Little bit stuck! Fuel issues? Weight issues? Piloting incorrectly?

[DanimalXIII]

Hey, I'm pretty much brand new to the game.

I was wondering if some of you would be able to give me a little bit of valuable insight, currently I can't seem to get any of my guys to orbit the planet decently and return...

I start off with One or Two Solid rocket booster(s) or 3 x FL-t 400 liquid tanks. (or something similar) I launch and keep my speed above 150 but under 200, until I'm about 10,000m altitude. Once I'm at about 10k meters I bank to about 45 degrees, and continue to climb with full throttle, occasionally decreasing my throttle (There's no point burning loads of fuel while the air is getting thinner, right?)

Once I jettison spent engines/fuel tanks I'm left with a FL-400 and I usually pick the LV-909 engine. Once my apoapsis is at 100k I cut my engines and start making maneuvers to get into an orbit. I've managed it once doing the above method, but unfortunately I ran out of fuel so my astronaut is stuck orbiting the planet with no fuel and no electrical charge; any other time I've tried getting into orbit I usually run out of fuel during my maneuver in orbit so just fall back down to the planet.

I've tried adding extra boosters/fuel tanks, but it seems as though the weight becomes an issue then (at a guess), and the craft becomes more unstable to fly, even with the aid of aerodynamics; I'm doing a career mode I've unlocked a few things, but I'm still relatively stuck.

Where am I going wrong? What can be done so I can get a successful orbit (and return?) I've tried to include as many details as possible to help.

Edited October 21, 2013 by DanimalXIII

[Camelotking524]

http://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation

Figure out how much Delta V your launch vehicle has. To get into a 100km Kerbin Orbit and return requires around 4000 to 4500 delta V.

From your post, it sounds like your rocket is lacking Delta V.

Also, Welcome to the world of Kerbal.

[blizzy78]

Once I'm at about 10k meters I bank to about 45 degrees, and continue to climb with full throttle, occasionally decreasing my throttle (There's no point burning loads of fuel while the air is getting thinner, right?)

Wrong. While ascending, what's keeping you from getting into orbit is drag. So the faster you get out of the atmosphere, the better. Also, as long as you're not in a stable orbit, gravity is pulling on your vessel. You need to burn fuel to counteract that. So again, the faster you can leave gravity behind you, the better.

As soon as you start your gravity turn by leaning to the side at 10 km, go FULL throttle.

[Scrogdog]

You don't want to stay at 45 degrees. Once you've banked and are stable, go to map mode and bring the angle more towards the horizon to increase speed and "fatten" the orbit. In that way you use your final stage to do most of the work and not the fuel in your command pod's service module.

[nhnifong]

Can you post a screenshot of your rocket? (F1 in-game) use imgur as an image host.

[DanimalXIII]

Thanks for the input, people.

Can you post a screenshot of your rocket? (F1 in-game) use imgur as an image host.

Sure, this is one I usually try fly with, or something similar

[blizzy78]

You don't need those wings in the middle. In fact, they will make it harder to turn the rocket in the atmosphere.

[Ariadne]

Once I'm at about 10k meters I bank to about 45 degrees

Too low. At 10 km the atmosphere is thick yet. If you choose this way to get orbit, you should turn to 45 degree at 25 km or more.

[nhnifong]

I tried building this just as it looks in the picture. the first stage was a little low on thrust but it was OK. took me up to about 20 km and 350 m/s. The second stage is definitely lacking enough thrust.

[Scarecrow88]

Unless you are playing in career mode, I would suggest leaving the science experiments behind until you are comfortable getting in to orbit.

[nhnifong]

It just needs a pair of liquid boosters on the side like this. Note the staging and fuel lines. Other than that, everything is fine! nice rocket!

If you don't have fuel lines, just leave them out and activate the center engine a bit later so you will have fuel remaining in the center tank.

[Sirrobert]

First of, that cockpit you have is meant for aircraft, not for rockets. I'd suggest going back to the commandpod. It's lighter and you can put a parashute ontop.

Secondly, I tryd recreating your ship, and launched it with Mechjeb. It indeed does not have enough deltaV to get into orbit (it's close though, as you can see: http://tinypic.com/r/rsa1za/5 )

As starter: You can ditch the wings. If you want wings anyway, keep the lower ones and ditch the top ones. Top ones only come into effect when you are to high for wings to have any effect

Question: Do you have radial decouplers already?

If so you can add some boosters on the side, and drop them off when they empty.

As you found that adding more fuel adds more weight, try adding more stages. Each time you drop a stage, you drop all the weight that comes with it. Cutting 1 long rocket into multiple stages can already provide extra deltaV, without adding any fuel

[SRV Ron]

A simpler design from career mode that not only made orbit, it had fuel enough for a Mun orbit and return. You will have to learn the fine art of orbital turn and energy management on this one.

To fly, go straight up until the SRB burn out, then stage and start your gravity turn. The second stage will get you to the 100k apogee with fuel to spare. Set up your orbital circulation maneuver and fire up 15 seconds before the node is reached. You will have to stage to complete the burn but should have plenty of fuel left for the Mun insertion, orbital burn, and direct return to an aerobraking landing.

Launch vehicle

Mun orbit

The return burn

Note resource management of both power and fuel for the LV-909 on the third stage.

Landing

[DanimalXIII]

Thanks for the input guys, it's very appreciated, and should get me on the right track.

How do I mark a thread as 'answered'?

[capi3101]

What you're going to be capable of doing is going to be highly dependent on the level of tech you've unlocked. That said, if all you're trying to do is get into Kerbin's orbit, I can tell from the Science Jr that you've got the tech. Shoot for 4650 m/s of delta-V; 4550 for the ascent and a mere 100 to deorbit (yes, it doesn't take all that much to land). Here's what I'd do: switch pack to the Mk1 Command Pod - it's less massive. Two radial chutes and an antenna on the pod, your sci junior underneath and lets go with three goo pods. That's your payload; 1.755 tonnes. Three fuel stacks - an LV-T45 in the center and two LV-T30s outboard (or all three LV-T30s if you don't have the -45 for some reason). Stick a decoupler under your payload and then add the center stack - three FL-T800 tanks to make things easy, or two FL-T800s, one FL-T400, one FL-T200 and one FL-T100; whatever tank combo you select, you want the same combo outboard. That's all you need to get into orbit.

Straight up to 10k, 45 degrees at 090 to 20k, follow the navball after that, and at 50k burn along the horizon until your apoapsis is where you want it. Watch your gee meter as you go; if it climbs out of the green zone, throttle back to avoid telescoping your stack. Cut your thrust when the ap is where you want it, coast above 70k, then set your orbital insertion maneuver node. Burn when you're ready (generally I burn at one-third thrust for three times the amount of time indicated by the node; that helps with precision). When your periapsis is above 70k, you're in orbit. Cut your thrust, do your science, turn retro and burn. When the periapsis goes below 30,000, you'll come in for landing. Wait until you're flying, then cut loose the booster - that will help with cleanup. Chutes out when you're ready (I usually go at 5k or so). Land and reap the science.

EDIT: To mark a thread as answered, you have to edit your first post; there's a box there that will let you switch the thread's status.