how to: Low tier passanger rocket

[martafix]

Hi, i want to ask rocket-pro, who know how to build low tier rockets. I'm trying to invent rocket with can get 5 kerbals(1Pilot+4passaners) to orbit around Kerbin and safely land back, but it usually ends catastrophicaly on start, or if it is good enought to make orbit, I dont have fuel to deorbit.

Thanks Martafix

[Red Iron Crown]

Welcome aboard! I moved this over to Gameplay Questions where the helpful folks will see it.  

[Tatonf]

Please define "low tier". Are you able to use something else than the Mk 1 pod ?

[steuben]

and pics of what you're building so far will help as well.

[martafix]

I have:
Pods: Mk1 Command Pod, Mk1 Cocpit, Stayputnik, Mk1 Crew Cabin

Engines: Swivel, Rentail, Terrier, Thud, Juno (D-25 Radial Engine, A7 Areosport Engine, these are from KAX)

SRBs Hammer, Flea, Thumper

Fins: Basic Fin, AV-T1 Winglet, Tail Fin, some wing stuff,

Fuel Tanks:  FL-T100, FL-T200,  FL-T400

Chutes: mk16 , mk2-r radial

and some radiators, battery,struts , service bay and Micro Landing Strut

I Hope it's enught, if not tell me pls what i need to unlock

 

 

[martafix]

VAB lvl 2

Lauch Pad Lvl 2

[steuben]

what techs do you have researched?

[martafix]

all to 45sience(with), I havent unlock only flight control from these, from 90sience and more I dont have unlocket any.

[Plusck]

Simplest and lightest (if you have the tech) is probably a Mk1-2 pod with a 2-kerbal crew cabin stuck on top.

With a decoupler, Rockomax 32 fuel tank + Poodle underneath, then another Rockomax 32 + Skipper under that, fins and parachutes and a couple of OX-STATs and/or batteries, you have a sub-20 part, sub-50 tonne, sub-20m high rocket which should get you to and from orbit with fuel to spare.

It's slow of the launchpad but you really only need the first stage to get going far and high enough for the Poodle to get started and do the rest of the job. Just don't be too aggressive with the gravity turn since TWR isn't great at any time.

If you don't have the crew cabin, two 1-person lander cans would do.

 

However, if you're missing any of the main parts here (Mk1-2 pod, Poodle, Skipper) then it'll be very difficult to take that many people up at a time. Or rather, you might get them to orbit but they'll probably crash and die on the way back.

Edited March 30, 2016 by Plusck

[steuben]

sounds pretty easy... with experience...

core stack:
2 mk1 crew cabins, mk1 command pod,  2 sets of tail fins (one top and one bottom), 3 ftl-400 fuel tanks, a relient on the bottom, and 4 or 6 mk2 radial mount parachutes.

boosters:
a couple of back should so you nicely.
 

decent profile, tail first until about 1600 m/s and then a series of controlled maneuvers to shed speed (or wild tumbling) down to 250 m/s and pop the chutes.

though that is a back of the envelope design. it should get you close.

[martafix]

I dont have any 2,25m parts:(

This is my actual design, but it works only if you are very lucky in orbiting. Second problem of this design are taifins, witch are required when SRBs burs, but at end of SRBs burn they causes big jiggeling and unstability

 

Edited March 30, 2016 by martafix

[steuben]

I'm going to amend my design. the boosters are stacks are 5 ft400s with a reliant

[Plusck]

1 hour ago, steuben said:

sounds pretty easy... with experience...

core stack:
2 mk1 crew cabins, mk1 command pod,  2 sets of tail fins (one top and one bottom), 3 ftl-400 fuel tanks, a relient on the bottom, and 4 or 6 mk2 radial mount parachutes.

boosters:
a couple of back should so you nicely.
 

decent profile, tail first until about 1600 m/s and then a series of controlled maneuvers to shed speed (or wild tumbling) down to 250 m/s and pop the chutes.

though that is a back of the envelope design. it should get you close.

