Jump to content

Loren Pechtel

Members
  • Posts

    1,198
  • Joined

  • Last visited

Posts posted by Loren Pechtel

  1. 7 minutes ago, Xd the great said:

    I want the powered explicit guidance in ascent autopilot to save some fuel for landing, how do i do that?

    Put it in a separate tank (there are some pretty thin ones in most sizes) and lock the tank.  Stage Recovery ignores the locks (it assumes the locks are for it's benefit), I have no idea what FMRS does but you certainly can unlock them manually if need be in that case.

  2. 46 minutes ago, Actually_New_KSP_Player said:

    Hey there, first time installed MechJeb to test it out and I have a question that I haven't found answer for yet. So, is it possible to recover my rocket boosters using MechJeb or control any decoupled part if there's mech jeb mounted? The problem is that I installed reaction wheels, batteries and chutes on my boosters, but haven't figured out how to give them specific command for autolanding anywhere and make something different for my main ship.

    This isn't the realm of MechJeb.  The game can only control one rocket at a time.

    My answer to this is a mod called Stage Recovery.  It *simulates* the landing--either chutes or a powered landing if it has fuel and control.  This is completely hands-off, if the stages are set up properly when you jettison them you get back the cash based on their landing point.

    There's also a mod whose name eludes me right now that lets you save the discarded booster and then fly it down after your main booster is in orbit.

  3. On 11/23/2018 at 6:16 AM, RB101 said:

    Is there any way to turn this "Abort" function off? I'm getting kind sick of having to constantly check on my equatorial rovers, to set the next way-point.

    While I can see an argument for being able to alter the timeout it shouldn't be able to be turned off.  The problem is that the calculation times goes at the square of the distance.  Given my experiences on Kerbin a worst-case route (KSC to the southern ice) would likely take upwards of half an hour.  There's no getting around this, without some very fancy pre-calculation based on a known roadmap this is inherent in pathfinding routines.  This is one reason games tend to mess it up.

  4. 6 minutes ago, Geonovast said:

    I don't think it's a dark / light side thing.  I think it's a signal problem, an you're in limited probe control mode.  This means that the probe can do "on-off" type of control, like set SAS mode.

    Hitting Z to go full throttle should work, you just can't adjust the throttle.

    If that's not the case some screenshots would really help.

    That certainly could be it but I've never had it happen to me before.  I never hire, I always get my staff from rescues.

  5. I'm in a low orbit about Minmus trying to rescue Kerbals.

    I have a SpaceY Penguin engine for propulsion, just over 3000 m/s of delta-v left, just over 13000 in battery charge available.  The craft it controlled by a probe core, it went up empty.

    When I'm on the darkside I can use the SAS to point where I want to but it won't hold and I can't light the engine.  When I'm in sunlight (I have solar panels) it works like it should.  Why won't my huge battery power it?!?!

  6. On 12/12/2018 at 8:53 AM, Kryxal said:

    I was going to suggest getting to 270 km before raising your periapsis out of atmosphere even before noticing that the contract calls for suborbital.  The radiator's pretty useless, the parachutes on the lower stage probably aren't worth the bother, and KER or MechJeb's delta-v readout might be nice, but if you can hit orbit as-is, a few tweak should get you there.

    Oh, and people are right about the decoupler, use the right size.

    I play with Stage Recovery (a mod that recovers dropped parts when they go out of physics range if they come down gently enough) and chutes are basically never worth it on 1.25m parts--you'll spend more on chutes than you'll get back when you recover the booster unless it drops very close to the launch site.  Chutes only for things you actually need to recover--Kerbals and science.

  7. I have 4 pieces of debris "orbiting" Kerbin--periapsis is at 45km.

    What's strange, though, is that they don't actually exist.  [x] Science! tells me what they are:  Crew: 0, Parts: 0, Mass: 0.0t No command pod.  My attempt to fly one to see what was really going on put me in atmosphere with no craft visible and the altitude meter not moving one iota (it's in a rather eccentric orbit!)

    I suspect these are ghosts of radiators.  On my last flight I had a craft without good heat shielding, I flubbed a maneuver and ended up hitting atmosphere about 300 m/s faster than planned and with my Nerva stage still burning the last of it's fuel.  The radiators burned off when my orbit was something like what these ghost parts have, then I blew the Nerva stage when it was burning the last of it's fuel (so it would get well away from me, no chance of running into it on the way down.)  It was destroyed when it went out of range, all I can figure it somehow those burned-off radiators got left in limbo.

    I also found 3 intact radiators and 1 broken radiator on a similar orbit.  While I have flown the rocket several times this is the only time I've entered with the apoapsis so high.

    Known issue?  Is the save game any use for debugging?  (Note:  The actual radiators are already deleted before I got to these ghosts.)

     

  8. In my opinion Minmus is easier because the lower gravity is more forgiving of getting the landing burn right.

    However, as you have experienced landing legs are bouncy.  I accept the drag penalty of a squatter rocket and it's much better behaved.  Also, in low g 3 m/s is asking for bouncing, land more gently.

