Kerbin Circumnavigation Challenge - updated for KSP 1.10

[zolotiyeruki]

26 minutes ago, linuxgurugamer said:

I drop my landing gear, seems to work.  I've dropped the gear at over 1650 m/sec without any problems 

Yeah,  few days ago I was testing a craft and was wondering why it was only going 1690m/s instead of the 1750 I was expecting.  Turns out I had forgotten to retract the gear.  oops.

 

Well done to Bryson, MakerTribe, and Bob_Saget54--the leaderboard has been updated with your impressive entries!

[linuxgurugamer]

Well, the gauntlet has been thrown down.

Working on a revised entry, the Speeder 1H, I've gotten a sustained speed of over 1710 m/sec (must have moar speed).

I'm not sure how you aren't overheating, especially after flying for 40 minutes at that speed.

@zolotiyeruki Would you consider possibly breaking things out into a couple of categories, either by weight or by number of engines?

@zolotiyeruki  Rules question:  Regarding clipping.  Could I clip a radiator onto a part and have it extend into another part, in order to move the heat around?

Edited September 15, 2020 by linuxgurugamer

[Bryson]

I try it again still G forces almost kill my crew, it was not a smooth approach to the runway, but manage to reduce the time just  a little.

Spoiler

 

[swjr-swis]

38 minutes ago, Bryson said:

G forces almost kill my crew

Tip: include a probe core. The probe core will take over flying while your crew are unconscious.

[linuxgurugamer]

44 minutes ago, swjr-swis said:

Tip: include a probe core. The probe core will take over flying while your crew are unconscious.

Make sure you have enough EC, otherwise the probe core will not do anything.

I found that if I have a probe core, I don't need a full cockpit, just a passenger compartment

[zolotiyeruki]

45 minutes ago, linuxgurugamer said:

Make sure you have enough EC, otherwise the probe core will not do anything.

I found that if I have a probe core, I don't need a full cockpit, just a passenger compartment

Actually, the rules state: " Your craft must carry a kerbal in a cockpit or capsule. "  So while a Mk1 passenger compartment would have relatively very little drag, and contain a kerbal, it doesn't count for this rule.

[swjr-swis]

1 hour ago, linuxgurugamer said:

Make sure you have enough EC, otherwise the probe core will not do anything.

Especially important if you're flying with RAPIERs like most entries in this challenge, since they don't have a generator. Good catch.

[Bryson]

I used 2 mk2 small cargo bay to put the radiators and 3 RTGs, here is the craft file.
https://kerbalx.com/Bryson/DeepSpace-Grasper-F
 

Spoiler

https://imgur.com/OTzxEdf

 

[Bob_Saget54]

@linuxgurugamer If you're overheating, what altitude are you flying at and what parts are overheating? I typically cruise at 22,000m-23,000m and nothing seems to blow up for me. The sustained heating effects on the aircraft led me to pose the little quip of the aircraft only being able to be used once.

Edited September 16, 2020 by Bob_Saget54

[zolotiyeruki]

Rats, I just about had Bob_Saget54 beat, but at the end of the trip, I found out I didn't have enough elevator authority to stick the landing.  Of course, this didn't become apparent until I was trying to land the thing at the end of a nearly-40-minute flight....

[GDJ]

Well, I'm able to maintain 1740+ m/s, but I gotta work on my landing procedures. I haven't been able to get under 40 minutes (best time: 40 minutes 24 seconds).

[Bob_Saget54]

I have a feeling that I will need to continue to refine my craft in order to maintain this lead...

[zolotiyeruki]

30 minutes ago, GDJ said:

Well, I'm able to maintain 1740+ m/s, but I gotta work on my landing procedures. I haven't been able to get under 40 minutes (best time: 40 minutes 24 seconds).

Yeah, it all comes down to the final approach.  Slow down too late or high, or too soon, and it takes a long time to get to the ground.  Slow down too low, and you burn up.  An extra 10m/s over a 40-minute flight adds up to about 25km, which seems like a lot, but it's only about 15 seconds of cruise flight, and it's easy to lose that much time.

