Stranded on Tylo with 2970dV?

[Tatonf]

With the 612 m/s from stage 3 this gives a total of 1698 m/s. As I said on the previous page, adding in the kerbal's EVA backpack of approx. 600 m/s gives 2298 m/s which should be just enough if you can do the EVA burn accurately (and quickly) enough.

This isn't enough. Due to the high gravity of Tylo you'll always lose a non-neglictible part off your delta-V burning slightly verticaly in order to not fall back.

[GoSlash27]

Is the calculation of dV that simple?

ChiefJohnson,

No, it's not quite that simple. I didn't show the entire process.

The entire process would be

2.8 tonnes of not- fuel and 2 tonnes of fuel. 4.8/2.8= 1.71 Rwd.

The natural log of 1.71 is .536

.536*9.81m/sec2 (standard g0)*320s (the engine's Isp) = 1,683 m/sec DV

So while it's not quite that simple, it's not really complicated either.

What I find really useful about the rocket equation isn't this form, but instead it's backward form.

instead of 9.81Ispln(Rwd)=DV which says what the thing you have built can do, working it backwards e^(DV/9.81Isp)=Rwd which says what you need to build to do what you want.

The first form is a good spot check of what you have already built. The second form is used to design your ship so it'll do what you need. If you get handy with this equation, you don't need an add-on and don't have to worry about being misled.

If you get *really* slick, you can build a spreadsheet that will do your designing for you and tell you at a glance which design is cheapest or lightest for what you're trying to do.

Best,

-Slashy

[davidy12]

Get as far as you can then use EVA.

[Warzouz]

This isn't enough. Due to the high gravity of Tylo you'll always lose a non-neglictible part off your delta-V burning slightly verticaly in order to not fall back.

I was surprised to do a 2265m/s takeoff to 10km orbit with a test rocket (TWR was around 4). OTOH, I don't remember which altitude I took off from.

[Mikki]

The math checks out, as far as I can see.

Try this: ..., with just enough vertical to clear the terrain. ...

Good luck.

Happy landings!

Good luck... and hit F5 for before Z...

[Tatonf]

I was surprised to do a 2265m/s takeoff to 10km orbit with a test rocket (TWR was around 4). OTOH, I don't remember which altitude I took off from.

Well, the orbital speed for a 10km orbit is 2152 m/s, with the planet rotating at a speed of 18 m/s, the absolute minimum you need is 2134 m/s.

I tested it and just surprised myself doing it with 2176 m/s ! I guess, the higher the TWR is, the less delta-V you loose fighting gravity. My ship had a TWR starting at 4.48 and ending at 10.24 (well, it nevered reach that last value since it didn't burn all of it's fuel).

I just found that there's some quite high mountains on Tylo (11 250m at 20.408889/-77.1725 for exemple) so I could spend almost all my delta-V going horizontal for a 11/12 km orbit.

But I don't think OP's TWR is enough for that kind of wizardry. I don't know the thrust provided by the jetpack however.

[ChiefJohnson]

Thanks for the short explanation of the manual calculations! If I got more questions, I will look it up:) Such a nice game, you learn so much new while playing it, getting a deeper understanding the more you play. Plus: Nice community, what is going on here? Guess you have to have some passion (and brains) to play this, so manners are more common.

[Padishar]

You're welcome. Due to the apparently quite tight margins involved, this might make an interesting "get this kerbal to orbit" challenge forum thread if you posted a save file (make a copy and clean out any other vessels, except the orbiter to rendezvous with). Maybe score it on amount of EVA propellant left once grabbed onto the orbiter (assuming the orbiter has its own crew capsule)...

[Captain H@dock]

I don't know the thrust provided by the jetpack however.

It has a TWR of less than 1. Source: You can't lift off Kerbin using it. Nor Tylo.

In fact the wiki quotes the jet pack as capable of providing a 3.2 m/s² acceleration. That would make it a .4 TWR compared to Tylo surface gravity, or 0.33 compared to Kerbin.