Pro SSTO builder/pilot Challenge

[Stoney3K]

OK, here's my entry, Barracuda One:

https://drive.google.com/file/d/0BxraMdXm6-GLak9sLS1udk4xQWM/view?usp=sharing

Wet mass (not including payload): 35,339t

Dry mass: 11,2t

Cost (not including payload): 89,328 Kr.

Development cost: 36,255 Kr.

Current configuration is an empty cargo bay, but a crew cabin seating 4 Kerbals and a docking port (for a total rotation capacity of 6) can be swapped in its place. The craft features a drone core so it can fly unmanned, and has a set of RTGs in the aft cargo compartment which can keep the reaction wheels going at night. The aft cargo compartment also has a docking port to detach or secure any payloads.

Most of the development costs were a single sub-orbital flight which I intended to fly all the way back to the KSC, but I got fed up flying a straight-and-level cruise for 20 minutes and ditched my test craft into the sea. (Note to self, engines are expensive to replace.)

In case of a catastrophic emergency or loss of control, the craft has an abort system which shuts down all of the engines, deploys the airbrakes, and arms the parachutes for deployment under 8,000m. This can also be useful in case of a missed approach.

Takeoff procedure:

SAS on, full thrust. Release brakes, and rotate off the runway to 5 degree pitch up.

Let aircraft gain speed up to 250m/s, climb at 20 degree pitch angle until 8,000m.

At 8,000m, switch SAS to prograde and allow it to pitch down to 5-10 degrees over the horizon.

Engage LV-T45's at 18km by staging. They will work together with the jets until they flame out at 23km, after which, slowly pitch up to 20km and burn towards 75km apoapsis.

From there, coast to Ap and circularize.

Re-entry is gentle: Shoot for a Pe between 50km and 30km, and keep a 5 to 10 degree nose up angle. You can engage the jets below 20km to re-estabilish high altitude cruise at Mach 3.5 and fly to your intended landing site.

Action groups:

1 - Toggle solar panels

2 - Swap engines (shut down jets, engage LV-T45's and vice versa).

Edited September 1, 2015 by Stoney3K

[Starhawk]

All right. I think I'm ready to try the Haste-Long Range SSTO.

I hope SpaceplaneAddict doesn't mind, but I've made a few modifications.

Removed radiators.

Removed fuel lines.

Disabled all control for vertical stabilizers.

Disabled yaw and roll for canards.

Disabled all control for outer two sets of trailing edge control surfaces.

Disabled yaw and roll for inner set of trailing edge control surfaces.

Disabled yaw and pitch for second set of trailing edge control surfaces.

Changed Rapiers to Manual Switching.

Changed rear brake torque to 24. (Just a hunch.)

Update:

Made orbit. She flew quite well so far, but I lost the solar panels due to overheating.

On only the nuke, she has a TWR of about .26 but 3335 m/s.

No docking equipment on the craft, so I'll do a rendezvous and the two kerbals can EVA over to the station for crew rotation.

No solar panels, so I'll have to land with whatever is left in the Cockpit.

OK. Rendezvous at 100x100 went fine. Only 91.38 power left for reentry though. Here we go.

Got interrupted by RL. Finally starting descent. Rapier fully charged the battery during the deorbit burn, so power is good.

Success! Deadstick landed safely at KSC with 1483 LF and 129 Ox onboard. Maybe the fuel and oxidizer could be counted as cargo? (still well over 7 tonnes of fuel onboard at rendezvous).

Handled fine, but heavy with so much fuel still on board. Ran out of power, but had plenty of control authority. Had to push her down pretty hard to not overshoot, and she responded very nicely.

No need to worry about fuelling the Rapiers. They draw from all tanks regardless of which mode they are in. And I figured I could just pump from radial tanks if I needed any more liquid fuel for the Nerva. Which, of course, I wouldn't unless I was going to Duna or something. Lots of long range potential here. I would recommend all the changes I made, and to add a couple of solar panels on the top of the fuselage or wings.

