Northstar1989

The roll-stability problems were actually what I was thinking of when I wrote that... It's good to know they're making steady progress... Agreed- but that's mostly because they're prioritizing the first stage (it's much easier to accomplish, and the reusable 2nd stage isn't much good without a reusable 1st stage...) I think you're being over-optimistic about the timeline for the Falcon 9r (the reusable variant). It will probably take much longer than SpaceX predicts, as is typical for such things. On the other hand, for the launch-assist tubes, we already have all the needed technologies for the 1st-generation tube proposed by "SpaceTram" developed with MagLev, high-speed trains, and particle accelerators. The greatest challenge is simply scaling them up... It probably won't happen nearly as soon as SpaceX- but that's only due to a lack of political will, or private funding, for such an enormous project to be carried out... One of my other points is that it's not entirely inconceivable for multiple technologies to be combined. For instance, if you build a version of the launch-assist tube that curves up to a vertical, instead of 10-degree, launch; and reduce the tube exit velocity to maybe only 1.2-2.4 km/s instead of 7-8; then you could use the launch-assist tube in combination with a SpaceX-style reusable launch vehicle to cheaply boost things to quite a bit higher orbits, or with much higher payload-fractions... (remember, due to the Rocket Equation, the first couple thousand m/s Delta-V are BY FAR the most expensive...) Perhaps you could also combine all three of the technologies I suggested- for instance a launch-assist tube, that launches a two-stage reusable rocket, that sheds its lower stage for SpaceX-style recovery, before the upper stage gives it its final boost to an orbital tether well above the Karman Line... IMHO, the biggest problem with the launch-assist tubes is actually that they're setting their sights too high- they're looking to provide the majority of orbital velocity from the ground, instead of simply using a launch-assist tube to push the rocket past the thickest part of the lower atmosphere where rockets are most inefficient, and into the upper atmosphere where the remaining Delta-V to orbit will be much cheaper due to the rocket equation and the smaller overall fuel fractions required as a result... Regards, Northstar

One more bit regarding the energy storage (more of you guys should actually read the articles on Wikipedia in detail before commenting) "The largest challenge for Gen-1 is considered by the researchers to be sufficiently affordable storage, rapid delivery, and handling of the power requirements. For needed electrical energy storage (discharged over 30 seconds with about 50 gigawatt average and about 100 gigawatts peak), SMES cost performance on such unusual scale is anticipated of around a dollar per kilojoule and $20 per kW-peak. Such would be novel in scale but not greatly different planned cost performance than obtained in other smaller pulse power energy storage systems (such as quick-discharge modern supercapacitors dropping from $151/kJ to $2.85/kJ cost between 1998 and 2006 while being predicted to later reach a dollar per kJ, lead acid batteries which can be $10 per kW-peak for a few seconds, or experimental railgun compulsator power supplies). The study notes pulsed MHD generators may be an alternative." Note that I edited out the (many) references from the article- as the hyperlinks don't work correctly by simple copy-pasting. Regards, Northstar

That's kind of the idea as proposed, actually- except for the part about the Moon-dust, which is nevertheless also a good idea... The energy-storage is certainly a problem- but it's not something we can't figure out with today's technology. After all we already store absurd amounts of power for particle-accelerators... I disagree that the chemical propulsion tube is in any way more likely (the challenges of building a rocket that can survive 1000-G acceleration are nothing to sneeze at), but it's certainly an option as well. Additionally, there's always the option of a sort of hybrid tube- one that relies on a combination of chemical charges placed behind the rocket and magnets to accelerate the craft to high velocities... Finally, on the subject of launch-assist tubes, let's not forget that it's a case of diminishing returns the faster you launch the rocket. The greatest savings to rocket mass and payload fraction are going to come from the first 8-10 Mach of acceleration... So you might be able to build a shorter tube with a reduced rate of acceleration, and still easily get a SSTO (or 100% reusable 2-stage) rocket to orbit with more reasonable cost/expense, engineering challenges, and still decent payload fraction... Regards, Northstar

The closest thing on the list to being feasible with current technology is actually the magnetic launch-assist tube: which we've had the technology to build since at least the 1980's... SpaceX's resuable vehicle has some problems with steep hypersonic re-entry on the lower stage, and even higher-energy re-entry on the upper stage from orbital velocity... Nonetheless, both of these technologies (SpaxeX-style reusable launch vehicles, and magnetic launch-assist tubes) are perfectly doable with today's technology. Sometimes you have to spend a lot of money (i.e. building a huge launch tube) in order to save a lot of money (i.e. drastically cutting the cost of getting things to orbit). Obviously none of these things have actually been built yet, even if we already have the technology- or we wouldn't be talking about them as possible instead of existing launch systems. But just because something HASN'T been done with today's technology *doesn't* mean it CAN'T be done with today's technology... Regards, Northstar

