sploden

A note on asymmetrical flameout: The reason this is bad is not just for maximum safety and reliability, but also (and more importantly) for maximum delta-V. If an SSTO has an even number of jet engines, the pilot is unable to safely and dynamically throttle down to just below the operational intake requirement in order to keep the jet engine running as long as possible, right up to the edge of space. I am surprised no one else mentioned this, and I noticed someone even criticized my design decision of not binding my intakes to the jet engine toggle group. The reason I didn’t bind my intakes to a toggle group is because on the way to space it’s best to keep the jet on as long as possible even if it is throttled almost all the way down. Further, putting the jets and rockets on the same toggle group is a big no-no in my book. This is also why I dislike rapiers; it’s impossible to separate the cycle modes and run them simultaneously, and Auto cycle-switching is the worst. If you want a plane that can teach both asymmetrical flameout and maximizing delta-V, I would probably think about building a plane with three jet engines and two rocket engines, but that seems out of scope for this project. A few other things I dislike: Extra torque on SSTOs seems like a delta-V wasting shortcut for fixing bad CoM/CoL balance (at least in this weight category) Escape systems waste delta-V and seem like a cop-out for maximizing flyability. Implausible-looking designs, such as intakes covering intakes, intakes that don’t seem like they could lead to the correct engine, control surfaces that aren’t aerodynamically placed, lifting surfaces placed in close conjunction with the body of the craft thus making it look like they shouldn’t have lift even though they still do (such as the boxy midsection of many biplane designs) Biplane SSTOs Dog bites Bee stings Lastly, I didn’t feel like docking. Generally it’s easy if you have plenty of delta-V, electric power, monopropellant, RCS ports that surround the CoM in some fashion and allow 6 degrees of translation, and a docking port that doesn’t require orientation change. The most important aspect of this challenge is getting to space easily and efficiently with lots of delta-V and getting back to KSC in one piece. So! To the testing and opinions... BSC Bolt Fuel tank size/fuel carried ratio seems odd Looks okay (except for the unshielded docking port) Has added torque Flight plan error margin on the way to space is small Amount of monopropellant seems low Delta-V is pretty low - I had 504m/s upon reaching orbit, 70,319m x 72.287m Could do without two of the rockomax engines, thus increasing delta-V again. Replacing entirely with two 48-7S’s would give even more improvement. Control surfaces are un-tweaked. Not the easiest to land. Big props for the separate action groups controlling the jet engine and the rocket engines Gecko v1-0 Doesn’t look very aerodynamic; middle canards especially would cause lots of drag IRL One ladder too many Seems big for an Aeris 4a Midsection radial intake placement isn’t symmetrical top to bottom Bi-plane isn’t my favorite design Asymmetrical flameout difficult to avoid when using my ascent profile Requires turning off rocket engine after starting Good amount of delta-V upon reaching orbit; 1931m/s at 73,089m x 74.293m Control surfaces are un-tweaked Big props for the separate action groups controlling the jet engine and the rocket engines HOTOL II c4 Odd RCS placement Odd intake placement - are the wings supposed to be liquifying the atmosphere and pumping it into the Rapier? Has added torque Would make more sense if action group 1 toggled the rapier’s cycle Rapiers should be in manual switching mode if they are used Has a weird tendency to flip backwards right after takeoff. Could really do without that reaction wheel. Perhaps I was flying it wrong, but it had 90m/s delta-V left after reaching a 70,544m x 73,769 orbit. Might have been able to add on 100m/s with a better flight. After I took it back to the spaceplane hangar and switched the rapier’s mode to Manual and changed the cycle toggle to action group 1, I was able to achieve an orbit of 70,531m x 84,183m with 745m/s left Fuel ratio is off Not the easiest to land Mallard SSTO Unstable - tends to flip out if not handled gently Has an escape system Jet engine and rocket engines should be on separate toggling action groups. This would allow an increase in delta-V. Achieved an orbit of 70,454 x 72,517 with 1358m/s of delta-V left. Could do without some of the extra fuel, which would increase delta-V Not the easiest to land Peregrino Odd radial intake placement - are the wings supposed to be liquifying the atmosphere and pumping it into the jet engine? Narrow wheelbase Would prefer a docking port that doesn’t require an orientation shift Would prefer to have the rocket engines on their own action group, the jet engine on another action group, and the intakes on their own action group (if at all) Used the 2nd stage to turn on the rocket engines to work at the same time as the jet engine in order to increase delta-V Achieved a 75,194m x 76,650m orbit with 1227m/s delta-V left. Slightly angled back wheels could cause disaster R-2 Rapiers should be in manual switching mode if they are used Would prefer a docking port that doesn’t require an orientation shift. Two intakes mostly in front of two more intakes that lead into RCS tanks…? Looks okay, except it's a biplane and has intakes coming through the tops and bottoms of the biplane wings Has added torque Achieved orbit of 71,610m x 73,054m with 1288m/s delta-V left. Wholfine Hybrid Looks okay, except it's a biplane and has intakes coming through the tops and bottoms of the biplane wings Rapiers should be in manual switching mode if they are used Would prefer a docking port that doesn’t require an orientation shift. Has added torque Achieved 70,289m x 75,995m orbit with 1016m/s delta-V left. It’s a tough choice. I am undecided at this point. But good job to the finalists; congratulations!

