Landing on Kerbal far targets

[SNDThunderfist]

What is the best approach to getting to distant ground targets on Kerbal for missions?

I have tried

• rockets, reentry, chute, but tend to not be close enough
• Airplane, but run out of fuel on the way. (The target is half way around Kerbal)

What works for this type of mission?

 

[Mahnarch]

Space planes, or anything in your general space and/or plane genre.

[MR L A]

You're running out of fuel with an aeroplane? 

Points to a few things ranging from bad design to bad flying. Post some images of your craft/find some threads about efficient flying and builds

[Laie]

6 hours ago, SNDThunderfist said:

What works for this type of mission?

Only getting there, doesn't matter if you ever can get back? For that, I've had great success with Dyna-Soar like thingies.

Notice that the rocket has much bigger wings than the plane on top. That's important.

It doesn't need to be a much of a plane: a command pod, something for a bit of fuselage, and a pair of winglets will do; even if you can't glide properly, but can merely control the direction of your fall, this will already give you a 10-20km circle around where you'd have come down with an uncontrolled pod. For scale, that's about the distance between the launchpad and the mountains.

And if it's a one-way mission, I'd say to not bother with wheels. A rolling landing will make design and execution a lot more complicated. Parachutes, however, are easy -- just rip the cord as you fly over the target area for an instant stop and descent.

--

EDIT: The Poor Man's Dynasoar. Doesn't require any particular skills beyond the basics of making orbit, and gets the job done nicely:

 

Edited August 30, 2018 by Laie

[Aeroboi]

@LaieGetting a airplane back to the KSC never covers the cost for the time it takes to retrieve it in which time one could have done a entire other contract. So my advice to the TS is to not recover your air/spaceplane in any case.

@SNDThunderfist With very early tech using a Juno it is easy to get to the other side of Kerbin with reserve fuel if you take some practice into building airplanes.

There are a lot of tutorials on building small space or airplanes. A typical craft for your purpose is a mk-1 cockpit with 2 junos on a Mk0 liquid fuel fuselage with small circular intakes on either side. Another 1 juno at the back on a FL-A10 adapter that is connected to a mk1 liquid fuel fuselage behind the cockpit.
2 elevons at the back (pitch), 1 elevon at the back (rudder), 2 wings either side (whatever is available) which each have 2 elevons for roll.
Then 2 x LY-01 at the front just under the wing and a LY-05 at the tail (tailsitter aircraft)
That is 21 parts. So you can still tug in a service bay with goodies in between the cockpit and the liquid fuel fuselage.

End result is small lightweight aicraft with 3 junos that can do sub 300 m/s at 10-11km altitude. Use Mechjeb autopilot to keep her there. The higher you can fly, the more gas mileage you get because the air gets thinner. The result is that you have fuel to spare and may just circumnavigate.
You can also put small incidence on the wing during construction (wing incline) that lessens drag so you can go a little faster higher up.

 

 

Edited August 30, 2018 by Aeroboi

[DualDesertEagle]

2 hours ago, SNDThunderfist said:

Airplane, but run out of fuel on the way. (The target is half way around Kerbal)

Usually just that and usually, if piloted correctly, the Aeris 3A already carries enough fuel to fly half-way around the planet (at least talkin' about 1.0.2, not sure if that's still true in the latest versions).

so unless the ratio of fuel consumption per range for 2 liquid fuel tanks and 1 Wheesley has changed, go with that and fly efficiently. Or build something like my flying wing that I used to circumnavigate Kerbin:

That thing carried more than enough fuel to do a full lap around kerbin (keep in mind I was going EAST and not west!) and still shuttle between the KSC and the old island base a few times.

[bigcalm]

The key to creating a long-range plane is down to aerodynamics.  You want your plane as slippery as a fish in normal flight, which basically means simple wings, not too many control surfaces and no sticky-out bits.  That way you can go faster using less fuel as you go.  For these purposes, you want a Mk1 form-factor plane - definitely not Mk2 which is significantly more draggy.  You probably want reasonably powerful engines - Junos are ok, but I prefer Wheelseys.

Kerbal Engineer can sort of calculate how far you can go, as long as you know your rough top speed (accounting for the fact that it'll be lower when fully loaded with fuel and higher when nearly empty).

