Need help in science mode, reach Mun and back with not too many science.

[RealDarko]

Hello

I have the following science branches researched:

Basic Rocketry, General Rocketry, Advanced Rocketry, Fuel systems. Also Engineering 101, survivability, stability and basic science.

My question is: Is possible with those pieces build a rocket capable of reaching the Mun, plant a Kerbal there and bring him back to Kerbin? I'm a lousy engineer and always short on fuel (or maybe too much weight?) My best rocket is now capable of reaching the Mun (reaching only the vicinity, not orbit it, cause If I orbit it will not have enough fuel to reach Kerbin) and then back to Kerbin, but nothing more, that rocket is also very hard to control, cause it carry a lot of fuel. So is possible to put Jebediah on Mun and bring it back with the pieces I have available? Or should I research more science before trying that? And If I need more science, which ones?

Thanks!

And I have a small request, any tip of doing a rocket capable of hauling probes, pods, science equipment, etc with enough power and fuel to reach Minmus and Duna and back? A rocket that can be the foundation of my space program.

P.S. I started playing with probes, but why I can't control them? Game says they have no SAS, do I need the advanced inline stabilizer to play with the probes?

Edited October 5, 2016 by RealDarko
Added a small insert

[Palaceviking]

Probes-  if you mean the stayputnik then no, it has no sas, and is terrible to fly without atmosphere and fins/aerodynamic surfaces to take advantage of it.

Stabilizers- give you turning and stability torque but you need a pilot or to be a good pilot yourself. 

First munshot- i would seriously consider putting a pilot on a free return trajectory for the science,  and yes you can do anything with enough boosters!

The first manned lunar mission was for orbit only, this is significantly cheaper and easier than landing and i would recommend following this path until you get a lot more comfortable. 

Edited October 5, 2016 by Palaceviking
More info

[Plusck]

Definitely, yes, with those parts.

You basically just need a Terrier and an FL-T400 tank in the lander stage, to get you down to the Mun's surface and back home. You could even use a bit of its fuel to complete the transfer to the Mun if necessary.

Before that, you need to get to orbit with a good amount of fuel left. A simple solution is a Swivel with FL-T800 and FL-T400 at the core, with 2x Thumpers and (very importantly) 2x FL-T800 drop tanks with fuel lines feeding the core stack. Add a couple of nosecones and you should still be under 30 parts.

59 minutes ago, RealDarko said:

 

 

And I have a small request, any tip of doing a rocket capable of hauling probes, pods, science equipment, etc with enough power and fuel to reach Minmus and Duna and back? A rocket that can be the foundation of my space program.

P.S. I started playing with probes, but why I can't control them? Game says they have no SAS, do I need the advanced inline stabilizer to play with the probes?

For probes, you need solar panels of some sort before going further than LKO. Once you get those, and have a design that can land and return from the Mun, just get rid of the command pod and replace with a probe core for Minmus, Duna and beyond...

The Stayputnik is very dumb, fun to play with at the very beginning but mostly useless after that. The OKTO is much much more useful - and you get solar panels at the same time so you can actually use it in space.

Edited October 5, 2016 by Plusck

[Kelderek]

I strongly recommend doing separate manned fly-by missions to the Mun and then later Minmus before trying to land on either of them.  You can obtain "in space near" and "in space high" science.  You don't even need to worry about orbiting, a flyby will suffice for getting science, it just needs to pass close enough to get the "in space near" science access.  EDIT: you may want to orbit if you have trouble setting up a free-return trajectory.

Your tech tree priority needs to be "Electrics" because doing missions beyond LKO will require a lot of power and you really need that first solar panel, you also get access to a better probe core from that node.  If you try to do a fly-by as I suggested before getting Electrics then make sure you slap on extra batteries and be frugal with your electricity usage (don't time warp with SAS left on).

In my career or science game I usually go in this order:

1. Mun fly-by
2. Minmus fly-by
3. Minmus landing
4. Mun landing

This always brings in adequate amounts of science to continue on this path.

Edited October 5, 2016 by Kelderek

[RealDarko]

13 minutes ago, Kelderek said:

I strongly recommend doing separate manned fly-by missions to the Mun and then later Minmus before trying to land on either of them.  You can obtain "in space near" and "in space high" science.

