What planet (or moon) do you have the worst time landing on?

[SpenSpaceCorp]

On the note of landing on Jool, I was able to do it in a version some time ago. it was easy to land on the "surface" (I believe was 150 or 250 meters below "sea level") with parachutes, but would have been a different story trying to return to orbit.

[GoSlash27]

I'm going to buck the crowd and say Eve. It's reasonably easy to land safely there, I'm just never really confident that it'll happen where I intended. Plus you're doing it with a big fragile lander and no room for error in the DV budget.

Best,

-Slashy

[cantab]

I find Mun and Minmus landings routine. I sent a 65 ton boat to Laythe. I landed on Tylo in a ship of near-Whackjovian proportions and got the Kerbal back into orbit afterwards. I dropped a rover on Eve and drove about 50 miles (no return though). That was after the rover had stopped off at Gilly, where it worked well. I took a lander meant for the Mun and got it to Eeloo.

The worst place for me, then: Duna. Duna remains my nemesis. The atmosphere lulls me into thinking it will help, only to be as useful as a chocolate teapot. I've messed up aerobrakes, had chuted landers tear themselves apart on parachute opening, and powered landers slam into the surface. The one rover I did land I then crashed driving.

[PB666]

Yes, Tylo is hard, because of the huge gravity and the dV requirements. Laythe is not easy either because its so litle land and the land tend to be rugged, you also want to land close to water.

Eve has some of the same issues however easier to find good landing spots, main issue landing is that the parachute shock is so hard it might rip landers apart.

Takeoff from Eve is hard on the other hand

Always keep some fuel in your tank on re-entry to basically give some thrust just before shock occurs and landing. Keep an eye on the (McJeb) Vessel-total thrust because if you overdo your thrust you chute will fail.

- - - Updated - - -

You can thrust toward gilly and get rid of the thrust once there.

[ShadowZone]

Definitely Tylo. That little tyrant...

[Bill Phil]

Jool.

All craft I've sent have mysteriously exploded before hitting the ground...

[Owen5595]

1. Tylo

2. Moho

3. Gilly

[EdFred]

Once I started designing landers that can land on a 30 degree incline and not tip over, all of them are easy. I see some of your landers and I just shake my head. All of my landers are wider than they are tall. Since then, all the landable bodies are a cakewalk. Yes, even Tylo. I don't even bother to look for flat places to land. I avoid crater/canyon walls, and I just land wherever.

[Commander Jebidiah]

Just asking but for landing on Tylo could you not just use a skipper stage for descent and a nuke stage for ascent?

Disclaimer: ive never landed on TYLO;.; or laythe, moho, eve, ike, vall, pol, bop, eeloo or dres.

[EdFred]

Just asking but for landing on Tylo could you not just use a skipper stage for descent and a nuke stage for ascent?

Disclaimer: ive never landed on TYLO;.; or laythe, moho, eve, ike, vall, pol, bop, eeloo or dres.

For me, it's 4 aerospikes and drop tanks for Tylo. Although, everything I do is with 2 man lander cans now.

Edited February 23, 2015 by EdFred

[Cooly568]

Jool.

I've not really had trouble anywhere else if I plan for it.

[problemecium]

Eve: for some reason now matter how slowly I land, how flat the terrain is, or how many struts I include, the blasted ship always explodes and/or flops over on contact.

[Renegrade]

Jool.

All craft I've sent have mysteriously exploded before hitting the ground...

That reminds me of my mission to land on the Sun (with a probe). While looking for the "night side", I ran into an invisible wall that told me that my probe melted. Ugh. Dammit Squad, everybody knows about the night side of the Sun!! It shouldn't melt my probes!

For me, it's 4 aerospikes and drop tanks for Tylo. Although, everything I do is with 2 man lander cans now.

Ew aerospikes.