  9. 2 hours ago, B-STRK said:

    @IgorZI wonder... is it possible to implement a kerbal's grab-and-position functionality as a module for a part, say a robotic arm, whether IR or some other implementation like Konstruction? I already know that the KIS module on a part like that makes the vessel act like multiples of kerbals within its affect range, but the actual grabbing still has to be done by a kerbal on EVA, dismounted from the vessel, when I'm thinking maybe the kerbal on/in the vessel with the robotic arm with the KIS module (or in other words, the vessel itself) be able to simply grab the part and position it (probably even screw it in, but yeah I get the picture why in terms of realism this might not be a popular idea to implement).

    I do ask because even if a vessel would be able to provide the lift power and range to reach a 3.5m diameter or larger part, because it's still the kerbal who has to do the grab-and/or-bolt, he or she might be too far out of range of the CoM of the part concerned to manipulate it ("Too far" tooltip). Someone else somewhere else in this forum (or maybe the subreddit?) made a similar observation about how tricky it would be under those conditions, and there are times I wish a robotic crane or mecha or such would just be able to bolt in a 5m diameter part on a node for a ground base KIS-style (... long story, but short version is, saving MaterialKit costs in Ground Construction by shipping prefab parts to bolt in), rather than have to manipulate robotic controls, and a magnet or a Klaw, to get the parts concerned to dock or fasten together. 
    Alternatively, could we have the existing KIS module actually also extend the grab and bolt range of nearby kerbals in its own affect range as well, so that even if we have no choice but to use an EVA kerbal due to coding mechanics, at least it'll be as if the robot or crane was doing the heavy lifting and reaching over beyond a kerbal's reach, or in actually be providing the heavy lifting and reaching that a kerbal alone could not do, and all the kerbal had to do was crawl under and screw in the bolts? 

    As a user I would love either of these. 

  10. 11 minutes ago, Snark said:

    Not super necessary, no, but I'm a big fan of limiting the blast radius, and it's not hurting anything, either.  No, there can't be a functional SRB that doesn't contain its own fuel, since solid fuel is non-pumpable and non-transferable.  But suppose someone modded a part with a bug in it and it had extra stuff?  I'd rather just keep things as narrowly focused as possible, better to just keep this mod out of it in that case.
    @Stratickus

    I can think of a legitimate case for something to have solid fuel without being an engine.

    There's a mod that adds landing rockets.  AFIAK they're not reloadable (although you can put it's controller on a rocket and use normal liquid engines, which obviously do reload) but what if KIS-style reloads for the rockets were made?

  11. 3 hours ago, Alexoff said:

    This oscillation and rotation started at 1.3 as I remember. It happened with big rockets everytime. I suppose that the problem is PID regulator, maybe it use FPS in calculation and when you has significant drop of frame rate SAS module work wrong. There is one possible and stupid way to repair ascending - you can start fast clicking Q and E buttons during ascending. It helps mechjeb by some way. Maybe there is another way - fixing of mechjeb PID regulator, but Sarbian still ignoring this issue.

    In my experience the MechJeb oscillation problem is a derivative of the underlying game oscillation problem.  You need more control authority.  What happens is that it does not correctly figure out when to start countering a turn and overshoots the target--so now it goes in the other direction.  If the control authority is low enough it overshoots by more each time.

    I have seen this is stock with an EVA kerbal.  Turn the jetpack way down and tell the Kerbal to stabilize.

  12. (Note that I hit this on 1.4, but I don't see anything about it being fixed in 1.5)

    Advanced transfer to another planet--I got the porkchop showing values that I expected, tried to create the node and it failed.  After a moment's thought I realized what was up--I was in a polar orbit (science mission going from the Mun to Minmus.)  Obviously the porkchop was drawn without actually looking at my orbit but the node creator didn't know how to cope with my orbit as I was never pointed in the right direction.  I wonder if this might be related to some wacky burns it's tried to set up in the past.

  13. 23 minutes ago, Starwaster said:

    That's for the core temperature. The 1210 isn't a maximum, it's the optimum temperature for core. Core temperature  is not checked at all for part destruction. Depending on how the core is set up it may shut down certain modules but it will never destroy the part. It will leak heat to the part but generally not enough to destroy the part. (depends on how it's configured)

    btw it is not stock behavior for Nerv to utilize core heat.

    No--those numbers are from the radiator, not the engine.

  14. On 11/27/2018 at 7:51 PM, Gordon Fecyk said:

    I've read elsewhere that on-rails time warp messes with the thermal model considerably. Fortunately, while you're accelerating with LV-Ns, you can only use physics warp. The LV-Ns used to put out a lot more heat than they do today, but I have had thermal issues pushing large asteroids around.