No, you're dead wrong. Building it BIGGER doesn't mean the technology required is unrealistic or futuristic. The launch-assist tube, for instance, doesn't require a single technology we don't already use for other applications... Regards, Northstar

The launch tube would accelerate the rocket at 30 G's along a 130 km tube in the first iteration of the launch tube (and would thus only be usable with unmanned rockets). There's nothing unrealistic or futuristic about scaling up existing magnetic technology to accomplish this- it simply would be a MASSIVE undertaking, in the same kind of manner as a space elevator would... (though not QUITE that large or expensive) We already dig tunnels longer than 130 km- the Delaware Aqueduct is a 4.1 meter diameter and 137 km long tunnel drilled through solid rock to provide New York city with approximately half of its water supply, for instance: http://en.wikipedia.org/wiki/List_of_longest_tunnels_in_the_world http://en.wikipedia.org/wiki/Delaware_Aqueduct However, the first version (later, lower-G versions for manned spacecraft are planned) of the magnetic launch-assist tube would likely be built above-ground anyways: "The tunnel tube itself for Gen-1 has no superconductors, no cryogenic cooling requirements, and none of it is at higher elevation than the local ground surface. Except for probable usage of SMES as the electrical power storage method, superconducting magnets are only on the moving spacecraft, inducing current into relatively inexpensive aluminum loops on the acceleration tunnel walls, levitating the craft with 10 centimeters clearance, while meanwhile a second set of aluminum loops on the walls carries an AC current accelerating the craft: a linear synchronous motor." Regards, Northstar

Boffins at the KSC had come up with a solution to Project Williams' engine difficulties... "Jerbo Kerman, I want you to re-initialize the starboard thruster on the count of three. Three, Two, One..." Northstar Kerman directed Jerbo Kerman in an unusually calm voice... "Roger that, Northstar. We have engine ignition on the starboard side! We'll keep it at no more than 20% from here to delay the problem with asymmetrical engine cut-off we experienced before..." Northstar breathed a sigh of relief. Another technical difficulty solved- even if the transfer burn was still going to take quite a few 'periapsis kicks' with the available power supply... Maybe, Northstar thought, he could keep a job for himself as an executive director at the KSC after all- even while Jake Kerman gradually took over his former role as lead director of the KSC... Regards, Northstar

Now I feel silly- it appears I didn't realize that all I had to do was restart the starboard engine that cut out earlier, and keep them at low-throttle to delay asymmetrical shutoff. Still, the plasma thrusters shouldn't have cut out quite so early/asymmetrically like that... Regards, Northstar EDIT: I'm still running version 0.10 of KSP-Interstellar. Is it possible this is one of the bugs fixed in 0.11?

@FractalUK Another problem with plasma thrusters producing asymmetric thrust: I am aware that I don't have nearly enough power to run the two plasma thrusters continuously at full-throttle, but I am not attempting to. I am only trying to get an even low-throttle burn across both engines, recharging the two generators (whose internal cycle-speed I am using as form of energy-storage for beamed microwave power- think of it as high-density flywheel energy storage, like so: http://en.wikipedia.org/wiki/Beacon_Power http://en.wikipedia.org/wiki/Flywheel#Applications) from microwave beamed power produced by a nuclear ground-station near the KSC, and a a solar power satellite in orbit of Minmus... The plasma thruster algorithm SHOULD be able to realistically handle distributing a limited supply of energy across the two thrusters at the throttle setting I had assigned here. At the throttle setting I was using, it should have taken several MINUTES to exhaust the vehicle's 2.6 GW of electrical storage (I intended to dial up the throttle, but start low after an earlier incident with asymmetrical engine cut-out at high throttle...) By the way, here is what happened when I had the plasma thrusters dialed up to high throttle earlier: As can be seen, one of the thrusters cut out WELL BEFORE the other, when there was still electricity left in storage... (both engines initially fired evenly- you can still see the remains of the starboard engine's flame trail here, as it had just cut out) I'm considering this a bug, and would like to see a fix released for it soon if possible... I can submit my craft-file if necessary (how do I upload a craft file on the forums again?) Regards, Northstar

