Pro SSTO builder/pilot Challenge

[Scarecrow88]

This sounds like fun, though I'm not sure how to work out my development costs.

I present Vamanos. I originally tried with 2xWhiplash Ramjet engines plus 2xLV-T45 Swivels, but swapped those out for 4xRapier. Test flights didn't go to orbit and all landed back at KSC, so the parts I chose to swap out were all returned for re-use. The only consumable used was fuel for half a dozen test flights.

Cost of the final craft, excluding the payload, is 71,426. If this makes it to orbit and back the only bits not returning will be the fuel used and the payload, if deployed.

Pilot notes :

Take off can be achieved at 90 m/s. Initial climb out seems best at about 30 degrees nose up. Any steeper and the speed starts to bleed off. Above 10,000m flatten out to build speed and when the Rapiers peter out in air breathing mode, press 1 to toggle to rocket mode and simultaneously close the air intakes. Keep your fingers crossed you have enough fuel to reach orbit.

Action group keys :

1. Toggle engine mode and air intakes

2. Extend airbrakes

3. Extend antenna on satellite if deployed

5. Toggle cargo bay doors

6. Deploy payload

Vamanos is designed for LKO. If successful, it can carry and return 2 Kerbals. It can also be used to deploy small payloads to LKO, and comes fitted with a small communications satellite.

Vamanos craft file

Edited July 29, 2015 by Scarecrow88

[Nich]

Nefrums I gave you credit for 6 kerbals. I am assuming you needed a pilot to fly back and didn't happen to have one on the station.

Scarecrow development cost are simply the sum of (cost - recovery amount) for each flight. Because you didn't track the cost I will have to charge you 9,000 assuming all landings were perfect. You flew more flights then me but have a slightly smaller craft and didnt lose a wing or go to orbit. If you want to go through your test flight again and multiply that by 6 we can use that as the cost seeing as no reverts no quick saves is dependent on the honor code anyways.

What is the recommended payload and what orbit should one expect to get it too?

[Scarecrow88]

All landings were on the KSC runway with no breakages. Target orbit is 100km, but it may be able to go higher - anyone able to get it to orbit may be able to confirm based on what fuel is still available. If I was continuing the test flights myself, I would probably aim for an initial orbit around 85km to allow a margin of safety/error. The payload fitted in the provided craft file is 730 kg and there is room in the cargo bay for 2 of those, so round that up and say payload capacity of 1500kg should be about right.

The first few test flights I did were to tweak the aerodynamics to get it to fly reasonably well and were kept local to the KSC. The penultimate flight was to test high altitude speed gain and transition from atmospheric to rocket engines. That's when I decided to change to Rapiers, and the final test flight was a repeat of the previous one to make the same checks using the Rapiers. I have just done another flight like this last one, which lasted 25 mins to a maximum altitude of 31000m and returned to KSC, and represents the flight that would have had the highest costs due to the amount of fuel used. The cost of that flight was 3100. I'm happy if you want to apply that cost to all 6 flights, or to apply your own average based on that cost.

Edited July 28, 2015 by Scarecrow88

[Nefrums]

Vamanos Test flight:

I did not like this ship Very hard to control and strange balance of LF vs OX

I managed to deploy the two satellites to LKO and return safely

Cost: 4148

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- - - Updated - - -

Neagle test flight:

I liked this ship at first. It was a low drag build tat could go suopersonic at sea level.

I do however believe that center of lift was a bit to far forward with made it react a bit to mush when pitching up...

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Cost 65,276

4 dead kerbals.

[GoSlash27]

Dubious but potentially awesome spaceplane

Jakalth,

Could you post this craft using wikisend instead of mediafire? I'm keen to try my hand at it, but my computer no likey mediafire.

Thanks,

-Slashy

[Jakalth]

@GoSlash27

Be sure to take my craft like a grain of salt. It's a serious ssto, but it's not the best way to do an "efficient" ssto, half the reason I posted it. The other half simply to show that there are silly ways of doing a true ssto. As well as to see if I could pull it off without testing the craft first. O_o

As for the craft file, lets give Dropbox a try: Here. I already have it as a backup site for uploads. Should be a direct download link with no messing around.

