Mini challenge - fix the Stearwing D45

[Gordon Fecyk]

1 minute ago, AeroGav said:

I reckon you can get to Minmus with 440. I haven't tested this feature yet, but I kept the Verniers and a smidgen of oxidizer in the hope of pulling one of these off

Ya I was looking at that. Couldn't figure out why the Verners weren't firing down though. Even tried controlling from the docking port. They were firing though; I even remembered to unlock the OX tanks.  Guess I'll have to practice more.

Made it to Minmus and attempted a landing. Landed hard when I attempted a Verner-assisted landing, though I'll figure out how to get them to thrust down properly.

I think I'd prefer the original Lite once I figure out horizontal landing. Thanks again!

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[Gordon Fecyk]

(never mind; I just constructed a lawn dart! I'll leave it here for amusement, but that's about all this plane is good for.)

Here's an updated FAR craft I was working on over in KSP 1.1.3. This is a prototype and is missing RCS functionality and drogue chutes:

Notable changes:

• No first-class cabin. While I can get it to orbit with a short rocket fuel fuselage and a cabin, it didn't leave much room for anything besides orbital rendezvous and refueling. While this version still needs refueling, it stands a better chance of going to Minmus once refueled. It can manage a Minmus flyby, barely, on its own.
• "Coach" class seating retained with internal parts attached internally, and not along the walls of the cargo bay. This should avoid messing with the stock drag model.
• Removed RCS ports except for Vernor engines. The Mk2 cockpit can hold a remarkable amount of monopropellant, but I wanted to streamline the craft first. Vernor engines may be enough for horizontal Minmus landing.
• Removed one pair of Mk0 fuel tanks. In FAR the craft easily reaches 24 km before the Ramjets flame out, and the third pair of tanks was just excess fuel.
• Added nose spikes and a small pair of nose cones up front. One cone surface-attaches to the nose, and the other just streamlines the shape a bit. Provides that extra safety margin for overheating.
• All science instruments retained in coach cabin. Removed original batteries.
• Added OKTO2 probe core for autopilot and Z-200 battery.

I'm planning on making more changes:

• Putting RCS nozzles back, but not the thruster blocks. The place-anywhere nozzles are lighter.
• Removing the bottom set of air intakes. After I bottomed out during one test run, I was flying just fine with the top set of intakes.
• May remove the Z-200 battery as the Mk2 cockpit boasts considerable electric charge as well as monopropellant storage.
• Adding drogue 'chutes for landing. I find anything returning from orbit in FAR needs these or one would easily drive off the runway.
• Try to add flap functionality to assist on takeoff and maybe reduce stall speed on landing.

How to fly:

1. Turn DPCR off, enable SAS basic stability hold, throttle up.
2. Stage the Ramjet engines and hang on for dear life! The thing will easily reach 250 m/s on the runway and may climb on its own.
3. Drive off end of runway, retract gear, and hard-pitch up! Keep pitching up until about 40 degrees pitch, maybe ever so slightly more. You will hit 100+ kPa dynamic pressure and won't be able to change course by much.
4. Go SAS prograde at, say, 5 km to 8 km up and stay there. Stage away the Ramjets when your speed stops increasing. I've reached 24 km before staging.
5. The Terriers should carry you the rest of the way up while pointing SAS prograde. Check your apoapsis and time to apoapsis; you want to do something approximating a gravity turn until you reach space.
6. Close your orbit when high enough.

I have not tried landing this thing yet. Maybe tomorrow when I have more time. However, if it flies anything like the FAR version of Thrimm's LTS Sparrow, you'll likely be gliding close to Mach 1 just above the runway. This is why a pair of drogues and maybe flaps would be a really good idea.

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Edited December 10, 2016 by Gordon Fecyk
This plane is a lawn dart; don't use.

[AeroGav]

14 hours ago, Gordon Fecyk said:

Ya I was looking at that. Couldn't figure out why the Verners weren't firing down though. Even tried controlling from the docking port. They were firing though; I even remembered to unlock the OX tanks.  Guess I'll have to practice more.

Made it to Minmus and attempted a landing. Landed hard when I attempted a Verner-assisted landing, though I'll figure out how to get them to thrust down properly.

I think I'd prefer the original Lite once I figure out horizontal landing. Thanks again!

--

I was on short finals about 400m up when i remembered all the things you need to do - open cargo bays, friction control adjustment, unlock oxidizer tanks, caps lock to coarse control mode, rcs on, it was a stressful moment .

The gear weren't designed for this kind of thing, are worryingly narrow and not much clearance with the cargo bay .

Also it is "wheelbarrowing" along the ground which makes it unstable.  I guess that's because it sits nose up on the ground and SAS is trying to level the deck angle.  Without SAS though there's nothing to correct yaw.