Are you sure you did this in 1.0.5? With just BACCs, that gives 3400m/s. WIthout controllable fins it is very hard to get into a decent ascent profile, with them the "tail-first" re-entry is virtually impossible - and needs huge batteries and a decent pilot to even attempt. Non-controllable fins will burn off on descent.

[Junafani]

I did some testing and managed to do it easily (I did in 1.1 pre-release, but it should work just as well in 1.0.5 since there aren't really anythiung game-changing in the update).

Cabin section:

• 1 x mk1 command pod
• 2x mk1 crew cabin
• 1x 1,25m heatshield
• 1 x mk16 parachutes
• 2 x radial chutes

Upper stage:

• 1 x FL T-400 fuel tank
• 1 x FL T-200 fuel tank
• 1 x Terrier

Lower stage:

• 5 x FL T-400 Fuel Tank
• 3 x MK-55 Thud
• 3 x AV-1 winglet

Thing handles like a wet noodle until you stage to upper stage. Perhaps adding more fuel to lower stage and putting 4x thud might help since then they aren't in triange configuration. Reducing gimbal limit might also help. I managed to get into ~93x73 km orbit with about half of T-200 left and did somewhat slow re-entry by putting periapsis to 30 km. One radial parachute showed temperature gauge few seconds but it stayed in the middle so not really problematic.

When you are using 1,25m parts those normal engines are bit lackluster compared to 2,5m engines. You could cluster them but since you do not have those fitting palte thingyes it is easier to just use Thuds since they can be just put into side.

Edited March 30, 2016 by Junafani

[martafix]

thx a lot, i have mixed my design with your, so it now works well, maybe i dont even need 2nd stage. Anyway , can you give me advice, what i should research next? i have researched 90cost electric, but I'm not sure what next..

[Plusck]

46 minutes ago, martafix said:

thx a lot, i have mixed my design with your, so it now works well, maybe i dont even need 2nd stage. Anyway , can you give me advice, what i should research next? i have researched 90cost electric, but I'm not sure what next..

This will vary from one person to the next.

In the 90s range, the OX-STAT and OKTO probe core (which you just researched) are vital for going further.

Next up (IMHO) is the barometer (more science experiments are equally vital - making it easier to rack up science points, including from all the places you've been before).

After that I reckon fuel ducts are the most useful (plus you get the long 1.25m tank).

And once you have those, difficult to say. One option is to get the Poodle and Skipper (and with rare exceptions you'll never need another 2.5m engine) since you have the tanks for them (with the fuel line). Another option is Advanced Flight Control (RCS, torque wheels and the most useful 1-man lander can). Or you get the radial decouplers... or...

Edited March 31, 2016 by Plusck

[AeroGav]

I'm more of an airplane/spaceplane person but i have built some rockets in early career mode and making something that doesn't lawn dart on re-entry is a problem lots of folks run into,  when trying to bring back more than just a capsule.    Being an airplane person, i solved this with fins, so i can steer it off the terminal dive it likes to get into and slow down so  you can get the chutes open safely.

https://onedrive.live.com/redir?resid=7003A8806D8A6B2C!716&authkey=!AK7nQaujPuAKeUU&ithint=file%2ccraft

I tried pretty hard to keep the ascent stage small and cheap, my own career games i'd probably have used side by side boosters on the lower stage, but that's more cost mass and drag.   I have kerbal joint reinforcement installed  i hope it doesn't flop around too much..

Bill of Materials

upper stage -

nose cone

heat shield

ft200 fuel tank

ft400 fuel tank

4 ox-stat solar panels

2 radial mount parachutes

mk1 passenger cabin ( 2 of)

4 steerable fins

mk1 inline cockpit

terrier engine

 

lower stage

3 ft400 tanks

swivel engine

3 steerable fins

 

ZOMG booster stage

6 Fleas

 

EDIT - upper stage in flight.   One is reminded of the scene from the Austin Powers movie...

 

Here's a  2 passenger variant in one of my career games, just before popping the chutes.  Body and fin lift mean we can slow down from even the steepest sub orbital trajectory to a safe parachute velocity.

Edited March 31, 2016 by AeroGav
xtra info