[Scarecrow88]

That's good feedback, thanks Nefrums. Having not flown it to orbit myself, I completely forgot about airbrakes. I'll have a look at re-balancing the fuel too.

ETA: I've just looked at the design again with a view to making the changes and for some reason the fuel load in the wings was only 50%. That wasn't intentional and would go some way to explaining the imbalance of fuel.

Edited July 29, 2015 by Scarecrow88

[Scarecrow88]

I thought I'd try for the Propilot award and flew GoSlash27's Probuilder craft. All I can say is that I must be a crap pilot as it flipped out on me at about 22,000m. I managed to get it under control and tried to continue the flight but it flipped out on me again. I transferred all remaining fuel to the forward tank, and decided to abort the flight to orbit and return to KSC as by that time I had lost too much speed to make an orbital flight viable. Landed back at KSC without any further drama. I will try again with another design.

[GoSlash27]

Scarecrow88,

Hm! That's interesting... I had intentionally designed this plane to be easy to manage, so it should be very difficult to flip.

Do you know what speed and pitch angle you were at when it happened? I'd like to try to reproduce it.

Best,

-Slashy

[Scarecrow88]

Best I remember I was at about 22000m and somewhere between 1000 - 1200 m/s. I think the nose up angle was about 15 degrees. I think the issue was caused by the shifting CoM as after I had transferred the remaining fuel forward I didn't have any more problems.

[GoSlash27]

Best I remember I was at about 22000m and somewhere between 1000 - 1200 m/s. I think the nose up angle was about 15 degrees. I think the issue was caused by the shifting CoM as after I had transferred the remaining fuel forward I didn't have any more problems.

Scarecrow88,

Thanks, I'll take a look at it this evening. As a quick fix, you might want to try disabling gimbaling on the rockets.

Best,

-Slashy

[Scarecrow88]

Ok, I'll give it another go, as I had just fired the rockets when I lost it.

[Nich]

Leader board updated, apologies for not keeping up blame Nefrums for creating the small kerbin 2 challenge Bottling my home brew after work today so I wont be able to finish up the testing the leftovers until tomorrow.

[GoSlash27]

Jakalth,

I just downloaded and installed the "Sangwich". We are in the process of administering last rites reviewing the launch procedures...

Full documentation to follow

Best,

-Slashy

[GoSlash27]

Just some pilot's notes from my run up to this point. I'm still in the mission.

Uhh...insufficient t/w on launch.It just fell on the pad like *kerplunk*

Got moving a few seconds later and didn't fall over. Positive news...

Halfway through fuel at roll maneuver

Good handling through boost phase.

The laggy launch made us late for rendezvous. Way late.

Boosters out of fuel way early; about 1400 m/sec... Gonna dump them while still suborbital. As much as I love markers...

This isn't technically an "SSTO", so the run might be invalid. Nevertheless, we will press on...

A race against time...

Made it! A little more limping to go, but I think we're out of the woods...

Passengers complaining about the faulty air conditioning...

Orbit achieved! Now to rendezvous with the station...

I elected to take the scenic route...

I can see my house from here...

That was a little suicide burn- ey...

Made it. The trip to Minmus is cancelled, though.

Successful docking. Good placement of RCS thrusters.

Transferred everyone but Jeb. Now what to do with this leftover fuel? Too little to go anywhere fun, but probably too much to bring home.

Hmm... my back of the envelope sez I have 1,124 m/sec to play with. That's at least enough to swing by Minmus and say howdy. Poor decision?? Perhaps. But that's what Jeb's good at.

More to follow...

-Slashy

[Jakalth]

I'll be testing all craft using just keyboard and mouse, my joystick is sick and needs a new potentiometer for the z-axis... poor thing... :\ I have kerbal engineer which lets me watch more of the vital stats of the craft as it's being flown but that is the only mod I currently have installed.