I created a specific power TWR chart (to replace my plain TWR chart) based on some info from Scoundrel:

PB-ION (0.23)      2.000 (  0.204g) (SP=41.24)
PB-ION (HN)        4.167 (  0.425g) (SP=85.93)
Vernor           150.000 ( 15.291g) (SP=103.11)
LV-N              26.667 (  2.718g) (SP=104.75)
PB-ION             8.000 (  0.815g) (SP=164.98)
LV1              133.333 ( 13.592g) (SP=189.85)
LV-909           100.000 ( 10.194g) (SP=191.49)
48-7S (HN)       120.000 ( 12.232g) (SP=194.44)
Poodle           110.000 ( 11.213g) (SP=210.64)
[COLOR="#FF0000"]Aerospike        116.667 ( 11.893g) (SP=223.40)[/COLOR] /thumbsdown
MK55R            133.333 ( 13.592g) (SP=235.68)
O-10             222.222 ( 22.653g) (SP=240.04)
LV-T45           133.333 ( 13.592g) (SP=242.23)
BACC             210.000 ( 21.407g) (SP=257.77)
S1 SRB-KD25K     216.667 ( 22.086g) (SP=265.96)
LV-T30           172.000 ( 17.533g) (SP=312.47)
24-77            222.222 ( 22.653g) (SP=327.33)
48-7S (0.21)     200.000 ( 20.387g) (SP=343.70)
Skipper          216.667 ( 22.086g) (SP=393.62)
Mainsail         250.000 ( 25.484g) (SP=441.90)
[COLOR="#00FF00"]48-7S            300.000 ( 30.581g) (SP=515.55)[/COLOR] /thumbsup
LFB KR-1x2       333.333 ( 33.979g) (SP=556.47)
S3 KS-25x4       328.205 ( 33.456g) (SP=580.14)
RT-10            500.000 ( 50.968g) (SP=589.20)
Sepratron       1440.000 (146.789g) (SP=707.04)
KR-2L            384.615 ( 39.206g) (SP=717.62)

My last Tylo lander featured a 48-7S and 909 hybrid design that worked well enough (the 909 was actually there so it could push a large fuel tank around more efficiently, unrelated to any descent/ascent activities)...

(Specific power is a blend of TWR performance and ISP. I put in the /thumbsdown and /thumbsup stuff as some people might not be able to see the color highlighting. All engine stats are current stats, unless there's brackets after them, which denote either the KSP version when that version of the engine was introduced, or if it's part of my Horrible Nerf mod (HN))

[Jouni]

(Specific power is a blend of TWR performance and ISP. I put in the /thumbsdown and /thumbsup stuff as some people might not be able to see the color highlighting. All engine stats are current stats, unless there's brackets after them, which denote either the KSP version when that version of the engine was introduced, or if it's part of my Horrible Nerf mod (HN))

What does the specific power of a rocket engine mean? It looks like it's the product of TWR, Isp, and a constant, but the constant doesn't seem to be anything other than a random number.

[EdFred]

Like Jouni, I have no idea what those numbers mean. And I don't want to glom on 6 48-7S engines for each aerospike. The 4xLV-909/'spike won't cut it either.

[LordFjord]

Hard landings? For me, definitely spaceplane landings on Duna. Lets just say the emergency chutes are used a lot - like each time

I've surely been there with a dozen different SSTOs, but not a single normal plane-like landing so far.

[Wabbit]

Tylo. It's like landing om Kerbin with no aerobraking or chutes.

[cantab]

Once I started designing landers that can land on a 30 degree incline and not tip over, all of them are easy. I see some of your landers and I just shake my head. All of my landers are wider than they are tall. Since then, all the landable bodies are a cakewalk. Yes, even Tylo. I don't even bother to look for flat places to land. I avoid crater/canyon walls, and I just land wherever.

A wide lander alone isn't enough to save you from tipping though. You need to also ensure you don't touch the ground with any significant horizontal speed, or you'll start to tip even in a wide lander. I think most novice lander tipovers are because of touching the ground while still drifting sideways, rather than by having an over-narrow ship.

And of course those of us who use FAR have a pressure to keep our landers fairly narrow. Though building the lander to go sideways in the fairing can work well.

