Do wings have any effect on planets/moons with low gravity/no atmosphere?

[Neil Kermstrong]

Might be a dumb question but I want to know because I am building a minmus outpost and got the idea of a vtol miner rover, and I want to land it a stylish/easier way: using it's engines to get lower down speed but higher side speed and glide until the ground

You can tell I don't know anything about aerodynamics

Edited September 20, 2020 by Neil Kermstrong

[m4v]

Wings won't produce lift without an atmosphere.

[Cattette]

To add upon this, wings have mass. So it's not a good idea to bring wings along if you don't plan to use them.

[Neil Kermstrong]

1 hour ago, m4v said:

Wings won't produce lift without an atmosphere.

 

2 minutes ago, Cattette said:

To add upon this, wings have mass. So it's not a good idea to bring wings along if you don't plan to use them.

damn I just landed in minmus's flats with wings and now I think they're the reason my vtol was losing control every time I thrusted

luckily I had a reaction wheel

[Gargamel]

5 hours ago, m4v said:

Wings won't produce lift without an atmosphere.

 

4 hours ago, Neil Kermstrong said:

damn I just landed in minmus's flats with wings and now I think they're the reason my vtol was losing control every time I thrusted

They didn't do anything on minmus.   If you were losing control of your Vtol, it's because the thrust wasn't balanced properly. 

[Grogs]

31 minutes ago, Gargamel said:

 

They didn't do anything on minmus.   If you were losing control of your Vtol, it's because the thrust wasn't balanced properly. 

Right, balancing a VTOL craft is quite a bit harder than a traditional craft with the engine at the bottom. And as the fuel level changes, so to does your center of mass.

Some suggestions are:

- Put your fuel either in the center (with equal weights fore and aft) or at the ends so that the center of mass doesn't change much with fuel level

- Put the large Vernor thrusters at the front and back of the craft and turn on RCS so they will help hold your attitude

- Use engines with plenty of gimbal range

- Lots of reaction wheels can help, but things might get ugly if you dock to a large station

- If all else fails, reduce the thrust to the set of engines on the side that's tipping up

- On low gravity worlds like Minmus, you might consider a design that lands with a regular rocket on the tail and then tips forward onto wheels/landing gear. You may still need some small engines on the front to tip the nose back up for liftoff.

[Entropian]

7 hours ago, Neil Kermstrong said:

Might be a dumb question but I want to know because I am building a minmus outpost and got the idea of a vtol miner rover, and I want to land it a stylish/easier way: using it's engines to get lower down speed but higher side speed and glide until the ground

You can tell I don't know anything about aerodynamics

Wings work by creating a pressure differential across the top and bottom of the wing.  Bernoulli's principle turns that pressure difference into force, which is the lift.  On planets that have an atmosphere, aerodynamics will play a large part in the design of a craft.  On planets that have no atmosphere, there's no pressure, so no Bernoulli, so no lift.  Also, there's no such thing as a dumb question.

 

[Fraktal]

2 hours ago, Grogs said:

On low gravity worlds like Minmus, you might consider a design that lands with a regular rocket on the tail and then tips forward onto wheels/landing gear. You may still need some small engines on the front to tip the nose back up for liftoff.

Last time I built a Mun-capable SSTO (Whiplash/Nerv),  I mounted a monoprop tank and a few Puffs to the bottom. I handled the deorbit and descent with the Nerv main engines then when I was about 500 meters above the surface and descending slowly, I flipped over belly-first, extended the landing wheels and used the Puffs to VTOL down. For takeoff, I expended the rest of the monoprop with the Puffs to give myself a kick upwards and get rid of the monoprop's dead weight, then fired the Nervs horizontally to begin circularization, rather than try to do a takeoff roll on the Nervs alone and risk crashing/tailstriking due to uneven terrain.

In munar gravity, achieving >1 TWR with Puffs requires so little thrust that the reaction wheels I included for maintaining a belly-first reentry profile were more than enough to cancel out any torque the Puffs might've caused.

[Neil Kermstrong]

Thanks for the help and tips guys

The vtol's only purpose was to land my rover anyway

[Spricigo]

 

15 hours ago, Neil Kermstrong said:

got the idea of a vtol miner rover, and I want to land it a stylish/easier way: using it's engines to get lower down speed but higher side speed and glide until the ground

First lets get or terminology correct. If you are planing an almost horizontal landing, that is not Vertical Take Off and Landing. on the other hand, the traditional craft @Grogs mention are VTOL.

Now, wing will not help you there, in fact they will hinder you(likely not much, still...). But a more horizontal landing actually makes a lot of sense for Minmus. Since the gravity is low, your approach speed also will be, and there is plenty of surface flat as..well,  Flats,  And wheels let the brakes to take care of some  of the deltaV after the touchdown.

Put the engines in the rear of the rove.' Coming form the low orbit, lower the periapsis to just a few meter above the ground*,  maintain retrograde with the wheels facing down. Burn just before the periapsis making the trajectory intercept the ground at safe speed, brake to a full stop. It may take some practice to get it right, but it is very satisfying when you do. (then you either automatize of switch back to less stylish/efficient but easier options)

 

 

 

 

 

 

[Neil Kermstrong]

1 hour ago, Spricigo said:

 

First lets get or terminology correct. If you are planing an almost horizontal landing, that is not Vertical Take Off and Landing. on the other hand, the traditional craft @Grogs mention are VTOL.

Now, wing will not help you there, in fact they will hinder you(likely not much, still...). But a more horizontal landing actually makes a lot of sense for Minmus. Since the gravity is low, your approach speed also will be, and there is plenty of surface flat as..well,  Flats,  And wheels let the brakes to take care of some  of the deltaV after the touchdown.

Put the engines in the rear of the rove.' Coming form the low orbit, lower the periapsis to just a few meter above the ground*,  maintain retrograde with the wheels facing down. Burn just before the periapsis making the trajectory intercept the ground at safe speed, brake to a full stop. It may take some practice to get it right, but it is very satisfying when you do. (then you either automatize of switch back to less stylish/efficient but easier options)

 

 

 

 

 

 

well the craft itself was a vtol but I just didn't want to land vertically

[Spricigo]

1 hour ago, Neil Kermstrong said:

well the craft itself was a vtol

I know that people usually have a particular kind of craft when they use the term. But the point is the term there is not necessary and even slightly misleading.

Helicopters and rockets are VTOL, we just don't call them that because we reserve the term for planes, vehicles that usually don't take off/land this way. Similarly, if we are talking about landing on Minmus, we expect everything to be land/take off vertically, to be a VTOL, we just don't need to say it and confuse things. We'd rather need to say when something is not a VTOL since that is what everyone is expecting.

Actually, you just did:

1 hour ago, Neil Kermstrong said:

I just didn't want to land vertically

But hey, don't focus to much in my pedantry with terminology. Let us take a look in your craft to see if we can offer some specific advice for how to improve it.

[jimmymcgoochie]

Wings are dead weight in space- only bring them if you’re planning on going somewhere with air (like Laythe or Eve, for example) or are flying into orbit from Kerbin’s surface with a spaceplane. Either way, they’re no use on Minmus and the best way to deploy a rover there is with a skycrane, as with the Curiosity rover on Mars; look at the stock ‘rover and skycrane’ craft to see how a skycrane can be done in KSP.