Gordon Fecyk

I wonder if that KORC tool takes ion engines into account. Nine tonnes, indeed. Not to mention, Teilnehmer's craft is super easy to reproduce from the screen shot alone. The only thing I couldn't figure out was whether he skimped on LFO or Xenon to get the mass under five tonnes. And whether he considered Valentina's mass in the total launch mass. Apparently kerbals are massless until they exit various command parts, and then they're 80 kg with full EVA kit. This deserves the @Turbo pumped and @Cupcake... seals of approval for micro-engineering. hah hah hah hah hah hah hah Here, let me get out my 2.5m lander can and do a whole tour of the system, including the surface of the sun. I wondered if SpaceOdissey was serious about that.

Have you submitted this to ferram4's project page on GitHub as an issue? I can't reproduce the problem, but it might be you're using a different build than me or you're using a different version of Module Manager or Modular Flight Integrator. I have Module Manager 2.7.5.0, Modular Flight Integrator 1.2.3.0, and finally the FAR DLL version is 0.15.7.2 but this is the one meant for KSP 1.2.2 and the version number doesn't mean much in this case... I forgot when I put it in there but my Created date says 25 JAN 2017.

I can't reproduce that problem with your craft. However I am finding that RCS block on the craft is fighting with the reaction wheels on the probe core you chose. That's a different problem. When I turn reaction wheels off, the thrusters appear to behave as intended. --

Low-Tech Space Plane and 4.5 t Lander to Kerbin 2, "Difficult" Version I managed to repeat the trip in just over twenty days with a single-stage-to-orbit craft that was just barely under 40 tonnes. With Valentina loaded in the command seat, the craft just hit 40 tonnes. I won't repeat the entire image set, but you can be assured the flight profile was almost identical. I'll post the most significant changes here along with a craft download link. Note that the craft is designed for Ferram Aerospace under KSP 1.2.2, which is still a developer version only, and as such I was able to reduce the wing and control surface mass at the expense of strength. Aero behaviour may change with the final release. The Craft, Revised: LTS Kestrel-FCL: The lander is identical. The lifter changes include reduced wing mass, one less pair of FL-T100 tanks, one less drogue chute, 2 x LV-T30 Reliant instead of LV-T45 Swivel main engines, and reduced fuel and oxidizer. You may inspect the craft file (16 KB zip), but again this is for FAR under KSP 1.2.2 so the mass of the wings and control surfaces will be normal if loaded without FAR installed. Loading Valentina Kerman into the lander's command seat added 80 kg, bringing launch mass up to 39.985 tonnes. Again, the mission was identical except I took longer to reach 18 km up. The Reliants compensated with +25 kN thrust at the expense of -10 s ISP. Also I could reach Minmus in only 9 days, and the total mission time didn't exceed 21 days. Val had a harder time loading the lander back; I ended up docking with her still inside, but it took a few reloads to eject her from the seat and clear the lander. I botched the first return attempt and broke the antenna I was using as an aerospike at the nose, so I reloaded from approach and tried again. This was the final result: Here is the video of the attempt. I cut out a lot of things to fit the music that @Thrimm picked for this craft back in August 2016, but the essentials are there.

My problem is with the specific assertion that, "fuel is dV." As in, "if I have twice as much fuel in my craft and nothing else changes, I have twice the dV." If the thrust and efficiency don't change, dV would increase with more fuel but 2x fuel is not 2x dV. We know this from the Rocket Equation, even without the direct observations I made in last night's mission. It'd be more correct to say, "fuel is a function of dV," or something like that. As for inclination at Minmus, I didn't bother with a plane change on insertion. It was only 160+ m/s, which is fairly normal for me flying to Minmus. I just made sure to land roughly on its equator so the ejection back to the Mun was more efficient. Also, doing my inclination change to Minmus at Mun PE saved me a lot of dV, in addition to doing the Mun assist. Not related to the fuel = f(dV) argument, my plotted Mun transfer had a fairly wild but still reasonable inclination, but the burn missed by quite a bit. I ended up plotting a polar Mun insertion to correct it, but again I landed near the equator so my ejection back to Kerbin was more efficient.

