[stock][medium orbital][controlled lander] The Medusa

[Darkshadow]

Introducing the new Darkside industries class 300 'Medusa'.

This medium orbiter is designed to get up to orbit and have plenty of fuel left over for manoeuvres (improved controllability to be added soon with additional RCS). Topping that off the Medusa has its characteristics hooded wing-let design, that allows a 3:1 glide slope to allow controllability in all stages of the return, although not intended to be landed in such a way (Our brave test pilots committed the ultimate sacrifice to find out) the craft has enough manoeuvrability in the final stages of decent to flow close to the coast before jettisoning the capsual.

View of the lander stage:

Lander on glide slope:

[Kosmo-not]

Lifter needs more thrust for the first stage. It was a pain to get it into orbit because it handles like a brick. After getting it into orbit, I checked fuel quantity, which led me to my next decision: as long as I had it up there, might as well...

[Darkshadow]

Lifter needs more thrust for the first stage. It was a pain to get it into orbit because it handles like a brick. After getting it into orbit, I checked fuel quantity, which led me to my next decision: as long as I had it up there, might as well...

Now that is impressive, that stage is hard enough to handle for orbit manoeuvres yet alone landing on the mun! Did you mange to return? Gliding down is the most fun part! (Why can I only design good landers and gliders?)

[Kosmo-not]

I didn\'t bother doing a return because I knew it had plenty of fuel to do so. Thus, I haven\'t tested the orbiter in the atmosphere yet.

[Seanoog]

DarkShadow.

A very good ship, I enjoyed taking off, an getting into orbit.

Also had one of the most un-eventful landings on the Mun with a balanced design, until I broke an engine on a hill.

I rated it as 4, because its a very good ship, but with a few modifications it could be better.

I say better, since I have my old Enterprise NX-01 Design (Can be found on the forums, some where), which are almost identical, I can see your design could possibly have been inspired by it.

However I do believe your Medusa design is probibly completly original on your part.

If I can find the craft file, I will post it here for you, an your welcome to reverse engineer it, as development on my design is complete...

Medusa evaluation:

I was inspired by your lack of struts, saving weight an all, but it was wobbly in orbit.

- Especially the 9 LFE\'s, were wobblying an been amplified by the winglets, this also had a knock on effect to the entire ship, as it resonated.

I found, that on one occasion your ship, completely toppled over, even with ASAS engaged, going straight up? No idea how it happened.

It was sluggish, to maneuver when above 20KM, with thin atmosphere, perhaps another RCS tank an 3 thrusters on the highest Tri-coupler module.

The launch stage, could do with a kick start with some SRB\'s on each outer column.

PS- this should be classed as a Mun Craft, as it had little trouble getting there.

[Darkshadow]

DarkShadow.

A very good ship, I enjoyed taking off, an getting into orbit.

Also had one of the most un-eventful landings on the Mun with a balanced design, until I broke an engine on a hill.

I rated it as 4, because its a very good ship, but with a few modifications it could be better.

I say better, since I have my old Enterprise NX-01 Design (Can be found on the forums, some where), which are almost identical, I can see your design could possibly have been inspired by it.

However I do believe your Medusa design is probibly completly original on your part.

If I can find the craft file, I will post it here for you, an your welcome to reverse engineer it, as development on my design is complete...

Medusa evaluation:

I was inspired by your lack of struts, saving weight an all, but it was wobbly in orbit.

- Especially the 9 LFE\'s, were wobblying an been amplified by the winglets, this also had a knock on effect to the entire ship, as it resonated.

I found, that on one occasion your ship, completely toppled over, even with ASAS engaged, going straight up? No idea how it happened.

It was sluggish, to maneuver when above 20KM, with thin atmosphere, perhaps another RCS tank an 3 thrusters on the highest Tri-coupler module.

The launch stage, could do with a kick start with some SRB\'s on each outer column.

PS- this should be classed as a Mun Craft, as it had little trouble getting there.

Thanks for the review. I know that it can reach the mun but most powerful rockets can, I wouldn\'t class it as a mun design though as it wasn\'t designed with that in mind. Secondly, yes the tri-coupled engines were based off someone\'s design I forget whom. Given the number of stock components and the types of symmetry I am not surprised that more designs appear similar.

I save on struts as it wrecks my fps. The toppling is a common problem with some of my larger designs, I think it\'s due to the centre of mass shifting as the fuel is used up. I\'m surprised as I had not occurred in my testing of the Medusa. Perhaps this is due from using 2x warp, I find that some designs sometimes do weird things they wouldn\'t do on a 1x warp.