My ascent was probably too aggressive leading to the loss of the solar panels. I wasn't sure if I was supposed to keep the pitch at 10 degrees or allow it rise.

SpaceplaneAddict, you now qualify for your Builder's badge.

Craft cost as outfitted was 56100 funds and recovery value was 48475. The loss of the Gigantor solar panels hurts quite a bit.

Happy landings!

Edited September 2, 2015 by Starhawk

[SpaceplaneAddict]

Pefectly fine with that, I encourage you as well to do so. Best of luck!

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I warn you though, the Rapiers will be cut off from some oxidizer, and the nuke won't be able to use the jet fuel on the side fuselages. Unless that's your plan...

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Saw the update

You lost the solar panels? Hmm, they were intact during my joyride in another save....

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Again, I think I'll take a shot at that Barracuda, seems legit.

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Another update, Can i have your "current" config? Thanks.

[Majorjim!]

No Joystick? Did they tell Picasso, no brush?

[SpaceplaneAddict]

YAYAYAYAYAY! A badge! OMFG and it's for my favourite activity! YAYAYAYAY! Did I mention I landed on Minmus and almost the Mun in the same trip? YAY!

[Nich]

@Spaceplane addict I too lost the giganors while I was finalizing my 70km AP They were directly in the shock cone. Honestly this craft only needs 1 or 2 OX-STATs but without them I have 3405 dV from LEO. Burning the nuke should keep them charged for the trip. I am thinking a no save no revert landing on Duna is out of the question as this craft has a lot of wing but not enough in my opinion for a safe landing. Considering a Jool or Dres crew rotation

[The_Rocketeer]

I fear I may have overdone this...

I give you the SSSP 100 - Hostess

Luxury seating for 96 passengers plus 4 flight crew for 100 Kerbs! Under testing she reached LKO with 4.5 tonnes (9000 units) of LF in hand, just about enough to reach either moon and return.

Specs:

Parts: 362

Tonnes: 336.6 (145.7 dry)

Cost: 542,804 (519,589 dry)

One test run, recovered at KSC, no death or destruction. I don't know what recovery at KSC nets these days (I did this in sandbox for it's own sake) but u can definitely deduct fuel cost (~22,000 since the tanks weren't dry). I think she's borderline to score positive (haven't done the numbers), but she's in a class all of her own

Flight Manual (comes on the back of a bar coaster)

Action groups:

1. Toggle all Whiplashs

2. Toggle all Whiplashs and all Intakes

3. Toggle all RAPIERs

4. Switch all RAPIER modes

5. Toggle all NERVs

6. Don't touch I just remembered it's broken (was supposed to set elevons to deployment for aerobraking but it's only set up correctly on one side)

Also, Brakes will deploy AIRBRAKES as well as wheelbrakes as per normal.

Ascent Flightplan:

Pre-flight: Disable LF feed from X200-32 tanks (one each side).

1. Activate Whiplashs and RAPIERs (airbreathing)

2. Full throttle. Rotate at 110m/s (near the bottom of the runway, if you run off the end don't panic), pitch up to 25 degrees.

3. At 7500m alt, reduce pitch to 10 degrees

4. Maintain attitude between 10 - 15 degrees until surface speed approaches 1100m/s (around 21000m altitude). Use action group 3 to activate closed cycle RAPIERs and action group 5 to activate NERVs. Then enable X200-32 LF feeds.

5. When Whiplash thrust drops below 15 per engine (check one), use action group 2 to shut off Whiplashs and close intakes (reduces drag).

6. Allow SAS to hold attitude fixed until Apoapsis exceeds 50,000m, then switch to track prograde.

7. Circularise at approx 72000m. You should be almost out of oxidiser by this time. Shut off RAPIERs and use NERVs only for further manoeuvres.

Re-entry Flightplan:

1. If airbraking from high eccentricity orbit, don't drop periapsis much below 40,000m or you'll probably make something blow up. USE THE AIRBRAKES.

