10 tourist tier 2 rocket

[Carl]

Messing around with the first tier of upgrades on the pad and VAB and wanted to build somthing to do mass to orbit tourist shuttling. Came up With This. Fairly low tech.

EDIT: Had to Revise it to the 3.1 form after posting this initial because of some issues that showed when i tried to use mechjeb accent guidance. Link and pictures updated.

 

 

 

How to fly it info. Takeoff involves locking rot and pointing her up and burning till apophisis is about 50k, then tilt her over to point at the horizon, be gentle, this has to be done low enough she's liable to flip on you if your too heavy, mostly easy to avoid, but inattention has forced a few reverts. Burn at the horizon till apophosis is past 70k, then start pointing down, watch your apophisis number, if it's going up very quickly .1km a second or more, pitch down a bit more, continue until perephisis is in lower atmosphere, then halt, warp to apophisis and circularise. Be that manually or with jeb.

 

Alternatively if you have Mechjeb Ascent guidance, just copy the setting i used from the screenshots.

 

For decent, lock jeb to retro grade, burn remaining fuel off, then discard, then lock to prograde and let her drop till chut time, kill mechjeb and open chutes. She will start rolling 30km up, and that continues all the way down, but as long as she's locked to prograde in jeb i've never had anything overheat, a quick manual hold of the Q or E key will tend to help if you think your in danger.

 

Pictures:

 

Yes, as you can see below at zero inclination and with mechjeb you can get it to orbit with 143m/s left in the liquid boosters. That's a bit of a special case though, at any other inclination or manually you'll likely get there with just a few hundred left in the final stage.

Edited December 30, 2016 by Carl

[Carl]

Updated with a modified and Mechjebless design.

[Aerospike]

Interesting design, but it looks like it could be made more efficient.

I have a couple of questions: (I'm at the office, so I can't load your craftfile at the moment to look at it in the game myself)

• I see radial chutes on the SRBs, how do you recover them? (I don't see the "StageRecovery" icon on your toolbar, so I assume you don't use that mod. Can Mechjeb recover stages as well?)
• What is inside that small Service Bay on each of the liquid boosters, is that also for recovery (some probecore perhaps)?
• And why is there a battery on the outside of each one? Doesn't that produce a log of drag?
• Why is there a heat shield on the front? That looks also very draggy. Why not put it at the back and reenter that whole thing retrograde?

If you put a probecore on the "main" craft, you could use the capsule for an 11th tourist

By coincidence I tried to solve the same "problem" as you recently: shuttling a decent number of tourists at once to generate funds. Here is what I came up with, it works pretty well and is easy to fly:
 

Spoiler

 

 

Some infos:
9 Kerbals
~129 t ; 132 parts
Requires medium level tech (level 6: "Specialized Construction" for the Airshells/fairings and "Precision Engineering" for the HECS, (Cubic) Octagonal Struts and TR-2V decoupler)
100% Stock (with the exception of 3 surface mounted lights for visuals only, I could easily remove them if you want a craft file.)
costs 53K funds to build, but thanks to StageRecovery that is reduced to ~19K funds + fuel

 

Full album if you want more pics/infos: http://imgur.com/a/kWAI5  (don't be fooled by the first picture, that is of my old, very low tech 3 tourist craft )

Edited January 3, 2017 by Aerospike

[Carl]

Somehow missed you post in here for a bit, notifications must have missed it or somthing.

 

1. the chutes are just to pull the SRB's away so they don;t blow anything up, no Sepetron tech.

 

2. Reaction wheels, batteries are to power those during coast to orbit phase if dark.

 

3. It won;t re-enter tail first, flips and burns up part way up.

 

I'm aware you could probe core it, in fact MJ does that allready, but KSP insists on putting jeb in every time so i've let him become a tourist shuttle pilot.

 

Interesting design of your own, looks like quite a bit more tech than i had though and i'm not fond of part clipping, which it appears you've done with the passanger cabins.

 

I actually have a WIP 22 tourist design that reuses the core stack of my mun tourist orbiter, but with new lifter. Still refining it though.

 

Edited January 3, 2017 by Carl

[nascarlaser1]

this reminds me of space taxi 1 and 2, two old shuttles I tried to build in 1.0. Sadly, space taxi 1 smashed into the ground at 1km off the ground, with a loss of 12 out of the 13 Kerbals onboard, I scrapped it and built space taxi 2. Sadly when I upgraded from 1.0  to 1.2, I forgot to transfer the craft file . I will try to build it again one day...

 

This looks like a really really fun ship btw, I cannot wait to download .

[Aerospike]

12 hours ago, Carl said:

Somehow missed you post in here for a bit, notifications must have missed it or somthing.

1. the chutes are just to pull the SRB's away so they don;t blow anything up, no Sepetron tech.
2. Reaction wheels, batteries are to power those during coast to orbit phase if dark.
3. It won;t re-enter tail first, flips and burns up part way up.

Interesting design of your own, looks like quite a bit more tech than i had though and i'm not fond of part clipping, which it appears you've done with the passanger cabins.

 

 

@Carl

Thanks for your reply. A few suggestion for simple improvements to your design.