[Seanoog]

Thanks for the review. I know that it can reach the mun but most powerful rockets can, I wouldn\'t class it as a mun design though as it wasn\'t designed with that in mind. Secondly, yes the tri-coupled engines were based off someone\'s design I forget whom. Given the number of stock components and the types of symmetry I am not surprised that more designs appear similar.

I save on struts as it wrecks my fps. The toppling is a common problem with some of my larger designs, I think it\'s due to the centre of mass shifting as the fuel is used up. I\'m surprised as I had not occurred in my testing of the Medusa. Perhaps this is due from using 2x warp, I find that some designs sometimes do weird things they wouldn\'t do on a 1x warp.

Sadly I am unable to find the craft file for my old Enterprise NX-01 ship, on the forums or my hard drive.

I\'d be happy to recreate it from memory, time after time, after time, after time of developing its design I am confident I could build it accurately from memory. =P

Building them now, as its annoying me I lost there designs...

The time your craft toppled over, it deffinitly was at 1x warp, I always fly in orbit with 1x.

[closette]

Hi Darkshadow,

I just had a fun ride with your ship - thanks for sharing it!

By way of review:

1. I second the motion to add more SRBs for launch. You may need two sets, which you can easily fit on such a tall first stage. At least 6 for launch and perhaps another 3 to take over after they are done and jettisoned.

2. For a fuel-efficient ascent through the atmosphere, a good set of rules-of-thumb that I have found is (write-up in preparation):

i. Get up above 100 m/s as soon as possible. You need an initial Thrust/weight ratio > 2 for this (which means you should pull at least 2gs). That should tell you how many SRBs to strap on for launch!

ii. By 5000 m, you should be going up at about 165 m/s. By 10000m, 270 m/s. A little above or below is OK, but much below that and you\'re wasting fuel and time.

iii. After 10000m, the 'optimum speed' rises exponentially and is almost impossible to keep up with, but you should certainly not be slowing down at any point in the ascent. (Your ship doesn\'t, I just included that for completeness).

3. In-orbit maneuvering of the tall stack was very slow. With the current atmospheric model there is no 'drag penalty' for mounting tanks sideways instead of stacking them. That\'s a big design change, but it would reduce your ship\'s rotational inertia (i.e. make it easier to point in the desired direction).

Oh, and please add some struts already! They are a tiny fraction of the mass and will allow us to use x2 time warp without the whole thing ringing like a bell!

4. I didn\'t go to the Mun, but played around with orbital rendezvous/docking practice after jettisoning the last stack in orbit. I am terrible at it, but had a lot of fun trying. Your ship will be my go-to 'rendezvous trainer' from now on!

5. After re=entry I had no idea how to control the glider, but had fun meandering around as it fell. The ground track would have looked very odd. It\'s a great idea all the same and a pleasant change from 'drop \'n pop' (chute, that is).

Hope some of this helps, and if you could post a new .craft file incorporating some of the suggestions on this thread I shall be first in line to try it!

I voted 4 stars out of 5 (-1 star for the slow inefficient launch).

[Seanoog]

Hi Darkshadow,

I just had a fun ride with your ship - thanks for sharing it!

By way of review:

1. I second the motion to add more SRBs for launch. You may need two sets, which you can easily fit on such a tall first stage. At least 6 for launch and perhaps another 3 to take over after they are done and jettisoned.

2. For a fuel-efficient ascent through the atmosphere, a good set of rules-of-thumb that I have found is (write-up in preparation):

i. Get up above 100 m/s as soon as possible. You need an initial Thrust/weight ratio > 2 for this (which means you should pull at least 2gs). That should tell you how many SRBs to strap on for launch!

ii. By 5000 m, you should be going up at about 165 m/s. By 10000m, 270 m/s. A little above or below is OK, but much below that and you\'re wasting fuel and time.

iii. After 10000m, the 'optimum speed' rises exponentially and is almost impossible to keep up with, but you should certainly not be slowing down at any point in the ascent. (Your ship doesn\'t, I just included that for completeness).

3. In-orbit maneuvering of the tall stack was very slow. With the current atmospheric model there is no 'drag penalty' for mounting tanks sideways instead of stacking them. That\'s a big design change, but it would reduce your ship\'s rotational inertia (i.e. make it easier to point in the desired direction).

Oh, and please add some struts already! They are a tiny fraction of the mass and will allow us to use x2 time warp without the whole thing ringing like a bell!

4. I didn\'t go to the Mun, but played around with orbital rendezvous/docking practice after jettisoning the last stack in orbit. I am terrible at it, but had a lot of fun trying. Your ship will be my go-to 'rendezvous trainer' from now on!

5. After re=entry I had no idea how to control the glider, but had fun meandering around as it fell. The ground track would have looked very odd. It\'s a great idea all the same and a pleasant change from 'drop \'n pop' (chute, that is).

