Take "MOAR BOOSTERZ" more seriously.

[Guest]

THE MOAR BOOSTARZ CHALLENGE.

Jeb became the administrator of the KSP..... Now he now makes all ships using SRBs!....

Rules:

- MUST BE STOCK.

- All ships propellant must be ONLY SRBs.

- No RCS

- No Mechjeb...

- No Hyperedit.

- No Kerbal Engineer.

- No Debug Menu.

- No infinigliding

Scoring:

SSTO : 1000

Orbital Ship : 400

Dock with another ship: 2000

Munar Ship : 900

Minmur Ship : 800

Dunar Ship : 2000

Evian Ship : 3000

Moholian Ship :6000

Joolian Ship : 5000

Dresian Ship : 4000

Eelooian Ship : 6100

Manned Ship : 100

Unmanned Ship : 50

Suborbital Ship : 200

Return from that place: Twice the points of that place you went.

Land at that place: Twice the points of the place you went.

Scoreboard:

obi_juan : 4200

Avera9e Joe : 1000

MarvinKitFox : 450

Edited June 8, 2014 by Guest

[christok]

I took Jeb to orbit and back just to try this out (not an entry because I used a Deadly Re-entry heatshield). I think that most of these points are probably too difficult or too much of a chore.

Having said that, perhaps I should ask for clarification. If by [Planetary] Ship you mean an orbiter rather than a lander, it might be fun to try.

PS: Consider allowing DRE and TAC life support parts. The game's just more fun with them and they don't make anything easier.

[rtxoff]

SSTO is simply not possible with SRB's

[Pecan]

Oh yes it is!

GAAHHHH! Now you've done it. As if I'm not already trying to do too many things at once, I'm going to have to prove that now aren't I.

*sigh* Give me an hour, I need to cook dinner first ...

[Rockstar04]

If by SSTO you mean you don't lose any parts I can see it being done. If you mean all boosters must be lit on the launch pad, and no more can be lit on the way up, I see it as much more difficult.

[Chrisd857]

Having said that, perhaps I should ask for clarification. If by [Planetary] Ship you mean an orbiter rather than a lander, it might be fun to try.

Another question about scoring - nothing for non-Kerbin moons? I don't know about ease, but landing on Gilly with only SRBs would be hilarious. Also, are separatrons considered SRBs?

[Pecan]

Ok, so cooking ran into eating and then ... anyway; Mk1 command pod, 5xS1 SRBs (core + 2 + 2) gives 4,743m/s although I added an IRW to make the gravity turn easier, reducing the deltaV to 4,704m/s. All boosters tweaked down to increase burn-time and action groups used to ignite 2, then 2 then 1 (for final circularisation). It doesn't fly well but it works if you time the burns properly.

[rtxoff]

Ok, so cooking ran into eating and then ... anyway; Mk1 command pod, 5xS1 SRBs (core + 2 + 2) gives 4,743m/s although I added an IRW to make the gravity turn easier, reducing the deltaV to 4,704m/s. All boosters tweaked down to increase burn-time and action groups used to ignite 2, then 2 then 1 (for final circularisation). It doesn't fly well but it works if you time the burns properly.

From a technical perspective this is not an SSTO, you used 3 stages, it really does not matter how you fire them through ingame staging or action groups it's the same purpose for staging.

However i forgot how powerful the new ARM SRB's are, they have enough dV to make an SSTO even without staging if you tweak the thrust right.

[zarakon]

From a technical perspective this is not an SSTO, you used 3 stages, it really does not matter how you fire them through ingame staging or action groups it's the same purpose for staging.

Technically that's more of a semantics perspective than a technical one..

If that doesn't count as SSTO, then neither would any of the "SSTO" spaceplanes that switch from jet to rocket engines

[rtxoff]

Well i tried to reproduce Pecans setup, it is not working, even at full thrust and only the Mk1 Lander you can't reach an apo of more then ~35km by the end of the booster 3+4.

Pecan it does not work that way....

Also the 4.700m/s dV is the vacuum value not the atmospheric one.

A single S1 without any payload has under 4500 atmo dV, so i am pretty sure now an SSTO is not possible.

Edited June 3, 2014 by gpisic

[cantab]

If you don't drop anything, it's an SSTO. Switching engines is fine.

[rtxoff]

Anyway, it's still not possible.

[frizzank]

Impossible and really hard are two very different things, especially when dealing with the internet....

[obi_juan]

THE MOAR BOOSTARZ CHALLENGE.

Scoring:

SSTO : 1000

Orbital Ship : 400

Dock with another ship: 2000

Munar Ship : 900

Minmur Ship : 800

Dunar Ship : 2000

Evian Ship : 3000

Moholian Ship :6000

Joolian Ship : 5000

Dresian Ship : 4000

Eelooian Ship : 6100

Manned Ship : 100

Unmanned Ship : 50

Return from that place: Twice the points of that place you went.

This scoring table shows that you did't try this challenge for your self.

"No RCS" and only 2000 points for a docking with another ship?

And only 1000 points for a ssto?

Is this challenge possible?

Many challenges we see are nearly or literally impossible to achieve, and usually very little thought has gone into them, these challenges just annoy people, waste forum space and show that the submitter hasn't really tried.