Northstar Kerman sat at his desk, massaging his giant Kerbal forehead, and reading memorandums... "The manned component of Project Amadeus shall henceforth be known as 'Project Williams'- signed Jake Kerman' "All new initiatives shall now pass by my desk first. Northstar Kerman will be charged with the execution of operations- signed Jake Kerman" "Payload engineers for Project Williams are to report directly to my desk, per a new equipment addition to Project Williams- signed Jake Kerman" "Who did this Kerbal think he was, exactly?!" thought Northstar Kerman. "I've been doing this job for over 4 Kerbal years, and now he wants to just push me to the side?!" Northstar Kerman was fuming. "Alas, though- such are politics" Northstar thought to himself... "Time to report to the control room for the launch of Project 'Williams'" Northstar Kerman thought with a great deal of resentment at Jake Kerman's new name for the manned mission being launched that afternoon... "Greetings, KSC, from space!" came the excited voice of Bill Kerman over radio transmission as the reusable launch vehicle cleared the atmosphere "We'll see you on the far side, after we get this baby circularized. Detaching reusable lower stage for recovery now..." "Roger that Bill, Jerbo. Enjoy the view" replied Northstar Kerman, turning off the radio as he finished his sentence... "That went better than expected- but what was this about an 'extra' payload that Bill kept referencing and Jerbo seemed so worried about?" asked Northstar Kerman, turning to Jake Kerman with a scowl. "You got the memo like everybody else, announcing I would be adding new payload to Project Williams. There's no time to discuss that now" said Jake Kerman, in a respectful but slightly dangerous tone that told Northstar that he was in charge now, and not to pursue the issue further... Northstar sighed- he would have to learn to control his famously-short temper in his new de-facto position in a subordinate again, even if officially he was Jake Kerman's equal... The control center was a buzz of activity... "Far side tracking station reports the Williams has reached target orbit" reported one boffin "We have reports of stage separation, and uploading the revised navigational parameters for the payload stage to finish the circularization now" "Lower stage is beginning re-entry" rang out the voice of another boffin a few minutes later. "Telemetry indicates the landing algorithm has initiated, and has good parameters for touchdown" announced yet another boffin still... "We have reports that the lower stage has safely touched down on the plains west of the KSC" reported a nameless boffin "Dispatching standby recovery crews now." "Telemetry is indicating payload-stage power-allocation system failure" announced one concerned boffin. "But we have data indicating that G-forces were not excessive, and the payload has successfully stabilized orbit" added the same boffin moments later... "We are GO for upper stage de-orbit burn" directed one particularly important boffin. "Upper stage is predicted to touch down on the eastern shores of the continent west of KSC, only meters from the ocean- dispatching naval recovery task force now" "We have confirmation of upper stage touchdown on a steep slope near the sea" reported one more Kerbal boffin. "No, wait- we have lost signal! The upper stage probably fell over on its side and jarred the radio transmitter's feeds loose again..." announced the Kerbal again, correcting his earlier report. Finally, one last boffin issued the final low-level report: "Payload stage navigation-system Minmus-transfer course data checks. Transmitting authorization codes for engine re-ignition now." And with that, the KSC control room fell into silence for several more minutes. At last, the silence was broken by the slightly shaken voice of Jerbo Kerman... "KSC, this is Jerbo Kerman. We seem to have a bit of a problem here. The engines cut out asymmetrically during the stabilization burn several minutes ago. Bill Kerman didn't bother to strap himself into his seat properly, and took a bit of a knock to the head when the vessel suddenly spun out of control..." A slight pause- everybody at KSC held their breath "Sorry about that- Bill lost his lunch again. He seems to have suffered a moderate concussion from the impact with the wall. He looks like he'll be OK, but he might not be fit to pilot for a while... I am switching over control of the multi-megawatt twin plasma thrusters to my console, and initiating burn at 5-10% throttle to avoid loss of control... " Another suspenseful pause before Jerbo's voice cut in over the comm again: "Readings are indicating just 0.1 kN of thrust, from only the Kerbin-side thruster. This transfer is going to take a LONG time KSC..." The control room entered a state of frenzy. Boffins scrambled over chairs and around desks, analyzing the power-system readouts from Project Williams- trying to figure out why the algorithm was incapable of allocating the available electrical energy evenly across the two thrusters despite the presence of sufficient supply for several kN of thrust in each engine for a minimum of 10-20 seconds at partial throrrle... Northstar Kerman got a concerned look on his face, and turning to leave the room, announced he would be in his office. OOC: This last technical-malfunction, like any malfunction I report on this thread, was not faked or staged in any way (including the loss of transmission from the upper stage- what actually happened is the upper stage tipped over just after touchdown, and the probe core on top was destroyed- despite the very low velocity falling over from a stationary position...) I am not clear why, but KSP-Interstellar appears incapable of allocating the limited supply of electrical energy available evenly across the two plasma thrusters. My guess is that it is an issue resulting from how the engines were connected in the VAB using symmetry mode... I'll be bugging FractalUK for a fix for this bug- but I don't anticipate a rapid reply. Expect a contingency mission to launch if I can't work this problem out somehow... Regards, Northstar

