paul_c

It doesn't when you're out of the atmosphere, but you didn't say you were - you said by the time the first stage was empty. Looking forward to the pics!

After a little bit of shuffling around modules, Jeb has prepared the lander, undocked and is heading for the surface of Ike..."You know that's not Ike, Jeb?"..."Its okay I'm doing the retro burn, I'm facing the wrong way"......glad he knows what he's doing!: 1st task is to achieve a low orbit: Landing on Ike, and its gravitational acceleration, is somewhere between Mun and Minmus, in difficulty: Landing done, science gathered, due to the short time taken we can launch straight away onto the same plane as the station: Achieve a nice stable orbit after take off, then push the Ap up to intercept, then tweak the plane and push the Pe up to nearly-the-same and wait for the rendezvous. The station is in a circular orbit, which makes things easier: Jeb brought back an almost-full 'small' fuel tank which was part of the science module but doesn't have a docking port on the end. So it needed to be ejected before his docking. I brought the speeds down very low, pinged it off and then docked Jeb. It seems a shame to waste it, so Val (with the double-ended docking ports) can go retrieve it: Its a bit of a nightmare, it feels like chasing your tail when its a 'debris' module with no SAS or stabilisation etc but she got it eventually: Docking backwards isn't so bad. You target it as normal, set your speed to say 0.5m/s, then turn rearwards and use small corrections to keep it on track. So Val's white command module has the extra fuel, which will come in handy: Jeb's off again to Ike. This is his ship with double science module and extra fuel: Despite careful planning, I landed in the same biome! And the same on the first hop! The shades of grey don't seem to correlate that well with biomes, once the sunlight is lighting it or not; Ike is much less well mapped than Mun or Minmus; and I'm unfamiliar so I don't really recognise stuff that well. Eventually, I hopped to something other than Midlands (to Lowlands): I'm short on fuel so I'll need to orbit but there are 3 more fuel modules on the station so I have enough for another trip. Its a partial success. In fact, I didn't achieve the station's orbit and ran out, so the station will need to come down and dock with Jeb and sort him out. 3rd surface trip, I'll need to 100% hit a new biome, so I think I'll just go for poles.

Well, with not enough money, no more pilots, and (bizarrely) the contracts of "science from space/surface of Mun/Minmus/Kerbin" completely drying up too, it would be difficult!

1. The RA100 is a relay antenna, not a direct one. Not that it matters because...... 2. Orbiting at ~80km you WILL get dropouts unless you have some kind of relay network around Kerbin due to the location of the ground stations being "over the horizon". Go a bit higher, and you'll be able to see a ground station all the time. If you do have a relay network, then because the RA100 is a relay not a direct, it will be trying to communicate with that relay network using the built-in aerial on the probe, which might not be powerful enough to do it. The above occurs WITH CommNet enabled; and doesn't matter what power the ground stations are.

So, after flying up the last fuel module, and checking contracts again, I've now officially run out of excuses to put off the interplanetary trip. So....I used: https://alexmoon.github.io/ksp/#/Kerbin/82/Duna/100/false/optimal/false/4/201 to find out the ideal transfer window, its better than trying to measure the angle of planets with a protractor pressed up against the monitor screen (which works quite well for Mun!) And time warped forwards. Then prepared the various tanks in the order to burn their fuel and eject: And I started my burn for Duna. I did it over 2 orbits, it turns out not too bad, there was little/no wobble due to my experience last time with a wobbly craft, but the TWR was only around 0.1 (in Kerbin). The patterns are the resultant orbits of the various debris, it took about 5 fuel tanks to leave Kerbin SOI: Not bad, it looks vaguely right: But after a correction burn, missed...... Plan A was to burn to kick up the Pe beyond Duna, but keep the orbit close enough it will encounter anywhere on it once the craft is near enough: Eventually after about 3 1/2 orbits I was captured by Duna: Didn't want to go splat into it though....so I did a radial out burn, to raise the Pe. Fortunately my inclination won't encounter Ike, which just causes trouble: Duna high, low and high atmosphere science gathered. The Science Jr and Goo is pinged off once used and data transferred: Due to my rough & ready Caveman approach, I think fuel will be tight later on, so I've used the 'antenna modules' fuel early on and will ping them off too, since they weigh 70kg per aerial (x16) of dead weight. Because they're in the middle, the undocking is more involved, I need to split the thing in two and then use A & D keys while approaching to 'bat' the empty module out the way: My random approach technique had resulted in a backwards Duna orbit. Since I was going to Ike anyway.....I thought I'd just change inclination to ~180deg, raise the Ap and then wait...... Ike is so big its inevitable I'd capture it, just that I'm now "paying" for the retrograde Duna orbit with a big dV correction to capture the Ike orbit. But its better than nothing: Weirdly, despite a reasonable Ap I 'fell out' of Ike orbit first time! So I did a small tweak in the resulting Duna orbit and recaptured about 5 'Ike months' later. Now I'm here, I'll leave the station in Ike orbit and use the lander to visit the surface. I'll try a 'single' science module first (I need to visit 3 biomes for the science) so a little more in-flight rearranging is done, to put the module onto the nose of the lander. Its resulting dV is 1360m/s which should be enough for an Ike landing and re-orbit/re-dock. I have no idea if I have enough fuel to get home, but I will keep going until I actually run out of it, blow up/crash, or return with all the science. Its do or die now. If I don't complete the challenge, so be it, I tried!!!

