Feedback on wide Mun lander

[suicidejunkie]

I think the RCS idea might be to have SAS turned on at touchdown, so the RCS thrust will automagically be used to stop impact-induced rotation. 

If you've got a pilot aboard to provide the SAS, then Shirley the pilot will have at least 1 star and could have been doing the simple technique of retrograde-hold during the braking burn to eliminate horizontal speed.  So there is no need for RCS at all.

 

[mk1980]

simple and ugly, but gets the job done.

 

might be a good idea to swap the service bay and material lab and put the lab below decoupler. these things blow up very easily during reentry now.

nosecones on the boosters might help if you have trouble keeping it straight during ascent and add only ~1k to the cost.

 

Edited May 6, 2016 by mk1980

[herbal space program]

20 minutes ago, suicidejunkie said:

I think the RCS idea might be to have SAS turned on at touchdown, so the RCS thrust will automagically be used to stop impact-induced rotation. 

If you've got a pilot aboard to provide the SAS, then Shirley the pilot will have at least 1 star and could have been doing the simple technique of retrograde-hold during the braking burn to eliminate horizontal speed.  So there is no need for RCS at all.

 

A  fair point, but in my defense I learned how to fly landers long before this option existed. My whole point was just that RCS is basically there to facilitate these sorts of small maneuvers, and it most certainly does make things easier for inexperienced pilots, so I don't understand why one would want to tell OP, who is already having problems staying upright on landing, to get rid of it and presumably just learn how to fly better. I certainly never meant to imply it was essential. Also, having an exactly retrograde approach will not change what happens if you land on a slope, so there would still be some benefit to having more SAS power. Anyway, this seems to be  turning into some sort of liquid fuel jettisoning contest now, so I will bow out. Maybe OP can let us know later what ultimately solved their problem, ala Stump the Chumps..

Edited May 6, 2016 by herbal space program

[RizzoTheRat]

2 hours ago, ToukieToucan said:

what did your launch vehicle look like?

Unusual 

The side boosters got it almost to a stable orbit (so the boosters didn't end up as orbital debris) and used the nuke to circularise.  It then pushed the tanker section to Minmus, landed in every biome, and still had enough fuel left to make it to the mun and land in 2 biomes there.

I was quite pleased with that mission

[herbal space program]

6 minutes ago, RizzoTheRat said:

Unusual 

 

 

 

That's a very nice ship! That super-wide design is sort of overkill for the Mun, but on ultra low gravity bodies like Minmus I'll bet it makes landing ever so much quicker. Thinking about it, the design reminds me of Pilae, which had the same problem to contend with.

Edited May 6, 2016 by herbal space program

[Clubbavich]

I think the problem with the OP's original design is that with 1.1, the landing legs are physically shorter. Shorter than they appear to be. They sink below the surface before they physically "land". The engine doesn't do that though... That craft was sitting on its engine. If it wasn't for that, it would have been fairly stable.

To make those legs reach the ground past the poodle, the attachment point of the legs needs to extend past the bottom of the fuel tank if they are to actually work as expected. That was a rather annoying thing I learned first hand....

Easy to test, put just the lander out on the launch pad and see if the engine is touching the pad or not. If it's not, then you're good to go. If it is, the legs need to be lower.

Edited May 6, 2016 by Clubbavich

[RizzoTheRat]

51 minutes ago, mk1980 said:

might be a good idea to swap the service bay and material lab and put the lab below decoupler. these things blow up very easily during reentry now.

Agreed, in the early game I don't bother recovering the materials bays, EVA to collect the data and then return with just pod, it makes re-entry a lot easier as you have a nice stable craft and don't need a heat shied (at least, you didn't in 1.05, dunno if the Mk1 pod can handle it from a Mun/Minmus orbit without a heatshield in 1.1.x

Edited May 6, 2016 by RizzoTheRat

[Norcalplanner]

29 minutes ago, Clubbavich said:

I think the problem with the OP's original design is that with 1.1, the landing legs are physically shorter. Shorter than they appear to be. They sink below the surface before they physically "land". The engine doesn't do that though... That craft was sitting on its engine. If it wasn't for that, it would have been fairly stable.

To make those legs reach the ground past the poodle, the attachment point of the legs needs to extend past the bottom of the fuel tank if they are to actually work as expected. That was a rather annoying thing I learned first hand....

Easy to test, put just the lander out on the launch pad and see if the engine is touching the pad or not. If it's not, then you're good to go. If it is, the legs need to be lower.

Or you can remove the Poodle and put on a Terrier. The combo of a rockomax 16 plus a terrier is a great power section for a Munar lander. Gives lots of extra delta v for biome hops and a nice wide base for landing. In the OP example, I'd echo those who suggest removing the adapter to save mass and lower the CoM for the lander.

[Clubbavich]

36 minutes ago, Norcalplanner said:

Or you can remove the Poodle and put on a Terrier. The combo of a rockomax 16 plus a terrier is a great power section for a Munar lander. Gives lots of extra delta v for biome hops and a nice wide base for landing. In the OP example, I'd echo those who suggest removing the adapter to save mass and lower the CoM for the lander.

I agree that there are other, more optimal options, but I wasn't intending to critique the OP's ships, I just wanted to point out a bug that very likely caused their problems. They didn't need to completely redesign their lander, they just need to make one small tweak and it would have been probably good enough for their purpose.

[mk1980]

2 hours ago, RizzoTheRat said:

Agreed, in the early game I don't bother recovering the materials bays, EVA to collect the data and then return with just pod, it makes re-entry a lot easier as you have a nice stable craft and don't need a heat shied (at least, you didn't in 1.05, dunno if the Mk1 pod can handle it from a Mun/Minmus orbit without a heatshield in 1.1.x

a service bay is a good substitute for a heat shield. those things have ridiculously high heat resistance (i think 2900K or something along that line). if there's a few batteries and (expensive) science sensors in the bay, it's usually a good idea to keep the service bay below the capsule.

[Vanamonde]

This exchange of spacecraft has been moved to Spacecraft Exchange. 

[Waxing_Kibbous]

A nice cheap-o way to make a lander more squat while including the Sci Jr is to attach a terrier to the bottom of the Sci Jr, radially attach fuel tanks to the Jr, and use fuel lines to the terrier, like so:

[RizzoTheRat]

Just done my first Mun landing of my 1.1.2 career.  Had previously done a flyby to get low and high Mun science and unlock the Skipper, which makes launching a lot easier, but I've used pretty much the same lander design for the last few careers.

Radial tanks gave enough dV to get from LKO to surface (almost, as you can see on 3rd pic), and the center tank had more than enough to get home.  A more efficient pilot could probably get away with a FL-T100 instead of a 200 in the middle but I didn't want to take the chance.  Radials should have been dumped for the trip home, but I forgot so wasted fuel there.  Pilot grabbed the data from the materials lab and goo canister then jettisoned the bottom part and re-entered with just the capsule.

 

 

Edited May 7, 2016 by RizzoTheRat