Need help! Apollo reappearance! Time went slow! Vessel is hard to change heading

[uboats]

I rebuild apollo project by using the original parts.

Since Saturn V is hard to recreate, so I redesigned the rocket but keep the Mun lander and CSM in the original initial connection (stage)

The rocket is not complicated at all and a single stage which is used to send the CSM and lander to Kerbin low orbit and can have 15% fuel left.

Then I used Service module to enter Mun transfer orbit and reduce to low Mun orbit (6km)

The structure has been strengthened, and the rising is stable (orange fuel tanks is a little bit off-sym, due to pair-adding. it only caused rotate not heading change. Not impact the rising).

Here is the rocket

https://www.dropbox.com/s/gu1z2b401ltwbl2/Apollo%20-%20Saturn%20Project.craft

I first build the lander as a sub part (which has a MJ2 only for d-V info), and then open a new project and first placed command module and choose the lander

and attach it to CSM. So I think the 3-person command module should be the kernel.

I experienced two major problems:

1. the time went slow that in the game 1s cost real time 2 seconds.

and the responsibility is laggy.

I do not know why, cpu cost is very low.

2. during straight rising, the rocket is hard to change the direction (heading). And even with all boost gone, this issue remained in the space.

I attached 8 RCS on CSM, this can do a little help for changing heading.

Then I decoupled the first stage that only CSM and lander are left.

Then I decoupled the two and turn around CSM to dock with lander like the real Apollo did.

However, with such a relatively small vessel, it's still hard to change heading (While for Kerbal X which has same command module and last stage, it is easy to control).

I thought it could be the MJ issue, but so I further decoupled the two duiring low Mun orbit.

But the problem was still there for CSM on the orbit. And the lander is too small to control the direction even turned on SAS (no sas module but using 1-person command module's)

**

Could anyone help me figure the two problems out? Especially the 2nd one. During rising and into Kerbin orbit, MJ on lander has same heading direction with CSM (it has slow heading change issue), after docking the lander, MJ has opposite direction (but the control is on CSM, and I did not use MJ), the problem exists, after CSM and lander separated, the problem still there.

Although I observed problem 1, but I do not think that's the source resulting in problem 2. Since for problem 2, even I heavily pressed the WASD, the vessel was hard to turn or turning very very slowly.

Edited November 10, 2013 by uboats

[vetrox]

Hmm, that rocket shouldnt be too laggy.

I will download it in a bit and take a look. It might be worth putting some winglets on the orange tanks to help with control during ascent.

It might be worth moving the reaction wheel further down the stage.

Edited November 9, 2013 by vetrox

[vetrox]

I cant try it with mechjeb attached. If you take it of and re upload it.

[uboats]

I have removed mj and updated the download link

thanks

Hmm, that rocket shouldnt be too laggy.

I will download it in a bit and take a look. It might be worth putting some winglets on the orange tanks to help with control during ascent.

It might be worth moving the reaction wheel further down the stage.

Is reaction wheel or SAS better?

Edited November 9, 2013 by Specialist290
Merging sequential posts by same author

[vetrox]

I have removed mj and updated the download link

thanks

I managed to edit the craft fil of the old one.

TBH its a very capable craft. I didnt fly it straight away. I added some winglets to the orange tanks, moved the reaction wheel to the bottom of the csm.

It wobbles but thats because of the lander. Those structural adapters have a habbit of making things wobble.

Once all the lower stages are dropped its very maneuverable. I didnt even need the rcs thrusters.

I would recommend you take the circular monopropellant tank off of the lander. It makes it unbalanced.

On my pc (i have a low end i7 processor) it runs super smooth.

I noticed when i launched it, if you leave it at full throttle the lower stage tears itself off. This could be what causes your unresponsive steering when ascending. However its quite capable at half throttle (you can set mechjeb to terminal velocity to make the most of your rockets). It might be worth learning how to get to orbit manually (if you dont already) as mechjeb makes wobbly craft wobble even more.

But I thought it was great. I've yet to build one like it. I really enjoyed flying it. I dont know how much dv it has but I reckon i could get it to duna. It had loads of fuel left over. I had enough fuel leftover from the lifter stage to help with the transfer burn I was most impressed.

It wobbles a fair amount but no more than the kerbal x I would say. Its the lander in the middle thats causing all the wobble. but gentle flying gets her up there.

Javascript is disabled. View full album

EDIT: Sorry i didnt take any screenshots during the ascent as i wasnt expecting it to go so well.