Just a thought- but there *IS* room for supersonic craft on Duna- although they will tend to be capable of kicking out to suborbital trajectories if you're not careful (as orbital velocity is only about Mach 2 or 3 on Duna, unless you're playing with a Real Solar System scale-up of the planet...) So far, the only supersonics have relied on KSP-Interstellar, though, as supersonic flight kind of requires either jet engines or rockets... (ion engines don't have enough thrust, propellers have a lousy velocity-curve, and the only rocket entry so far relied on LV-N's without using FAR...) There's the "Last Dancer"- a [FAR] hypersonic which would explode in a wonderful display of fireworks if run on the current version of KSP-Intersellar, due to its lack of precoolers; and my own [non-FAR] supersonic "Eagle Mk2"- which hasn't completed the challenge yet as I can't land the darn thing with the extra reactor-fuel that miraculously appeared when KSP-Interstellar updated... I guess you could create a non-Interstellar supersonic craft if you used high-ISP chemical rockets (just don't burn them too long!) or NERVA's with FAR installed though (the problem with LV-N's and stock-alike NERVA's is that they produce a lot of drag in the stock aerodynamics model due to their high mass- not so in FAR, as they are dense, and likely located at the rear of the plane) Regards, Northstar P.S. My skills in aerospace design have grown CONSIDERABLY since I launched the Raven Mk2. At some point in the future, after I land or fail to land all my current models, I might introduce a newer lineup of Duna-planes for this challenge, or a similar Duna-flying challenge of my own I've been talking about creating, using some of the lessons I've learned lately in aircraft design...

Nice plane, by the way. Some good ideas there. You could improve the design a bit by reducing the part-count if you installed the Multipanels mod (which basically gives you upsized versions of the Ox-STAT solar panel, though they look a bit ugly, as they are literally just resized OX-STAT panels, and the base is too tall for the scale). This might even allow you to throw on a few more wings and ion engines and build an even bigger version... Alternatively, the NearFuture mod has nuclear reactors which, though not nearly as power-dense as real reactors (or the ones in KSP-Interstellar, which are modeled after real-life reactors), still produce more EC/ton than any of the solar panels except the OX-STAT panels facing directly towards the sun (and in a plane, most of the time they will be at a significant angle). This might reduce your weight for the same actual electricity production- as the reactors would produce more power than the solars except when flying around Dunar noon- and would allow you to have powered flight at night... Finally, if you want to really optimize your design, install Procedural Dynamics (better known as "Procedural Wings" though the mod was never actually called this). It will allow you to basically create wings of any size and shape you desire, and the lift coefficient properly scales for large-sized wings (as well as based on other more subtle wing parameters like root-to-tip width ratio: it's basically halfway to FAR in terms of realistic lift equations), so your larger planes will produce slightly more lift compared to their wing area, like in real life... (lift increases exponentially with wing area in real life- though the curve is somewhat balanced by increased drag) I play with all these mods myself (especially Procedural Dynamics, on Geschosskopf's suggestion- how else would I build giant flying wings like the Raven Mk2 without overwhelming my CPU with part-count and 50 separate lift equations for each wing section?) Procedural Dynamics will be especially helpful for you- since it most strongly benefits craft with large, thing wings like your ion-flyer/glider (like in real life, in Procedural Dynamics thicker wings produce more lift than thinner wings- but I believe their lift coefficient actually decreases, so it's less lift per ton of mass, making thin wings preferable on lightweight gliders...) Regards, Northstar