I have a problem with this assertion after flying my attempt last night. It appeared to take three times more time to do my Minmus insertion at 161 m/s (1m 33s) than it did to do my Mun insertion at 207 m/s (30s). Granted, this is the stock estimated burn time, but this is usually close enough and these are based on full thrust. By Mun insertion, I had just-slightly-less than half of my fuel remaining.

Low-Tech Space Plane and 4.5 t Lander to Kerbin 2 I wanted to see if I could lift a suitable craft to LKO with @Thrimm's LTS Kestrel, modified for Ferram Aerospace. This was my first complete result. All craft and crew returned to KSC undamaged and unharmed, even if it took fifty-five Kerbin days or so. Note that this version of FAR is the dev build and aero behaviour may change with the final release. The Craft: LTS Kestrel-FC: 42 tonnes including 4.5 tonne lander. No parts higher than Tier 5 tech, I think. I'll try to shave two tonnes off somewhere to qualify for 'Difficult.' The Lander: "Lawn Chair v2:" Just over 4.5 tonnes, with small reaction wheel, battery, antenna, FL-T800 tank and Spark engine. Command seat only inside Mk1 service bay. I'll link to the remaining pictures rather than create a huge picture post. I don't use Imgur and I thought albums were still broken. Val prepares by pocketing two flags Val loads up into the Service Bay Jeb treats this thing like a fighter on an aircraft carrier Lighting afterburners at 35 degrees pitch Lighting main engines at 18 km up MECO at 75 km AP Closing orbit with just 240 m/s dV Deploying our lander Plotting Mun assist to Minmus, saves at least 100 m/s (even if it does make the trip 30 days longer!) Course correction at Mun PE Minmus insertion Minmus landing Minmus Flag (Milestone reached!) Minmus transfer to the Mun Mun insertion Mun landing Mun Flag (Milestone reached!) Mun transfer to the Kestrel Low Kerbin Orbit insertion and deciding to let Kestrel do the rendezvous instead Jeb plotting lander rendezvous (eight hours faster than letting Val do it) Val completing rendezvous and pushing the lander into the bay (She closed one of the doors to align the craft) After fifty days or so Val gets a comfy seat Set a course for home, Jeb Re-entry was surprisingly sedate when there's a load closer to the front Oops, Jeb overshot (it was either that or risk destroying air frame trying to turn at Mach 2) Is this a runway or an aircraft carrier? From Mach 1 to zero in about ten gees (ouch!) (This also would have killed the KSP 1.1.3 wheels) In the end, ship, lander and crew safe at home (and didn't need to reload once!) I have video of all of this, but it'll take some time to cut. The craft is in the FAR Craft Repository thread at the Spacecraft Exchange.

Remember that we could capture at Jool using Laythe twice. You can do something similar outbound by passing behind Laythe twice once out of Tylo's influence. That would get you out of Jool's SOI at least. If you really need to, you could pass in front Jool itself on another (granted, really long!) orbit to slow down with respect to the sun. I took a crack at it once but like you only managed to scrape Dres' orbit. But I wasn't all that patient; I could have lowered my sun PE just enough to plan another Jool encounter, then pass in front of it. I'd again suggest taking a look at Hazard-ish; he used two Jool assists to get an ion-powered Segway down from Eeloo of all places, then passed in front of Eve and Kerbin a few times to slow down further. It looked like he too could only descend to Dres' orbit on the first pass. --

This was something I noticed when I started testing the dev build: There's no deploy mode (Safe / Risky / Always) option to select. I do have Advanced Tweakables enabled because I can set autostrut options and fuel flow priorities. The chutes behave much like the KSP 1.1 / FAR official release chutes, but maybe ferram4 hasn't updated the RealChute Lite code yet to the current RealChute release. Hasn't stopped me from designing around it like I did in KSP 1.1 though. --

That's the difference between "Modify" and "Full Control" on the simplified permission set on Windows' NTFS file system. Permission to change permissions is part of Full Control, where Modify is permission to change files but not their permissions. I have a feeling the "Creator Owner" permission, included with default permissions on Program Files and Program Files (x86) where Steam usually sits, is confusing things. The "owner" is whoever created the file or folder, and that will almost always be a local administrator. There's also a difference between an administrator and an elevated administrator; elevation occurs if you answer "yes" to a User Account Control prompt, or if you provide an admin username and password when working as a regular user. It should be enough to add Modify permission to the "Users" group for the SteamApps \ Common folder to fix this so you can delete files in there. If this isn't enough, let me get in front of my home PC and come up with a better solution. --

