Orbital Toast Voyager Quest

Altaïr

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#2
Sorry but I tried, it clearly doesn't work. I could barely reach Jupiter's level with it.

That second stage can provide 1327 m/s of delta-V, and you need 1856 from LEO.

You have to design a more efficient launcher to succeed. We can give you some advice, but please don't try to fool us, we did that challenge ourself, we would notice.
 

Altaïr

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#5
Okay :)

Some advice would be great.
Ok, here are a few ones.

Firstly, you have probably noticed that your payload is not the most aerodynamic thing you could imagine... To avoid losing power because of drag, enclose it into a fairing. Then discard the fairings once you're about to leave the atmosphere.

Then the launcher itself. Your second stage is good, but it doesn't have enough fuel by itself to do the full job. It's ok if your previous stage still has significant fuel to spare though. You can also add more fuel to it, the choice is up to you.

Finally the first stage, this one is the main problem. Of course it does the job, but as is it's a SSTO: it sends to orbit the whole thing all by itself. That works, but this is inefficient, you need a very heavy stage for that. Using two stages to reach orbit would be more efficient. This allows you to switch to an efficient propulsion at mid-flight (Valiant/Frontier engines), while dumping a lot of dead weight.

With this you should be able to crack the challenge :)
 

Mooncrasher

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#8
Remove fuel from the top stage and put it in the bottom stage. Altaïr already said your top stage looks fine, but now you went very big on it. It should be smaller than the middle stage.

Much more important is the TWR on the first stage. Much too high now! Go back to 3 hawks like you had in the first rocket.
 

Altaïr

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#9
Ok I have a new design. It's still not getting all the way there.
That's better. You're close to the solution, by just making a few improvements you can crack the challenge by a good margin.

Your main mistake here is the first stage. You have too many engines! Your thrust/weight ratio is above 2.5. It's good to have some power at lift-off, but not that much. Something around 1.5 would be more suitable. Eventually a bit more, but when it's above 2 it's clearly too much.
Remove some engines, and with the weight you saved you can add a bit more fuel, you win on all aspects.

For the second and third stages, the engines are well chosen. The only problem is that your third stage has a lot of fuel: 50 tons. If you add the payload (25 tons) and the engine's weight you're at 77 tons. That's a lot for that small engine, it only has 40 tons of thrust. Alleviate it a little and give the fuel to another stage to compensate.

With those changes you should be good :)

edit: damn, Mooncrasher beats me to it!
 

Altaïr

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#12
I'm so close I can taste it but its just not there yet.
Your first stage is very big! Its size was pretty good in your previous attempt. You burn a really large quantity of fuel with the least efficient engines. The sooner you can switch to an efficient propulsion, the better. If necessary, instead of 3 Hawk, you can use a single Titan for a bigger kick at lift-off.

Transfer some fuel from the first stage to the second (eventually a bit to the third), and it should do the trick.
 

Altaïr

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#14
Attempt 2 not sure if this works though
The last pic is good, but isn't there a problem with the other pics?
The first one is one of your previous attempts, the second one seems to be a failure, and on the third one on the contrary you seem to have a lot of remaining fuel.
 

Mooncrasher

RCS rocket good
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#16
Screenshot_20211203-194845.png Screenshot_20211203-195021.png Screenshot_20211203-194157.png
Not quite correct. I reached orbit a similar amount of fuel, perhaps more, and didn't make it.

Perhaps swap the three hawks for a titan, slightly more thrust and TWR might mean less gravity losses.
 

Altaïr

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#18
Actually I tried, it's possible to do it with that launcher, with a very agressive flying technique. But with what you had left of fuel in LEO, that was too low.

Moon's advice is good, I would also transfer some fuel from the first stage to the second stage (let's say 15 tons) to get a more balanced rocket.

Then it's all about your flying technique. As you have a good TWR, start building your horizontal speed as soon as possible. Don't be afraid of flying at high speed in the atmosphere, the air pressure decreases very fast: it halves every 2000 meters. At 10000 meters it's only a bit more than 3% of the ground pressure. Your ship is very well shaped anyway, so don't hesitate to use a very aggressive trajectory. With all this the victory should be yours :)
 

Orbital Toast

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#19
Actually I tried, it's possible to do it with that launcher, with a very agressive flying technique. But with what you had left of fuel in LEO, that was too low.

Moon's advice is good, I would also transfer some fuel from the first stage to the second stage (let's say 15 tons) to get a more balanced rocket.

Then it's all about your flying technique. As you have a good TWR, start building your horizontal speed as soon as possible. Don't be afraid of flying at high speed in the atmosphere, the air pressure decreases very fast: it halves every 2000 meters. At 10000 meters it's only a bit more than 3% of the ground pressure. Your ship is very well shaped anyway, so don't hesitate to use a very aggressive trajectory. With all this the victory should be yours :)[/QUOTE
It’s been a while since I have been back and I still can’t figure this out I have tryed all the tips and trick and I am still stuck so advice would be great
729CC069-6CCD-45CF-A283-98677550C7AB.png
 

Altaïr

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#21
That looks good, though you didn't take the screenshot at one of the specified marks:
Screenshot_20220506-113940_Chrome.jpg

As Mars orbit is elliptic now we had to change the rule because the liberation speed is not the same depending on where you cross Mars orbit.
However you're well passed the 11.360.000 km (by almost 1 million), and barely below the speed threshold defined at that level, so we can accept it. Otherwise you'd have to time-warp to the next mark and take a screenshot there.

So let me congratulate you on your Voyager quest, Mooncrasher will give you your badge.
 

Orbital Toast

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#22
That looks good, though you didn't take the screenshot at one of the specified marks:
View attachment 83380

As Mars orbit is elliptic now we had to change the rule because the liberation speed is not the same depending on where you cross Mars orbit.
However you're well passed the 11.360.000 km (by almost 1 million), and barely below the speed threshold defined at that level, so we can accept it. Otherwise you'd have to time-warp to the next mark and take a screenshot there.

So let me congratulate you on your Voyager quest, Mooncrasher will give you your badge.
Thanks :)