I personally didn't notice it either, until I looked at the TWR before and after. I guess you have upgraded the launchpad and don't have the 18t limit?

"Pointy end up, flamy end down". Make the front pointy.

si2504, this is a bit confusing because you've jumped on someone else's thread, and also not really given much info apart from your big rockets wobble. Then you've misattributed a shift of Centre of Mass forwards, with some kind of instability. I dare say, what is actually happening is that the weight/mass balance isn't the issue, but the drag is higher at the front than the rear. As speeds build, the aerodynamic forces destabilise the rocket (as swjr-swis mentions above). It would help to post some pics of the design. Of course, stage 2 needs to have its aerodynamics balanced as well as stage 1 (and stage 3, etc)....... Also, AFAIK KSP doesn't simulate "boil off" of fuel over time, tanks are modelled as perfectly sealed (unless you have a weird mod in place.....)

I did think about multiple engines, or having a T45 engine for the Duna burn, but I decided against it for a few reasons: 1. It will be difficult to attach multiple engines on multiple modules 'in line' 2. Its going to wobble/oscillate when an engine is thrusting. Last time on the big Minmus spaceship thing, the wobble was severe enough to mean I could only use about 1/3 throttle of a Terrier anyway 3. Other aspects of the burn are going to be very approximate anyway, for example the amount of dV, managing the staging with undocking stuff, etc . And without manoeuvre planning anyway, its always going to be a thing which just needs a lump of thrust near Kerbin, then a bunch of adjustment later. I realised too, that there's no point having more engines than command modules - they're excess weight. I'm (now) in the vacuum of space, the only time I need a certain TWR is later on, "can I land on Ike" (I ought to actually check its physically possible with the Terrier and the fuel!!!) Anyway......the drudgery of supply missions to fly the fuel up is almost over: I have one more module to deliver, then I can plan for leaving Kerbin. Then it will be (hopefully) one more flight from KSC to deliver the recovery module. Technically.....I only need 2x command modules on it for the Ike landings (when the thing splits into a station and a lander)......Val....you've seen the film "The Martian", right? I promise I'll come back for you.......a bit later.

The danger (well its not really a danger....an inefficiency) with shooting for a "direct to rendezvous" is overshooting then needing a correction (and possibly another correction, etc). Each correction 'costs' fuel, because in orbital mechanics, changes cost fuel not time; and the bigger the change needed, the more the cost. Compare it with a "conventional" rendezvous, lets assume to a 100x100 station: 1. Launch to (say) 75x75 initial orbit, which might take 10-15 orbits to intercept or thereabouts I don't know the maths but that might be 90deg phase behind 2. Observe the distance apart and at (say) 1-2 orbits to go, burn for a 75x100 orbit. 3. Then take another few orbits, then go to (say) 99x100, and take another few, then make a tweak to intercept close, by orbiting (say) 99.7 x 100 4. Once close, dock Steps 1-3 all "go in the same direction" and of course, note that for a controlled docking at slow speed, the orbits must be similar so the final orbit will always be ~99x100. By setting a time pressure on the docking, you lose the ability to remain doing the closing approach from "one side" over a number of orbits, instead you must do a big "get the intercept" then another big "slow down to control approach speed" burn. Sure its possible with the same fuel use, but it would need an amount of precision in the ascent to know quite precisely, where you'd be to do that big, (less than) one orbit "get there" encounter. Think about it.....in the worst case scenario, as you sit on the launch pad, the station is whizzing around at >2000m/s. So as each second passes, its 2000m further away than the previous second. So your precision to get within 2000m is a single second of "launch window", assuming you know exactly how the ascent will go. Fair enough its true to say that the actual way to fly it would lie somewhere between the "conventional" and the "hit it in one" style, ie you'd do sensible corrections during the ascent, but with the margin (of not worrying about when you'll encounter/dock) taken away, efficiency can no longer be maximised. I appreciate its a lot of fun and dynamic if you can pull it off though!

