The Reusable Launch Platform Challenge

[Northstar1989]

(Picture of SpaceX's "Grasshopper" rocket performing a flight-test of technologies to be used on the Falcon 9r)

This is a challenge to create a 100% reusable vertical launch platform to carry payloads to orbit of Kerbin. This is NOT a spaceplane challenge, but rather more in the spirit of creating Space-X style rockets (if the image of the Space-X test rocket above didn't queue you in)

Please try and keep in (at least somewhat) believable- for instance please don't air-hog (more than 3:1 ratio of intakes to engines) or use the jet engines as a launch platform- which is in fact banned in the rules, as jet engines are very OP'd... (generally, jet engines have little place in this challenge, except as mothership craft- although I'll make an exception on the jet/RAPIER engines for any player using Real Solar System or Advanced Jet Engines, since it indirectly/directly limits the fraction of orbital velocity they can achieve...)

The Rules:

1. Your rocket or shuttle MUST take off vertically (exceptions made for "mothership" plane designs- see below). No spaceplanes allowed for this challenge.

2. ALL parts must be landed and/or recovered on Kerbin. IF you use drop-tanks or boosters, they must safely touch down back on Kerbin while loaded (in stock, this means they can only be decoupled right off the launchpad, or as a late drop just before making orbit...)

EDIT: I have just learned about Flight Manager for Reusable Stages. You are allowed to use this mod. FMRS will allow you to drop stages deep in the atmosphere (where they would normally be destroyed after exiting physics-range), and manually fly them back to the ground- once landed it lets you recover the vessels and/or merge them into your main save. This should make more realistic Space-X style launches (with the Falcon 9r, the lower stage would never actually exit the atmosphere) and Space-X style launches while using Real Solar System without insane upper stage TWR values possible.

3. Balanced mods are allowed. Examples include: Novapunch2, KW Rocketry, B9 Aerospace, Near Future Propulsion, Firespitter, Space Shuttle Engines, and KSP-Interstellar (with special restrictions- see below).

Vessels using KSP-Interstellar are restricted in the following ways:

- No use of fusion, antimatter, or fifth-generation fission reactors may be used (the ones not unlocked until you discover fusion power- the fourth gen MSR reactors are as high-tech as you're allowed).

- If making use of ground-based Microwave Beamed Power (this is not only allowed, but in fact encouraged for awesomeness) no more than 18 GW of thermal power in reactors with solid-state generators attached are allowed (that adds up to around 3 GW of electricity to beam- hint, 4 Akula reactors are worth *precisely* 18 GW). The reactors must all be located outside of loading distance from both the launchpad and runway- but need not be located near the KSC (mountains and the island runway both work well as reactor sites, for different reasons).

- You may supplement your ground-based Microwaved Beamed Power with up to 3 MW of beamed solar power from orbit (no orbital reactors allowed). Relay networks are allowed to help get this power to your craft, as well as the ground-based beamed power (only really useful if you circularize on the far side of Kerbin).

- No use of DT-Vista engines. No use of upgraded plasma thrusters (the basic ones, however, are allowed).

4. Alternative launchpads on Kerbin ARE allowed. This means you can set up an Extraplanetary Launchpad anywhere on the surface if you want. Launches from platforms supported by securely anchored Hooligan Labs blimps are also allowed, as are drop-launches from "mothership" type planes (like is being done by Copenhagen Suborbitals in real life). If you use a mothership plane, it MUST separate from the rocket at below 32 km in altitude in a non-ballistic trajectory.

5. Your rocket/shuttle may only detach payload with mechanical decouplers or docking-ports (this is, from a roleplaying perspective, to avoid potential damage to the reusable vehicle from explosive decouplers). Strut it if you're worried about stability...

6. You may stage your reusable vehicle a MAXIMUM of three times- this includes detachment from "mothership" platforms, detachment of drop tanks, and separation of any upper/lower stages. This is to keep complexity reasonable.

7. Your entire system (including blimps, alternative launchpads, drop tanks, payload- anything that comes within physics loading range) may have a maximum of 128 parts. This is to keep things fair/accessible for players with older CPU's (turn up the graphics so you get better screenshots if your CPU is awesome, don't whine about part-count limits).