Low-Tech Space Planes by Thrimm Aerospace, modified for FAR (Note: KSP 1.2.2 with FAR dev build. Aero behaviour may change with final release.) @Thrimm developed these great space planes about six months ago. Some folks asked about FAR compatibility, so I thought I'd give it a shot. This is the end result of on-and-off play and even experimenting with the FAR dev build for KSP 1.2.2. Here are the craft files. (79 KB, KSP 1.2.2) That is the wrong link; Here's the right one. LTS Dove-F: Required Tech: Aviation (T3), Advanced Rocketry (T3), Landing (T4), Engineering 101 (T1). Optional Tech: Survivability (T2), Electrics (T4) Power Plant: 8 x J-20 Juno, 2 x LV-909 Terrier, 1 x LV-T45 Swivel Capacity: 1 x Crew, optionally 1 x OKTO, Batteries, Science Thrimm built the Dove as a proof-of-concept for a low-tech space plane, but with an OKTO as auto-pilot it works as a rescue craft early in Career mode. With stock aerodynamics, this craft could only reach about 5500 m before needing to light the main engines, and even then in KSP 1.1.3 we didn't have fuel lines at this low tech level so the original Reliant would burn out too soon. FAR lets us take these Junos over 8000 m up, and in 1.2.2 with default fuel flow enabled we can use the Swivel and Terriers all the way up to a 75 km apoapsis, shut off the Swivel, then use the Terriers to close orbit. More tail planes help with yaw stability on take-off. Instructions: Enable DPCR in FAR. Climb to about 8 km to 10 km, point 20 degrees, stage main engines. Throttle off and shut off Swivel after achieving 75 km apoapsis, then close your orbit with the Terriers. You'll need to start closing pretty early with the low thrust but you'll save a lot of fuel. On re-entry, point radial-out and shut off Terriers. You'll likely lose control at 20-25 km altitude, but your Junos should light back up shortly after. Find prograde, then pull up to level flight. Stage drogues no higher than 100 m altitude when over runway. LTS Sparrow-FC: Required Tech: Basic Rocketry (T1), Supersonic Flight (T5), Landing (T4), Fuel Systems (T4), Engineering 101 (T1), Aerodynamics (T4) Optional Tech: Survivability (T2), Electrics (T4) Power Plant: 2 x J-404 Panther, 2 x LV-T45 Swivel Capacity: 3 Crew, 1.1 tonne cargo Thrimm tells us this is for crew training and tourism, but the FAR drag model lets us use less fuel on ascent. I replaced the Mk2 liquid fuel fuselage with the Mk2 short cargo bay from his LTS Kestrel. The Sparrow-FC can fill the original Kestrel's role as a small satellite launcher. This example launches a 1.13 t FT-L200 fuel tank. Instructions: Enable DPCR in FAR. Launch with Panthers in Wet mode (Abort action group) and point up 35-40 degrees. High dynamic pressure will give you maneuverability problems at too low an altitude, so climb quickly. Stage Swivels at 16 km up or higher, and try to avoid exceeding 10-12 degrees angle of attack. Cut thrust when hitting 75 km apoapsis and point prograde in Surface mode to reduce drag. Use RCS action group to open cargo doors once in LKO. On re-entry it may help to balance fuel between the rear and forward fuel tanks, otherwise descend and land similar to the Dove-F using the drogues. You might have trouble leveling off due to high dynamic pressure and (I think) Mach Tuck; if so, shift fuel more to the rearmost tanks or try turning DPCR off and pitch up gently! LTS Kestrel-FC Required Tech: Basic Rocketry (T1), Supersonic Flight (T5), Landing (T4), Fuel Systems (T4), Engineering 101 (T1), Aerodynamics (T4) Power Plant: 4 x J-404 Panther, 2 x LV-T45 Swivel Capacity: 2 Crew, 4.5 tonne cargo Similar to how the Sparrow-FC can serve the Kestrel's original role, I thought with FAR's drag model I could get away with more cargo capacity. First I had to replace those really narrow wings though, since FAR laughed at them as this craft turned into a lawn dart. Swiping the wings from the Dove and Sparrow seemed to do the job. Everyone uses the Rockomax Jumbo-64 "Orange Tank" as the benchmark for Mk3 single-stage-to-orbit craft, but I wondered if the largest Mk1 tank, the FL-T800, could be a benchmark for Mk2 craft. It seems to work as long as I expanded the fuel capacity of the original craft as well; note the extra FL-T100s at the rear. Instructions: Enable DPCR in FAR. Launch with Panthers in Dry mode. Aim 40-45 degrees up, and switch to Wet mode (Abort action group). Ironically, higher dynamic pressure seems to keep this craft stable on ascent. Stage the Swivels at 19-20 km up, and avoid an angle-of-attack greater than 10-12 degrees. Cut thrust at about 75 km apoapsis and point prograde in Surface mode to reduce drag. Use RCS action group to open doors once in LKO. Re-enter, descend and land similarly to Sparrow-FC, but its larger mass will mean greater momentum and possibly a more difficult time leveling off and avoiding Mach Tuck. I tried using the elevons as air brakes once, and it didn't end well for the wings. Fortunately, the drogues still worked if I adjusted the deploy altitude, and an almost-empty craft will survive a nose-first impact at around 22 m/s. I'll make corrections if needed, for instance if I got the tech tiers wrong. --

