Jacke

Oh yeah, at times staying on the ground running straight can be a challenge. Even well behaved rods sometimes end up doing...interesting things. And @Triop, can you share the .krt file for your 1000m drag race ? I'd like to use it to test.

Cool rat rods, dudes! I've used sepratrons on all my rocket sleds except RS-2, AKA "Serious Buzziness". 12 of them provide a bit more thrust than a Flea SRB for 5s (at full fuel) and are lighter, though the Flea burns for 8.8s. RS-5, AKA "Kompak Trak", my Dragweek entry, uses just 36x 4s 80% fueled sepratrons. But I've found that sometimes when mounting the sepratrons, due to some weirdness or another (tilting them off-axis?), they provide little to no effective thrust, but I imagine still add to mass and drag. Was playing around with the original Rocket Sled today (making it stock as well as trying to make it crash less without a radical change). I'd advise being sure the sepratrons are helping. And sometimes you can get lost in designs when it might be better to back up to something simpler. Wow, that Fuel Deliver Overlay is neat. As well, I have noticed that when drawing from more than one tank, all the tanks are drained at the same time. Makes the CoM movements less dramatic. I think they should get another chance to fix that issue. As I found out myself, it's easy to be distracted and not realise something's not working.

In response to @Triop's Adventures and to enter into his Dragweek contest I developed a number of rocket sleds of increasing speed. They go very fast in a straight line down the runway. And they even can stop. If they don't crash. The latest one, Rocket Sled 5, AKA "Kompak Trak", is very very fast in a very very straight line and stops real real well. It even doesn't crash. https://kerbalx.com/Jacke/Rocket-Sled-5

If you had a reference for this Philosophy of Angles, I'd be interested in it. I think I know what you mean. A quick search didn't turn up anything useful. I think unless you're going to indulge in fancy stuff like Eve and Kerbin gravity assists (sort of like the MESSENGER Mercury orbiter) (and there are mods below that can help find simple ones of those), this might be the best solution. 1. Launch from Kerbin surface into the plane of the orbit of Moho. That takes out that plane change as much as possible considering #2. 2. Optionally, wait until (or get closer to) Kerbin passes through the relative ascending or descending node around Kerbol with respect to Moho, to reduce the delta-V of some of the next maneuvers. The timing of the transfers from #3 should include this. 3. Use a porkchop tool like in MechJeb or any of the other mods / external tools following to find a near minimum transfer injection maneuver within the assumptions of these tools. The best tool is likely Arrowstar's. 4. Set up the maneuver(s) from #3. Use one of the best maneuver node editors. Besides one internal to MechJeb, these 2 are still in support, Dmagic's Maneuver Node Evolved and as 5thHorseman mentioned, Precise Node. 5. You might (should) get a intercept with Moho's SoI. You may be able to set up the capture maneuver node. If so, you can using the maneuver node editors to carefully edit the nodes to minimize delta-V or get a more desired interaction with Moho (eg. polar pass for polar orbit). 6. Appropriate mid-course correction burns can help to get better interactions and even minimize delta-V. I think MechJeb's Maneuver Planner tool can help here.