8. Screenshots must be provided of: launch, staging, at least two different points in your ascent, the circularization burn, recovery of all parts (except alternative launchpads/mothership-planes/blimps obviously), at least one point during re-entry of the final stage, and any additional burns you perform.

9. Payload fuel/engines may be used in ascent.

10. Payload must achieve a stable orbit with a semi-major axis of over 100km (SMA = periapsis+apoapsis/2). That's an 100 x 100 km, or 110 x 90, or 120 x 80 km orbit, etc... For players running Real Solar System in a real-sized scale-up, simply making it to a stable orbit past the atmosphere is enough...

11. Jet engines may be used as following- for a "mothership" vehicle, which must detach the actual rocket or shuttle below 32 km in a (relatively) level flight pattern; and for controlled landing of a shuttle or reusable rocket stage (they may ONLY be activated below 12km on the way back to the ground). Otherwise, they are banned- especially for rocket liftoff! At no time, even when used in a "mothership" vehicle or in a shuttle for return, may the intake:engine ratio exceed 3:1.

And, of course, hopefully it goes without saying: no hyperediting, no part-clipping, and no debug menu functions.

Distinctions

Scoring for this challenge will NOT be in terms of points. It will be in terms of "Distinctions". This is to encourage friendly and cooperative spirit instead of brutal competition, as well as to allow players more freedom to invent something creative and awesome. Some distinctions will be very difficult to earn, however... You will not be able to earn all of them in one submission, but multiple entries are allowed.

Iron Man- Complete the challenge without quicksaving after launch (or takeoff of a mothership design). I'm relying on your honesty for this one.

'Smart' Payload - Make use of your payload's fuel or engines to help bring a larger marginal payload to orbit (one that your rocket/shuttle could not otherwise manage to lift to LKO).

Heavy Lifter - Lift a "dumb" payload of over 20 tons on a reusable rocket.

Super Heavy Lifter - Lift a "dumb" payload of over 50 tons on a reusable rocket.

Motherland Lifter - Lift a "dumb" payload of over 100 tons (naming inspired by Russia's new proposed 100-ton lifting capacity super-heavy lifter, which would be one of the largest launch platforms in the world since the Saturn V or Russia's previous Energia design- only exceeded by the USA's SLS Block 2 and China's proposed Long March 9 rocket...)

Reusable Shuttle-Transit-System - Launch a payload of at least 24 tons to orbit using a shuttle-style (VTHL) vessel.

Buran Mk2 - Launch a payload of at least 30 tons to orbit using a shuttle-style (VTHL) vessel (the Russian space shuttle 'Buran' was capable of outperforming a US Space Shuttle in nearly every way, from crew capacity of 10 instead of 7, to a superior thermal protection system, to a cargo capacity of 30 tonnes instead of 24. However the Russians only built one, launching it 8 years after the American STS program began, and never re-used it...)

Slow Climber - Launch with a Thrust-Weight-Ratio of less than 1.1 from a ground or blimp-based launchpad.

Fast Climber - Launch with a Thrust-Weight-Ratio of more than 3.2 from a ground or blimp-based launchpad.

Piggyback Launch - Launch a shuttle "piggyback" on a larger fuel tank or booster (note that this will take inward thrust to keep stable).

Whiskey-Tango-Foxtrot - Experience and document (in screenshots) a major error, oversight, or design flaw that by all rights should have caused your rocket or shuttle to crash and burn.

Home in Time for Dinner - Launch a reusable vehicle with a manned command pod that detaches as part of the reusable stages and returns to Kerbin.

EXTREME Reusable - Deliver a payload to Munar orbit before returning the reusable section home to Kerbin.

Green Mountain Men - Launch your reusable launch platform from a ground-based launchpad at over 3600 meters above sea-level.

High-Altitude Balloon Testing - Launch your reusable launch platform from a blimp-based launchpad at over 6400 meters above sea-level (this is possible while staying anchored to one of Kerbin's tallest peaks- some of which reach to over 6700 meters).