Given Kerbin's radius is 600km, then the distance to travel round it is 2*pi*radius = 3.7 million metres

In the screenshot below, it's telling me that my Mk1 plane with weird bits from a few mods attached (but it is mostly stock, the forward bits are mostly due to the fact I didn't have access to any canards in career at the time), at a speed of around 500ms (which due to experiment, I know is the average speed) has a burn time of 2h23m = 8580 seconds.   8580 * 500ms = 4.3 million metres.

From the maths, I can see that I should be able to circumnavigate Kerbin and return with a little bit of fuel left.

I know from experience this is correct - I can take that design, fly it to the north pole, land, fly to the badlands on the other side, land, fly to the south pole, land, and return to KSC with around 5-10% fuel remaining.  Naturally, YMMV.

 

 

 

Edited August 30, 2018 by bigcalm
er, Kerbin's radius not Kerbal's radius. That'd be like, er, a few centimetres?

[Gargamel]

Not to sound rude, but a point of order:

Kerbal:  Little green dude.

Kerbin: Home planet of the Kerbals.

Kerbol:  The sun (unofficially). 

 

Carry on!

[DualDesertEagle]

19 hours ago, bigcalm said:

 definitely not Mk2 which is significantly more draggy.

Are u sure about that? Going just by the looks I'd say my Mk2 flying wing is more aerodynamic than ur plane.

[qzgy]

1 hour ago, DualDesertEagle said:

Are u sure about that? Going just by the looks I'd say my Mk2 flying wing is more aerodynamic than ur plane.

Mk2 fuselages are notoriously draggy. Although I'm not quite sure how much more draggy it is and if it is significantly less or more draggy. Would need to do proper testing for that.

[Gargamel]

1 hour ago, DualDesertEagle said:

Are u sure about that? Going just by the looks I'd say my Mk2 flying wing is more aerodynamic than ur plane.

Your real world physics have no power here!

[DualDesertEagle]

11 hours ago, qzgy said:

Mk2 fuselages are notoriously draggy. Although I'm not quite sure how much more draggy it is and if it is significantly less or more draggy. Would need to do proper testing for that.

I think I'll stick to making Mk2 flying wings anyway coz I think they look nice. Using the big airliner wings with fuel tanks in 'em gives me all the range I need and even without them I've made a flying wing that can fly half-way around kerbin and go to lots of survey locations. Even flies well with just one Wheesley engine. But as soon as I unlock the big wings I'll replace the structural ones and basically make the same plane that I've already shown u. 

[Scarecrow]

There have been quite a few global circumnavigation challenges in the past.  You could always do a search for 'circumnavigation' in the challenges thread to see what designs people have used, and take inspiration from those.  Most of the challenges have insisted that participants stay within the atmosphere or below a specified height, so the entries have been aircraft.  If your own aircraft are running out of fuel then it's just a question of tweaking the design, as it's definitely possible to fly half way round Kerbin and back again.

[DualDesertEagle]

9 hours ago, Scarecrow said:

There have been quite a few global circumnavigation challenges in the past.  You could always do a search for 'circumnavigation' in the challenges thread to see what designs people have used, and take inspiration from those.  Most of the challenges have insisted that participants stay within the atmosphere or below a specified height, so the entries have been aircraft.  If your own aircraft are running out of fuel then it's just a question of tweaking the design, as it's definitely possible to fly half way round Kerbin and back again.

The best design doesn't work tho if fuel is wasted by pilot error, which ranges from flying in too thick air to too heavy maneuvering, so the best thing u can do is have a plane that levels out at the ideal speed without SAS (which would keep the plane oriented the same way for longer, creating a bigger oscillation in altitude) at let's say 10 000 meters. That way u wouldn't even have to disable the SAS from time to time to let the nose drop back to level flight and pick up speed again.

[Gargamel]

15 hours ago, DualDesertEagle said:

I think I'll stick to making Mk2

My Kerby sense is tingling, but I believe somewhere in the 1.3-1.4 range, the mk2's became very draggy.    Since you're still playing 1.0, the mk2 may actually be better.   But I will admit, for aesthetics, they are my personal favorite. 

[DualDesertEagle]

9 hours ago, Gargamel said:

My Kerby sense is tingling, but I believe somewhere in the 1.3-1.4 range, the mk2's became very draggy.

I wonder why they did that coz to me Mk2, properly put together, looks much more aerodynamic than 1.25 m, plus it provides some lift which allows u to build nicer looking planes in general.