Also you only need one radial decoupler per orange tank. This is what explodes each time you seperate the lower stages.

[uboats]

First of all

Thanks for all your detailed test and comments!!!

I managed to edit the craft fil of the old one.

TBH its a very capable craft. I didnt fly it straight away. I added some winglets to the orange tanks, moved the reaction wheel to the bottom of the csm.

It wobbles but thats because of the lander. Those structural adapters have a habbit of making things wobble.

So If I directly strengthen the lower stage and CSM and connect the lander without adaptor, it would be more stable?

I was afraid that smaller decouple could not get a strong connection.

I noticed when i launched it, if you leave it at full throttle the lower stage tears itself off. This could be what causes your unresponsive steering when ascending. However its quite capable at half throttle (you can set mechjeb to terminal velocity to make the most of your rockets). It might be worth learning how to get to orbit manually (if you dont already) as mechjeb makes wobbly craft wobble even more.

Did you mean launch from Kerbin? half throttle to launch? I made a mistake that I found the center engine did not activated.... so it ascent slowly.

I just used mj to see dv only. But since I used to consume all fuel during mun landing, so this time I let mj did that.

Its the lander in the middle thats causing all the wobble. but gentle flying gets her up there.

Also you only need one radial decoupler per orange tank. This is what explodes each time you seperate the lower stages.

I thought single decoupler for surround orange tanks would not have strong strength.

Do I need to change a smaller fuel tank for CSM? And add a second stage between lander and lower stage for transfer orbit?

Since After all surrounding 6 tank dropped, the rocket is too long too heavy for a single engine.

Edited November 9, 2013 by uboats

[uboats]

BTW, since lander has no crew, So how did you first decouple CSM from lander then decouple lander from low stage?

[vetrox]

First of all

Thanks for all your detailed test and comments!!!

So If I directly strengthen the lower stage and CSM and connect the lander without adaptor, it would be more stable?

I was afraid that smaller decouple could not get a strong connection.

You may have o experiment with this one. I would first try and link each stacked fuel tank together with a couple of struts. If you look closely when your launching and you have shed your outer orange tanks, you will see which bits need stitching together.

Remember when you are flying mechjeb is quite violent with its flying which is why i dont have it any more.

Did you mean launch from Kerbin? half throttle to launch? I made a mistake that I found the center engine did not activated.... so it ascent slowly.

I just used mj to see dv only. But since I used to consume all fuel during mun landing, so this time I let mj did that.

When i flew it the center engine wasnt activated. I assumed that was how it was designed. I used half throttle at launch and then slowly increased it. Next to your nav ball is a G meter. I try and keep it in the green to prevent random explosions.

It ascended slowly at first i guess but it did better than some of the stuff i have cobbled together. Its something you get used to when you get many hours of game time under your belt. When do you start your gravity turn? With your ship i started at about 12km

I thought single decoupler for surround orange tanks would not have strong strength.

Unfortunatley the way the game engine works, is every part can only have 1 attachment point. So although it looks like your orange tank is attached to both decouplers the second one isnt actually doing anything. So in essence you are already using only one decoupler. If you are worried you can always hide some struts in there.

Do I need to change a smaller fuel tank for CSM? And add a second stage between lander and lower stage for transfer orbit?

Since After all surrounding 6 tank dropped, the rocket is too long too heavy for a single engine.

Personally i would leave it as it is as it allows for plenty of error. if you wanted you could ditch one of the tanks in the last lower stage. This would save quite a bit of weight and get you some extra dv. You might even find you gain more. You will have to play around and make mk2 and 3 versions of your craft.

BTW, since lander has no crew, So how did you first decouple CSM from lander then decouple lander from low stage?

That first picture was quite deceptive. I decoupled the lower stage first, then decoupled the csm from the lander. The decoupleing force pushed the lander back into the lower stage so that picture makes it look like its still atached.

I had to do my seperating and docking quite quickly at that point as i was mid-transfer burn. Using up the leftover fuel from the lower stage. Everything seemed to manuever very well without the rcs.

NOTE:I placed those rcs blocks quite hastily so i wouldnt copy them, they were most awkward.

The only thing i would say is remove the RCS from your lander. Theres just no need for it as its so lightweight its very easy to handle even with that heavy mono tank. I noticed when i dropped the descent stage and was flying back to rondevous with the csm that I could only fly half throttle because that mono propellant tank made things awkward. I must admit, it does look prety cool with it though!

Edited November 10, 2013 by vetrox

[uboats]

Thank you very much.

I hope there could be a 'like' button for your post.