Microwave Powered Launch - Launch with a microwave-powered thermal rocket in your launch stage initially producing over 840 kN of thrust.

Plasmodynamic Flyer - Launch with a winged shuttle utilizing one or more (KSP-I or NearFuture) plasma engines producing over 32kN of total thrust in-atmosphere, which separates from all other forms of propulsion before reaching 32 km in altitude (your best bet in achieving this is using microwaved beamed-power from the KSC).

Glider Return - Return one or more stages to Kerbin via an unpowered glide which does not make use of standard parachutes (drogue/semi-deployed parachutes less than 300 meters from the ground and fully-deployed parachutes 50 meters from the ground are allowable, *IF* the stage can continue in a horizontal descent rather than hanging from the parachutes.)

Shuttle-Style Return - Return the uppermost stage of your reusable launch platform to KSC's runway utilizing drag chutes (parachutes deployed just prior or after touchdown) on the runway, and S-shaped banking turns to aerobrake in the upper atmosphere (if you're not sure what those are,

- note that he does it wrong, however, as the real Shuttle turned up to 70 degrees of bank on each curve, and he maxes out at much less...)

Lift vs. Drag - Complete the challenge with a shuttle-style launch platform while having FAR installed.

The ULTIMATE CHALLENGE - Complete the challenge with any style of vessel with both Real Solar System and FAR installed...

I look forward to seeing the entries!

Successful Missions List (in order of submission)

1. Jouni - Motherland Lifter

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

And above all, HAVE FUN!

Regards,

Northstar

Edited September 22, 2014 by Northstar1989

[Northstar1989]

EDIT: I apologize for the missing images- Imgur lost my example craft's screenshots some time after they were first posted...

Here is an example of my own reusable launch platform that I've had in operation for some time, to show the challenge is feasible to complete:

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This would have qualified for the following distinctions:

'Smart' Payload

Slow Climber (note that the screenshot it missing proving TWR < 1.1 at liftoff, as it was taken a little late- but I'll take your word for it if it's close in the screenshot)

Microwave-Powered Launch (receives a peak of approximately 1.8 GW of thermal energy from an 18 GW reactor set generating 3 GW of electricity, and a 2.3 MW solar power satellite orbiting Minmus, to produce about 1700 kN of thrust at peak power)

Regards,

Northstar

Edited September 22, 2014 by Northstar1989

[Overjay]

I request an addition in rules - WARP TO DAY BEFORE LAUNCHING!!!

Really, I've had enough of this DARKNESS in the Minecraft videos/tutprials. A person does his stuff in complete darkness.[sARCASM] Awesome, bring me moar. [/sARCASM]

[Claw]

Hmm, I like this idea. Maybe I can modify my Ultimate VTOL, since it can make it to Minmus. Thoughts? Are there restrictions on jet engines?

[ihtoit]

Possibly an entry, though this is the only screenshot I took, it is in fact an SSTO with a recoverable boost stage (tail landing on boosters, no chutes. Do I get the "We're not sinking, we're CRASHING!" award?) and six claw-equipped cell modules each with its own power supply and radio. Mods: Luvodicus (rockets), KWRocketry (tanks & batteries), Kosmos (mono tanks), MechJeb, KSPInterstellar (heatsinks). Pad weight: forgot, mass mid-transfer orbit: 96.6t. This is an experimental mission to see if I can plant a radially offset claw onto a rock. The answer being yes, if I can manage to do it before the game has another random oops. Probably need to stick moar struts on it as well, those girders do like to flex...

(yes, that's Kerbin behind and Mun just off the nose.)

All that said, pretty much all my heavy lifts (300-1200t) are SSTOs, wouldn't be too much of a stretch to hook up a probe core to the boosters and have them return to Kerbin once orbit insertion is complete, no guarantees of actually landing at KSC tho...

Edited June 1, 2014 by ihtoit

[Northstar1989]

Hmm, I like this idea. Maybe I can modify my Ultimate VTOL, since it can make it to Minmus. Thoughts? Are there restrictions on jet engines?

http://i.imgur.com/lfZhFQj.jpg

http://i.imgur.com/nIGKAE2.jpg

Please try and avoid air-hogging.