Aeris 4a Improved 08 I don't see the original Aeris 4a as being an absolute beginner's SSTO, but more of a "next step" SSTO, given that it has a docking port and multiple engine types. My craft improves upon the execution of the original craft's scope. Takes off at about 50 m/s No tailstrike hazard Easy to fly Teaches a few "next step" engineering ideas Turbojet full throttle until about 39km Capable of achieving low Munar orbit and returning to Kerbin Capable of landing on Duna Awesome

My testing notes: Bullfrog Aesthetically interesting Too much torque; precision maneuvers difficult Narrowish wheelbase Good part count CRPLTV Aborting while controlling from probe core is potentially lethal - that capsule moves fast Probe core should be flipped and placed on the opposite side Hovers at approximately 2/3 throttle Good part count Damselfly Hybrid rocket/jet design is cool Aesthetically interesting A little too much torque Balance is off Good part count H.A.L.O. Aesthetically interesting Jet-only design - precision maneuvers difficult Good part count Abort shuts engine down - good Too much torque for my taste Needs a second parachute in the back for landing evenly upon aborting Kerbol Flying Object Very high part count Quite large Torque is too low TWR is too low Wheel arrangement is questionable LeapFrog LV-IVTOL Aesthetically interesting Too much torque for my taste Narrowish tripod landing gear base Medium-high part count LLTV “The flying bedstead†Very high part count Nice replica design Jet-only design - precision maneuvers difficult Abort system works well Part clipping present Morpheus Kinda bulky Medium-high part count Can drive on the ground Command chair transition from the pod is a little cumbersome No abort system Discards a capsule on launch Omega 16 VTOL mk6 Good part count Balance is off Struggles to roll and yaw. Pitch is better. Would prefer horizontal orientation controls - difficult to fly as a result. Pack Mule Medium part count Aesthetically interesting Works well Pavo VTOL Medium-high part count Impossible to take off without SAS Legs attached to parachutes Seven parachutes Parachutes and forward engines triggered on #1 Requires 100% throttle to take off Part clipping present Rocket VTOL Craft named “rocket vtol†has no rockets Jet-only design - precision maneuvers difficult Abort action group doesn’t cut engine, problematic because aborting doesn’t split the craft Good part count Rocket-power VTOL 2 Medium-high part count Requires 100% throttle to take off Feels sluggish - needs more torque, either RCS or reaction wheels; just more Snack Wagon VTOL Good part count Aesthetically interesting Could lose the science parts Balance is off Good amount of torque Side engines unnecessary Tern Medium-high part count Not sure why it starts mounted to a launch clamp Expected pushing space would release the launch clamp (Went back to SPH to remove the launch clamp and make it start with legs out, then continued testing) Cool missile thingies Aesthetically interesting Lots of part clipping Hybrid rocket/jet design is cool No abort mechanism VTOL Ostrich Good part count Jet-only design - precision maneuvers difficult Aesthetically interesting VTOL Training Or Learning Recursive name is recursive :-) Good part count Simple design is easy to understand at a glance Would prefer horizontally oriented controls VTOLPV7.1 Rocket Chair Good part count Aesthetically interesting Can be flown without SAS Discards a capsule on launch Part clipping present Wernhermobile Medium part count Balance is off Would prefer one toggling action group per engine bank (i.e. 1 = jet, 2 = middle rockets, 3 = outer rockets) Kinda big, but torque is good. Becomes increasingly imbalanced as fuel is used. Jet engine should use fuel from the rocket fuel tanks, which should move forward, to consolidate the fuel source and thus increase the balance throughout the flight. I think the Jet is toggled on action group 1.