How can I obtain "science" without the science pod??

[DD_bwest]

you can get alot of science points in orbits of minmus and mun before having to plan a landing.  it can be done with what you have, but id prefer to wait until you have propulsion systems,   i love the spark lol

getting the eva reports for flying above all biomes is pretty easy,  also consider sending 2 material bays to orbit of each of these as well, yank the results out and bring back home.   the amount of science youd get for those 4 + the eva reports would make things much easier.

[Plusck]

4 hours ago, Plusck said:

You basically just need a Terrier and an FL-T400 tank in the lander stage, to get you down to the Mun's surface and back home. You could even use a bit of its fuel to complete the transfer to the Mun if necessary.

Before that, you need to get to orbit with a good amount of fuel left. A simple solution is a Swivel with FL-T800 and FL-T400 at the core, with 2x Thumpers and (very importantly) 2x FL-T800 drop tanks with fuel lines feeding the core stack. Add a couple of nosecones and you should still be under 30 parts.

I just did a test run with this, to make sure it was doable without too much trouble. I put dual Goo cannisters and a thermometer on the pod, but no materials bay. No monoprop in the command pod (I should have reduced ablator to about half or less, but forgot to do that). I lost the goo on re-entry - partly because I had zero electric charge left having forgotten to add a battery, so I couldn't maneuvre at all. In any event, be sure to remove the data before reentry.

The hard thing about that craft is the high TWR to begin with, then a much lower TWR when the SRBs run out. Either you leave the boosters at 100% thrust and turn very very aggressively off the launchpad, or you dial down the SRBs a bit (70-80% should work) so that they last longer and be a little less aggressive with the turn (but only a little, seriously).

Whatever you do, though, you'll never empty the drop-tanks before the SRBs run out, and TWR drops significantly when they do, so you do need to do a less-than-perfect gravity turn (aiming to get prograde to drop to 45° at about 16-20km, rather than the more efficient 10-12km). You really want to have somewhat more than 300 units of fuel left in LKO, otherwise your Mun landing will have to be flawless.

On my run-through, I was not aggressive enough turning off the launchpad, and had a huge (900 m/s or so) circularisation burn. This left things a bit tight to make the landing and return from the Mun. Pics here: http://imgur.com/a/slJmI

Edited October 5, 2016 by Plusck

[DD_bwest]

27 minutes ago, RealDarko said:

How can I obtain "science" without the science pod??

every crew report, eva report, and results from science experiments will give you science,  every biome will yeild more science.  for eva reports there is a corresponding biome in low orbit above each. you can pull results while you eva and then store when you re enter the pod.

if your using manned missions that is.  its much better science wise to go with manned missions

[RealDarko]

I think I will need a easier to pilot rocket lol

[DD_bwest]

46 minutes ago, RealDarko said:

I think I will need a easier to pilot rocket lol

i find early manned rockets easier than the small early probes.  it seems counter intuitive but top heavy rockets can be more stable.  think of an arrow head. even something as small as changing your fuel flow priorities to empty lower tanks ona stage before the higher ones will help stability a little. plus the manned pod has a good reaction wheel in it.

what does your gravity turn look like?

[Plusck]

57 minutes ago, RealDarko said:

I think I will need a easier to pilot rocket lol

Did you try copying the craft I pictured above? Turn on SAS, full thrust, launch and immediately hold down D until you're about 15-20° off vertical, then turn on prograde hold (your pilot having been in orbit, he should have that option now). It should basically fly itself to orbit from there.

[Kelderek]

Don't forget that in a science mode game you are free to over-engineer your rockets all you want.  You don't have to worry about funds, part counts or mass limits.  In a career game you have to be a bit more careful, but it is FAR easier to go to the Mun or Minmus earlier in the tech tree simply because you don't have those limitations.  You're allowed to EVA whenever you want so that gives you access to more science through EVA reports.  Using the tech nodes you said you've unlocked I whipped together this crude vessel to give you an idea of what is possible:

It's not an ideal design, and hurts from not having access to things like struts yet, but it has a lot of delta-V and could probably do landings if you want

P.S. I am plaing the 1.2 pre release, so it's possible some of this vessel, like the Experiment Storage Unit in particular (on top of the command pod) may not be available to you yet, but it's close enough to get the job done.