[Lt_Duckweed]

Quick question, would having some wings in a bay be against the rules?  Basically, be able to open the bay for some extra lift during takeoff, but be able to close them away during cruise to have a lower cruising altitude (depending on the exact craft dynamics a lower cruising altitude can be counter intuitively more efficient).  They wouldn't be physically clipped, just located within the bay.

[linuxgurugamer]

2 hours ago, zolotiyeruki said:

Actually, the rules state: " Your craft must carry a kerbal in a cockpit or capsule. "  So while a Mk1 passenger compartment would have relatively very little drag, and contain a kerbal, it doesn't count for this rule.

Ok, thanks for that.  

1 hour ago, Bob_Saget54 said:

@linuxgurugamer If you're overheating, what altitude are you flying at and what parts are overheating? I typically cruise at 22,000m-23,000m and nothing seems to blow up for me. The sustained heating effects on the aircraft led me to pose the little quip of the aircraft only being able to be used once.

23000, and I'm flying at about 1710 m/sec, overheating issue seems to be solved.  I was having a problem with the Mk2 cockpit overheating, but I think I have that solved.  I just put the cockpit back after seeing @zolotiyeruki's comment about it needing to be a cockpit and not a passenger compartment, with some changes.  I won't know until I've done a complete flight, but my last test was on track to do a sub 39 minute flight, until I messed up the landing.  It was a test, I have a bit more refinement to do before doing a "official" attempt.  

[Krazy1]

On 9/13/2020 at 5:56 PM, swjr-swis said:

You are not using that airframe to its full potential yet. I suspect a combination of relying too much on the autopilot mod, resulting in a less than optimal flight profile, and a not quite optimally balanced plane.

I got the impression from your screenshots that more must be possible, so I did a manual rebuild (you offer no craft file, and I'm in still  on 1.3.1 anyway). Parts-wise, the only things I think I changed from your build are the precooler at the front instead of the structural tube, the slightly smaller Big-S elevon 1 for the canards, and I used larger landing gear (2x LY-35 and 2x LY-99). I did offset parts somewhat different to balance it better for zero CoM shift.

  Reveal hidden contents

Lap 1. Notice it starts out with marginally more LF than yours due to the precooler (+40 LF), but it has already used significantly less for its first lap (3634 vs 4472). Consumption only gets lower from here as cruising altitude slowly increases with diminishing fuel load.

For comparison, your first lap:

And lap 2 of both:

I didn't continue beyond that, the difference is clear.

So get tweaking, there's more to be had from this design.

Parting tips: an extra set of wings would allow this frame to cruise a few km higher, with only a small penalty to its cruising speed, for even less fuel consumption. Along with the extra fuel it'd add a few laps more. As for tweaks and flight profile: if you balance your plane well and design for it to be at equilibrium at its cruising altitude, you shouldn't need any manual adjustment during the whole flight - it should stay level at its optimum and adjust automatically to the changing fuel load. My personal opinion: for this particular challenge, using the AA mod is actually a disadvantage from stock.

 

Clarification: this is not an entry to the challenge - it's basically @Krazy1's plane rebuilt in 1.3.1 with a few tweaks and flown a bit differently. Just showing there's room for improvement in this entry.

P.S.: @Krazy1 I can PM you a link to the tweaked craft file if you want it; just let me know.

@swjr-swis Thanks for trying to help here but it seems that the dramatic change in speed could not be explained between the small changes you suggest. You managed to go over 1700 ms/ and I definitely could not go over 1600 m/s. You were a few thousand m lower but still doesn't seem to explain it. Plus your fuel burn rate is lower too. I'm thinking the difference between KSP 1.3 and 1.10 are very significant or perhaps I'm still having trouble with re-root causing drag to increase due to a bug. I don't follow the autopilot comment, at least while flying at cruise altitude, manual flying requires constant small corrections which are less efficient. I flew the climb and descent manually - certainly could be room for improvement but it wasn't terrible. My CoM shift was nearly zero. I'll try give it another go later, maybe this weekend. I'm trying to manage my first career game with 15 contracts and orbits that were jumping all over - I wish this game wasn't so buggy. And plus I feel like garbage from a medical condition and breathing smoke for a week in OR. Anyway... 