I hope my explanation below doesn't make things worse. It helps to understand velocities as vectors and how a complex transfer is made of a number of delta-V vectors. What's wanted is the minimum total delta-V, the linear sum of all the component delta-V's, that as vectors produce the transfer to a relatively more inclined and elliptical orbit like Moho's. This is a complex problem and I don't think it has an exact solution or even a simple approximation solution. The problem of doing a Moho transfer is the same as a Mercury transfer in the Solar System: it's not just a transfer orbit to the target orbit, which is difficult itself because it's a highly elliptical target orbit (which complicates finding the timings for minimum delta-V just for that). It's also that Moho has a relatively highly inclined orbit. That means you have to do a plane-change maneuver as well, either by itself or combined with one or more of the other component maneuvers. Plane-changes are best done when the velocity around a primary (ie., around Kerbin when tilting the orbit around Kerbin) is minimum. Part of the craft's velocity in the frame of Kerbol is that of Kerbin's going around Kerbol. The plane-change delta-V component for that can't be minimized unless you first use a maneuver to greater apoapsis around Kerbol. Jumping back to the Solar System, that's one of the reasons why transfers to a very highly inclined Solar orbit are often done first with a Jupiter transfer. It's not just using Jupiter for a gravity assist but using the greater Solar apoapsis to decrease the velocity component around the Sun to make that delta-V component for the plane change smaller. But unless an outward maneuver from Kerbol is added into a voyage to Moho, that's usually not done. So that component of the delta-V total to transfer to Moho is usually always going to be the same. Then there's the plane-change component of the orbit around Kerbin. That can be minimized by launching at the time close to Kerbin being at its relative ascending or descending node with respect to Moho. Then wait for the rotation of Kerbin to launch in an orbit around Kerbin coplanar to Moho's around Kerbol. So, the transfer to Moho is split up into a few delta-V's, two to four or more. Some can be combined into a smaller number of maneuvers. Those delta-V's are all vectors. If they are closer to being parallel to one another, then the overall transfer is better. If not, it's worse. And the problem is those component delta-V's don't all have their minimum values at the same time. Often not even close to the same time. Which is why the delta-V spent to get to Moho or Mercury can vary by more than double even for "good" alignments. And thus hard to find the best time and best series of maneuvers to transfer to both of them. It's why it's often settled on a set of maneuvers that should be close to best then using an continuous analysis methods like a pork-chop plot to find the launch windows. Rather than hoping to beat such a complex problem into a completely analytical best method to find the elusive true minimum delta-V by any given set of maneuvers. Confused yet? I am and I kind of understand it all.

How about making a challenge for the maximum depth under control, ie. can stop at that depth and rise again to the surface.

I'd like to enter my Rocket Sled 5, AKA "Kompak Trak". https://kerbalx.com/Jacke/Rocket-Sled-5 For driving, as instructed on the KerbalX page: Load, let settle, engage SAS, launch! On SRB burnout, pop ‘chutes, then apply brakes. More details on how I developed it here.

I think I've got it. Rocket Sled 5, AKA "Kompak Trak". https://kerbalx.com/Jacke/Rocket-Sled-5 Instructions on the KerbalX page. Rebuilt everything. Used tougher wheels. Not driven, steering enabled on the front, but may not be needed. Now 36x4s Seperatrons (RS-4 used 32x3.5s) to make up for added drag. RS-4 topped out about 408m/s. RS-5 gets to 401 and will have SRBs burning when it crosses the 1000m finish line. 6 drogue 'chutes low down at wheel mount level can be fired right after SRB burnout and shouldn't tip the vehicle forward or back. 6 to slow it fast to get below speeds where a little bounce can destroy the whole thing. The twin fins are what makes this beastie keep on track. Finally figured out using a rear fin at these speeds leads to yaw-opposite roll coupling. Say SAS wants to turn a bit left to stay on track. The small fin deflection also causes a small roll to the right. As the wheels even rolling have drag, the right roll presses down the right wheels and reduces the left yaw of the SAS input. And can overwhelm it completely at times. A forward fin will deflect in the opposite direction, opposing the roll effect of the rear fin. Also, the fins are lower to reduce roll effects overall. And the forward fin is clear of the pod hatch. Make it work as small as I could get it. And best of all, now tough enough that I can get screenshots while under thrust. So it should work for others now.