So test your challenge yourself first to make sure it is possible, you don't have to be successful but you'll soon know if the challenge has a hope of being completed.

But I want to make a challenge like this. And I think some of them are possible.

[rtxoff]

Impossible and really hard are two very different things, especially when dealing with the internet....

It is open to you to prove me wrong, try by yourself and eventually you will find the truth.

[HafCoJoe]

This sounds AWESOME. Totally in. SAS is still fine? Can SSTO's be staged after reaching orbit?

[cantab]

Single Stage To Orbit. So what do you think?

[HafCoJoe]

Single Stage To Orbit. So what do you think?

kbro.

UPDATE:

Here's my progress (I'm surprised I actually had open time so soon):

Javascript is disabled. View full album

The random gray line is a captured asteroid.

So I went interplanetary once and missed the Mun on corrections twice. It was fixed tho.

Edited June 4, 2014 by Avera9eJoe

[Pecan]

Anyway, it's still not possible.

:-( You're right, my model doesn't work. Not sure why you can't get an Ap above 35km, I have no problem with altitude - keep coming up a couple of hundred m/s of stabilising orbit though. I still think it is possible to SSTO with SRBs but it'll probably be an exploitative build and not something I have more time for at the moment. Still, challenges are meant to be, well, challenging and I hope I'll be back to this in a few weeks. For now, you win :-)

[Mazlem]

Last Friday night I watched The_lolbster on Twitch launch into orbit around Kerbin, then go to Duna and land. He has other videos of going to the Mun and Minmus. No liquid fuel, no RCS, just solid fuel boosters and sepratrons. The launch ran at 1fps and took 30 minutes!

Edited June 4, 2014 by Mazlem

[MarvinKitFox]

Ugh. My closest to a SSTO gave me a 72 x 65 orbit. ARGH!! that's about 12 m/s short!!!

Maybe if I add another 40 S1 SRB's?

Ok, after 30+ tries, I can safely say: *I* cannot get a true SSTO SRB-only into Kerbin orbit.

Even the very exploity tricks like launching from a 300-m tall launch tower don't *quite* do the trick.

And no form of winged-aerodynamic-thingy gets even close.

Sighs.

Edited June 4, 2014 by MarvinKitFox

[christok]

Ugh. My closest to a SSTO gave me a 72 x 65 orbit. ARGH!! that's about 12 m/s short!!!

Maybe if I add another 40 S1 SRB's?

You've certainly done better than me. I'd count that. A decaying orbit is still an orbit. Let's hear what Fyre Flare accepts, since I don't have a say.

May we see the rocket?

[MarvinKitFox]

You've certainly done better than me. I'd count that. A decaying orbit is still an orbit. Let's hear what Fyre Flare accepts, since I don't have a say.

May we see the rocket?

I don't count it.

Didn't take a picture, as I though "Oh sure, I can optimise the launch curve better than that, this is only my third attempt"...

hehehe.

Never got anything better than a 75km x -10km after that, and that is something like 100-120m/s short.

Here is a typical "good" run.

final orbit 97 x 12 (48m/s short, would have been 15m/s short if my aim was better)

((running MJ on the trials, will not need it for a final run once I have times&angles all worked out))

Method is easy.. plenty SRB to get to just below terminal velocity, then triggering next set of srb with tailored thrust levels keeps me within 85%-105% of TV.

Launch at 85* to 8500m, then more-or-less follow orbital prograde for gravity turn..

Delay last firing until alt=47500, to allow burnout at 72km.(else how circularise)

Aim using one reaction wheel, and plenty of light batteries for power.

If i don't make orbit, use maneuver node planning to see what delta-v burn *would* have made it.

This run is 62m/s short. If i handled my turn better making apo 70-72 instead of 97, would have been 15m/s

Still not orbital

[rtxoff]

If you can't get an single S1 with an reaction wheel attached into stable orbit adding boosters won't help no matter how many more. The total dV won't get more because of that.

It maybe helps a bit getting a more optimal ascend path because you have not to fire all the boosters at once. Still 4500m/s dV is a very theoretical value for getting into orbit. It can be done but only with the most optimal ascend. You simply can not do that with boosters only. Also a single S1 has less then 4500dV atmospheric.

[Jouni]

If you can't get an single S1 with an reaction wheel attached into stable orbit adding boosters won't help no matter how many more. The total dV won't get more because of that.

It maybe helps a bit getting a more optimal ascend path because you have not to fire all the boosters at once. Still 4500m/s dV is a very theoretical value for getting into orbit. It can be done but only with the most optimal ascend. You simply can not do that with boosters only. Also a single S1 has less then 4500dV atmospheric.

It's easy to get vacuum Isp over 4700 m/s with SRBs: burn the RT-10s first, because they have the best mass fraction, and use the S1s later, because they have better Isp. My current design has 4440/4779 m/s, which is significantly more than most of my launch vehicles have with nominal payloads.

The real problem is drag. SRBs have drag coefficient 0.3 instead of the usual 0.2, increasing delta-v losses and changing the optimal ascent path. It might be enough to delay the turn by 5000 m * ln(0.3/0.2) ≈ 2 km, but I'm not sure how much delta-v the ascent requires. Just delaying my usual ascent path by 2 km got me to a 203x-112 km orbit, so it might be enough to add one RT-10 for circularization.