Edited September 16, 2020 by Krazy1

[Krazy1]

On 9/13/2020 at 10:32 PM, linuxgurugamer said:

• Power: 6 CR-7 RAPIER engines, running in open cycle only
• Air Intake: 5 Shock Cones, 4 Engine Precoolers

@linuxgurugamer Curious why so much air intake? It seems 2 shock cones would be plenty for 6 RAPIERS. 

[Krazy1]

On 9/14/2020 at 9:27 AM, swjr-swis said:

Presenting the swis-circ 2b. 8 laps in 05:20:24.

Pure stock, twin RAPIER powered, hybrid Mk2/Mk1 fuselage to combine the high temp tolerance of the Mk2 cockpit with the low drag high fuel density of the Mk1 LF tanks.

Since it starts with 832 of LF space unfueled and lands with 116 unused, this design has the potential of another 3-4 laps with some prioritizing and a bit more tweaking.

Highlights below, full imgur album here.

 

@swjr-swis Sorry to have to do this... but you mentioned in a prior post that you're using KSP 1.3.1 and your Imgur post title also says this. This clearly violates rule #1 to use 1.10.something. Perhaps @zolotiyeruki can invoke Smokey Yunick... somehow? 

May I be banished to Eeloo for outing the guy that tried to help me. 

[GDJ]

2 hours ago, Bob_Saget54 said:

I have a feeling that I will need to continue to refine my craft in order to maintain this lead...

Well, I did say I like competition.

[Bryson]

I improve my craft once again, my apologies if this annoying... but this is fun for me. I reach the location in 41:23 but couldnt land until 43:++
 

Spoiler

https://imgur.com/mryIhYj

 

Edited September 16, 2020 by Bryson
Images

[swjr-swis]

4 hours ago, Lt_Duckweed said:

Quick question, would having some wings in a bay be against the rules?  Basically, be able to open the bay for some extra lift during takeoff, but be able to close them away during cruise to have a lower cruising altitude (depending on the exact craft dynamics a lower cruising altitude can be counter intuitively more efficient).  They wouldn't be physically clipped, just located within the bay.

Up to OP to rule on this, but something to consider: when opening and closing a cargo bay, there's a bug in which KSP will sometimes 'remember' the drag values/forces that parts in the bay were experimenting, and you end up stuck with them even when the bay is closed again.

 

3 hours ago, Krazy1 said:

@swjr-swis Thanks for trying to help here but it seems that the dramatic change in speed could not be explained between the small changes you suggest. You managed to go over 1700 ms/ and I definitely could not go over 1600 m/s. You were a few thousand m lower but still doesn't seem to explain it. Plus your fuel burn rate is lower too. I'm thinking the difference between KSP 1.3 and 1.10 are very significant or perhaps I'm still having trouble with re-root causing drag to increase due to a bug.

I did comparisons right after 1.10 dropped, I didn't really notice any significant differences in aero performance, but I'll reinstall 1.10 and do the run there.

 

3 hours ago, Krazy1 said:

@swjr-swis Sorry to have to do this... but you mentioned in a prior post that you're using KSP 1.3.1 and your Imgur post title also says this. This clearly violates rule #1 to use 1.10.something. Perhaps @zolotiyeruki can invoke Smokey Yunick... somehow? 

I looked through the rules before I entered my attempt and didn't notice version being specified, but now it is indeed there in rule #1. Edited in afterwards? I guess that invalidates my attempt.

I won't have opportunity to do another long-range run again in a bit, there's work and life and stuff to deal with and even at an average of 40 min/lap with a plane that practically flies itselfonce on cruise, it's a long time to keep an eye on the game screen while needing attention on other things.

