Vessel with way too much delta V?

[Serenity]

Hey everyone, just wonder if this is considered ''normal''

I felt like it had too much delta V so i am really curious if its not that much, that orbit is with a single burn from launch.

https://imgur.com/a/7A51JBX

Edited April 26, 2018 by Boyster

[juanml82]

You barely have any payload, just a nosecone and a reaction wheel, so I guess going from the pad straight into solar orbit is reasonable. If you actually want to see the dV, I recommend you to get Kerbal Engineer Redux. It says it's not compatible with 1.4, but I've been using it without any issue and there is a modified dll somewhere in the mod's thread.

[Snark]

It's worth noting that going from 1.875m, down to 1.25m, then up to 2.5m is going to give you hideously awful aerodynamics.  Suggest putting a 1.875m-to-1.25m adapter on top of the fuel tank, then the reaction wheel on top of that, then a 1.25m nosecone on top of that.  Would be a lot more streamlined.

But yeah, you're basically just a flying fuel can, so it'll have quite a lot of dV (especially since the Skiff has a high TWR-- you get a strong, launchable amount of thrust from a high-efficiency engine that only weighs 1 ton).

[DoToH]

3 hours ago, Boyster said:

I felt like it had too much delta V

There's no such thing you call "too much delta V"

 

On topic:

My math gives 3945m/s ASL or  4913m/s VAC assuming you put a 0.1 t probe.

Approximately the delta V needed to reach Kerbin orbit  with pre 1.0 atmo-soup. Not too much

Edited April 27, 2018 by DoToH

[GDJ]

2 minutes ago, Snark said:

It's worth noting that going from 1.875m, down to 1.25m, then up to 2.5m is going to give you hideously awful aerodynamics.  Suggest putting a 1.875m-to-1.25m adapter on top of the fuel tank, then the reaction wheel on top of that, then a 1.25m nosecone on top of that.  Would be a lot more streamlined.

But yeah, you're basically just a flying fuel can, so it'll have quite a lot of dV (especially since the Skiff has a high TWR-- you get a strong, launchable amount of thrust from a high-efficiency engine that only weighs 1 ton).

Well, with the fat bottom it would be somewhat easier to keep it self aligned at least (drag hitting the bottom of the rocket). IRL this does work with model rockets.

[Snark]

5 minutes ago, GDJ said:

Well, with the fat bottom it would be somewhat easier to keep it self aligned

The current design is horribly draggy at the front end, which is generally not a recipe for aero stability.

Sticking an adapter on top will not only make the front end more nicely aerodynamic, but one can also set the fuel flow priority to drain the bottom tank first, which will further help stability.  Plus, it's got a gimbaled engine.  Also, easy to add some fins at the bottom for stability, if it's an issue.

[Serenity]

I was just testing the drag numbers with different skins in the fuel tank when i realized the crazy delta v that vessel has, it wasn't meant for anything.

Thankfully the skins didn't have any difference.

[GoSlash27]

I'm seeing very little data in those screenshots.

3 hours ago, DoToH said:

There's no such thing you call "too much delta V"

I'm from the opposite school of thought. Any DV more than the minimum required to achieve the objective (plus a predetermined reserve) is too much. It's just fuel you won't ever use, tankage to lug it around in, and bigger engines than you really need to push it. All just dead weight and wasted money.

Best,
-Slashy

Edited April 27, 2018 by GoSlash27

[Gargamel]

7 hours ago, DoToH said:

There's no such thing you call "too much delta V"

 

5 hours ago, GoSlash27 said:

I'm from the opposite school of thought. Any DV more than the minimum required to achieve the objective (plus a predetermined reserve) is too much. It's just fuel you won't ever use, tankage to lug it around in, and bigger engines than you really need to push it. All just dead weight and wasted money.

I like to be in the middle of these two thoughts.  I like to meet my mission requirements, and have a little extra to go around if needed.  If extra Dv is carried, and it doesn't have severe consequences on other parts of the mission (including cost), I'm ok with that. 

[Curveball Anders]

7 hours ago, GoSlash27 said:

I'm seeing very little data in those screenshots.

I'm from the opposite school of thought. Any DV more than the minimum required to achieve the objective (plus a predetermined reserve) is too much. It's just fuel you won't ever use, tankage to lug it around in, and bigger engines than you really need to push it. All just dead weight and wasted money.

My slightly AR design self cries a little every time I have do dump a stage with remaining fuel

[DoToH]

18 hours ago, GoSlash27 said:

I'm from the opposite school of thought. Any DV more than the minimum required to achieve the objective (plus a predetermined reserve) is too much. It's just fuel you won't ever use, tankage to lug it around in, and bigger engines than you really need to push it. All just dead weight and wasted money.

You are right, but.... there is no "too much delta V", maybe too few places to explore. Can we agree if I say it that way?

Edited April 27, 2018 by DoToH

[GoSlash27]

4 hours ago, DoToH said:

You are right, but.... there is no "too much delta V", maybe too few places to explore. Can we agree if I say it that way?

DoToH,

 I'm afraid not (which is cool; we don't *always* have to agree ) I do get where you're coming from, but DV is always a fixed quantity in these matters... or at least falls within a fairly narrow range. You lay out the mission, and figure out required DV. Then you take that DV figure and design a rocket that will provide it. Taking a rocket with the ability to generate a huge DV and then attempting to find a mission for it is attempting to design backwards by my way of thinking.
 Even if I were inclined to create a stage with an ungodly high DV, I'd probably go with a cheaper and lighter staged rocket unless I had a really compelling reason not to.

Best,
-Slashy

[foamyesque]

On 4/26/2018 at 8:11 PM, GoSlash27 said:

I'm seeing very little data in those screenshots.

I'm from the opposite school of thought. Any DV more than the minimum required to achieve the objective (plus a predetermined reserve) is too much. It's just fuel you won't ever use, tankage to lug it around in, and bigger engines than you really need to push it. All just dead weight and wasted money.

Best,
-Slashy

 

I submit that there's no such thing as 'too much delta-v'... just 'not enough payload'. :p