s range, enough to reach Duna or Jool.

 

[Ulminati]

I'm reading up on the various KSP engines during lunchbreak today. Aerospike engines on the boosters seems like a promising idea. The VSP R&D department will draw up plans for the Mk 1 of the Löngböat transMünar delivery vehicle once I get home from work

 

[Hellraiser]

Yeah, but that was accidental as Ulm noted. I also lost track how many times I attached the fuel pipes wrongly or forgot to place them.

The problem with aerospikes is that they have no vector thrusting but you don't really need it when still in the atmosphere and winglets work. Also their thrust isn't all that good so the payload can't be too heavy. That and they kind of tend to overheat things.

 

[Burning Bridges]

Yes, in principle the idea is good, but if you reverse the fuel direction the result is the opposite of what you want.

I'd also suggest to add more fuel. I have just run a quick test with this ship and reached 6500 m/s with the unmanned pod. I have no time to run another test with the 1 man capsule, but it should still be good for 6000 or so.
Even if you add some more payload, it should be enough for most interplanetary stuff.

http://www.global-explorer.de/20121211/Phallus.craft

 

[Ulminati]

I think replacing the boosters on a Mjödhorn with non-vectored engines for additional thrust, fixing the fuel linkages and possibly replacing the LV-909 on the polse with a LV-N atomic rokkit engine might be sufficient. My current ascent trajectories are far, far from optimal. Lots of fuel is wasted.

Counting fuel tanks, the Phallus appears to have 2790 litres of liquid fuel compared to the 1620 litres on the Mjödhorn III. The payload also appears to be similar to that of a Mjödhorn II (slightly lighter since it has no silar panels, seperatrons or parachute). In Kerbin orbit Mjödhorn II functioned indistinguishably to a Mjödhorn I. (Slightly better actually, since I got a better gravity turn). Since the Mjödhorn III could make it to the Mün in spite of my inept piloting and fuel transfer management, I've to trouble believing the Phallus could too

But it's also worth considering that I really like messing about with rocket designs. I'd like to build something silly, highly entertaining and notoriously unreliable for sending SV off to the Mün in style.

 

[Burning Bridges]

Counting fuel tanks, the Phallus appears to have 2790 litres of liquid fuel compared to the 1620 litres on the Mjödhorn III. Since the Mjödhorn III could make it to the Mün in spite of my inept piloting, I've to trouble believing the Phallus could too

Why shouldn't it? You may have misunderstood some things about rocket design. It's not about minimizing fuel . Phallus could make it to any place in the solar system, with a normal payload (1 man capsule / lander etc).

 

[Ulminati]

Why shouldn't it? You may have misunderstood some things about rocket design. It's not about minimizing fuel . Phallus could make it to any place in the solar system, with a normal payload (1 man capsule / lander etc).

There's a gas station across the road from my office. At the time of writing, petrol is 1.63€ per litre. I'm minimizing fuel!

 

[Burning Bridges]

Well ok. I only wanted to point out that if the Phallus uses more fuel (I believe it's actually more like 34.5t), it will also get you a LOT further, for the price of slower acceleration.

In the end you will add more tanks, you will see ...

 

[Ulminati]

Bonus lulz -- I was trawling the KSP forums for a nice table to help me determine optimal gravity turn timings and ascent burn rates and came across this little gem. this is the kind of shit that turned CRPGs into Dragon Age 2 and FPS games into Codblops:

I guess the main reason I wouldnt buy this game is that its for "smart" people. I dont think I would get the full benefit of the total game.

It seems too hard to fly

Too hard to dock

And I dont understand the nav ball at all. In fact every craft I have in the demo makes it straight up in the air about 344,000m and then does nothing. How are you supposed to get in a circular orbit around the Earth?

And the flight controls make no sense. Either I go to turn and the thing goes the opposite way or the rocket spins out of control. The nav ball has no directions on it, just numbers.

Hurr durr where es quest compass!?

 

[Burning Bridges]

I guess that's the outpour of a 11 year old.
Personally I don't like their forum at all. If you go into the suggestions forum and suggest something like a new planet or supporting credit cards the thread will be locked after two posts.
There is not that much to discuss that way.