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Hmm, after some testing, I can't even try the BadHat atm due to not having mechjeb... I'll have to go back to this one some time either with mechjeb, or with a version that doesn't have the MJ module. *hint hint*

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The Neagle...

attempt 1: tried to take off but ended up tail slapping the nerv and loosing it that way... turned around and recovered it for full value minus the nerv.

attempt 2: got it up to about 9Km and it had a little pitch foible(my fault). In attempting to recover it, the craft went into a flat spin and I was unable to fight it out of the spin until about 4K where it finally got into a tail down configuration. Problem there is the craft didn't have enough pitch authority to pull it's own nose down, and even with the engines at full throttle, they were unable to fight off gravity due to the intakes now facing the wrong way(not the designers fault with the engines, they simply couldn't spool up enough to produce the thrust required that way.) Due to this combined issue, the craft entered the drink in a tail down configuration at about 70m/s and was a total loss... was only able to salvage a single fuel tank and 2 of the landing gear, the rest went to the deep bottom with all hands lost... :\

current pilot score = -(it's over 100) for being a bad pilot and not keeping tighter reins on this craft...

I'll have to try again when I'm not as rusty and see if I can handle this wild horse of an ssto.

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The Noobs Friend...

attempt 1: take off was a little slow, but smooth as silk. This thing needs the whole runway, but flies very well indeed. got to orbit easily, flying SAS + kayboard and achieving orbit the old fashion way, using no orbital nodes(not easy to do efficiently, but this craft had enough fuel). Achieved a 102Km x 103Km orbit with ease. Had just enough fuel to deorbit. Deorbit was smooth and quick. Reentry was a little harry due to actually deorbiting a little too sharpy(my bad) but the craft took it without flinching and soaked up the heat like a champ. Used both the airbrakes and pitched the nose up 30 degrees to slow the craft down quickly. It had no issues with the high nose pitch and actually fought me the whole time, trying to return to strait and level. This is a good sign, it wants to be stable. Got the craft slowed down fairly well, but at about 32Km it started getting too much lift and started trying to climb again, so I had to nose it down a bit instead to try to dig back into the atmosphere again. This was all with the airbrakes still deployed, I was going fast... 2200m/s at reentry... nosing down didn't cause any troubles, the craft simply pulled its own nose back up once it dug deeper into the atmosphere. It slowed down enough that by 25Km, I no longer had any heating issues on the craft and was able to turn the airbrakes off, gliding into the deep atmosphere non-powered.

I had intentionally undershot the runway, but this craft wants to fly so much that even with the engines idling(I was dangerously low on power by this point due to no power gen on it...), it was starting to overshoot the runway. So once again, airbrake time for a few seconds, and a little more throttle, SAS was starting to cut out from lack of power... The approach to the runway was uneventful, but the landing was a little ugly. I ended up nosing down too hard but pulled up at the last second and somehow flared the wings enough too stall the craft about 130m above the runway. touchdown, no damage and a recovery cost of 22,879Kredits launch Kredits was 23,884. 1 flight, no retries needed.

Pilot score: -0.987, 1 Kerbin to orbit and back again. efficient, inexpensive to operate, and flies very well.

Edited July 29, 2015 by Jakalth

[GoSlash27]

Another pilot's log. Hopefully not the last one!

Change in plans. Going to drop off the extra fuel at the orbital tank. A swing by the Minmus would be fun, but wouldn't be worth any points.

600 units of monoprop is way more than I can ever imagine needing. I usually only use 15 units for a ship of this size.

Still, I'm happy to have it on this flight just in case...

Jeb 1 day later...

Docked with tanker. Offloading 220 units of fuel.

Retroburn complete. Here's hoping I guessed right...

-Slashy

- - - Updated - - -

Photo record and final pilot's log:

http://s52.photobucket.com/user/GoSlash27/slideshow/Flight%20of%20the%20Sangwich

Night landing deadstick. Who knew kerbals were religious??

Yea, though I walk through the valley of the shadow of the Kraken, I shall fear no rapid unscheduled disassembly...