[EdFred]

A wide lander alone isn't enough to save you from tipping though. You need to also ensure you don't touch the ground with any significant horizontal speed, or you'll start to tip even in a wide lander. I think most novice lander tipovers are because of touching the ground while still drifting sideways, rather than by having an over-narrow ship.

And of course those of us who use FAR have a pressure to keep our landers fairly narrow. Though building the lander to go sideways in the fairing can work well.

True, but I don't watch the ground when I am landing. I have my altitude above terrain readout from KER on the HUD, and only look at that, the navball, and TWR, during landing. Keep the retro marker pointed straight up and you don't haven issue with sliding sideways. Also, my last Tylo lander was narrower than the lifter and interplanetary stage it sat on, and had no trouble with the launch when I experimented with FAR this weekend. In fact, I had too much dV, and dropped an entire stage from the lifter, and was still probably 1000dV over what I needed. I don't have a screen shot of it right now, but just think 2man lander can with 4x symmetry cubic struts and -400 tanks with aerospikes with the HD landing legs, with an additional pair of -800 tanks on each side of the can. Then the drop tanks were the Rockomax 16's all stacked under the lander can. Those got jettisoned on descent save the last one - which gets dropepd on ascent. So while it's wide, it's not gigantically wide, just wider than it is tall.

[FleetAdmiralJ]

Well, if it's Laythe and space planes, that's definitely #1. I can't land planes well anyway, and trying to land it on the very hilly lands of Laythe is extra hard. But if I just need to land a capsule, it's not too bad.

If this includes actually GETTING to the body as well as landing, I would say Gilly is the hardest. In my current save I've been sending a few probes to series, and my failure rate even having enough dV to get to Gilly is about 50%, which is pretty high considering I tend to overbudget.

Tylo is definitely a challenge as well, but if you have the dV and the TWR necessary, it's very taxing but not necessarily difficult.

Edit. Speaking of landing on Tylo, I will just put this here...

http://www.twitch.tv/fleetadmiralj/c/4571446

Edited February 23, 2015 by FleetAdmiralJ

[Sampa]

Jool (jk, you can't land there...it's a gas giant!) I actually have no trouble landing anywhere since I rarely leave Kerbin orbit (too much of a hassle)

[Vectura]

Out of all the things I have actually landed on... The Mun. More gravity than Minmus, lacking the atmosphere of Kerbin, Eve, Duna etc. A complete pain in the arse.

[Renegrade]

What does the specific power of a rocket engine mean? It looks like it's the product of TWR, Isp, and a constant, but the constant doesn't seem to be anything other than a random number.

I picked it up from here:

Specific power for a rocket engine is calculated as (F*Ve/2)/mass in watts (I've listed specific power as KW/Ton), where F and Ve are calculated at Pa/Pe=1... which, since there isn't a Pe listed for the parts:mad:, I've just used vacuum stats as that is the peak F and Ve for the engine. That means specific power takes into account both TWR and Isp, and combines it into a handy number.

I used Thrust*Isp(vac)*9.82 / (2000.0*Mass). It has the same results as the chart he posted a few pages before that so I assume I haven't left anything out

(the 2000 is a combination of the /2 and converting between kg and tons (/1000). The only random value in here is 9.82, which is a number that vaguely looks like g0 if you squint hard enough)

Like Jouni, I have no idea what those numbers mean. And I don't want to glom on 6 48-7S engines for each aerospike. The 4xLV-909/'spike won't cut it either.

Basically a blend of TWR and specific impulse - I'm still working on the exact usage and scenarios, but trust me, an aerospike is not what you want. If you go to Tavert's charts, you'll notice that the high TWR charts are dominated by the KR2L and 48-7S (and you want a pretty good TWR for landing on Tylo, Kerbin local of ~1.6 by the time you're slowing down appreciably). I'm working up my own version of said charts so I can easily exclude engines (KR2L isn't exactly something I'd want to haul to Tylo unless I'm putting a really big base down there or something), but it's not ready yet.