Depends on the version. Earlier versions of TAC Fuel Balancer did, in fact, allow that- but newer version search for whether a resource is defined as "solid" or "liquid" based on the fuel-feed type (Monoprop, etc. count as "liquid"), and don't allow dumping of any solid fuel. Since UF4 is defined as non-transferable so it can't be moved around in flight, it also counts as "solid" in TAC (if I remember correctly, in real life, UF4-based reactors usually have the UF4 as a liquid solution... But KSP-Interstellar uses the solid fuel crossfeed rules for them so that players can't freely pump uranium around their ship.) That would be a 5% load... (I originally used TAC Fuel Balanced to edit it to that before takeoff on Kerbin- this was before tweakables) Regards, Northstar

Indeed- that's why you want a magnetic launch-assist (so you can get to speed and altitude very quickly, and don't have to spend large amounts of time building up speed when your window is so short) and an unmanned rocket (human pilots can't match the accuracy and precision of a drone- and no lives are lost if anything should go wrong...) Note I said "rocket", *not* "plane". A magnetic launch assist tube doesn't work so well with a plane... (all that wing area shooting out of a vacuum tube into atmosphere at Mach 26, at 6 km altitude and a 10 degree angle above the horizon? Forget about it- any plane would burn up or spin out of control... Even the rockets require a massive cooling system estimated to make up 10% of their mass to manage the heat at that speed/altitude...) Regards, Northstar

Indeed. I think most players got so involved in their pancake-monstrosities, they forgot that such rockets could NEVER fly in real-life. There's a difference between exploits and realism my friends... Nobody would even consider a Moon mission "small" in real life. SLS is entirely appropriate for the Delta-V required for such a mission (just remember how big Saturn V was). What's not appropriate is how little Delta-V it takes to get to orbit in KSP, even with the thick syrup-atmosphere and unrealistic drag model. What the game REALLY needs is a closer scale to reality- like moving it from it's current 10% scale to a 20% or 30% scale... (the reduced planetary curvature would increase minimum orbital velocity) Of course, Squad has already declared that they're NEVER going to do that, because it would make the game "less fun", which is a shame... Personally, I play with NovaPunch and StretchyTanks. You think SLS is big? Try a 5-meter rocket with StretchyTanks and a Novapunch 5-meter engine! You quickly learn to think bigger when your rocket parts are bigger- although I'll admit, it takes a few months to really get the hang of. I doubt there will be any complaints about the SLS parts being "Overpowered" a couple months from now, when everybody has gotten used to launching bigger payloads, except from newly-returning players... And, if you don't allow yourself to build pancake-rockets (I play with that restriction, for instance), then an SLS can't launch half the payload of a 12x4 Rockomax mega-monstrosity... I agree wholeheartedly. If you think that bad interface and bugs like wobbly joints is what actually constitutes "difficulty" in a game, then we're not going to see eye-to-eye on ANYTHING, my friends... Regards, Northstar

