Jump to content

Unplayable after FAR


hansman1982

Recommended Posts

Also of note, your center of lift was above the center of mass. That equates to an unstable rocket. Stable rockets need the center of lift below the center of mass.

*edit*

The further below CoM the CoL is the more stable the rocket. If it is really far below CoM you might actually have trouble turning at all :P

Link to comment
Share on other sites

screenshot9.png

Ok, I lengthened the rocket. Now it just wobbles it's way up until the SRB's separate and then they collide into the rocket (another problem lately is they tend to release in to the main core of the rocket) and destroy it.

Link to comment
Share on other sites

According to all the indicators in that last SS it should work. The only think I can think of is that KSP does not tend to like pendulum rockets much, and your stage 4 TWR is a little high but within acceptable limits.

*edit*

Actually, I was thinking about it. Your boosters are set over your fins such that if there is any rotation at all they are going to collide when you decouple...

Link to comment
Share on other sites

Keep your SRBs low. Yes, that keeps their mass positioned low, but it also keeps their drag positioned low. In addition it gives them a better chance to stage without colliding with your ship.

Edited by Eric S
Link to comment
Share on other sites

Ask yourself, would those rockets fly in real life? No way. There is a reason for the way rockets look. You cannot install an aerodynamics mod and then say stuff like they flew without it and expect your rockets to fly with the mod. Insane.

Link to comment
Share on other sites

If you want to use 4 SRB use this configuration:

CZ-2F_TEL.jpg

@Brabbit: I had the same question some time ago... I want to use it but i want to know if the future improvement of aerodynamic would be similar to FAR

Link to comment
Share on other sites

Well there's your main problem. Your rockets are too small. They're unfit for having enough thrust to get to orbit. You're not building model rockets here, you're trying to get to space.

Link to comment
Share on other sites

@hansman1982: Your main problem is that huge TWR and your push to speed like a maniac through the lower atmosphere. In general, aerodynamic forces are proportional to the dynamic pressure q:

q = 1/2 * air-density * velocity2

Now, consider the fact that you're going about 2 times as fast as my rockets tend to go at that altitude, so you're dealing with aerodynamic forces that are 4 times as strong as my designs. If you were to maintain control you'd probably end up getting into even stronger aerodynamic forces and destroying your vehicle as a result.

Here's what I'd do with your rocket: get rid of the SRBs, switch out the LV-T30 for LV-T45 so you have more control; this is especially important near Mach 1 where your fins won't be as effective at maintaining control.

When you launch, wait until it's going about 60 m/s and then start your gravity turn; that should allow you to reach orbit effectively. Leave the MJ ascent autopilot off and instead try using Smart ASS's KillRot function.

Link to comment
Share on other sites

According to all the indicators in that last SS it should work.

KSP doesn't have a center of drag indicator, and even if it did, it probably wouldn't match the FAR drag model, and the center of drag depends on the angle of attack, so it would move as soon as the craft wasn't aimed directly prograde.

Link to comment
Share on other sites

@Eric S: FAR modifies the CoL indicator to model the updated aerodynamics; also, the CoL / CoD should not vary significantly based on angle of attack; you are mistaking the Center of Pressure with the Center of Lift / Drag. The Center of Pressure moves significantly; the Center of Lift does not unless you start to get stalling and flow separation.

Link to comment
Share on other sites

Oh, I see. 4srb is overkill for such rocket. I ignite them in pairs and still need to throttling down main engine. It flies but it's not very good design.

image.png

Edited by zzz
Link to comment
Share on other sites

  • 1 month later...

@OP

I do feel your pain, but it says more about how bad the aerodynamic modeling is in vanilla rather than how it broke your rocket (or my beloved spaceplanes for that matter).

It looks like you're on the right track now (it took me about a week's worth of rage-quits before I started to get it).

Link to comment
Share on other sites

I could launch things fine, most of my launchers are semi-asparagus, but still rocket-looking. They only needed bigger and better fins. But as it threw all the telemetry from mechjeb of, I decided to wait until the base game aerodynamics get improved, as mechjeb will be updated for that.

Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...