I had 550 fuel in orbit but only 100 by this point, so i mustn't be very good at orbital maneuvers.  Could do with a battery too though we managed.    I prefer RTGs but this ship does avoid endgame level techs pretty well.  Whiplash and Nuke are the big ticket items, at 500 science points unlock cost each.

 

[Gordon Fecyk]

On ‎12‎/‎8‎/‎2016 at 5:55 PM, AeroGav said:

I haven't tested this feature yet, but i kept the Verniers and a smidgen of oxidizer in the hope of pulling one of these off

It works quite well. Enjoy.

Managed to get to orbit with a lot more than 440 units LF now, so I managed to get to Minmus and return. Used the same Mun assist as from the Refuel at Minmus stock scenario.

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[AeroGav]

15 hours ago, Gordon Fecyk said:

It works quite well. Enjoy.

Managed to get to orbit with a lot more than 440 units LF now, so I managed to get to Minmus and return. Used the same Mun assist as from the Refuel at Minmus stock scenario.

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I really need to improve my gravity assists !   I only really use vernier landings when landing on the flats at some fraction of orbital velocity,  as you've seen.   Would you say the vernier VTOL style landing is better than a tail sitting spaceplane landing then,  not having to worry about busting the engine or rotating forward onto the gear?

Regarding the re-entry :  I don't know if you were trying to hit KSC or not.  I must admit, it's thankless and i seldom bother in sandbox.  In fact I never bother with return flights except to prove the craft can re-enter and land safely.  I have loads of Kerbals camping on Minmus and Duna.

If you were trying to aim for KSC at all I'd say it isn't necessary to pitch up so much coming back from LKO, the plane's pretty heat resistant and coming in at such an angle makes it hard to predict where you'll end up,  in fact you'll come down more gradually at moderate pitch angles where the wings are still lifting instead of stalled leading to a less intense, though longer, heat pulse.

A wonder how well this technique works on the Stearwing?      It's more heat resistant than this mk1,  but the mk1 does have very large wings for its size, so it glides well and tends not to fall below 35km until it's going really slow

 

On 09/12/2016 at 2:07 AM, Gordon Fecyk said:

 

I have not tried landing this thing yet. Maybe tomorrow when I have more time. However, if it flies anything like the FAR version of Thrimm's LTS Sparrow, you'll likely be gliding close to Mach 1 just above the runway. This is why a pair of drogues and maybe flaps would be a really good idea.

--

Yeah I must admit, realistic though it is,  I was never a fan of it's landing speeds.   I started calling it the "widowmaker" mod.

I much prefer the crashes you get with stock aero model 

 

[Gordon Fecyk]

4 hours ago, AeroGav said:

Would you say the vernier VTOL style landing is better than a tail sitting spaceplane landing then, not having to worry about busting the engine or rotating forward onto the gear?

I think next time I'd follow retrograde down a lot further, then rotate to horizontal with just a few metres left. This particular approach wasted a lot of fuel on the less-efficient Vernors, and I only took it noticing that I was on a pretty high plateau and moving close to horizontal to it. Otherwise, I think this really would only work on Minmus or Gilly, or maybe Bop and Pol assuming you could get a refueled craft out there.

As for gravity assists, I only learned once I observed this car jump and took notice of the Mun assist. After that I asked about what I saw, and learned a lot. Now I can abuse the Mun and Ike to get between Kerbin and Duna with less fuel.

And for landing at KSC, that's something I need to learn more about. It's more important when I play with Ferram Aerospace on 1.1.3, because landing anywhere else from orbit is tough with the lack of flat land and the very quick approach of the space planes I've used so far. Yes I can cheat and use lots of parachutes, and have done so. It's becoming a matter of pride though. I did try gliding more considering the large amount of lift your craft has, but couldn't get any lift. Now I know I don't have to have such a large angle of attack to glide.

Overall, I think you won your own challenge.

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Edited December 11, 2016 by Gordon Fecyk
Grammar

[AeroGav]

I found a bit of time to polish my D45NL (nuke, light - surely a contradiction!) today with lessons learned from the maiden voyage.  More batteries, fewer Vernors, repositioned landing gear,  repositioned drop tanks (now out on the wing tips where they are more in line with CoM).

The craft file on the KerbalX page has been updated accordingly.

I have yet to take this updated version to space, but it did get tested another way, when attempting to answer this question -

On 07/12/2016 at 9:47 AM, swjr-swis said:

I really disliked the idea of dropping the jets (I may want those when coming back from orbit)

So, how risky is it coming back dead stick?   What if we're forced down on adverse terrain, will that kill the crew?

Here's some footage of me simulating the "adverse terrain" landing test.   It took a few attempts to get the airplane to intersect the "terrain" at it's stalling speed and in a realistic landing attitude, hence the jinking maneuvers as i try to bleed off speed.  But what the heck, blowing stuff up is fun.