Launch tower at 80km?

[Llama1017]

Those Scott Manley fans will know what I'm talking about.

In one of his videos (I forget which one), he says he can edit the quicksave file and make the Launch Stability Enhancers go all the way up to 80km to skip the whole launch thing.

Anybody know how to actually do this?

Thanks!

[NoMrBond]

It would probably be easier to just use Hyperedit

[Llama1017]

It would probably be easier to just use Hyperedit

Well, I kinda wanted to put a platform up in space for Kerbals.

[NoMrBond]

You can move whole ships, platforms, modules containing Kerbals etc

Why did you need it attached to the ground, just curious?

[Llama1017]

You can move whole ships, platforms, modules containing Kerbals etc

Why did you need it attached to the ground, just curious?

I dunno. Just thought it'd be cool.

[Crown]

In the persistent file there is a section for the vessel which says "orbit". There you can find a line named "SMA". I think this is the spot where to edit.

But here's a problem: At 80km altitude, pinned to Launch Enhancers, you would go roughly 197.8 m/sec. But orbital speed at this height is about 2'200m/sec. Which means after decoupling the space craft it will fall back to the planet. Reaching orbital speed with this conditions looks quite difficult to me.

[SnappingTurtle]

How can it be harder than starting at 0m and 0m/s?

[Llama1017]

In the persistent file there is a section for the vessel which says "orbit". There you can find a line named "SMA". I think this is the spot where to edit.

But here's a problem: At 80km altitude, pinned to Launch Enhancers, you would go roughly 197.8 m/sec. But orbital speed at this height is about 2'200m/sec. Which means after decoupling the space craft it will fall back to the planet. Reaching orbital speed with this conditions looks quite difficult to me.

I can't get that to work.

[HeadHunter67]

How can it be harder than starting at 0m and 0m/s?

Put a typical spacecraft into an 80km circular orbit. Now kill its speed to about 198 m/s and watch what happens.

The idea of an orbit is that your ship is moving forward faster than it's falling, so it keeps missing the ground. When it starts its orbit more-or-less stationary, it has only the radial velocity of the planet, which is insufficient to prevent gravity from having its way.

[SnappingTurtle]

I still say it can't possibly be harder than launching from the ground.

[Llama1017]

I still say it can't possibly be harder than launching from the ground.

You guys aren't getting what I'm saying. If you actually read my reply to NoMrBond, you'd see that I want a platform. Not for launching, just to put up above the atmosphere BUT still have attached to the Launch Stabilizers.

[Enigma179]

I still say it can't possibly be harder than launching from the ground.

Maybe it wouldn't be, but there's one snag; when you launch from the ground, you go straight up then turn as air resistance decreases; this is because it's more effective to prograde with your apoapsis in front of you rather than behind, so you want to get and maintain vertical velocity as you give yourself the sideways velocity you need. When burning prograde, your apoapsis will get further from you; if it's in front of you that's not a big deal because if you want to burn at apoapsis you just cut the throttle for a minute or two. If it's behind you, you just gotta burn at an upward angle and pray.

No doubt it'd take less delta-v than launching from the ground (should take just about 2000 delta-v I think) though.

[Tw1]

Did you get it to work?

It's not the SMA you want to edit, there are two other values that are more important. I did something like this once by editing the values for hight and altitude, or something like that. Making sure the state was still landed was quite important, and it got buggy very quickly.

[Somerled]

Easiest way is to open up your .craft file and add 80000 to the y value (second of two numbers, for the cartesianally challenged) for the 'pos' of all parts. Also, play with the 'height' value of the Launch Clamp part, though it's not necessary.

Why would you want to do this? To impress the ladies with the size of your launch tower.

And for inverted launches, of course. Launch upside down at 80km (Scott Manley said any higher makes physics go phwonk) and generate velocity with the help of gravity. After all, the best place to raise your periapsis is your apoapsis.

[Where I saw it, Scott Manley himself: http://youtu.be/JLxMda_tVPg?&t=791]

Edited July 29, 2013 by Somerled

[GermanB]

Can you make it 2 868.75 km high(geosinc orbit height)? If so, then you can even skip the gathering of orbital speed.

[Busstop17]

@SnappingTurtle it's not. You will fall to Kerbin for a bit before you gain enough 'sideways' velocity with your rocket. Looking for how to get the tall launch tower as well here.