[Plusck]

1 hour ago, RealDarko said:

How can I obtain "science" without the science pod??

EVA, right-click on the instrument, click on "take data", then either board the pod again or right-click on it and click "store experiments".

If you have made a crew report (from right-clicking a manned command pod), EVA and right-click on the pod, "take" the experiments and then board or right-click and store again. That way you can do another crew report (from a higher altitude, different SOI, on landing, and so on).

[RealDarko]

19 hours ago, Plusck said:

Did you try copying the craft I pictured above? Turn on SAS, full thrust, launch and immediately hold down D until you're about 15-20° off vertical, then turn on prograde hold (your pilot having been in orbit, he should have that option now). It should basically fly itself to orbit from there.

Tried but is not getting me anywhere. Maybe I mounted it uncorrectly? Can you please post a pic?

[Plusck]

1 hour ago, RealDarko said:

Tried but is not getting me anywhere. Maybe I mounted it uncorrectly? Can you please post a pic?

Here are the craft files: B1 Mun attempt variants.zip. There are two craft in there.

The first one ("basic") is what I pictured yesterday. It is quite minimal with a low part count (if you remove all but one pair of nosecones it's exactly 30 parts). It is a bit tricky to get to orbit efficiently since it is underpowered once the boosters have gone.
To get to orbit: full power on launch pad, SAS on, launch, and after it reaches about 40-50m/s start gently pushing it over to 80° to vertical (heading right - east - of course). When the prograde yellow circle catches up with your heading, click on SAS "prograde hold". Stage the boosters, and right-click the drop-tanks so that you can drop them when empty. Action group 8 toggles gimbal on/off for both rocket engines (the Swivel and, later, the Terrier) if you want (all the wavering around annoys me and makes me think it's inefficient).
The really important thing to watch is the exact moment the gravity turn crosses the 45° line. It should be about 18-20km. If it is much lower or higher, you should probably revert and try again. If lower, you're likely not to make orbit due to the low-powered Swivel core, and if much higher you'll be losing more fuel to gravity.
If you do it really well, you should have just enough fuel to complete the Mun transfer burn on the Swivel stage. My best attempt was slightly short of that, and I needed to stage to the lander stage with about 100m/s still to go...

Spoiler

The other variant is an over-engineered version of the same basic design, but with Reliant booster stages replacing the drop-tanks. It's also significantly heavier and more expensive (though that only really matters if you're playing career). You could easily add a materials bay under the last decoupler if you want.
It's much more forgiving to fly due to the controllable fins and higher TWR.
You should use the same basic approach for the gravity turn (aiming at 80° by the time you reach 90-100m/s, then using "prograde hold" all the way to orbit), but this time you can be more aggressive in the initial turn and/or throttle down to ensure that you pass the 45° line at around 9-12km instead. If you miss that mark, the fins provide enough aero control to throw the rocket about quite a lot to perfect the turn (where the "basic" rocket would certainly spin out of control).

You should reach orbit with a nearly-full tank for the Swivel, and still have some left on circularising in low Mun orbit. You could even use some of it to deorbit and start your suicide burn - but that will make it impossible to plan ahead perfectly since you'll only get the final burn time once you've started the lander stage. However, you're pretty much guaranteed to need about 32-35 seconds total for the suicide burn, so if you start burning that far away from ground impact you'll be fine.

Spoiler

 

Oh yes - neither craft has any solar power, just one battery (incidentally, batteries and the smaller science experiments add weight to the part they're attached to, so if it's a core element there is no off-centre weight distribution; however, goo cannisters add weight as discrete parts - so they need to be balanced. There's therefore no point trying to balance a goo cannister on one side with batteries, thermometers etc. on the other side: it won't work!).

Therefore, once you lose the Swivel you'll be on battery power only until you get home, so don't leave any of the SAS "hold" options on if you don't need it. Still, there should be plenty of power to get you down to the Mun's surface (retrograde hold) and back up (stability assist only).

Edited October 6, 2016 by Plusck

[DD_bwest]

i really think a quick trip to minmus orbit with a bunch of science gear first might make things easier for you.  lots of easy biomes to hit when in orbit for eva's. Plus it really isnt much more than the mun, you just have the inclination to work with. 