 

[Ulminati]

VSP TOP SEKRAT. CLEARANCE LEVEL ALPHA 2 AND ABOVE ONLY

BB, I have just recieved the initial readings from the classified "Project Löngboat". The telemetry is off the charts. It looks highly promising, but the directorate has some concerns about the risk of discarted Blutonium-238 fuel containers impacting near Polant. I expect a full report on calculated impact sites before I can clear large-scale testing.

I'll suppress press reports about "A great big Penis across the sky" as long as I am able. But we cannot keep the lid on this forever.

SC.

 

[Burning Bridges]

^ Zat is an impressive looking rocket, but too expensive.

 

[Burning Bridges]

"Macht Den Weltraum Frei!"

That thing above looks very impressive, and the performance should live up to expectations.

We however, offer a low cost alternative for everyone who is concerned about the ramjet prices, or the insane taxes in Kenmark. We looked at the basic design of the "Mjodhorn" and felt we could turn it into a rocket for everyone.

We present you our new "Volksrakete", which is able to bring an (almost) full FLT 800 tank into Kerbin orbit . We think that it's an ideal platform for cheap interplanetary flights.

The rocket is mass produced at Volkswagen and a basic model can be yours from as low as 150.000 Reichsmark.

http://www.global-explorer.de/20121211/Volksrakete_1A.craft

Please enquire for the custom made units from Focke Wulf.

 

[Ulminati]

You wouldn't believe how wobbly this thing is. It tears itself apart before reaching orbit in half my tests.

 

[Burning Bridges]

It shouldn't. Why don't you just play around with some struts?

I like the looks of it, actually.

 

[Burning Bridges]

And yes, the aerospike should be superior to the LVT-30.

 

[Ulminati]

Public press release, Viking Space Programme

As part of planned emergency procedure drills, a Kerbonautical Kraft was left to disintegrate in the Kerbin atmosphere early this morning. This was not - we repeat - NOT in any way, shape or form a thermonuclear attack on Polant. Kerbals are nonetheless advised to stay clear of any debris that may or may not make it to the surface as our scientific research indicates they may have picked up "residual radioactivity" from crossing flight paths with previous missions from the Koviet union.

If you hear loud explosions or see burning trails across the sky - DO NOT PANIC! Simply call the VSP toll-free number and we'll send a containment and recovery community participation team to the site.

 

[Ulminati]

I've managed to get the Löngboat stabilized, but it seems to have problems reaching orbit. I can get it out of Kerbins atmosphere using the first two stages and the nuclear engine should theoretically have more than enough fuel to do whatever the fuck I want then. But I continuously fail to reach the 2300m/s lateral speed I need to initiate a Low-Kerbin Orbit before passing apoapsis. Still practicing my gravity turn timings. I think that's the key to my failures. I was going to post a Löngboat fail extravaganza, but frankly, watching the same ascent over and over gets a bit dull.

 

[Burning Bridges]

Perhaps 4 tanks is not enough?

A NERVA adds a lot of extra weight, are you sure need it? I personally use the LV909, for "normal" purposes. Of course, for maximum performance, you should always go for the NERVA, but it will result in a heavier ship overall.

 

[TOME]

I guess the main reason I wouldnt buy this game is that its for "smart" people. I dont think I would get the full benefit of the total game.

It seems too hard to fly

Too hard to dock

And I dont understand the nav ball at all. In fact every craft I have in the demo makes it straight up in the air about 344,000m and then does nothing. How are you supposed to get in a circular orbit around the Earth?

And the flight controls make no sense. Either I go to turn and the thing goes the opposite way or the rocket spins out of control. The nav ball has no directions on it, just numbers.

 

[Ulminati]

Perhaps 4 tanks is not enough?

A NERVA adds a lot of extra weight, are you sure need it? I personally use the LV909, for "normal" purposes. Of course, for maximum performance, you should always go for the NERVA, but it will result in a heavier ship overall.