Northstar Kerman knew his career was at an end. Less than an hour before, he had received word that the Kerbal International Congress (KIC) was appointing a co-director to 'assist' him in his management of the KSC. While the issue of Project Amadeus- and what the congress-Kerbals viewed as his wasteful and excessive spending of funds- had not been mentioned in the document; Northstar Kerman knew this was the real reason for the new 'co-director', who would likely take over most of the operations of the KSC in the coming days... If he played his cards right, and was lucky, though, Northstar knew that he could probably at least still continue to work at the KSC- likely in a new position alongside the boffins, developing some of the systems for future exploration missions... In the meantime, he thought, massaging his forehead for a few more seconds before examining the files on his desk, there was still work to be done. Northstar had been busy for most of the past few days since the congressional hearing preparing for the launch of the manned component of Project Amadeus- until the shocking news he received earlier this day that had temporarily distracted him from this work. Over the past week, boffins at the KSC had been testing new microwave-powered launch systems to work out the kinks in the technology. Of course, none of them had enough thrust to even get off the launchpad with the meager sum of power they were receiving from the solar power transmitter in Minmus orbit. But, from the 1-2 second burns the test-rockets had managed before smashing back into the launchpad, the engineers had somehow managed to collect enough data to work out the remaining bugs in the power-management systems, and made last-minute improvements to the new medium launcher for the manned phase of Project Amadeus... Northstar could already imagine the criticisms he would hear at his congressional meeting later the next day... "Why didn't you just use the same reusable launch vehicle as the one for the unmanned components of the project for this one?" (the engineers had deemed the heavy reusable launcher overkill- and had designed a simpler and lower-maintenance medium lifter for the manned segment. Fortunately, too, as the heavy lift vehicle was still undergoing repairs from its recent saltwater bath) "Why is a manned mission even necessary?" (Northstar had dictated that a large load of scientific equipment be included in this portion of the mission- and he had plans for further use of the mobile laboratory later...) "Why use a microwave-powered medium lifter when we already have perfectly functional light and heavy chemical lifters?" (Northstar knew he would have to explain how the power-generation equipment connected to a microwave transmitter could be re-used on mission after mission, while the actual microwave receivers and thermal propulsion systems were much lighter and cheaper, and easier to maintain as they had far fewer moving parts...) "Why rely on experimental, new electric propulsion systems on the payload of this mission, when we could just use chemical rocketry and the reusable heavy lifter?" (Northstar didn't know how he would address this critique- he would have to explain he had plans for future re-use of the mobile processing lab, and that launching Xenon to refuel the new multi-megawatt plasma thrusters would be much lighter and therefore cheaper than launching a massive tanker full of chemical fuel to some of these distant locations- yet he didn't want to explain just where he was planning on sending the mobile laboratory after Duna...) Northstar was already exhausted thinking of the critiques- but he knew that one question would be difficult to answer above all: "Why did the KSC already have a working design for an 18 GIGAWATT mobile nuclear-powered microwave transmitter under construction before Asteroid-684 was even detected?" Northstar Kerman knew this criticism would be the straw that broke the camel's back- as much as he would try to explain that he foresaw the need for a cheaper way to get things to orbit in future years, with diminishing funding levels, and that it was not only a worthy investment on Kerbin- but an excellent testing-ground for the same technology on Duna, where the weakness of Kerbol's sunlight meant it would be sorely needed (already, recent experiences deploying the design had taught the engineers that 4 large wheel bases were not enough points of contact with the ground to prevent tire blow-outs on bumpy terrain, for instance). The politicians would likely have none of his explanations, Northstar knew- and they would try and see to it that he spent the rest of his career at the KSP cleaning toilets if he didn't do a good job alleviating this particular concern... The technology, nonetheless, was effective- after installing the 18 GW transmitter, not only did the thermal rockets soar into the sky (as planned), but they greatly outperformed expectations- one test rocket made it to a high suborbital trajectory, and likely could have even made it to LKO, for instance: OOC: I hope you guys enjoyed this particular post, even though there was a lot of meta-analysis and discussion of why each action was taken rather than action this time around. I promise it's about to pick up from here though- I just wanted to get as much of the boring stuff out of the way as possible before some of what's coming next... Regards, Northstar

No, I meant to say increases. Read what I said carefully- I said *drag* increases, not the drag coefficient. The drag coefficient decreases, but actual total levels of drag continue to increase. Drag approximately forms an "S-curve" (gradual increase --> rapid increase around Mach 1 --> gradual decrease) Regards, Northstar

Keep in mind the rotation speed would be synchronized with orbital velocity such that the lower tip speed would also be Mach 12 at its lowest point- so the aircraft or rocket would be getting hooked by something temporarily moving at the same speed. Using a magnetic launch-assist tube would also help, by reducing the time from launch to tether altitude (rockets in the tube could safely be accelerated at relatively high G's due to the lack of air in the tube and the controlled environment) as well as providing nearly all the velocity necessary to reach Mach 12 in the upper atmosphere (the exit velocity from the launch tube at 5-6 km altitude could be up to Mach 26). This would be safest and work best with unmanned cargo craft, of course. A number of engineers seem to think it's possible- so I'm inclined to agree with them. Keep in mind this is in the high reaches of the UPPER atmosphere- where there's a LOT less air pressure to cause drag. In fact, the altitudes where this version of the Skyhook would reach to would be best reached with rockets- essentially more of a low suborbital trajectory than atmospheric flight. Regards, Northstar

The challenge is already closed, but if it were still open, the answer would have been "No", as I don't consider it to be a well-balanced mod. Sorry for not getting back to you about it while the challenge was still open (real life and stuff...) Regards, Northstar

@FractalUK Fractal, you are familiar with the Krag's PlanetFactory mod which adds the "Sentar" gas giant and corresponding moons, yes? (Here's a link if not) http://www.reddit.com/r/KerbalSpaceProgram/comments/1q008p/expansionkrags_planetfactorysentar_system/ Well, I was wondering if you might be able to add some resources for the gas giant and moons of the Sentar system- which is supposed to be a (very rough/approximate) KSP player-made analog for Saturn and its moons... I have no idea what resources might be appropriate for a Saturn analog, but you can PM me (so I won't miss a reply on this thread) if you'd like me to do some of the research for you on that... Regards, Northstar