What about adjusting fuel flow priority on the upper tanks? Assuming you have something like a Twin Boar with an orange tank stacked on top... If you turn on Advanced Tweakables in KSP 1.2 (I forget where that is though) you can instruct a given stage to draw its fuel from certain tanks first. Give tanks near the bottom a higher priority than those on the top, and you keep centre of mass higher up as you ascend. You can adjust priority on the fly as well. --

That did it. I'll need to experiment with placing probe cores around the body of my craft, or simply rely on more reaction wheels. The cores I'd want to use have included reaction wheels most of the time, so I can rely less on engine gimballing. --

This actually makes sense. Though it would make design rather interesting to put a probe core on the other side of a fuel tank. I have ideas now, and will return after some playtime. --

Is this the Steven-Tylo or the Iktomi? Sounds like that crew forgot to pack extra dice. /me ducks

I could fly the ship by hand easily enough. It was when I tried enabling prograde hold in SAS, while controlling from the backward-mounted probe, that the ship would pitch in the wrong direction. Before launch of this oddity, I changed the "Control from here" setting from the pod to the probe to make sure the nav ball pointed up or down as I intended. That much worked. I didn't pay attention to the other angles though. --

I was wondering how you were doing. Back when you were asking for gravity assist help, I took your save and tried to fly your proposed mission. Having Ferram Aerospace installed made the Laythe landing interesting and the takeoff impossible, but that's just me asking for the pain; if I could reach 250 m/s airspeed the rest of the ascent would work. Your craft loves to pitch up. Vall was rather hard; without the Rapiers in closed-cycle still attached, I couldn't hand the whole ship safely. And I had no idea how you were going to take off from Vall with a full load of fuel and oxidizer without some kind of long, high jump ramp, because I sure couldn't. And there was no point in putting monopropellant in the Mk3 cockpit back on Laythe; that was silly of me to take on so much extra mass. At one point I landed, refueled and launched your complete Tylo lander at Vall. Maybe after a few runs back and forth I could have refueled your mother ship in orbit as long as I didn't put any oxidizer in the top tank. I never did get past Vall. That moon has surprisingly strong gravity and a more surprising orbital speed. The transfer from Laythe to Vall wasn't stupidly expensive though; no more than 1200 m/s if I recall. A Laythe-Laythe outward assist might have saved some dV. --

When KSP 1.2 came out, Scott Manley brought up the concern of having to rotate a craft back and forth to see navigation waypoints on the nav ball. I thought I'd be clever and try mounting a probe body backwards on top of a crewed command pod, and see if I could land by pointing 'prograde' while controlling the craft from the backwards probe. No such luck; the craft would pitch wildly and then accelerate upward. I haven't yet tried rotating the backwards-mounted probe 180 degrees around its axis to see if I can get a 'prograde' vector that was actually retrograde. I'll try that when I'm home next. Aside from mods, has anyone come up with a clever way to view these waypoints while flying retrograde? --