Maybe, maybe... ? Handling on reentry and heat dissipation are excellent!

Yess! So long as I don't screw it up, we've made it!

Stabilizers came off as expected, but successful mission!

Nice spaceplane! Jebediah approves!

Final tally:

Value at launch $82,418

5 kerbals delivered to orbit

1t of fuel delivered to orbit

Value at recovery $52,465.

12 points for delivery, -30 points for flight cost.

Total points -18 points.

This plane could easily get the multiplier for Minmus, but it's not an SSTO as it sits. Good handling and way more supplies than it needs in all phases. It really needs more t/w off the pad.

Clearly not cost-efficient (we knew that going in), but very forgiving, even for someone who's never seen it.

Best,

-Slashy

Edited July 30, 2015 by GoSlash27

[GoSlash27]

Scarecrow,

I tried disabling the rocket gimbals, but it flies about the same either way.

It is difficult to force it to depart from controlled flight, but possible if you really yank it the moment you kick in the rockets.

There is no reason why this maneuver should be necessary, so my best advice is to let it pitch up on it's own. It will maintain forward flight to orbit so long as you don't force it to do something else.

Best,

-Slashy

[Jakalth]

ProBuilder1.0...

Take off was nice and easy. It flew smooth and stable all the way up to orbit. I was able to achieve a 70Km x 70Km(barely) orbit with this craft. It has a bit too fine of a fuel load, in the hands of a Novice like me, to really get much higher then that. I didn't have the most efficient flight profile... I did have 4 Kerbal passangers on board during the flight though. But, since I'm lacking a space station to dock with, and the fact that I was unable to maneuver the craft enough to reach a station once in orbit, I had to content myself with a 4 Kerbal joy ride. The reentry took a long time really. I Only had enough fuel to retroburn into a 47Km reentry orbit, and I judged the entry position wrong too boot... I had the airbrakes deployed by 60Km and once again pitched the nose up 20 degrees(probably too shallow... should of gone steeper, in hind sight), but this, along with the entry angle, ment the parts were exposed to excessive heating far longer then needed. Many of the parts on the craft were glowing red hot by the time I got it down into the thicker parts of the atmosphere. At this point, I double check my fuel levels, yep, completely tapped out... Not a drop of liquid fuel or oxidizer left in the tanks. Looks like it's a dead stick flight from here on out. Time to nose down to level and deactivate the airbrakes and hope she holds up to the additional heating from not slowing down anymore.

I remembered to close the air intakes at about 20Km, hopefully to buy me a few extra Km of glide. This helped. The craft, flying dead stick, proved not to be the most efficient glider I've ever used, but she was stable and responded nice and smooth. This at least meant I'd get good distance since I wouldn't be flaring the wings by accident. I tried to extend the glide as far as possible, but my bad judgment in orbit ment I was going to be short of the runway. She remained stable all the way down to the deck and down to speeds of only 90m/s. And looming in front of me were the mountains just west of the KSC... Thankfully, I've gotten quite skilled at making mountain landings thanks to my little Drifter series of science aircraft. The landing ended up being rather easy with the crafts wheels touching down in the rolling hills just before the mountain range. All be it, I had to use some RCS to help me avoid becoming part of the hill side... Landing was finished, monopropellant, oxidizer, and liquid fuels all read 0. successful trip, even if it ment a bit of a hike to get the crew back home.

Purchase cost of 24,667 kredits

Recovery value of 23,630(x92% for landing on other side of mountain, distance from runway modifier) for 21739 kredits

Cost = 2928(-2.9)

4 kerbals on a joy ride = ???

Fun of flight = priceless

Total score = -2.9(better if a partial score is given for the attempt at getting crew to orbit)

The score would of been only -1 if hadn't botched the reentry burn. This craft lands so nicely, even in the ugly terrain of the mountain range.

Only downfall to this craft, initially the vertical stabilizer was disabled. Once enabled again, it flew a lot straighter again.