Hope some of this helps, and if you could post a new .craft file incorporating some of the suggestions on this thread I shall be first in line to try it!

I voted 4 stars out of 5 (-1 star for the slow inefficient launch).

Thank you closette, will look forward to your write up.

Firstly -Have you considered for fuel efficent flying?

I find I get, more Total distance by setting a throttle setting that only has me, only just accelerating. Rather than FULL Throttle brute force approach.

An it gives you better control, an time to react

Secoundly -Do players really judge re-entry crafts? I haven\'t really spent much time developing mine.

What do people look for?

Dark Shadow.

Please find included my ENTERPRISE-01 craft.

It originally began development over 4 months ago, so its well revised.

Please feel free to reverse engineer it... for your Medusa Mk2

I\'d like to bring special attention to the 4 winglets on the launch stage, they increase Roll rate + increase control in atmo.

The SRB\'s are grouped in fours with winglets to keep temps in control, will happily fall away when jettised, an shouldn\'t hit the tri-couplers.

Also give the launch stage that extra kick, it needs.

I have secured the launch stage tri-couplers as low as possible on the last tank, to reduce vibrations + secured them to the centre tri-coupler.

Engage the centre tri-coupler stage half a tank before the outer launch stage runs dry.

You should achieve 70KM circular orbit with 15+ Full tanks.

Any think more about this craft I can update you about I will do..

Will create a new thread shortly show casing the ENTERPRISE-01 craft in full.

Will also create other threats as I am nearly finished my TRIDENT-1 craft... 8)

[closette]

@Seanoog,

I have in fact spent considerable time on the fuel efficiency problem, not that I\'m an expert, but the rules-of-thumb seem to be borne out.

IF you were climbing through a uniform-density atmosphere, the most fuel-efficient speed would be the spacecraft\'s terminal speed with no additional acceleration. So I agree with you there.

However (1) you need to get up to that terminal speed (~100 m/s near Earth\'s surface) as quickly as possible and (2) the atmosphere isn\'t uniform density, so as you pass from one 'slab' into a less dense one, you need to accelerate a bit to keep up with the increasing terminal speed.

The terminal speed of most spacecraft as a function of altitude y is about 100 m/s exp(+y/9900m). That means the required acceleration to keep up with it is given by dv/dt = v dv/dy = 1.0 m/s exp(+y/4950m), which starts out small (1.0 m/s) but gets close to 1g by the time you reach 11000 m.

I do need to write this up (like my tagline says, accept nothing on authority) but need to find the time to do so.

P.S. I was first to download your ENTERPRISE-01 craft and will give it a whirl later. Thanks for providing it.

[Darkshadow]

Oh, and please add some struts already! They are a tiny fraction of the mass and will allow us to use x2 time warp without the whole thing ringing like a bell!

Hi Closette, thanks for the review. Also nice work with the maths. My problem with adding more struts is that they really reduces my fps, thought it is slightly less of a problem now thanks to the latest patch, so I will get on with experimenting with more struts.

[closette]

@Seanoog,

I tried your Enterprise, didn\'t quite understand the staging, and ended up with this 'headless' Mun landing.

I think you need one more stack decoupler between the tank with the 'lander' fins and the final stage engine. Otherwise it flew just fine.

[Seanoog]

@Seanoog,

I tried your Enterprise, didn\'t quite understand the staging, and ended up with this 'headless' Mun landing.

I think you need one more stack decoupler between the tank with the 'lander' fins and the final stage engine. Otherwise it flew just fine.

How did you manage to land it like that?

I am afraid, I neglected to mension it wasn\'t intended as a Mun landable craft. (My bad)

However, how did you find the craft apart from this over sight on my part?

Please remember, this is an old design, an I rarely make my craft like that any more, did if fly true?

Did it leave you with ample fuel to complete orbital transfers? Single burn to the moon?

Does it stand, as a good guide to help DarkShadow improve his Medusa design, which is the reason why I post it on this thread.

Importantly where does it need improving?

Mun landable - Priority.

[closette]

ENTERPRISE - I had fun with the craft - plenty of liftoff thrust (in fact one has to throttle back a bit to avoid overheating). On subsequent relaunches it fell apart on the pad under its own weight. I\'ve had craft do that, and I guess it\'s a feature of KSP? Sometimes reloading the craft in the VAB helps.

On ascent it was very stable, even at 2x warp.

On pitchover it seemed to suffer from 'adverse roll', even when almost out of the atmosphere. I\'ve noticed that most large ships do that, and I think some threads have commented on that. It took some RCS and joysticking to keep at 90 degree heading.

Other than that, staging went fine and that\'s a big mass to put into orbit. The Mun landing was 'just because', and ended up that way by pure chance. I doubt I could do that again!

Thanks for sharing it.