[Krazy1]

30 minutes ago, swjr-swis said:

I looked through the rules before I entered my attempt and didn't notice version being specified, but now it is indeed there in rule #1. Edited in afterwards?

I think you're correct. I did not see the first line about v1.10 either originally.

[zolotiyeruki]

7 hours ago, Krazy1 said:

@linuxgurugamer Curious why so much air intake? It seems 2 shock cones would be plenty for 6 RAPIERS. 

The shock cone intakes have less drag than anything else you can put on the front (or back) of a 1.25m stack.  Even less, I believe, than the really-long tail connectors, which have a lower Cd but a higher surface area.  If you stick a shock cone intake on the back of a RAPIER and offset it into the engine (so it doesn't block thrust), you'll see a significant reduction in drag.  But it's not realistic, which is why it's specifically disallowed.

3 hours ago, Krazy1 said:

I think you're correct. I did not see the first line about v1.10 either originally.

Dangit, I was hoping nobody would notice the edit.  Yeah, that rule should have been in place from the start, since aero and thermal seem to get tweaked between versions.  I'm going to allow it under Smokey Yunick, since it was my fault that rule wasn't there.

 

5 hours ago, Bryson said:

I improve my craft once again, my apologies if this annoying... but this is fun for me. I reach the location in 41:23 but couldnt land until 43:++

Don't worry about being annoying--there is nothing wrong with multiple entries.  Your time on the leaderboard has been updated!

[swjr-swis]

7 hours ago, Krazy1 said:

@swjr-swis Thanks for trying to help here but it seems that the dramatic change in speed could not be explained between the small changes you suggest. You managed to go over 1700 ms/ and I definitely could not go over 1600 m/s. You were a few thousand m lower but still doesn't seem to explain it. Plus your fuel burn rate is lower too. I'm thinking the difference between KSP 1.3 and 1.10 are very significant or perhaps I'm still having trouble with re-root causing drag to increase due to a bug.

Ok I had a moment to spare to run a test lap on the 1.10.1 install. Fresh reinstall off Steam (without DLC to save load time), and a direct copy of the tweaked craft copy&pasted right out of the 1.3.1 save, and directly loaded onto the runway. Screenshots at the first lap and a split second later with the game version information shown, just to prove it's really 1.10.1.

Spoiler

Reposting the 1.3.1 first lap to compare more easily.

The first lap in 1.10.1.

Confirmation that it is actually 1.10.1.

The results are, as I expected, pretty much negligible. In fact if anything, the craft is performing marginally better in 1.10.1 than in 1.3.1. It would seem I am at a disadvantage doing my runs in 1.3.1.

Note that I rebuilt your craft from scratch based only on your screenshots, since I can't load a 1.10.1 craft in 1.3.1 and you haven't shared it anyway. Without having the original, I can't 100% guarantee I got it all exactly the same to start with, before I made the changes I listed.

Offer is still open to send you the craft file, so you can compare them for yourself and verify it performs as shown. I'm specifically not posting it here to respect your choice of not sharing your craft, but I have no issue letting you have it - it's your design anyway, with a few tweaks.

[swjr-swis]

14 minutes ago, zolotiyeruki said:

If you stick a shock cone intake on the back of a RAPIER and offset it into the engine (so it doesn't block thrust), you'll see a significant reduction in drag.  But it's not realistic, which is why it's specifically disallowed.

The part that is actually not realistic is the generic drag cube calculation of the game applying full drag on a 'face' that is in reality producing THRUST (it's an engine after all). Not arguing about your rules, it's your challenge, just commenting on the 'realism' thing.

 

20 minutes ago, zolotiyeruki said:

Yeah, that rule should have been in place from the start, since aero and thermal seem to get tweaked between versions. 

Differences, as shown in the post that I got in just after you, are really negligible, and in fact look in favour of 1.10.1 as far as I can tell without doing the entire run. But again, your rules. I'm fine with it not qualifying if you intended from the start to only allow 1.10.1.