Northstar Kerman sat in his office, rubbing his forehead anxiously, until he heard a knock on the door. "Come in" Northstar replied. Striding into his office in firm, confident steps, was yet another of the normally-nameless KSC boffins- Dinkelstein Kerman- with a large grin on his face. "What is it?" asked Northstar Kerman irritability. He didn't have the patience for boffins and more of their foolish ideas right now... "Sir- I've been discussing it with some of the other engineers at the KSC, and I think I have a plan for how we might nudge that asteroid off its collision-course with Kerbin, and still manage to capture it." "Yes?" asked Northstar Kerman, growing more impatient. "Well, Sir- me and some of the engineers were discussing the friction coefficients of the asteroid's irregular surface- and we think the Amadeus might be able to achieve enough grip with the surface that it could physically nudge the asteroid's orbit off its course with a weak impulse from its engines, and not spin out of control or have as much trouble with slippage against the surface as did our early attempts to de-orbit debris in this manner..." "So you want me to take a multi-million credit piece of equipment, with carefully-constructed grappling hooks that we simply can't get to deploy now for some reason- and just use it like a giant BATTERING RAM?!" Northstar Kerman half-shouted, growing increasingly frustrated with this particular boffin. "Yes Sir- that's exactly what we want you to do- although I would hesitate to call it a 'Battering Ram' in your meetings with the Congressmen" Dinkelstein Kerman replied, in a small voice, trying not to offend Northstar Kerman further... "GET OUT OF MY OFFICE!" Northstar Kerman boomed, in an explosively angry tone, making a dismissive gesture towards the door to Dinkelstain Kerman. Dinkelstein beat a hasty retreat, with a look of profound distress on his face... Northstar, meanwhile, collapsed into his chair- with a very different expression on his face now... "Sometimes the simplest ideas are the best- now how come I didn't think of that..." Northstar muttered. The next day, Northstar Kerman stood before a congressional inquiry, reporting on how, despite equipping the Amadeus with expensive and innovative new grappling hooks; saving Kerbal lives had boiled down to simple use of the Amadeus as a sort of battering ram- a task that could have been accomplished at much less expense by a simple, tiny, and cheap ion-engine probe... OOC: I hope you, the readers, enjoyed this particular post. The Amadeus drifted a short distance away from the asteroid and the matched velocity again- it will accompany it through the atmosphere so the asteroid stays in physics-loading range and experiences drag... This will also serve to keep it close by, should the manned mission manage to get the grappling hooks working when the asteroid gets much closer to Kerbin; and to allow it to stabilize the asteroid's orbit if the aerobrake should turn into an aerocapture... Further, the Amadeus will likely perform a transfer to Duna or one of my orbital scrapyards (spacedocks) around the Mun or Minmus when its mission is complete- where its leftover fuel and carefully-engineered nuclear reactor parts (in its NERVA engine) should prove useful to my future colonization efforts. Last, but not least, I have now managed to re-direct Asteroid-684 off its current trajectory, and demonstrated a method I could use to stabilize its orbit after aerocapture, if that should prove necessary. Kerbals will frolic and dance in the streets of Kerbin cities everywhere tonight, and the three fuel tankers I launched from before will transfer their fuel and dry-mass (which will be salvaged for spare parts) to Duna... Northstar Kerman, however, might be out of a job (never let it be said my Kerbals don't believe in accountability) after the asteroid redirect mission is finished- which would mark a convenient point to transfer the storyline to a new thread about my Duna colonization, as well as an excuse to take my space program in entirely new directions... Regards, Northstar

I've been thinking much along the same lines lately, and would really like to see an increase in the scale (maybe to 1/5th- as that would make adjusting the files an easy case for the devs of multiplying all planetary parameters by two), but it's quite explicitly been listed as something that is NEVER going to happen- so you can pretty much forget about it. The nodes, etc, all fixed obviously broken things that made the game harder than real life. Increasing the scale would fix something that is IMHO obviously broken (jet engines can, for instance, push you nearly to orbit with air-hogging: not so much just because the ISP, velocity curves, etc. are inaccurate, as because orbital velocity is SO DARN LOW with a 1/10th scale Kerbin...) It would also make the game more visually appealing, if you ask me, if planetary curvatures were reduced a bit as a result of having larger diameters... Stock rocket parts are also currently to approximately 64% scale- so increasing the planetary scale from 10% scale to 20% scale would bring them a bit more in proportion... Regards, Northstar

