Landing struts not long enough

[Spaceweezle]

How would I go about making these struts protrude enough without having some obnoxious draggy part ?

These are the longest struts I can use at the moment, as you can see, just a whisker short.

[Tex_NL]

Simple: use the translation tool to slide them down.

Just wondering. Where are you planning to send that tower? You might not need three engines.

[Gaarst]

The bigger landing struts are also longer, though heavier. You might want to consider using them.

[Clipperride]

I think my solution would be to build a squatter, but fatter lander stage. If you swapped the single long propellant tank for 4 smaller ones you could have one centrally and three radially mounted tanks. If you addthe Terriers to the radial tanks (or all 4, it's hard to see the number on your screen shot) and then fit the landing legs as low as you can (the bottom "mount" point of the landing legs will be sitting on the stripped line at the top of the engine) they just reach the ground.

If you want to keep the stage as is, I reckon you'll need to add some girder segments to use as attachment points. Yes, that will add to drag, but you are only in the atmosphere for the first few minutes of the mission (assuming you dump them before reentry)

One other option (especially if you are planing on a Minmus landing) is to land gently and do without the legs altogether. Your current design has quite a wide footprint which makes life easier.

[Spaceweezle]

Hey,

Thanks man, I had no idea such a thing existed.

This ship is going to land on Mun and return, I had already done just that with a single LV909 though there were some situations where I needed to rectify miscalculations with more haste. I opted for three LV909's because I need that bonus ISP to counter my ineptitude for making accurate burns, or sensible ones for that matter.

Thanks again!

Edit:

@ Gharst - These are the longest struts I have access to.

@Clipperide - That's an interesting idea. I might consider doing that if this translation thingy doesn't work right. The thought of landing without legs kinda scares me though.

Edited October 14, 2015 by Spaceweezle

[Mastikator]

You could land flat on the engines if you want, they break at >7m/s so just try a softer landing. You probably don't need radiators either, I'd get rid of those as well as the landing struts.

Edited October 14, 2015 by Mastikator

[Spaceweezle]

Those rads aren't for show. Like 90% of my missions end up with me re-entering at 2400+m/s, usually because I've run out of fuel.

At least this way I can guarantee safe re-entry, fuel or no fuel.

[Lynch]

*Design tip; build a thicker, shorter lander to avoid tipping off.

[Spaceweezle]

*Design tip; build a thicker, shorter lander to avoid tipping off.

If I recall correctly, that was what I used in early beta with the same Tri-coupler design shown above. It worked fabulously. I was just trying my hand at designing non-cookie-cutter lander's, if there is such a thing.

One benefit I am noticing with a longer overall rocket is more stability in atmosphere.

[Snark]

Those rads aren't for show. Like 90% of my missions end up with me re-entering at 2400+m/s, usually because I've run out of fuel.

At least this way I can guarantee safe re-entry, fuel or no fuel.

How are you entering? With care, should be able to handle it without radiators.

In particular: with a long skinny design like that, you can get quite a bit of lift just from the cylindrical fuselage of the rocket, even without wings. This lets you do a "spaceplane-style" reentry that keeps your altitude high (i.e. out of the barbecue zone) for a long time while you slow down.

Angle the rocket so that its body generates lift by deflecting air downwards-- i.e. the front (leading) end should be high, the trailing end should be low. Aim for ~30 degrees off of simple prograde/retrograde alignment. Does wonders; you should have no problem, as long as you avoid setting your initial periapsis too low.

[Clipperride]

Landing on the many Minmus flats is simple due to the very low gravity, but it is a little tougher on the Mun, but still very achievable on flat ground. It doesn't take much of a slope to make low, wide landers my craft of choice. Not always so easy in Career Mode though!

[Spaceweezle]

How are you entering? With care, should be able to handle it without radiators.

In particular: with a long skinny design like that, you can get quite a bit of lift just from the cylindrical fuselage of the rocket, even without wings. This lets you do a "spaceplane-style" reentry that keeps your altitude high (i.e. out of the barbecue zone) for a long time while you slow down.

Angle the rocket so that its body generates lift by deflecting air downwards-- i.e. the front (leading) end should be high, the trailing end should be low. Aim for ~30 degrees off of simple prograde/retrograde alignment. Does wonders; you should have no problem, as long as you avoid setting your initial periapsis too low.

Most of my returns to Kerbin result in me having to use atmosphere to reduce my Apoapsis by several million meters before I can enter under 3200m/s, I typically re-enter at 2400-2800 which causes most ship components (including the ship itself) to combust)

Until I have enough fuel efficiency to be able to retro burn down properly, rads are always included.

[Val]

Maybe you could try one of these designs?

The left one has more fuel. The other 2 have same amount of fuel as yours. The right one can decouple the tanks and legs after leaving Mun, but only has one engine. They're all shorter, wider and the legs can touch the ground.