Finished testing; the Damselfly is my favorite. Runners-up are the Pack Mule and the Snack Wagon. *Sequential screenshots; no reloading or reverting

A note on torque: My theory is that everyones' computers have different levels of power and different game graphics settings, and thus everyone will have a different perspective toward the controllability of a particular craft, whether in torque or in thrust-weight ratio. What I have done to approach some sort of standardization is turn down my graphics to the point where seconds measured by the game are very close to the passage of real time. This is how I have been testing the entries.

1. If you take off without SAS, the craft leans forward (rockets are much more noticeable). Granted, people won't be doing that too often, and it's probably a nitpick. I tried my hand at balancing this craft, and it’s tough. So I’ve modified my definition: “Not conspicuously imbalanced; able to be flown without SAS.†Kinda subjective, but works. 2. The stock craft is also much heavier. What I did to test this was to do the same course I ran through with my own craft. I find it easier to do the course with less torque. Here is my take on the Damselfly, with the above considerations.

Has my vote so far. There are a couple of issues: 1. Balance is off. 2. Too much torque for my taste. Good idea on the dual jet/rocket configuration. I had thought of something like it but dismissed it as too complex, not bothering to try it out. Kinda wishing I had now. I just now tried swapping my aerospike with a jet engine and adding four 48-7S's, and was able to reach orbit.. I guess it would be a kind of Bad Thing if I resubmitted, so I'll abide.

VTOLPV7.1 Rocket Chair Simple - No complex multi-type engine system to futz with. 57 parts. Safe - 3-way abort system triggered through staging, clicking the abort button, or using action groups 9 and 10. Tuned - Hovers at approximately 2/5 throttle, allowing for precision as well as agility. Versatile - Includes a probe core to allow navball orientation switching or unmanned flight.

The Chair is a manned craft. What is your definition of "trick?"

Hard, but possible. This was good cardio.

NikkyD, perhaps these will inspire you... The Chair Hummingbird MinLKO 6d The Bumblebee MinLKO 8b MinK 1a Minisistilikio As you can tell from tavert's MinLKO 8b, it's possible to achieve orbit with a turbojet onboard with just 2 oscar B's worth of fuel, with a craft weighing 1.51 tons (and I think this can be decreased slightly :-).

Name: Minisistilikio 3 Weight: 1.136 tons Parts: 13 It seems that something changed between .22 and .23. It's quite a bit harder to achieve orbit with the Minisistilikio in .23 than it was in .22 (hence the MechJeb).

I built another SSTO with 9 parts. Here's the mission:

XolotlLoki, if you don't mind my asking, why is my entry not included in your spreadsheet?

I don't think I would post anything like what I posted here in a BSC Aeris 4a challenge. If and when Xeldrak posts that challenge, I will create a completely different craft that is suited to the BSC guidelines. (Actually, I already have created such a craft; just waiting for that challenge to come along. )

Made this SSTO before I read the instructions; missed the low part count goal and 80km requirement. It should be capable of going to an 80km orbit, but oh well. This was the second landing attempt. I think it's 22 parts, but doesn't matter anyway since it's not a legitimate entry; I started from ~71km.

Maybe I'm calling it something it isn't... I'm referring to the prograde indicator, the green yellow circle on the navball.

Yeah, it takes a bit of practice to fly the tiny ones. If you do what the SPH description text says, it might work better. I had about 35% of my liquid fuel left over after achieving 70km orbit. If you drain out some of the oxidizer beforehand it might be easier, although I didn't do this to create my entry screenshots. SPH Description Text: Regarding #3, this works better if you start turning towards 10 degrees well before you reach 10km altitude, in order to utilize the greater pitch authority from the thicker atmosphere. Try to build up as much speed as possible using the jet engine. 2000m/s is a good goal; YMMV. "Vector" is referring to the vector indicator, not your angle of pitch. Side question, why are the octagonal and cubic octagonal struts not allowed? It's an interesting design challenge, but I'm failing to see the reason, as all it does is add weight by requiring larger solutions, such as the Radial Attachment Point I used on my spaceplane, which is 40 times heavier than the Octagonal Strut.

Okay.

Define "enough Mono gas."

I'm not on your spreadsheet...

Hmm... Anyone remember the order before it happened? I know I was fourth for most of today.

Maybe this is the only way to "disqualify" on the dotvoting site?... There are usually 6 people in the finals, so perhaps the ones with 48 were the top 6, excluding bombo1.

Instructions unclear. Now I have a frog stapled to my face...

It has landing lights. I only noticed serious tipping problems if you turn on RCS, and turning on RCS voids the warranty...