Isp tends to be worshipped around here, but it isn't everything, and a difference of 350-380 to 390 is .. very small. The aerospike's high Isp is basically stomped flat by it's fat mass - let's say you have a 11.15 ton payload - it will take about 175kn to give that a good Tylo landing TWR, or one aerospike. On the other hand, it will take 6 48-7Ses to get that same thrust (slightly more thrust, actually). You'll then need 9.818t of fuel to land (total: 22.468 not counting tankage) with the aerospike, and the 48s will need 10.536t of fuel (total: 22.286). The lighter mass of the 48s (half) more than makes up for the extra fuel they take. (Note that I've left off the engine mass for TWR calcs - the final TWR is only 88.1% of the target TWR for the aerospike and 97.57% of the target TWR for the 6x48s)

John FX has updated Tavert's program with more up to date stats, and you can see the Skipper peeking in at points (and even the T30, although it has a very narrow niche). You don't even SEE the aerospike at all in the new charts until you hit the 'atmospheric' version (and 'atmospheric' gives away to 'vacuum' immediately on Duna, and within a handful of seconds on Kerbin). Looking at pre-NASA charts, the T30 used to be in the place of the KR-2L. (my next Tylo landing will probably involve T30s, in preparation for 48-7s nerfs~)

Random aside: I added in the 0.18 version of the Aerospike to my TWR chart thingy. Had to drop a 0 from the version number as it was too wide to fit~

PB-ION (0.23)      2.000 (  0.204g) (SP=41.24)
PB-ION (HN)        4.167 (  0.425g) (SP=85.93)
Vernor           150.000 ( 15.291g) (SP=103.11)
LV-N              26.667 (  2.718g) (SP=104.75)
PB-ION             8.000 (  0.815g) (SP=164.98)
LV1              133.333 ( 13.592g) (SP=189.85)
LV-909           100.000 ( 10.194g) (SP=191.49)
48-7S (HN)       120.000 ( 12.232g) (SP=194.44)
Poodle           110.000 ( 11.213g) (SP=210.64)
Aerospike        116.667 ( 11.893g) (SP=223.40)
MK55R            133.333 ( 13.592g) (SP=235.68)
O-10             222.222 ( 22.653g) (SP=240.04)
LV-T45           133.333 ( 13.592g) (SP=242.23)
BACC             210.000 ( 21.407g) (SP=257.77)
S1 SRB-KD25K     216.667 ( 22.086g) (SP=265.96)
LV-T30           172.000 ( 17.533g) (SP=312.47)
24-77            222.222 ( 22.653g) (SP=327.33)
48-7S (0.21)     200.000 ( 20.387g) (SP=343.70)
Skipper          216.667 ( 22.086g) (SP=393.62)
Mainsail         250.000 ( 25.484g) (SP=441.90)
[COLOR="#ff00ff"]Aerospike (.18)  250.000 ( 25.484g) (SP=478.73)[/COLOR] /OMFG~ /nerfplox
48-7S            300.000 ( 30.581g) (SP=515.55)
LFB KR-1x2       333.333 ( 33.979g) (SP=556.47)
S3 KS-25x4       328.205 ( 33.456g) (SP=580.14)
RT-10            500.000 ( 50.968g) (SP=589.20)
Sepratron       1440.000 (146.789g) (SP=707.04)
KR-2L            384.615 ( 39.206g) (SP=717.62)

Now you see why it was nerfed, and why the 48-7S is on the chopping block

I'd probably slip in a little mod to let you attach a decoupler to that old one, and use it EVERYWHERE. It's like an air-compatible 48-7S, but with 1/8th of the part count ! D:

TL;DR: Isp is like L/100km (or "mpg") in a car. Having a good number here is good - but it isn't everything.

[EdFred]

24 x 48-7S will not fit on my lander nicely. 4 aerospikes do. The aerospike IS what I want.

[Renegrade]

24 x 48-7S will not fit on my lander nicely. 4 aerospikes do. The aerospike IS what I want.

Well, if that's your favorite engine, that's your favorite engine, I guess.