2. If you have LF left over, transfer the bulk to the X200-32 tanks for best weight distribution. Use action group 2 to re-enable Whiplashs and Intakes (you won't need the RAPIERs now).

3. Final re-entry profile should be nice and shallow. Make retro burn from below 90km, set periapsis around 10,000m and expect to land about 1/8th of an orbit short of periapsis.

4. USE THE AIRBRAKES.

5. Don't steer too hard or you'll tear the wings off.

6. Take care to touch down gently in a pitch-up attitude greater than 10 degrees. This avoids landing on the nosewheel and minimises airspeed at touchdown.

Final notes:

The plane is very responsive to steering once it's shed its wet weight, and it's got a heck of a lot of lift. Despite its size, you should be able to land safely at 50-60m/s without fearing a stall.

Edited September 2, 2015 by The_Rocketeer
wrong engine name (Wheesley)

[Vegetal]

Well, here goes mine without any testing.

Craft File: http://1drv.ms/1ihpsyv

The Space Whale 1. With a wide landing gear base, tail-strike protection wheel and simple control surfaces, it is (hopefully) easy to manage.

Instructions: Action 0 is Rapier Switch.

On take off, it should rotate easily, and the tail should be safe. It is a little underpowered, so I recommend staying shallow right after take off, otherwise, it's probably a normal SSTO ascent. Once in LKO it should have enough fuel to rendezvous with a station on pretty much any orbit, maybe it can even orbit the Mun.

On reentry, I recommend keeping the airbrakes open and prograde hold, avoid trying to correct the trajectory above 500 m/s, just let it glide until it's a safe speed to maneuver. It has plenty of LF, so even if you end up far from KSC, it will probably have enough fuel to get there. The CoG almost doesn't change, but stay alert to any control weirdness and correct it by pumping fuel forward before getting too low.

I would try piloting, but I don't enjoy doing it with the keyboard

[GoSlash27]

Scoring question: For tankers or payload delivery, is the value of the payload deducted from the cost of the flight?

Example: I deliver $1,000 of fuel to orbit and burn $1,000 of fuel in the process. I therefore land with $2,000 less value. Does this flight cost 1 point or 2 points?

Thanks,

-Slashy

[SpaceplaneAddict]

LOL, I just remembered something. When testing the Haste, you removed the radiators right? Well, that may have been the only thing keeping the solar panels intact during my joyrides.

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One thing, we're allowed to copy existing craft that work? Well, time to start a new engine confing for the Haste, and a new name...

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@The_Rocketeer My laptop cried all the way back to the store I got it from when it saw the part count...

[The_Rocketeer]

Well I had a go at the pilot award today in Vegetal's Space Whale 1. The entire flight was a success, met a station in orbit (100x100), re-entry successful, perfect touchdown.

Then things got weird. The tailplane just started randomly losing parts as I was rolling to stop. Here's the F3 log:

I promise I didn't go near the launchpad!

EDIT:

@SpaceplaneAddict yes, my desktop thought I was asking a lot too. Still, I love a white elephant I'll try to build something more sensible for you!

Edited September 2, 2015 by The_Rocketeer

[GoSlash27]

Then things got weird. The tailplane just started randomly losing parts as I was rolling to stop.

This is a known bug. I think we need a ruling on this. It's not really fair to penalize a pilot for a flight that was ruined by a bug.

I'd recommend amending the rules to state that flights that encounter the "collision kraken" don't count.

Best,

-Slashy

[Starhawk]

This is a known bug. I think we need a ruling on this. It's not really fair to penalize a pilot for a flight that was ruined by a bug.

I'd recommend amending the rules to state that flights that encounter the "collision kraken" don't count.

I agree with Slashy, except that I call it the 'Wing Kraken' because it always seems to hit wing parts and control surfaces.

Also, on the question of payload cost. It makes sense to me that payload cost not be included in the initial craft cost for calculations.

Happy landings!

[Vegetal]

Yay success! Any comments on performance or improvements rocketeer? I put the CoL further back than I normally do, to be on the safer side as I didn't do any testing. I don't like nose heavy planes.