[Snark]

Most of my returns to Kerbin result in me having to use atmosphere to reduce my Apoapsis by several million meters before I can enter under 3200m/s, I typically re-enter at 2400-2800 which causes most ship components (including the ship itself) to combust)

Until I have enough fuel efficiency to be able to retro burn down properly, rads are always included.

But that's my point-- at low speeds like that, you can manage without radiators if you use aero lift to help your re-entry. Getting fried happens because you get too deep into the atmosphere while still going too fast. Using aerodynamic lift helps to keep your altitude up high until you've bled off the deadliest of your speed.

It won't work for super-fast reentry (e.g. coming home from Jool)-- you'll need a heat shield for something like that. But it works just fine for coming home from Mun or Minmus; up into the low 3000's is no problem at all.

Of course, if using radiators works for you, then by all means go to it. Just pointing out that there's an alternative, which can save you a bit of mass and drag on your lander.

[Pecan]

Some errors (the correction of which will greatly supplement your facility with exo-atmospheric transportation of all varieties. I'm in loquacious mood):

1. 3 909s do not give you "bonus ISP". They all have exactly the same ISP because they're the same engines. They REDUCE your deltaV because although you have the same ISP you have to carry around more mass to get it (three engines instead of one). The only thing three engines gives you is more thrust.

2. Radiators are not good for re-entry. If it's 2,400 degrees OUTSIDE (alright, you said m/s, but I'm making a point) the last thing you want is radiators bringing it inside. Hint: heatshields are insulators

[Spaceweezle]

But that's my point-- at low speeds like that, you can manage without radiators if you use aero lift to help your re-entry. Getting fried happens because you get too deep into the atmosphere while still going too fast. Using aerodynamic lift helps to keep your altitude up high until you've bled off the deadliest of your speed.

It won't work for super-fast reentry (e.g. coming home from Jool)-- you'll need a heat shield for something like that. But it works just fine for coming home from Mun or Minmus; up into the low 3000's is no problem at all.

Of course, if using radiators works for you, then by all means go to it. Just pointing out that there's an alternative, which can save you a bit of mass and drag on your lander.

By "Aero-lift" you mean having draggy parts to minimize aerodynamics ?

I have experimented with flying horizontally and found most of my science modules were overheating. If I re-enter retrograde they are shielded by the engine and other components that are more heat resistant. Is there a better way to use Aero-lift than flying horizontally ?

Some errors (the correction of which will greatly supplement your facility with exo-atmospheric transportation of all varieties. I'm in loquacious mood):

1. 3 909s do not give you "bonus ISP". They all have exactly the same ISP because they're the same engines. They REDUCE your deltaV because although you have the same ISP you have to carry around more mass to get it (three engines instead of one). The only thing three engines gives you is more thrust.

2. Radiators are not good for re-entry. If it's 2,400 degrees OUTSIDE (alright, you said m/s, but I'm making a point) the last thing you want is radiators bringing it inside. Hint: heatshields are insulators

No, I meant "bonus ISP" for vac comparative to other engines. Perhaps I should have phrased that differently.

As far as the game is concerned, Radiators dissipate heat. I can visually see them constantly depleting heat from all components, reminds me of a 55 monk in Guild wars lol. I have yet to see my Radiators transferring heat into the object on which they are attached. Since they weigh a measly 1 kilogram and save me from blowing up, I don't see the problem.

- - - Updated - - -

Maybe you could try one of these designs?

http://i.imgur.com/xFxOWAM.png

The left one has more fuel. The other 2 have same amount of fuel as yours. The right one can decouple the tanks and legs after leaving Mun, but only has one engine. They're all shorter, wider and the legs can touch the ground.

Pretty cool designs. I actually didn't think to add tanks between Tri and the engines.

At least your legs are working better than mine. I landed on Mun and blew all three engines on a pointy bit lol.

[Snark]

By "Aero-lift" you mean having draggy parts to minimize aerodynamics ?

I have experimented with flying horizontally and found most of my science modules were overheating. If I re-enter retrograde they are shielded by the engine and other components that are more heat resistant. Is there a better way to use Aero-lift than flying horizontally?

A typical "direct" reentry for a ship like yours (i.e. without a heatshield) is to go bass-ackwards, with the ship pointing directly retrograde and leading with the engine. This is because A) the engine is often the most massive component, so the craft is aerodynamically stable that way, and it's also usually the most heat-resistant part.

I'm not sure what you mean by "horizontally"-- what I'm saying is to adjust the ship's attitude by around 30 degrees, so that the nose isn't pointing straight backwards, but rather is pointing somewhat downwards.

This causes the incoming air stream to hit the underside of your ship, which generates lift.

It's true that this means that any radial components on that side will take a dose of heat, but in practice, I find that it's not a problem. The main danger is to science instruments, since they're both expensive and not very heat-resistant. But that's easily solved by just mounting them all on the same side of the craft, and making that the top side rather than the underside during reentry-- so the angled entry actually shelters them.