Jump to content

To Orbit...

Fellow314

By Fellow314
in KSP1 The Spacecraft Exchange

 Share

Recommended Posts

Rune

Rune

Posted
Posted

Really cool looking. And it must come cheap! A few things, tough, just because I also like receiving suggestions and ignoring them ;) (or not):

-Do you really need the reaction wheels? Trust your control surfaces in the lower atmosphere, and once you are out, you can take your time turning, unless you have something unbalanced (which you shouldn't, eyeballing it).

-Do you need that much RCS? If it is you only in-space propulsion, awesome, but maybe you could switch the part with a Mk2 docking port, which carries more than enough monoprop for a few dockings, and has the docking port and such. Then again, I totally get that the shielded docking port makes a very cute nose. But maybe a payload bay with a small RCS tanks inside, for small satellite delivery and such?

-The other kind of RCS ports have much higher heat tolerances. And considering how many of those you have there, they won't increase part count appreciably.

 

Rune. I say these things because this is totally something I would have built for myself, which in other words, means I like it a lot. :)

Link to comment
Share on other sites
Fellow314

Fellow314

Posted
  • Author
Posted (edited)

Thanks! :D:D:D

I was aiming for cheap.  My new design philosophy, since I can't just pack a bundle of air intakes on any old thing any more, is to keep all the expensive bits, recovering anything that's not a fuel tank or an SRB, in essence.  I resent the two wing parts that fall away with the fuel tanks :D

 

The reaction wheels are partly aesthetic and partly structural.  I find mounting engines and RCS units on them easier than on that fuel tank, where they tend to end up wonky..  And it makes it a doddle to fly.  It's overdone though, I know.  They also make the body the right length for the wing.

The RCS is the only propulsion for any orbit over 120Km.  A better pilot than me (or rather, mechjeb) could probably get away with less.  

I have real trouble mounting the other RCS units, especially at the back where it's all control surfaces and engines and no space.

 

Oh, and there's some slightly cheaty hidden aero parts at the back that I'd totally forgotten were there, which is slightly annoying.

Edited by Fellow314
Link to comment
Share on other sites
Fellow314

Fellow314

Posted
  • Author
Posted

 

Continuing with a theme. 

18 Tonnes into orbit.

No RCS at all this time (possibly not actually a feature :D ), fewer reaction wheels for a much larger vessel as well,

Reaches a 100 x 100Km orbit with about 100 M/s Delta V left.  Double that with the cargo out and it has just enough to get back on the ground where you want, or, as in the carefully prepared, bail out to the island via a really unusual approach path, album shows, somewhere close to where you want.

Most of the power's supplied by the enormous fireworks on the side, which means getting lots of height from them before they're dropped, at which point the TWR falls to 1.  I suspect this beans the profile is inefficient??

https://www.dropbox.com/s/djz9fmilf38rcoj/Cargo%20One%20NMJ.craft?dl=0

 

 

QiF2m3a.png

 

 

Link to comment
Share on other sites
Red Dwarf

Red Dwarf

Posted
Posted (edited)

You've got a really fascinating design philosophy going there. I'm a big fan of creative alternate shuttle concepts (see signature), and you're doing some impressive work. I don't think I've ever seen SRB's mounted like that! And the design of your cargo rocket... I'm honestly surprised it has enough delta-v to make orbit with the configuration you have. What sort of ascent profile are you following?

Edited by Red Dwarf
Link to comment
Share on other sites
Fellow314

Fellow314

Posted
  • Author
Posted (edited)
5 hours ago, Red Dwarf said:

You've got a really fascinating design philosophy going there. I'm a big fan of creative alternate shuttle concepts (see signature), and you're doing some impressive work. I don't think I've ever seen SRB's mounted like that! And the design of your cargo rocket... I'm honestly surprised it has enough delta-v to make orbit with the configuration you have. What sort of ascent profile are you following?

 

Thanks :D

The ascent profile's governed by the SRBs which may be slightly too big for the weight of the craft, providing an enormous percentage of the required deltaV.

The TWR at launch is 1.7, rising to 3.6 and falling to just 1 after the SRBs drop, so the profile has to be lots of up before any sideways.  Mechjeb does it for me, I'm afraid, and consistently reaches an 100Km orbit with around 100 M/s Delta V (before the cargo's unloaded) so it's a close run thing.  (I suspect this is woefully inefficient and the sign of a poor design)


I'm not sure the concept's going to suffer too much more scaling up though :)

Edited by Fellow314
Link to comment
Share on other sites
Red Dwarf

Red Dwarf

Posted
Posted

Do you fire the aerospikes through the whole ascent, or do you throttle them back as weight decreases? Judging from the numbers you gave, you might even be able to cut your liquid engines entirely and sit on your SRBs for a good portion of your ascent. 3.6 really is a lot more than you need. With that much kick behind it, you could totally expand your orbiter, and give it more delta-v in orbit, or a crew compartment or something. You could also thrust-limit the SRBs just so they burn a little longer.

Link to comment
Share on other sites
Red Dwarf

Red Dwarf

Posted
Posted

The K16's reentry troubles might be remedied by a different descent profile. You might just be hitting the atmosphere at the wrong angle, pitched too low to slow down effectively. If you don't present enough wing surface to slow down in the upper atmosphere, you run the risk of overshooting, burning up, or potentially worst of all, reaching the mid to lower atmosphere with too much speed. That can lead to the sort of finicky flying you're running into. Before I worked out the right angle of attack for my Fermion's descent path (35 to 45 degrees above the velocity vector), the best way I found to slow down was to intentionally stall it, flat into the wind, and then drop like a rock :P. Once I worked out the right way to fly it, I never had issues again.

Other things might be the cause of your control problems. It might be that you have too much lift for the size of your shuttle, or the dry COM is out of position with the COL. That, or some other aerodynamic characteristic could be causing it, like the leading edge of the wings. Or you could just add reaction wheels until it ceases to be an issue :wink:

Link to comment
Share on other sites
  • 2 weeks later...
Fellow314

Fellow314

Posted
  • Author
Posted (edited)

Er, distracted again, but this one's finished.

 

Three Kerbals, LKO, Not a lot of tech required, nothing more than level 2 anyway, which makes the launch profile interesting.

 

Fully recoverable and there's enough fuel left in the launcher to fly it back across the ocean to the runway for 100% recovery.

 

1 - toggle intakes

2 - Turbofans

3 - Toggle dry/wet (just leave it on wet for the launch)

4 - Main rocket motor

5 - Decoupler/Sepratrons

0 - Chutes

 

f2gyD0n.jpg

https://www.dropbox.com/s/3rrb2r14sa888n2/Done%20LT3-2ST%20%20NMJ.craft?dl=0

 

Edited by Fellow314
Link to comment
Share on other sites
  • 1 month later...
Fellow314

Fellow314

Posted
  • Author
Posted

I figure I may at least put these links in here :)


This is the smallest I thought I could make an SSTO with a cockpit for the K prize:

 


This was created in response to a comment in the Jool Mission challenge thread.  I think it's smaller than the first one and fits in a cargo bay.  I'm quite pleased with this one, but the wings, I think, are an optional extra :)

 

Link to comment
Share on other sites
  • 2 months later...
  • 4 weeks later...
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
 Share
Go to topic listing
×
×
  • Create New...