I think the analogy of an aimbot in a shooting-game is a good one. Part of the core of KSP is that you sit there and fly/drive/whatever a rocket/vehicle you built. However we must also consider that KSP isn't a competitive player-vs-player game and that for some, it extends their enjoyment of the game, or gives them a route in, to use some kind of autopilot. I agree too, that if there is a strong focus on 'flying', then they need to sort out joystick support properly, just like a flight simulator. So I would agree that some kind of progression, starting out with a fairly narrow (to guide newbies in the right direction, excuse the pun) pathway of building a conventional rocket which goes up, gradually turns horizontal and eventually after a few iterations of design you can orbit nicely. And once some kind of experience is demonstrated in each aspect, then an automation feature is gradually opened up. Fairly similar to how the idea of pilots gaining experience and unlocking SAS controls ought to work (but is currently broken - there's going to be some wailing from newbies who started in 1.11.1 when that's turned off again!!!) Make it too easy, too early on, and the depth of involvement is lost.

Is this for any/all vehicles you design in the VAB or one particular craft? I would advise doing a check with a simple vehicle.

Two solutions: 1. Space out the fairings and solar panels (and any other kit) so that the fairing will deploy safely. If needs be, stop accelerating, then deploy, then throttle the engine up again. Or wait until the engine is stopped etc (but see below). 2. Solar panels are delicate - don't rely on just one or a handful, put excess panels on in case of breakage. (Kerbals on EVA are good at breaking them too). Also don't forget.......the actual most efficient time to deploy a fairing is when its weight penalty exceeds the aerodynamic benefit.......which occurs sooner than 70km altitude at Kerbin! (Think about it....) Solar panels, on the other hand, can be deployed just before engine (with alternator) cutoff + battery depletion time. In other words, depending on how many batteries and what electrical demands, some time after engine cutoff, which will be much later than ideal fairing deployment time.

This. They need to get to grips with why the engine(s) seem to work fine on a test stand, but don't once attached to a spaceship and flown in the profile they have in mind for the thing. Unlike an aeroplane or helicopter this thing is 100% reliant on the engines working properly to make a landing. Yes I know the SNs are allocated for these testing phases but there is a cost to crashing, both monetary in cleanup; possibility of damaging other kit; regulatory and reputational costs too. I would not be surprised if the FAA once again want quite a detailed investigation into the latest crash and want to see changes made - on their terms, not SpaceX's, which will be like walking through treacle compared to if SpaceX themselves could dictate the pace of advancement.

I am not sure why you have dismissed simply starting out in KSP (again) with no mods, then perhaps adding a sprinkle of them as you progress.

Personally in KSP I don't worry too much about when to launch, to rendezvous with something, if its on the equatorial plane. If its not equatorial, then obviously there is a defined (well, two) instantaneous "launch windows" per day which will intercept with no extra plane change. It is much more important to 1) get the launch right (for other stuff, eg staging, get the Ap high enough, don't lose comms, etc) and 2) get as good as possible onto the same inclination. Yes, even if the station is on the eq plane you could still waver off it with a manually flown launch, so its worth looking at it when ascending. It is far cheaper on fuel to match the inc on the way up, than get into a low orbit then change it. And there's an amount of skill in flying it to a precise inc - you need to think about the left/right as well as the gravity turn, also bearing in mind for some of it you'll be coasting up so you can't turn/change then. Personally if the station is at 115x115km I'd launch deliberately 'late' (a bit) to a 70x70 or thereabouts orbit, then change it to 70x115, then do a few orbits to catch up (but not overtake) the station, then gradually match the orbit eg 110x115, 114x115 to get a nice close intercept, then with about 2km to go (or less if you're using tools to help you fly) start pointing and flying at the station.