[Kelderek]

@RealDarko asked me for more detail about the image I posted  further up in this thread and I thought it might be useful to share it here too. I break down the design into the various stages and show the parts I used and some descriptions.  Perhaps it will be useful for others as well as the OP.

http://imgur.com/a/hDDwG

[RealDarko]

IT seems I'm missing something basic here. I always pilot my rockets manually, but on the current Kerbal version my Jebediah pilot can automatically aim to Prograde hold. But how in the world will I get a stable orbit this way?

[Kelderek]

14 minutes ago, RealDarko said:

IT seems I'm missing something basic here. I always pilot my rockets manually, but on the current Kerbal version my Jebediah pilot can automatically aim to Prograde hold. But how in the world will I get a stable orbit this way?

At the start of your launch you will always have to manually pitch over to the east at least a little bit (10 degrees or so) to get the rocket leaning in that direction.  From that point on though you can often (not always) just switch on the prograde hold SAS option and it will do a very natural gravity turn toward orbit.  It all starts from that initial manual turn to the east, once the rocket has even a small tilt, gravity will naturally pull it toward the horizontal.  The trick is to have a balanced rocket so that it gets to horizontal at the right time, not too soon or too late.  This depends mostly on the TWR throughout the flight.  If your TWR is on the low side then holding prograde may lead to your rocket getting horizontal way too early.  If your TWR is too high then your rocket will barely tilt over at all and will try to go straight up.  Your goal is always to be roughly horizontal by the time your apoapsis is around 60 Km.

The further your rocket is from being perfectly balanced, the less likely you are to be able to just set a prograde hold and let it go - you will have to use much more manual control during your ascent.  You can still have a reasonably efficient launch if you can do manual control well enough.

[DD_bwest]

an early tip of 5 to 10 degrees and holding prograde as a gravity turn was a concept i didnt realy get until more recently and still dont fully understand the physics.  i think its because when you tip a little ita adds horizontal velocity that the gravity cant cancel out, so that vector slowly adds velocity.  as this happens itll slowly move your prograde closer to the horizon. which if your following prograde you will keep adding more and more horizontal velocity.

getting it down right can take some practice.  i usually try to be tilted 45 degrees and around 300-400m/s when i get 10km up

[RealDarko]

Ok, imagine my AP is at 70 km, should I keep the pilot pointing prograde and control myself only the burning?

[Plusck]

1 hour ago, DD_bwest said:

an early tip of 5 to 10 degrees and holding prograde as a gravity turn was a concept i didnt realy get until more recently and still dont fully understand the physics.  i think its because when you tip a little ita adds horizontal velocity that the gravity cant cancel out, so that vector slowly adds velocity.  as this happens itll slowly move your prograde closer to the horizon. which if your following prograde you will keep adding more and more horizontal velocity.

getting it down right can take some practice.  i usually try to be tilted 45 degrees and around 300-400m/s when i get 10km up

Good description, imho. And if you have a reasonable TWR in your last lifter stage (1.4 or so) that is probably the best combination of angle, speed and altitude.

I started trying to describe it before reading your post, and the result is very similar: "Gravity will always pull you down, constantly at 9.81m/s² (very slowly reducing as you gain altitude).  So by aiming slightly off the vertical, you slowly gain vertical velocity (some of which you lose, every second) while adding horizontal velocity (which you don't lose). Your angle of flight therefore drops towards the horizon. If you get the starting angle right, you just follow the curve and, just as you reach a horizontal speed which is enough to make that -9.8m/s2 into a circle around Kerbin, your vertical acceleration is precisely zero."

I don't think anyone actually gets the starting angle precisely right though. My best ever gravity turn probably needed a 50-100 m/s circularisation burn...

1 hour ago, RealDarko said:

Ok, imagine my AP is at 70 km, should I keep the pilot pointing prograde and control myself only the burning?

At that stage, the most important info is "time to Ap". If it is very short (20s or so) you're a genius and should keep burning while an acolyte feeds you grapes and ambrosia. For us mere mortals, time-to-Ap starts running away as you get to that point, so it's probably more like 5 minutes away. So you continue until it's something reasonable to work with (say 75km) then coast to Ap to circularise.
 