From my testing, I would imagine it's the LY-05 front gear failing leading to loss of the vehicle. Do you ever hear the "whump" of the Separatrons burning out before a crash? It has happened a few times for me during testing. However, those post-burnout crashes are rare. If it's happening before the finish line, I would imagine the SRBs are still burning, as they have 3.5s of fuel. As about 0.1s to 0.2s of that burn happens before crossing the start line, the SRBs should burn out about 0.3s to 0.4s before crossing the finish line. From what I normally do, I pop the chutes about a full second or more after crossing where the finish would be. I also delay using the brakes until under 150m/s, as the braking of the main gear puts more stress on that LY-05. Cutting the fuel to burn from 3.5s (70%) to 3.0s (60%) did make the Rocket Sled 3 work (same as RS-4 with a Girder Adapter and a Command Seat in place of the Mk1 Command pod to save 500kg), although crashes still happened. But doing so on the RS-4 may put it behind the TR-1-OP. I do have a good percentages of RS-4 runs that work (as long as there's no screenshots; I only started doing them after I got RS-4 to work and then it failed every time I did a screenshot under power). Unfortunately, there must be enough different between our two game installs to somehow push it closer to yielding. I think I'll have to change that front end to something more durable. If the speed drops too much, well, you know what that means.... MOAR BOOSTERS!

And now I see that after going to flight and reverting one or more times, the RCS Build Aid icon disappeared from the stock launcher. Logs on Dropbox and screenshot in the spoiler showing RCS Build Aid detected by Toolbar Controller and not hidden by Janitor's Closet. When I exit the game and restart, the RCS Build Aid icon is back, but will disappear again after going to flight one or more times. https://www.dropbox.com/s/el09vuyceq5a7vt/20190314b.RCSBuildAid.no-icon.zip?dl=1

I was getting this error today after upgrading to the new RCS Build Aid (no icon in stock launcher). Removing all my mods, clearing GameData of non-Squad directories, and reinstalling solved this. (Managing most of my mods via CKAN helps to do this.) That may be more than is required to resolve this cruft issue block RCS Build Aid, but this should fix things, as it did for me.

Cool name, @Triop! Yup, I figured no use hauling fuel that won't be burnt before the finish line. Thanks, @NBDesigns! I had to work to beat your time. As as team Panic Attack and I'm sure others have learned, going at these speeds makes also going straight a tricky challlenge as well. "Serious Buzziness" and the other rocket sleds crashed so many times. And still do on some runs. But lordy, lordy, lordy, what's the name of this wickedly fast beastie, @Triop ? I almost thought I'd never get one as fast without almost copying it. Almost thought. I don't have the track in my testing rig, so I used top speed around crossing the finish line (as eyeballed). So, I'm wondering, how fast my next TF1000 entry is. Rocket Sled 4, AKA "Risky Buzziness". Risky because if I took a screenshot while the SRBs are burning, it crashed. No screenshot under boost, no crash. Dang. EDIT: BTW, needs SAS to stay on track. And when past the finish, needs both 'chutes and brakes to stop. Especially if still on the runway. https://kerbalx.com/Jacke/Rocket-Sled-4

That's no problem, @Triop The Rocket Sled 2 was easy to modify to be stock only. Just be sure to let it settle, turn on SAS, and pop those 'chutes as soon as it hits passes the finish gate. https://kerbalx.com/Jacke/Rocket-Sled-2 And considering your latest entry, I'm going to have to up my game to beat that speed demon.

Here's my rat rod. Modelled after a rocket sled I was working on as an early mission for a career mod. Pure SRB design. Needs the mod Smart Parts to fire its second set of Separatrons. Steering is disabled becuase if controls are touched, even with Precision on, it crashes. Has a couple of drogue 'chutes to pop after burnout after the finish. https://kerbalx.com/Jacke/Rocket-Sled And not being satisfied with Rocket Sled's performance, here's Rocket Sled 2! Simpler and faster! Again, 1 Smart Part, but now it automatically stages to pop the 'chutes just before SRB burnout. This one depends on SAS to stay on the track. But with SAS, it should pass the gate. May leave the runway shortly after, but shouldn't crash. https://kerbalx.com/Jacke/Rocket-Sled-2