As for that bug, it's really annoying. Luckily it didn't hit you in flight, that would suck, having to restart a successful flight.

[The_Rocketeer]

Yay success! Any comments on performance or improvements rocketeer? I put the CoL further back than I normally do, to be on the safer side as I didn't do any testing. I don't like nose heavy planes.

I agree on the nose-weight, it's on the tipping point of becoming an issue on this craft. I'd like my CoL slightly nearer the CoM to keep the drag profile down during ascent.

Re-entry was warmer than I'd like too. I came straight in from 100km to a 10km periapsis, kept prograde and deployed all brakes, but the nose section got a thorough cooking. Also the PV panels under the tailwings got a bit warm.

Fuel allowances were also either well judged or a bit risky. I drained the RCS dry by mistake (fortunately after docking) but I'd not left it on for more than 30 seconds or so. It seemed like there was plenty of room for more tho - were u using it for ballast?

All in all, pretty good - not a failure

[Nich]

So I have not been deducting payload cost however if you want to figure that out and add it to the post I am perfectly fine with subtracting it. If your craft drops off payload I suggest you add a "stock" payload with a known cost for your pilot.

Sorry to hear about the Kraken attack. Here is what I am planning on doing.

1. For mid to low scoring entries I will allow simply guessing what the recovery value would have been. Luckily you have a screen shot right at the end so we can just drain the fuel and see the recovery value displayed as cost i believe.

2. However for a potential Top score (1st-3rd) I will require a revert/retry

3. If a second Kraken attack happens the craft will be labeled as Kraken Bait.

Also people have gotten into a bad habit of not documenting their exploits. This is fine for already certified Pro Pilots however if it is your first time or you are potentially taking 1st-3rd place please document your adventure so everyone else can ride along for the fun.

[The_Rocketeer]

I would have produced a better report but tbh I thought it was a basket case after the kraken attack. Honestly Nich, if you want to disallow entries on grounds of insufficient evidence that's totally fine with me I plan to repeat the flight anyway.

[Vegetal]

I agree on the nose-weight, it's on the tipping point of becoming an issue on this craft. I'd like my CoL slightly nearer the CoM to keep the drag profile down during ascent.

Re-entry was warmer than I'd like too. I came straight in from 100km to a 10km periapsis, kept prograde and deployed all brakes, but the nose section got a thorough cooking. Also the PV panels under the tailwings got a bit warm.

Fuel allowances were also either well judged or a bit risky. I drained the RCS dry by mistake (fortunately after docking) but I'd not left it on for more than 30 seconds or so. It seemed like there was plenty of room for more tho - were u using it for ballast?

All in all, pretty good - not a failure

Well, I have to ask Nich then, if I can update the spacecraft with input from the pilot . It isn't clear to me, after all, it wasn't a test flight per se, it was the evaluation already. That's very Kerbal if you ask me hehe.

Apart from the CoL issue, everything was pretty much as I imagined. My spaceplanes always get crispy on reentry, but never really melt. Take it as a manufacturer quirk

The RCS thing, well....I am pretty efficient with monoprop when docking, on smaller craft I'm usually ok with the 15 units on the Mk2 cockpit, but I like some more on bigger craft like this, I thought that quantity was enough to allow for sloppier docking. I can increase it a little, after all the idea is to make an easy to use SSTO. LFO levels were ok I guesss? I left an excess LF on purpose, to avoid having to be ultra accurate on reentry, and from my experience, when dealing with Mk3 planes, it's better not to abuse them when hypersonic.

It's interesting because I followed a philosphy of simplicity for my design, and yours seems to go the direct opposite. I think I'm gonna have a go with the Hostess

[Nich]

@Vegetal - Actually you can alter the craft based off his suggestions however his cost will also be incorporated into your development cost. You have earned a Pro builder badge as the flight was successful even though it cant be counted for the official score board.

@The Rocketeer - with 18 kerbals to LKO you will have 24 points depending on your cost it will be first or second place so yes we need an official recovery value. I am happy to award the Pro Pilot award though as you completed the flight even with Kraken interference.