1. attach the SRBs to the TT-38K radial decouplers towards the top end (you can also move the decouplers upwards on the second stage, so that the overall SRB position relative to the rest of the rocket stays the same) -> that way the top gets pushed out when separating instead of the bottom and they don't hit the rocket. I just downloaded your craft, adjusted the SRBs/decouplers and removed the chutes -> worked flawless when I tested it.
2. attach the batteries on the side of the reaction wheels inside the service bay, they fit easy wihout any clipping. that should improve aerodynamics and make the rocket more efficient.
(2a. You have 6 LV-T45s on your second stage for pitch/yaw control, you only need the reaction wheels for roll control, do you really need so many reaction wheels?)
3. That is because your most heavy part is at the nose. Maybe if you could put all that stuff on the Mk1 cockpit to the back you could achieve a stable tail first reentry.
Bonus1: remove the mono-propellant from the cockpit. you don't have any rcs, so that is just dead weight you are carrying
Bonus2:I just flew your craft (with modifications 1 and 2) to a ~74x88 km orbit without even using the third stage (manually, no mechjeb etc involved). I think you could replace that single LV-T45 with a LV-909 for more efficiency in vacuum. So I also tried to reenter with the last stage still attached -> stable tail first reentry even with all the fuel gone at the end (I used that fuel to break, as I didn't know if the engine could take all the reentry heat.)

 

My design requires a bit more tech, agreed and there is indeed some part clipping, but it is minimal.
I too dislike excessive part clipping for vessels in career mode, but I have a few exceptions where I consider it acceptable, for example with this craft:

1. There is a very small overlap of the passenger cabins, but it hardly affects the internal volume. Similar reasoning can be used for the fuel tanks below the cabins. The craft would probably work just as well without offsetting the cabins/tanks to stay inside the 2.5 meter diameter, it would just look not as good in my opinion. However I agree that this is a "fringe case" for clipping, especially with the fuel tanks. To stay 100% true to my own "rules", I would have to remove a bit of fuel from the tanks to compensate for the lost volume.
2. There are parts clipped inside the Rockomax Brand Adapter: That thing is completely empty, so I do not consider putting parts inside as cheating. There is an Advanced Inline Stabilizer on the top (below the service bay) and 3 octagonal struts on the bottom (that are used to attach the passenger cabins) inside, but they do not overlap with each other.
3. There is a column of cubic octagonal struts running from the Rockomax Brand Adapter all the way down to attach the "orbital craft" to the upper stage of the rocket. Yes they are inside the cabins and tanks, but they hardly have any volume, so I see it as a "structural modification" (to access the center node of the Rockomax Brand Adapter at the point where LV-909 engines end).

@nascarlaser1

Are you talking about Carl's craft or mine?

Edited January 4, 2017 by Aerospike
fixed typos

[Carl]

1. They should be attatched at the top, your not using a mod that adjust that or i haven;t missed a setting in the options somwhere have i?

 

2. DoH i think the batteries where a last minute addition, also yes you need the reaction wheels. Two problems showed without them. A) during coast phases aligning for subsequent burns was impossible without them. B) the gimbels tended to be a tad over sensitive at some altitudes, but if restricted too insensitive at some other altitudes. The reactions dampen it all out somehow.

 

3. I figured it was aero but that makes sense too, the top stack was actually built earlier before i got 1.25m service bays and i didn't want to mess, (also i had a devil of a time getting the solar panels through reentry). so thats why the reactions are on the pod.

 

4. Oh it's got a lot of dv, i used the swivel last stage because when i flew it i had to do the circularisation burn with it. But that may be you moving the batteries. orbit insertion needs a better TWR, also i may not have had the terrier when i made that, again can't remember, (then again not sure where in the tech tree that is so duh).

Edited January 4, 2017 by Carl

[Aerospike]

@ SRB attachment: I haven't used any mod to adjust part placement. I just loaded your craft and had a look. The placement can also be seen in the first picture of your original post: the radial decoupler is on the bottom tank(s) of the second stage(s) and about midway the length of the SRBs. just move it up to be between the second (from bottom) tanks on the second stage(s) and the top end of the SRBs - then the SRBs separate cleanly without any parachutes.

@ reaction wheels: makes sense. I guess my rockets before the "SpaceBusXL" posted above have all been a lot smaller and didn't need so much force to control them.

16 minutes ago, Carl said:

i used the swivel last stage because when i flew it i had to do the circularisation burn with it. But that may be you moving the batteries.

Moving the batteries inside the bays + removing the weight (and drag) of the chutes on the boosters. And if you remove the mono propellant from the mk1 capsule, you'll get another (very small) improvement

Anyway, I like how much you got out of the low tech parts. I kept using much smaller crafts and unmanned probes until I had a lot more science (and parts) available. I'm just now starting to build bigger stuff
Thanks for the conversation and happy launchings!

[Carl]

headdesk my fault, it's not the separation that i have the chutes on this one for, thats the 22 tourist design that needs that. This is to stop them hitting the pad on the way back down.

 

Other that  that good points. And thanks for the praise :).

[nascarlaser1]

8 hours ago, Aerospike said:

@nascarlaser1

Are you talking about Carl's craft or mine?

Both!

[Aerospike]

@nascarlaser1

Here ya go: https://drive.google.com/drive/folders/0B97_OqRbLEUXS2swc2xDSlBESkk?usp=sharing (craft files + images)

I reworked the craft slightly because I reconsidered my own "rules" regarding part clipping after @Carl's comment about the clipping:

• The cabins, tanks and engines on the orbital section are now no longer in a 2x2 config, but only in 3x symmetry -> that way the clipping is reduced to a minimum and now basically only the sidewalls overlap each other.
• Since that reduced the capacity from 9 to 7, I created an extended version with double the passenger cabins -> total capacity 13 (a Kerbal lucky number! )
• Removed the long launch clamps. I thought they would add "realism" on the launch pad, but I don't like how close the are to the SRBs and they are actually not necessary.
• I renamed them in SpaceBus2 and SpaceBus2XL respectively.
• NOTE: if you want to land without detaching the tanks+engines on the orbital section, hit the "B" key (or whatever key you have brakes bound to) to deploy the chutes without activating/decoupling the previous stage!

Enjoy!

Edited January 5, 2017 by Aerospike