This phase of the challenge is grindy too. I am constructing the inter-planetary spaceship with no real idea of its eventual performance, nor its performance requirement. Its all based on guesstimates from 'what feels like' enough fuel, etc. Also because of the lack of planning nodes etc, the approach and intercept of Duna, Ike and the return is likely to be much more haphazard/random, so there's plenty of excess fuel. 2nd module, more fuel in the grey tank. The module's engine/controller has just been pinged off: 3rd (a 'single' science pack): 4th, more science (single): 5th, more fuel, with another approaching in the distance: 6th was a 'double' science module. More space junk pinged off too: 7 and 8, more science and fuel: 9....(starting to lose count): 10 I think? Its getting difficult to see the modules without rotating the ship around and using pen & paper to keep tally: Lost count now, but there's more stuff: 36tons and 165 parts in LKO isn't bad for Caveman Challenge: I think there's 11 modules to go, then I'll need to wait (timewarp) for the ideal transfer window to Duna. I've no idea how I'm going to do the burn, it will be slow (1x Terrier engine) so the ejection angle will be anyone's guess, and with no accurate dV readings off the staging readout either, and a meaningless ship velocity due to the long burn, I might just do a guesstimate based on timing the burn until Ap is 84Mm, then adding say 10% or so more burn and see what happens. Or splitting the burn into "get out of Kerbin SOI" then another with the map to touch Duna's orbit? I know I can intercept Duna in a foolproof way - if I'm behind it, I'll circularise my solar orbit to slightly smaller than Duna's (but the amount smaller than its SOI), and if I'm ahead, I'll circularise a bit bigger. Its hopelessly inefficient but guaranteed to intercept (so long as I'm on the correct inclination....)

Pragmatically, I think they need to get to a point where they can have the TWR <1 with good control; as well as TWR>1 obviously. And don't forget there will be a not insignificant ground effect too. Whether this is achieved with greater reliability, 2 engines (ie redundancy), RCS assistance, depends on a number of things being engineered or developed to a point further down the line than they're at now. Things like an engine not producing thrust when commanded to, is obviously a major issue which they can't have happen too often, if at all. Once they have the control in the 0.8 > TWR > 1.2 'zone', the landing gear issue is rendered somewhat moot. So is the post-landing explosion scenario - they could in theory, hover 5cm above the pad at TWR=1.000 and land safely with almost no fuel remaining. Obviously this is inefficient on fuel so later on, they will want to coordinate the whole de-orbit, approach, landing to use less fuel but still retain the good amount ((reserve) fuel for) of control.

There aren't enough to reach Duna, its just something to have on it just in case I can't intercept Kerbin again. I figured that 16x aerials gives 800Mm range, so plan B is that if that happens I can transmit the data for around half the science, then either do more contracts or launch a trip to Eve too. I would be almost dead though, and I'd need to fund ~600k for another astronaut pilot. It would be a big setback. (And I'd still need to have visited Duna!!)

The orbital construction of the Inter-Planetary ship begins. First a fuel module (more on this later) is joined to a "main" module (with 10x docking ports and one at the end too): Extension module (+10x docking ports, plus one at each end): Crew module B (Val). Its placed here initially, to make a later rearrangement easier: Antenna pack 1: Antenna Pack 2: Crew module A (Jeb). This one does the science gatherings and landings: The fuel module is the first to go on, the idea being it will be used up with the main ship doing the rendezvous and docking manoeuvres, then towards the end of construction, jettisoned and replaced with a fresh, full fuel module for the long trip.

Why launch into 80x80km orbit? Why is 14km Pe at the Mun the best?

The good news is, it earned a bunch of science points for "In flight over shores....." experiments and it has enough to upgrade the tech tree and buy some bigger landing legs.

I suspect it was a deliberate destruction before letting people near it. With its (maybe) landing leg failure and lean, the remaining fuel was at the bottom and helping it remain upright. If they'd pumped or vented the fuel out, it would have probably become less stable and fallen over - before the fuel was out - so blown up sooner or later anyway. So they needed to resolve the situation before the road closure/evacuation time window was up. Get the data off it, double check its received okay, get a shedload of pics and videos of critical components once it had landed; then press the button. I imagine some parts will be recoverable for later examination anyway.

2 mins until takeoff 7 mins until crash landing

I went for the Gigabyte B450M DS3H because it was cheap and technically I didn't need wifi (if I did, I would have probably gone for a motherboard with it). However it only has 1x M2 slot, and I ran out of disk space! I started with 1x256GB NVMe SSD and 1x 1TB 2.5" SATA SSD. I have about 600GB of data over the years, lots of digital pics etc amongst other stuff. Once I'd gotten into gaming and downloaded a number of big games, it was getting tight constantly shuffling stuff around. I wish I'd gone for a motherboard with 2 slots. In the end, my solution was to buy a 2TB hard disk (as in, spinning iron) as a 3rd drive, figuring that its a backup of data and I can move games I don't currently play onto it too. So if it goes pop, I can re-download those games and the data was a backup. But obviously 2 M2 slots would have meant I would have had more upgrade options. Its uo to you whether you want the future flexibility of easy upgrades. Don't forget that you'll need a dedicated graphics card. Also, with a M-ATX board, they often take up 2 slots, and also the 3rd slot becomes awkward to use because its use might block the fans of the graphics card. But I imagine for general web browsing etc you don't need a powerful one, a £50 card will do fine.