I wanted a nuclear rokkit.
Anyway, it turned out I simply needed to do a way, way earlier gravity turn than I was expecting. I managed to get to the Mün with plenty of fuel remaining and, well... Gotta sort through about a hundred screenshots

 

[Hellraiser]

My experience with NERVAs is that you should always try to get them as high as possible first and burn them at the standard 90 degree east heading (matching your prograde in periapsis) as early as you can if you want to get them into orbit. Although usually I launched them on monster rockets. The smallest one with a NERVA I ever made was the intended Perun Eve return lander. Four aerospikes+tanks around a middle Nerva stage for Eve escape and deorbit around Kerbin. Even that was ridiculously overpowered with the four aerospikes side-rockets.

 

[Ulminati]

UPDATE 5: NUCLEAR LAUNCH DETECTED

Spoiler

The following documents were leaked from the top secret VSP Skunkwërks R&D Labs


Projekt Löngboat - Nuclear Delivery System

Important: Burn these documents after reading. If this information ever got out, not to mention word on how many Kerbucks we spent on this program, we'd be the laughing stock of the Kerbalnautical Kommunity.

To test the feasibility of Löngboat, a new Kommand Kapsule was designed. This module contains everything necessary for controlling both manned and unmanned flights. A Kommand module, a probe core, solar panels, battery, parachute, safety seperation rings, ASAS stabilizers and a RCS system withpropellant.

As the stated purpose from the directorate is to land on the Mün and return, a liquid fuel engine and moderate tank was attached to the Kommand Kapsule unit, as well as landing gear.

The heart of the Löngboat is a LV-N Blutonium 238 Nukulear engine. To protect the Kerbalnaut and launch crew, it was necessary to construct this almost entirely out of lead. We're going to need a Lööööööng rokkit to get this thing off the ground.

A standard liquid fuel engine with vectored thrust completes the Löngboat main orbital stage. Tests showed that additional thrust was necessary to achieve liftoff.

Auxillary Aerospike engines were fitted to the Löngboat to build up a reasonable kruising speed. As well as steerable fins to help keep what our engineers affectionally refer to as "A god damn wobbly death trap" moving in a reasonably straight line.

The aerospikes proved insufficient to the task and were replaced with slightly more powerful "classic" liquid fuel engines. These, too, proved insufficient until we eventually just gave up and added a solid fuel booster stage.

Liftoff proceeded as planned. Some wobble was still present in spite of additional reinforcing struts

The SRBs got the Löngboat to 2.5km, at which point the liquid engines took over. The löngboat was still accelerating, but fuel was being drained rapidly in the auxillary tanks.

At 16.5km, the auxillery tanks were depleted and discarded. At this point we began our slow (ever so slow) gravity turn.

The main stage was *almost* sufficient to bring the Löngboat out of the atmosphere. Sadly, the ground speed was nowhere near what was necessary to bring the Löngboat into orbit. A LOT of Blutonium had to be burned as the Löngboat skimmed through the upper atmosphere.

Sufficient speed was achieved while still skimming the upper atmosphere and an orbit established. But at an exorbitant fuel expenditure.

8 minutes after launch, the Löngboat was a 5-second prograde burn away from having established an orbit around Kerbin. The material costs (including failed launch attempts) are estimated at roughly 4x the 5-year budget for the Polant space program.

Once the Löngboat no longer had to fight gravity and drag it proved highly efficient at its task. An orbital transfer to Mün still left the Löngboat with ample fuel reserves to perform orbital maneuvers. Conpare this to the Mjödhorn III, which had drained nearly all of its liquid fuel at this point and had to perform final adjustments using RCS thrusters only.

Approach to the Münar surface. After several costly maneuvers to establish an equatorial orbit rather than the nearly polar one the Löngboat somehow entered a landing site in the large equatorial crater was settled on.

The blutonium engine was discarded with a sliver of radioactive isotopes remaining to ease the maneuvering of the Kommand module. Since one of the useless interns had forgotten to switch off the RCS system during munar transfer, the module was entirely depleted and dependant on the ASAS gyro and liquid engine vectoring for maneuvers.

One small step for Viking. One giant leap for--

*boom* *crash* *bang*





Viking Space Skunkwerks internal memo


Björni.
This was the best image of our new ground research station on Mün we were able to salvage. Thankfully one of the solar panels ended up pointing upwards, so we can continue collecting measurements. But I highly doubt we'll be able to use it as a press photo.