Oh, and definitely no part-clipping abuse allowed (I assume that's how you can get that out of the atmosphere). In fact, I'm going to add a note about that... I kind of assumed that "no part clipping, no hyperediting, no debug menu functions" was implied...

Regards,

Northstar

[ihtoit]

I know you said no spaceplanes, but I want to try a ballistic launch from the bay of my K52a...

B9 uberwings, twenty jet engines, 22 intakes, 8m S2 Wide cargo bay. Thing goes suborbital up to over 140km on the first skip!

[Northstar1989]

I know you said no spaceplanes, but I want to try a ballistic launch from the bay of my K52a...

B9 uberwings, twenty jet engines, 22 intakes, 8m S2 Wide cargo bay. Thing goes suborbital up to over 140km on the first skip!

I'll make you a deal. Install Real Solar System (create a separate save file for it, remove it again before loading up your standard one), and you can use it as a "mothership" for your launch platform (Real Solar System increases orbital velocity by a LOT).

Mothership launches in real life are from planes like the White Knight 2: http://en.wikipedia.org/wiki/Scaled_Composites_White_Knight_Two

Regards,

Northstar

Edited June 1, 2014 by Northstar1989

[ihtoit]

no chance at RSS, but I did actually complete my first ever suborbital insertion to polar orbit (perfect 90 degree inclination with no mechjeb on payload! 70x170 orbit tho ) and night landing!

Javascript is disabled. View full album

All flight manoeuvres were performed totally manually. Even the insertion burn was done manually, after which I immediately had to jump back and retake control of my plane before it reentered the atmosphere.

(EDIT: and during my approach I blew up all but four jet engines trying for an atmo start - I was too high! Hence the redeployment of the rockets just for that bit of extra push)

Edited June 1, 2014 by ihtoit

[Claw]

Please try and avoid air-hogging.

Oh, and definitely no part-clipping abuse allowed (I assume that's how you can get that out of the atmosphere). In fact, I'm going to add a note about that... I kind of assumed that "no part clipping, no hyperediting, no debug menu functions" was implied...

Regards,

Northstar

Okay, well I'm not sure what you define as air hogging because that's always a touchy subject. The reason it has 8 intakes is because that's the symmetry of the rest of the ship. I typically only use 3 intakes per TurboJet so I get your point. If I were to use less and put them elsewhere, I didn't think it would look as good. I'm not arguing, just explaining why there's 8. If you're going to make it a rule, what is your limit? I could remove 4 and keep it balanced, if that's a problem.

Also, it doesn't use part clipping to get out of the atmosphere (although I'm sure the "air hogging" helps). In fact, believe it or not, there is no ALT+F12 part clipping done on this. It's all allowed by the VAB, so as far as "regular" part clipping, I have no idea what your personal limits are. As for part clipping to get out of the atmosphere, I assume you're referring to a K-drive? but I don't know how those are built. So if you think I'm clipping as a means to cheat then I'm sorry for leaving that impression. It gets out of the atmosphere using the 4x radial rocket engines mounted above the external command seats.

The basic craft only weighs 3.5 tons and has a high TWR. If if matters, here's the rest of the Ultimate VTOL challenge album showing no infiniglide or k-drives or whatever: http://imgur.com/a/nW4eO#0

I get what you're saying about air hogging (though I don't know your limits), but I don't really know what to say about clipping because I didn't "hyperedit" or use any "debug menu functions." Yes, there is "normal" part clipping, but please clarify if you mean absolutely ZERO clipping.

As it stands, the thing is capable of delivering 40% of it's weight in cargo and is completely reusable.

[Northstar1989]

Okay, well I'm not sure what you define as air hogging because that's always a touchy subject. The reason it has 8 intakes is because that's the symmetry of the rest of the ship. I typically only use 3 intakes per TurboJet so I get your point. If I were to use less and put them elsewhere, I didn't think it would look as good. I'm not arguing, just explaining why there's 8. If you're going to make it a rule, what is your limit? I could remove 4 and keep it balanced, if that's a problem.