[The_Rocketeer]

It's interesting because I followed a philosphy of simplicity for my design, and yours seems to go the direct opposite. I think I'm gonna have a go with the Hostess

Haha, it's fair to say that not many of my designs come out quite so... gargantuan. I set myself the goal of an interplanetary SSTO for 100 Kerbs. Why in God's name anybody would want such a craft is their business. With an orbital refuel to brim the tanks, I reckon Jool is within reach, possibly even a Laythe landing and return.

@Nich, speaking of which (above), is refuelling allowed, or are we really talking about a SSTD craft here? What about asteroid mining? If I drop a crew compartment for an ISRU and replace the docking port with a claw, I reckon I'd be in business...

I'll submit a fresh attempt in due course, running out of free time today.

[Vegetal]

Hmmm.....I might keep it as it is then, for the most points, as it seems it was quite reliable already. After reentry, what I do for the final approach is to keep the aircraft level using SAS, and pumping fuel around util the pitch indicator is just above center. Then proceed to landing.

What's left for it to be official, just the recovery value isn't it?

[Nich]

Refuel is not allowed

ISRU and mining is allowed. I have already attempted an SSTEverywhere "Neagle Infinity" however I messed up the COM/COL shift and on empty reentry lost 4 kerbals (and someone else also lost 4 kerbals) So if I fixed it I would have to add in -400ish points)

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@Vegetal - Correct if rocketeer doesnt fly it again today or tomorrow I will have some free time Friday

[The_Rocketeer]

Hot off the press: Have flown again this evening, total success (except reentry balls-up wasting LF).

18 Kerbs to 100x100 LKO.

Total fuel spent: 155 Mono, 4924 LF and 3155 O (does someone have figures for cost per unit? Flying in sandbox so I can't just subtract recovery..)

No deaths or damage.

I called this the Space Whale 1a because I topped up the monoprop tank. In the event I didn't need the extra dV, but it also helped with the CoM/CoL gap. That's all.

Ascent was straightforward, I adopted a 20 degree pitch from rotation, dropping to 15 degrees at 5000m and 10 degrees at 10000m to gain thrust. Slight underspeed caused an engine flameout. Consequently had to switch modes at suboptimal velocity, but completed ascent safely.

Orbited once to phase for station encounter. Docked and stayed so for another 6 or so orbits because the sun had set at KSC and I prefer to land in daylight.

Reentry was fine except the cockpit nearly blew up. I tried to keep the prograde tracking on for as long as possible, but lost faith at 20,000m with the heat bar nearly full (check the pics) and pulled up slightly. I think I must've had a better glide profile last time, because I also seemed to descend and slow much more quickly, and consequently had to spend an extra 400 LF or so cruising to the runway. In true Kerbal style, I had a horrible moment where I thought I was going to overshoot the runway or break off a wing, but managed to get the plane down intact.

Javascript is disabled. View full album

Notes to Vegetal:

1. Sorry I wasted the fuel, might've cost us a point or two.

2. The plane wants to roll off vertical when gliding, nearly ruined our day on final approach. I guess its because the CoM is higher than the CoL. Might be an idea to put the wings above the windows rather than below.

Edited September 2, 2015 by The_Rocketeer

[Nich]

I like that docking technique I will have to try that sometime. I will calculate the cost later tonight when I get home.

[Vegetal]

Ah nice! From your album, it still has plenty of fuel for a higher orbit rendezsvous.

As for the notes, 1 - That's why I put extra LF there. Better waste some fuel than having dead kerbals! And 2 - If I did that, I would have to change the landing gear setup, and that would be another plane completely. If I design something now, it will be a more ambitious project

When I gave my instructions for reentry, they were more like guidelines. I usually pitch up a little from prograde myself with most of my designs, so you did the right thing. I will tell you one thing though: You are a monoprop guzzler! You used half of it, I'm impressed

Anyway, congrats on the flight man, I'll have a try later in your design if the framerates allow.

And Nich....what technique?