Landing on Laythe

[W. Kerman]

Hello.

 

I was wondering what the lightest craft you ever made that can get into Laythe orbit is. Also, tips on Laythe landings would be appreciated. 

 

Thanks! W. Kerman

[IncongruousGoat]

4.88 t, using a rapier first stage, twitch second stage, & a chair inside a service bay *ahem* budget command pod (mass not including deorbit stage). However, I'm completely sure someone better at aerodynamics & atmospheric flight than I could come up with something significantly lighter. Jet engines are tricky, I tell you.

As for landing... heating is negligible, so don't worry about that. For picking a site, trial, error, and blind luck are fairly effective, if tedious. Parachutes are always good as a means of not turning your lander into an explosion. If you can build spaceplanes, one of those is a pretty good bet, due to the oxygen atmosphere and all. Just, whatever you do,  remember to make your vehicle aerodynamically stable. Seems a lot of people (including myself) underestimate the thickness of Laythe's atmosphere on ascent.

[Aegolius13]

I just built a  Laythe SSTO for about 7.6 tons.  It had way more than enough fuel to get to orbit, so I bet the mass could go down at least a ton.  It was a nice little plane with some amenities (real cockpit, no staging, control surfaces), but some of those you can cut if weight is paramount.  

I can't find a link to it at the moment, but @Nefrums did a legendary Jool 5 mission where the ENTIRE CRAFT weighed like 10 tons at the start.  So whatever he used for the Laythe portion is probably close to the lowest possible mass.  

 

As far as tips:

-You want a relatively low stall/takeoff speed due to the thin air and bumpy terrain.  Generally this means using more wing, and angling the wings, more than you would at Kerbin.

-Also due to the thin air, control surfaces are not as effective as on Kerbin.  Reaction wheels work comparatively better, though.  

-Rapiers are a little slower to start, but actually work well longer into the atmosphere and should be able to get your apoapsis into space. 

-As far as landing technique, it's tricky to even find an island, let a lone a level patch on one.  Trial and error may be needed to find the right descent path.  I generally err on the side of overshooting, since you can slow your plane down or turn around for free, but if you come up short you have to burn fuel.

-Don't be too picky on landing sites, especially if your plane is relatively small.  You don't need a perfectly flat site, and in any event, almost anything is going to be less bumpy than the unimproved Kerbin runway.  

[Nefrums]

30 minutes ago, Aegolius13 said:

I can't find a link to it at the moment, but @Nefrums did a legendary Jool 5 mission where the ENTIRE CRAFT weighed like 10 tons at the start.  So whatever he used for the Laythe portion is probably close to the lowest possible mass.  

Not entierly true. That was a Rapier/ion lander, and those engins where used for other things as well, like kerbin ascent.

A dedicated Laythe lander with a panther as a first stage and a spark as second stage would probably be the lightest.

It is sometimes better to land on low autetude on Laythe. As the airbreathing engins get alot more thrust on sea level than they do at 5km. And it is easier to get to the speeds where engins like panther/whiplash/Rapier works best if you start at sea level.

[Ripper2900]

Note that Laythe's atmosphere may be shallower than Kerbin's, and the density is lower at sea-level. But from about 10000m, it's in fact denser! 

This implies that you can use jets at higher altitudes before flameout, but you get HOT if you accelerate to orbital speeds with jets in the middle altitudes. 

I advise that you do a slow initial ascent followed by a relatively steep final ascent to get out of that drag and heat quickly. 

[Wjolcz]

What do you want to land? If your payload is a probe only then go for a heatshield+parachute combo. If something more complicated it might be good thinking about an SSTO.

[Monkey Taylor]

I know how to get to Laythe, but I struggle with making rocket designs so bad I can only just abouut get onto a 87ap 75pe orbit of kerbin

Edited November 26, 2016 by Evenus