Also, it doesn't use part clipping to get out of the atmosphere (although I'm sure the "air hogging" helps). In fact, believe it or not, there is no ALT+F12 part clipping done on this. It's all allowed by the VAB, so as far as "regular" part clipping, I have no idea what your personal limits are. As for part clipping to get out of the atmosphere, I assume you're referring to a K-drive? but I don't know how those are built. So if you think I'm clipping as a means to cheat then I'm sorry for leaving that impression. It gets out of the atmosphere using the 4x radial rocket engines mounted above the external command seats.

The basic craft only weighs 3.5 tons and has a high TWR. If if matters, here's the rest of the Ultimate VTOL challenge album showing no infiniglide or k-drives or whatever: http://imgur.com/a/nW4eO#0

I get what you're saying about air hogging (though I don't know your limits), but I don't really know what to say about clipping because I didn't "hyperedit" or use any "debug menu functions." Yes, there is "normal" part clipping, but please clarify if you mean absolutely ZERO clipping.

As it stands, the thing is capable of delivering 40% of it's weight in cargo and is completely reusable.

I don't know how you define believability, but I wouldn't consider that craft even remotely believable- since the only reason it can get to orbit is due to how EXTREMELY OP'd jet engines are in the stock game (their TWR is just crazy compared to real jet engines, for one).

I'd like to see you try to build something that actually seems believable- like a rocket or a shuttle... Please try and refrain from anything using jet engines as the primary means of ascent... (spaceplanes might not be quite as unrealistic, but they're not for this challenge)

Regards,

Northstar

[Northstar1989]

no chance at RSS, but I did actually complete my first ever suborbital insertion to polar orbit (perfect 90 degree inclination with no mechjeb on payload! 70x170 orbit tho ) and night landing!

http://imgur.com/a/uFNja

All flight manoeuvres were performed totally manually. Even the insertion burn was done manually, after which I immediately had to jump back and retake control of my plane before it reentered the atmosphere.

(EDIT: and during my approach I blew up all but four jet engines trying for an atmo start - I was too high! Hence the redeployment of the rockets just for that bit of extra push)

OK, that's basically a spaceplane. Didn't I say to stick with *VERTICAL* takeoff?

I would've allowed a mothership launch platform- something that releases a rocket from level flight at high altitude- but that's just pushing the rules too far...

Why don't you try something more conventional, like a Space-X style launch, or a proper mothership deployment of a real rocket?

Regards,

Northstar

[ihtoit]

doesn't the fact that it was a ballistic insertion count?? :\

[Kasuha]

I don't know how you define believability, but I wouldn't consider that craft even remotely believable- since the only reason it can get to orbit is due to how EXTREMELY OP'd jet engines are in the stock game (their TWR is just crazy compared to real jet engines, for one).

I'd like to see you try to build something that actually seems believable- like a rocket or a shuttle... Please try and refrain from anything using jet engines as the primary means of ascent... (spaceplanes might not be quite as unrealistic, but they're not for this challenge)

Regards,

Northstar

You know, you're the organizer of the challenge. So it's your task to define rules. And that also involves giving out your notion of "believable" or "air hogging".

There's no point in spending time on designing a ship with which I have no problem just to hear from you that it does not match rules you have in your head. Put them here so everybody knows in advance what to match.

Edited June 3, 2014 by Kasuha

[Northstar1989]

You know, you're the organizer of the challenge. So it's your task to define rules. And that also involves giving out your notion of "believable" or "air hogging".

There's no point in spending time on designing a ship with which I have no problem just to hear from you that it does not match rules you have in your head. Put them here so everybody knows in advance what to match.

I clarified it a little more in the OP, but I'm trying to keep it from getting too long (it already drags on if you ask me...) Generally, just stay away from jet engines unless you're using them for a "mothership" launch platform (a large plane with no rocket engines- that releases the rocket from relatively level flight), enormous pancake rockets (I can't see any use for them in a reusable rocket anyways- generally they burn through their fuel too quickly to be useful), and infini-gliders or kraken-drives. Other than that, almost anything goes...