So've I, for over 50 years, for my memory goes back to at least Gemini 12. From what I've seen and what I've read, it takes something more, usually international competition, to penetrate consistently into people's thoughts to maintain the political will. Don't expect commercial space programs to replace this, for there's no market that's really worth it outside of LEO and GTO business. There's nothing out in space that doesn't have a cheaper source or alternative on Earth, beyond wanting to go to space like Malory wanted to climb Everest, because it's there. There's defence from the threat of Earth impactors, but that's a hard sell. As we saw with Constellation, political pork to subcontractors doesn't appear to be enough to maintain a space launch system program of enough quality and activity long enough. From the initial USAF contracts that started the development of the F1 engine to the all-up launches of the first Saturn V's was 10 years. The Shuttle program only kept enough going by expanding to take over most NASA and DoD launches. Constellation didn't have Apollo-level support and eventually couldn't find the right path with what resources it had. SLS appears to be going the same way. And if the programs aren't maintained, they're not a faucet that can be turned on again in a few years. No engineering product or project is like that. Be idle long enough and you start almost all the way back again. As others have pointed out, NASA is a lot more than SLS. Even NASA's space programs and projects are a lot more than SLS. SLS not being the new Saturn program isn't quite NASA's fault as it has a lot more to keep going than just SLS. And what could NASA have done to do this better? In some ways, NASA has done what it needed to do with the Commercial Crew Development Program, to ensure there's 2 launch systems and crew spacecraft capable of accessing LEO. Losing that twice, between Apollo and Shuttle and later between Shuttle and now, is bad for keeping space in people's minds. In the end, maybe the only thing that will truly drive consistent crew space exploration beyond LEO will be competition with China.

I think that would have been due to the Google Gmail and Drive outage recently. Seems to be back now. https://www.theguardian.com/technology/2019/mar/13/googles-gmail-and-drive-suffer-global-outages

I saw that at the time, but I still emailed as I didn't know if and when he was going to show up again.

Thanks! Fixed!

Cool idea, dude! Looks like this is a job for Trajectories! Specifically the recent recompile (v2.2.2) by @PiezPiedPy, available on CKAN and links in this post.

The owls are not what they seem. Neither are the cacti.

I said 100m/s just to get a low-speed estimate of maximum flight time. At 600m/s, the circumnavigation could be done in 2 hours. One session. Do it! It's what the late Jebediah Kerman would want. Cool!

I have a cunning plan.... Fly around Kerbin. Even at 100m/s, it'll take under 11 hours. You just need an aircraft with a range of 3800km. An amazing aircraft.

That's tragic.

A good solution. But for Gemini 8, that wasn't Neil Armstrong's intent, nor were the Gemini and Agena docking target separated by spinning. After docking with the Agena, an RCS jet on Gemini stayed active due to an electrical short and the docked craft started rotating. Armstrong kept stopping the spin by manual orbital RCS on Gemini but the spin kept coming back. While they did think the problem was initially on the Agena, Armstrong noted the drop in orbital RCS propellant showing the fault lay with the Gemini. Concerned about something else going wrong with the still near-fully fueled Agena, he decided to undock. And by the usual method of unlocking and using the orbital RCS to pull away from the Agena. Unfortunately, that made things worse as now the leaking RCS had a smaller moment of inertia to spin faster. Final solution--done by Neil while spinning close to 300°/s--was to kill the orbital RCS and then activating and using the reentry RCS system to despin. Now they had only 25% of reentry RCS and if it was activated, the flight had to be aborted ASAP. https://en.wikipedia.org/wiki/Gemini_8#Emergency

Well, that makes me sad. But understandable. What's the distance, over 3 times as far as Pole2Pole? And I suspect less interesting with the slower change of latitude. And the problem is when you push the speed to get it done faster, you risk Kerbal-killing krashes. How about trying a session once a week? Maybe find a way to spice it up?