    The simplest solution is to add more radiators to your craft. One design I built borrows from one of the stock scenario missions (look up the Jool Aerocapture scenario in-game). It attaches some radial-mounted radiators to Mk1 liquid fuel-only tanks and the LV-Ns attach to those.

    hzsChEN.png

    If you wanted to get clever, you could drag the radiators so that they appear to cover the LV-Ns:

    mBwONVq.png

    The radially mounted radiator panels will only cool the part they are directly attached to and one part past that. In these examples that means the fuel tank it's directly attached to, and both the first tank it attached to plus the LV-N attached to it. You can't attach anything radially to the LV-N itself, but this is an acceptable workaround.

    Note that all radiators require electric charge to work, so make sure you have batteries and a source of electric charge. The LV-Ns themselves generate electric charge so that counts.

    Things get stranger and stranger.

    I unlocked the graphene radiators, put 4 large ones on (there's one Nerva engine) and tried it.

    Things finally appear to be stable, each radiator is dumping 20kw of power.  However, they are showing:

    Rad Temp: 199.6K/2698K

    Part Temp: 1507.1K/2698K

    Core temperature: 1507/1210K

    Skin temperature: 1331/1210K

    What's really going on with the heat?  1507.1K/2698K looks fine but what are the other temperatures?  1507/1210K should go boom but it's flying fine.

    (And why do the pesky things want to deploy on the pad?)

  15. This is driving me nuts.  I'm trying to send a scientific mission to orbit the moons.  On 1.2 I had no problem, slap a few radiators on and it works fine.  Now, however, I have yet to come up with anything.  I've attached every radiator I have to the fuel tank above the engine, they accomplish almost nothing--a few hundred watts of heat per radiator. 

    I think something must have changed in the physics.

  16. On 11/25/2018 at 9:58 PM, Orc said:

    Hi all,

    I'm not qualified to comment on the more technical side of KSP's handling of things, but to answer the OP directly:

    I've had good results with building a tourist rocket with the two (or even three) crew cabins ABOVE the Mk1 Capsule. Yes, I know, sucky draggy thing on the way up. But I've sent tourists as far as Minmus Orbit and gotten them back safely. You don't even need the MK1 to be carrying a heat shield. This configuration wobbles and spins like crazy upon re-entry into the lower  atmosphere (sub-20K) but it holds together. Use one of the big central parachutes coupled with two or three radial drogue chutes for slowing down, or go with two radial regular chutes with two or three drogues. 

    Two or three air-brakes help enormously but they don't become available when local tourist contracts are the primary way of earning the big bucks.

    Regards

    Orc

    You don't even need a capsule at all.  It's perfectly acceptable to have everyone in passenger compartments.  Something I did once that worked reasonably well for a suborbital flight was to put decouplers on the top of the rocket and nose cones on them.  Blow the cones and re-enter sideways (so long as the reentering bit is symmetric head-to-tail you can do this pretty well) for as long as you have the control authority.  I never tried that with orbital flight, though.

  17. On 11/12/2018 at 2:36 PM, Pecan said:

    Getting to space is easy.
    Getting to orbit is quite easy.
    Docking is hard, interplanetary is hard, re-entry is hard, landing is hard.  \o/  Fun, isn't it?

    (Be of good cheer.  All the other things you've already done show that it's not you and it probably isn't even KSP - it's just spacecraft)

    Going to space is easy??

    I came up with a design that I think could have both flown and landed.  Unfortunately, it was unflyable due to control oscillations--MechJeb's usual 90 degree turn ended up being more than 180--and the return even more--each twist getting farther off and it tumbled before reaching 20km.

  18. 8 hours ago, Brikoleur said:

    Without seeing pictures it's hard to be sure, but I get the impression you're having a CoM problem, or just possibly a stubby nose problem. These are the most common causes of rockets being unstable.

    On the way up, your rocket has to be nose-heavy and have a pointy nose. That way aero forces will keep it pointed the right way.

    On the way back, assuming you're re-entering tail first, you have to have a heavy tail. Normally this sorts itself out by itself because your engines are heavy and your body will be light, since you will have burned all your fuel.

    If you want to re-enter nose first, you'll have to do a quite a bit of somewhat intricate balancing -- you'll have to design your craft so that it has a pointy and heavy nose even with empty tanks. (This is in fact one of the harder challenges in designing reusable SSTO aircraft.)

    Yeah, but long, nose-heavy craft that land in water are in trouble.  It's a balancing act for which I haven't yet found the right balance.

  19. I remembered this mod and decided to see if it would allow me to reliably land a pesky beast--lands safely on land, but bounces back up and blows up when it lands in water.  From your description of the math it's probably going to do it wrong--but in this sort of case I think the math is being done wrong.  You're assuming the rocket is falling and it's a purely propulsive landing--but a good use for this is like on the Soyuz, reducing the landing speed of something that's already under chutes.

    1)  Figure the rocket is already at terminal velocity (there's no reason for suicide deployment of chutes), without the booster it will not accelerate.

    2)  In computing the burn effects apply planetary gravity at velocity zero, zero gravity at the rocket's current velocity, the curve is a y=x^2 over this range.

    3)  Provide an offset number, initiate retrofire this many meters above/below the computed point--let us tweak it for a particular rocket if the math isn't spot on.

    4)  How about some stack-mounted versions?

×
×
  • Create New...