Regards,

Northstar

P.S. I hope it need not be said that since a RAPIER is neither a particularly good jet engine nor a particularly good rocket engine, but mainly useful because it encompasses both functionalities, it really shouldn't be used at all... However, I'll make an exception with both jet engines and RAPIER engines if you use Real Solar System- as it makes them relatively a lot less powerful- as long as you stay away from a more than 3:1 intake ratio.

Edited June 4, 2014 by Northstar1989

[Northstar1989]

doesn't the fact that it was a ballistic insertion count?? :\

What real-world mothership plane uses a ballistic insertion that reaches past the edge of the atmosphere?

Like the other poster so far, it looks like you mostly tried to re-use an earlier design rather than one made specifically for the challenge (note I didn't put my own example on the scoreboard- I'll save that for something specifically designed for the challenge... Maybe a believable mothership design, since I'd like to show players what I meant by that, and it's an extremely difficult engineering feat to actually pull off...)

Regards,

Northstar

P.S. I've clarified what is allowed for "mothership" designs a bit in the OP- the new rule is that the mothership must separate from the rocket below 32 km in a non-ballistic trajectory. As I've said before, though, with motherships and anchored blimps, as long as it is a stable design that could still conceivably land in one piece (no non-reusable drop-tanks, etc.) without the rocket attached, you don't need to actually recover that portion of the craft...

Edited June 4, 2014 by Northstar1989

[Kasuha]

Please try and keep in (at least somewhat) believable- for instance please don't air-hog or abuse the OP'd jet engines as a launch platform... (generally, jet engines have little place in this challenge, except as mothership craft- although I'll make an exception on the jet/RAPIER engines for any player using Real Solar System, since it indirectly limits the fraction of orbital velocity they can achieve...)

This does not count as clarified to me. What is "believable"? To me, anything that works is believable. We're in a sci-fi world after all. What is "air-hog"? I don't consider four intakes per engine air-hogging. What is "abuse of jets"? One jet per 15 tons is "legal use" or is it already "abuse"? What is "little place"? How big is that "little"?

I'm not asking you to make a long description. I'm asking you to be specific and technical. Vague terms are not helpful, they don't make people stick to your values. If you don't have anything better than vague rule, it's probably better idea to drop it altogether.

Edited June 4, 2014 by Kasuha

[Mesklin]

What is about my DH-1 ship series (cargo variant), is it legal using jets or not?

[Northstar1989]

What is about my DH-1 ship series (cargo variant), is it legal using jets or not?

It's a good idea- but you're going to have to redesign it a little.

The actual variant in the book does have jet engines, true- but they're mainly for getting off the launchpad and landing again. In real life, jet engines are heavy and have terrible TWR- thus they're not useful for vertical ascents. The engines on the lower stage of the book variant were designed for raw TWR and power (more similar to LV-30's) as the majority of the power had to come from the rocket engines- not the jet engines, which have much lower ISP in real-life (due to a major dev error- including IntakeAir in ISP calculations, the jet engines have approx. 12-16 times the ISP of those in real life) and become practically worthless at the high speeds a rocket eventually reaches... (real-life orbital velocity is much higher than in KSP, but the velocity curves are much the same)

Remove the jet engines (and I suggest the intakes- which will then be useless), stretch the lower stage fuel tank a bit to compensate (the lower stage in the book you're copying used LiquidMethane:Oxygen mix, which is significantly denser than the LH2:LOX used in the upper stage. Since both your stages use the same stock fuel, you need a relatively longer lower stage than in the book to get the same fuel mass ratios...), and consider using LV-30's in the lower stage so the thing can still get off the launchpad (the extra fuel mass you can lift will compensate for the reduced ISP in the lower atmosphere- and the vehicle in the book lifted off with engines similar to LV-30's and a TWR barely over 1...) Oh, and the vehicle in the book uses static solar panels on the upper stage, like the OX-STAT panels, to allow for supply of electrical power even in-atmosphere- they're also lighter, and theoretically more reliable, so I would recommend switching to them entirely over deployables...