1 hour ago, Kelderek said:

At the start of your launch you will always have to manually pitch over to the east at least a little bit (10 degrees or so) to get the rocket leaning in that direction.  From that point on though you can often (not always) just switch on the prograde hold SAS option and it will do a very natural gravity turn toward orbit.  It all starts from that initial manual turn to the east, once the rocket has even a small tilt, gravity will naturally pull it toward the horizontal.  The trick is to have a balanced rocket so that it gets to horizontal at the right time, not too soon or too late.  This depends mostly on the TWR throughout the flight.  If your TWR is on the low side then holding prograde may lead to your rocket getting horizontal way too early.  If your TWR is too high then your rocket will barely tilt over at all and will try to go straight up.  Your goal is always to be roughly horizontal by the time your apoapsis is around 60 Km.

The further your rocket is from being perfectly balanced, the less likely you are to be able to just set a prograde hold and let it go - you will have to use much more manual control during your ascent.  You can still have a reasonably efficient launch if you can do manual control well enough.

Or if you're limited to OKTO probes or inexperienced pilots... and then being able to follow prograde manually is a necessity.

 

All in all, the one really important bit of info is (in stock) only visible in map view: time to Ap. (not going to plug mods, but this is one bit of info in the external view I find hard to do without)

What you really should be watching, from about 12 km upwards, is your time to Ap. It shouldn't change much at all during this phase of ascent. With a reasonable TWR, it should be about 40s. If your TWR is low it should be more than that. You can easily tell whether you've got it right because time-to-Ap should remain constant. If it's falling, your TWR (and/or your flight angle) is too low, if it's increasing, your TWR/angle is too high. Simply adjusting thrust or flight angle to keep time-to-Ap constant should put you on the optimal flight path - or if too far from prograde, should tell you what your optimal flight path should have been.

[magnemoe]

On 5.10.2016 at 8:09 PM, Kelderek said:

I strongly recommend doing separate manned fly-by missions to the Mun and then later Minmus before trying to land on either of them.  You can obtain "in space near" and "in space high" science.  You don't even need to worry about orbiting, a flyby will suffice for getting science, it just needs to pass close enough to get the "in space near" science access.  EDIT: you may want to orbit if you have trouble setting up a free-return trajectory.

Your tech tree priority needs to be "Electrics" because doing missions beyond LKO will require a lot of power and you really need that first solar panel, you also get access to a better probe core from that node.  If you try to do a fly-by as I suggested before getting Electrics then make sure you slap on extra batteries and be frugal with your electricity usage (don't time warp with SAS left on).

In my career or science game I usually go in this order:

1. Mun fly-by
2. Minmus fly-by
3. Minmus landing
4. Mun landing

This always brings in adequate amounts of science to continue on this path.

An free return is hard to do while getting close to Mun science, however without solar cells is safest. 
Else I tend to go directly for orbit around Mun. 
Minmus, if you go there you can just as well orbit and land, jumping around on Minmus give loads of science. 
it might be an idea to launch the second Minmus mission as the first leave as you have unlocked so much science you have more.  
You can do most biomes on Minmus at the dV cost of one Mun landing 

In carrier I tend to do Mun landing first because of contract. 

[Kelderek]

1 hour ago, magnemoe said:

An free return is hard to do while getting close to Mun science, however without solar cells is safest. 
Else I tend to go directly for orbit around Mun. 
Minmus, if you go there you can just as well orbit and land, jumping around on Minmus give loads of science. 
it might be an idea to launch the second Minmus mission as the first leave as you have unlocked so much science you have more.  
You can do most biomes on Minmus at the dV cost of one Mun landing 

In carrier I tend to do Mun landing first because of contract. 

I used a variation on the rocket I posted above to do landings in my current career game.  I had different technology nodes unlocked so the design wasn't exactly the same, but it was nearly identical to what I linked before.  That vessel was able to hit 5 biomes on Minmus and just barely succeeded in hitting two on the Mun - it was a close one on the DV for the second Mun biome, but I had a quicksave in a good spot just in case it wasn't enough.  It is certainly very easy to do run multiple missions to hit more biomes, but I generally avoid this if I can, I prefer to move on to interplanetary as soon as my technology enables it.  The Mun and Minmus are plenty of fun, but they have much lower science multipliers than everything else in the system.