[Scarecrow88]

Had another go with ProBuilder1.0 as I don't like to be beaten, especially by a design that no one else seems to be having problems with. My 3rd attempt presented the same problem - the craft flipped out shortly after igniting the rocket engines, and with absolutely no control input from myself. One second it was flying fine, the next the nose pitched up and all semblance of control was temporarily lost. At that point the prograde vector was about 10 degrees and the nose of the craft was a few degrees higher, lined up with the top of the prograde circle. I also noted prior to this point that the craft would deviate from an easterly heading, but reading a post above, enabling the yaw control on the tail fin resolved this problem.

My 4th flight was finally successful. I'm not sure what I did differently, other than perhaps gaining most of the speed slightly lower than previously and making sure that any attitude corrections were done very gently. Orbit achieved was 82km x 81km and 6 Kerbals were delivered. Return from orbit was to the runway at KSC with no breakages and a thimble full of fuel left, so total flight cost was just fuel.

On a separate note, where are you guys getting the recovered costs from, as I can't see them anywhere. I'm flying in Sandbox mode if that makes a difference.

[Nich]

Yes I do not believe sand box gives you the recovery info. I made an easy career with 200% science and max science/funds to start for this challenge. Then it was 2 Mun landings to fill out the tree.

[Nich]

Shashy you have earned your PRO SSTO pilot designation even though it was not technically an SSTO you made it to orbit dropped of kerbals and fuel without save/reverts

Scarecrow You have earned your pro pilot designation even though your score is highly negative (not going to bother adding it up) I have however changed the rules that you now have to get to orbit and return safely first attempt. Dont worry you will be grandfathered in or you are welcome to try a new craft

I think I the leader boards updated if I missed your entry please let me know.

As for the Neagle if anyone else wants to try it the plane becomes very touchy above 300 m/s with a full load you need to have your 10 degrees set before 250 m/s then you should not touch the arrow keys again. Also you do not lift off the runway but run off the end. It has enough lift to maintain level by the time it hits the end of the runway. At 22-24 km switch to follow propagrade into orbit. I do plan on creating a second attempt of 102t payload to orbit without touching the arrow keys at all. Coming Soon

Also I have an idea for the badge I will submit it and see if everyone likes it/wants to improve it before if becomes final.

Edited July 30, 2015 by Nich

[GoSlash27]

Hmm. The Neagle appears to be quite a handful. I think I'll have to give it a go this evening!

Best,

-Slashy

[Jakalth]

I'll be trying the Neagle again, hopefully later today. i can see the craft turning out some fairly good numbers if it can get past the transition to rockets and out of the atmosphere. it's center of weight/lift balance is the main issue. They are perfectly in sync, but the design would fly better with the two spaced out a bit. We'll just have to see. I know what I did wrong on my first set of attempts.

[GoSlash27]

Okay, I've got the Neagle.

I'm going to go conservative with it and just rotate out crew/ transfer fuel in LKO. Same as I did with the Sangwich.

The challenge right now is just to orbit it without killing everyone.

Wish me luck!

-Slashy

- - - Updated - - -

Welp... short trip. I ran it off the end of the runway at full throttle. It immediately pitched up violently and entered an inverted flat spin. I was unable to recover and went into the water. Total loss and all hands lost.

Perhaps a slower takeoff may help whoever tries it next...

*Follow-up troubleshooting flights (not for points)*

I was able to get it off the ground by reassigning roll to the canards, disabling the ailerons, setting fine controls, and taking off very carefully. It got worse when I added power. Every time, pitch excursions leading to an unrecoverable inverted flat spin.

It's just plain too tail-heavy and too draggy in front.

I was able to get it to orbit by unloading the farthest- aft tank and handling it very carefully until it built up speed. It seems to stabilize after that.

Of course, that means you have to slog on the single nuc to orbit because the RAPIERS give out early, but it *is* doable. The ship got hot, but held.

I had 25.48t and 1623 fuel at orbit. By my math (somebody doublecheck my figures), I had 3,009 m/sec DV on orbit.

Best,

-Slashy

Edited July 30, 2015 by GoSlash27