The one thing you need to do is remove the jet engines. They're simply too OP'd in the stock game. This is why I edited the OP a while back to warn players to avoid using jet engines in their rockets (I'll allow them in "mothership" vehicles, but that's mainly because those use jet engines in real life anyways... Rockets don't.) The rest is just advice I'm giving you on how to make sure the thing can still achieve orbit without jet engines.

And no, you won't get the same performance without the jet engines- but neither did the vehicle in the book. The leftover Delta-V values you're reaching orbit with are just absurd (much more than the rocket in the book), and mainly due to your use of OP'd jet engines... You can still get single-stage to the Mun and back with refueling in LKO though...

Regards,

Northstar

Edited June 5, 2014 by Northstar1989

[Northstar1989]

This does not count as clarified to me. What is "believable"? To me, anything that works is believable. We're in a sci-fi world after all. What is "air-hog"? I don't consider four intakes per engine air-hogging. What is "abuse of jets"? One jet per 15 tons is "legal use" or is it already "abuse"? What is "little place"? How big is that "little"?

I'm not asking you to make a long description. I'm asking you to be specific and technical. Vague terms are not helpful, they don't make people stick to your values. If you don't have anything better than vague rule, it's probably better idea to drop it altogether.

OK, I've further clarified the description, and added Rule #11, which totally bans jet engines except for two very specific, well-defined circumstances. Are you happy with the current state of the rules?

Regards,

Northstar

[Northstar1989]

What is about my DH-1 ship series (cargo variant), is it legal using jets or not?

I saw you re-designed the DH-1 to only use a single jet engine for landing. In its re-designed state, it would qualify for this challenge, so why not submit it?

Regards,

Northstar

[Raven.]

I got a shuttle that can meet this challenge with minimal modifications. However, it will be next week before I can get it online since I'll out of town for a week. But once I get back I'll be sure to post it.

[Jouni]

I built a quick and dirty SSTO rocket.

62 parts, launch mass 816.3 tonnes, payload 103.3 tonnes.

Landing was a quite difficult, because the LFBs were a bit higher than the central KR-2L engine. I also had only about 50 m/s left for the landing, so the timing of the final burn had to be exact.

[Northstar1989]

I built a quick and dirty SSTO rocket.

http://www.cs.helsinki.fi/u/jltsiren/ksp/ssto_lifter_1.jpeg

62 parts, launch mass 816.3 tonnes, payload 103.3 tonnes.

http://www.cs.helsinki.fi/u/jltsiren/ksp/ssto_lifter_2.jpeg

http://www.cs.helsinki.fi/u/jltsiren/ksp/ssto_lifter_3.jpeg

http://www.cs.helsinki.fi/u/jltsiren/ksp/ssto_lifter_4.jpeg

http://www.cs.helsinki.fi/u/jltsiren/ksp/ssto_lifter_5.jpeg

http://www.cs.helsinki.fi/u/jltsiren/ksp/ssto_lifter_6.jpeg

http://www.cs.helsinki.fi/u/jltsiren/ksp/ssto_lifter_7.jpeg

http://www.cs.helsinki.fi/u/jltsiren/ksp/ssto_lifter_8.jpeg

http://www.cs.helsinki.fi/u/jltsiren/ksp/ssto_lifter_9.jpeg

Landing was a quite difficult, because the LFBs were a bit higher than the central KR-2L engine. I also had only about 50 m/s left for the landing, so the timing of the final burn had to be exact.

100 tons to orbit on a 800-ton SSTO rocket?

Something sounds a little fishy there... The math doesn't figure- even with the exceptionally powerful STS parts...

Did you use FAR by any chance? That's the only way I can figure that thing would be able to make orbit...

Regards,

Northstar

[Jouni]

100 tons to orbit on a 800-ton SSTO rocket?

Something sounds a little fishy there... The math doesn't figure- even with the exceptionally powerful STS parts...

Did you use FAR by any chance? That's the only way I can figure that thing would be able to make orbit...

9.81 * 355 * ln(816.3/220.7) ≈ 4555.

The initial Isp of the rocket is around 307 s. By the time the boosters burn out, it's around 365 s, and the core still has over 40% fuel left with Isp 380 s. Therefore 355 s should be pretty good estimate for the average Isp.