I'm a Steam user too. The Steam client is supposed to take care of permissions problems; the "Common" folder in %programfiles%\steam is read-write for non-administrator users to work around broken games that don't behave on current editions of Windows. And no, I won't recant "broken." It seems Unity games in general suffer from this because of how the Unity engine itself is designed. Valve tries really hard to make older pre-XP games work and this usually means breaking the rules for things put in Program Files. Maybe some process restored the original permissions for the Program Files folder's contents, which includes non-admins (and admins under User Account Control) having only read access to this folder. This is as it should be on a new Windows installation. Nothing stops you from putting Modify permissions back for the BUILTIN\Users local group for that folder. Just bring up its properties, go to Security, then Edit, and turn on Modify for the "users" group. If you make another Steam-managed folder as Jammer suggests, the client should adjust that folder's permissions as well. I won't rant, I won't rant, I won't rant...

OK, I got it, and with 1100+ units liquid fuel left after Laythe orbit insertion. Step 1: Pass in front of Laythe and get a pretty high Jool AP. dV: 0.4 m/s. Step 2: Plane change. dV: 23 m/s. Step 3: Pass in front of Laythe from Jool AP to tighten orbit. dV: 23 m/s. Step 4: Set up Laythe aerocapture at 45 km up from Jool AP. dV: 190 m/s. Step 5: Aerocapture at Laythe. dV: 400 m/s minimum via aerobraking. Observed speed at 50 km up was under 3 km/s. Step 6: Adjust Laythe PE and AP to suit. Pick your landing site and profit. I have video of the full attempt now. Enjoy. --

OK, that made more sense than trying to land on a low gravity body like Pol. Fuel would stretch a lot farther in Laythe's atmosphere. I think others have already suggested more than one braking pass in front of Laythe. On my example I'd plot another Laythe encounter near Jool AP. The end result of that and maybe another braking pass would be an orbit with a close match to Laythe's such that the next encounter would be at a reasonable speed for aerobraking. Hazard-ish did a lovely example on a Tylo run ; skip ahead to 2:30 to see the manoeuvres used. Only instead of trying to get Jool AP out to Tylo's or Pol's orbit, try to keep it within Laythe's. Or something like that. --

AeroGav, I loaded the save file successfully. Thanks for putting this back at Kerbin Escape so I can see about tweaking the original encounter. The first (and so far last) time I tried something like this I was able to get a Jool capture via Tylo with no dV cost, but I think Abastro's right in that passing in front of Laythe may shed more speed. It has a faster orbit due to being closer to Jool, and the dV savings can approach twice the moon's orbital speed, though you can't get too close of course. The rule I learned was to shed speed by passing in front of moons, and gain speed by passing behind them. Let's see what I end up with. [a few hours later] So my first attempt passing in front of Laythe got me in a reasonably safe orbit: I tried transferring to Pol, but doing that cost 190+ m/s for the approach from Jool PE and then 590+ m/s capture at Pol; more than what was left. I barely used 0.5 m/s to get this Laythe-based Jool capture, but in the end that wasn't enough to capture at Pol. You can probably do better. I have Kerbal Alarm Clock installed, which lets me see ascending and descending nodes even for incomplete conics (see green >> arrows top-right near Sun AP), so I was able to place my Laythe adjustment at the most efficient place. Maybe when I come back to this I'll try for a higher Jool AP and raise PE there so capturing at Pol isn't as expensive, or I'll try using Laythe to do a plane change at the same time as the capture; flybys other than at the equator can change the orbit plane too. I could even try flying in front of Tylo as you originally planned, just in a different spot. One more thing: How did you plan to land the refueling module? The module inside the cargo bay had no oxidizer, and only two sepatrons for what I think is supposed to be braking and landing. Maybe you planned on de-orbiting the mother ship, detaching the module, then burning back to orbit. --

Do you have this save available for experimentation? --

I feel bad for the poor kerbals riding in that contraption. At least kerbals can go EVA while landed at Kerbin at first. Did something similar with two Mk1 storage bays and an OKTO to explore the Mun before we invented wheels.

Hm, so you want a sharper nose on supersonic aircraft, but not one of these spikes except for instrumentation. Probably why the Bell X-1 had them. That would also explain why the nose cone design article didn't mention them. The spike would sharpen a blunter nose though, as with the Trident missile. Kind-of a compromise between good supersonic performance and package size. I'll take KSP questions related to this back to the FAR Spacecraft Exchange thread. --