Having already tried that with relatively large pieces of space debris in the past, and had no joy with it, I doubt it's going to work for an asteroid either... Thanks for the response though! I guess the good old "thrust cannon" method should work fine for averting a Kerbin impact though... I'll probably set the periapsis for about 48-54 km if I can get it there: that should hopefully lead to an aerocapture, or at least bleed off a bit of the asteroid's velocity; and allow me to safely wait for the manned mission to arrive without worries that I won't be able to bump up the apoapsis again far enough to make sure the asteroid doesn't aerocapture if I can't get a good grip on it... (that MIGHT lead to another impact next orbit around Kerbol at some point- but I'll worry about that when I come to it...) Regards, Northstar EDIT: Actually, the thruster-cannot method, while effective, proved a bit too imprecise. As such, I resorted to your method after all... Even though I was considering that particular method all along, I'm always one to keep my word and give credit where credit is due, and appreciate your responding to my request- so enjoy the reference to "Dinkelstein Kerman" in my next exposition.

Asteroids. Are they currently re-scaled along with the solar systems? If not, for realism and balance (with the larger part sizes), they should be- at least assuming they were at 10% scale, like the stock solar system. In real life, there are a lot bigger Near Earth Objects floating around than 30 meters diameter... (the maximum asteroid size in the stock game) The "Potentially Hazardous Object" catalog maintained by NASA, for instance, is only defined as asteroids with diameter larger than 100 meters, that pass within 0.05 AU of Earth, and NASA had 1458 asteroids listed in February, 2014 (NEOWISE estimates indicate between 3500 and 6200 such asteroids exist) http://en.wikipedia.org/wiki/Potentially_hazardous_object The config to alter the base asteroid sizes can be found at GameData/NASAmission/Parts/PotatoRoid/ Funny how the devs internally called them potatoes. Regards, Northstar

The Amadeus is in position: Facing precisely away from the asteroid, in an almost perfect velocity match (the Amadeus is in fact drifting towards the asteroid at approximately 0.04 meters per second), and with a great angle set up for the grappling hooks... There is a problem, however- the grappling hooks won't deploy! Any attempt to eject them does absolutely nothing. I cannot get them to separate from the winches at all- even boosting towards the asteroid with full cable length fed out, and then canceling the momentum doesn't carry them out from the winch controllers... The problem *might* be that I built the hooks directly onto the winch plugs in the VAB, instead of attaching them manually with a Kerbal... Anyways, I am left with the following two-step plan: (1) Wait until the Amadeus' engines have inched right next to the asteroid surface (remember, it is approaching at a VERY slow speed) and then FULL POWER TO ENGINES! The 2.5 meter NERVA's should pack more than enough punch in their propellent stream to knock the asteroid's periapsis above Kerbin's atmosphere at this distance- causing it to miss the planet entirely... (I *could* also set an aerocapture periapsis, and attempt to capture with the same technique- but risk being unable to sufficiently adjust the asteroid's trajectory if all I have to work with is engine thrust momentum-transfer) (2) Deploy a small, high-speed manned vessel with a single Kerbal to hook up the grappling hooks by hand (my understanding is that a Kerbal should be able to fix the hook connection issue, allowing them to connect properly) and then attempt to adjust the asteroid's trajectory again to set it up for an aerocapture through Kerbin's upper atmosphere (realistically, a low-atmosphere aerocapture, while likely more effective, might cause the asteroid to detonate if rich in volatiles...) I list the plan because I don't think it's particularly good. While better than smashing the ship into the asteroid whole-sale, is is still a long shot from a carefully controlled course correction and capture if simply sending a Kerbal to the asteroid (which I was planning on doing anyways, to collect samples from it while still in Kerbol SOI- and already have a roleplaying explanation for...) doesn't work... So, I would like to hear from you, the readers of this thread, if you have any better ideas you can come up with as an alternative. Or any idea how I might make the KAS grappling hooks work without needing to wait for a Kerbal to reach the asteroid (the manned mission is set to occur when the asteroid is closer- to reduce mission time as well as Delta-V requirements for course-corrections) If I like your idea, and use it, you'll get a small roleplayed nod from Northstar Kerman himself in my next exposition on the Amadeus. Let me know your ideas (post them here)- I have need of them whether you're enticed by that offer or not! Regards, Northstar