ajburges

Tech is a minor issue. I was able to do my Mun landings with either a HG-5 on the mother ship or just going in the blind with a pilot. DSN is a little OP at level 2 (compared to the parts you have). I have RA-2 dishes which can talk to each other across most bodies SOI. This is sufficient for pretty much any ground cover network. The worst case is Jool and it's sphere of influence is only 25% greater than the RA-2 power (and Jool is already a special case with its numerous natural satellites). I plan for interplanetary communications will be handled by high power arrays (4+ RA-100s) in perpendicular polar orbits of each planet beyond any natural satellites. That would allow 50% signal to reach Eeloo even when Kerbin is in opposition and better paths will be available more frequently. My research suggests that just jumping on and off rails can accumulate accuracy errors that can result in seconds of ark traversal per orbit in a synchronous satellite. That kind of error wouldn't allow networks to stay calibrated for centuries. The speculation I saw was that there is a change in floating point precision during that process. If that is true, then scale of the orbit would have minimal effect on the loss of precision.

So it is well known by now that precision orbits for a comm sat network are difficult. My understanding is that there is a precision switch making it impossible to align an orbit period to high accuracy. Anyone know of a good formation with extremely high coverage that requires minimal upkeep? I considered highly eccentric orbits, but those still come with bunching and that still results in blackouts. I am currently considering a 5 satilite constellation. One satilite (likely a polar scan and science sat) will act as an alignment timer for a Draim tetrahedron. While sensitive to bunching, a Draim tetrahedron at least uses elliptical orbits and it's high altitude makes period adjustment easier. Fewer satilites means fewer manuvers to recalibrate. The timing sat allows me to mitigate the disadvantage of measuring relative mean anomalies of 90° by instead aligning to time to apsis to different timer orbits. Finally, blind spots are preceded by loss of a network link allowing clear signaling of when calibration is required. The only disadvantage I see to this solution is the lack of low dV delivery. Each sat will need to execute its own inclination and Pe lowering burns.

I though I did, but I could be mistaken. I also forgot to mention that the save is modded. Vessel uses KER module. KER (prototype compile) Docking port alignment indicator Part Angle Display Precise Node RCS Build Aid KAC Waypoint Manager

For my first Mun landing of a fresh career I took a different route: Typical lander that doubled as the engine for transfer stage tank (topped by re-entry pod). Cross-feed worked fine on the way to the Mun, but once I docked with the tank for the return journey (using RCS for the last dV to orbit) I found that I could neither draw fuel from the tank nor transfer its fuel to the lander for the burn. If I disabled "Resource Transfer Obeys Crossfeed rules" I could transfer the resources as expected. Anyone know why a vessel that had fine fuel flow before decoupling did not allow cross-feed when re-docked to the original configuration? Save file if it helps. Vessel(s) begin with "Luna 1" https://drive.google.com/open?id=0B6bFMWl7xYibSWtUbklvdl9Nbkk

You need to remember that Pe is displayed as altitude. Once you develop proper intuition for it, that negative number correlates to dV required for orbit. Remember an object at rest on the surface is locked at Ap of orbit traveling at sidereal velocity with constant 9.8 m/s^2 radial acceleration.

Yeah, I've only used it for rovers. Do remember though, you can use them for... CubeSats ...I'll see myself out now.

Figured I'd put my support as well. Mods like this are why I choose the Patience Fairy over the Hype Train. 1.2 will be nice, but I choose not to play without mods like KAC.

A little known advantage of a retrograde Munar orbit is that a retrograde ejection is fairly close to the gate orbit altitude for Duna and Eve. This means you can get to these destinations with a dV capacity of about 1300 m/s if you have Munar mining set up. Not much savings, but it's there. Certainly can help in delivering large stations and Eve landers. Free return trajectory is easily the biggest advantage though. Ground resonance orbits would also change. Not something I think about often, so I don't know how that would be an advantage. It also requires non-polar inclined orbits. Maybe it could get you a better station orbit radius for a high/low latitude mining base. While we are thinking of mining, a retrograde orbit could give you a safer approach/departure from a mining outpost.

This. The real hype is when my mods are updated. Except once that happens I will be happily playing.

Ah yes I see. The idea is to reach the slightly denser region before bleeding most of the speed so you increase your dissapation rate before you sink as much heat into your craft. From my own experience I can postulate on an alternative. If your craft has high thermal mass, it can easily limit total temperature below 1200 on even a shallow approach. MK3 bodies work well for this because of the mass vs volume effect. The temp guages on batteries may almost touch red, but they will simply stay there (unless you panic). Though I must confess, a Pe of ~43 km (from LKO) has always been kind to me. It also allows easier calculations for phase of deorbit burn.

Can you please explain how this would work both in simulation and IRL? If we frame the problem in terms of every: we have a chunk of kenetic energy we need to dispose of. We do that primarily by converting it to heat by compression and drag. Given the same starting energy, the longer approach should give more manageable temperatures (assuassuming net positive heat dissapation in the craft).

The only report I've seen of successful Munar sling shots is carefully crafted multi-encounter sling shots. In summary: you eject from the Kerbin system in such a way that you will reencounter it (via resonant orbits). Then you proceed to slingshot through the system ensuring you keep resonant orbits with Kerbin until you gain enough velocity for an encounter with the desired body. This approach does give incredible dV savings, but a the cost of being tricky and taking in game years for a transfer.

Depends on what stage you are at sub-orbital and what you goal is. For obvious reasons, vertical thrust of about 1g will cancel the effects of gravity. But all that does near AP is change orbital phase. Generally, you want to thrust prograde as that is the only vector that will increase your kinetic energy state. Making assumptions about you situation, I am assuming you are talking about you gravity turn. An efficient gravity turn should not see you extend time to AP by much, but instead hold it at a value (a minute is an easy number to work with) until the AP is in the desired range. If you lack the thrust to do that, your stage is lacking in thrust to achieve the desired gravity turn or you are not flying the right gravity turn for the desired orbit. If your stage lacks thrust, you may need a bigger kick from previous stages to give your engines time to work. Diagnosing a bad gravity turn can be hard and needs much more information. Can you provide more details about your craft and flightpath?

I had trouble understanding relatively in college. Can't imagine dealing with it in KSP. But of trivia: did you know GPS algorithms need to account for relativity? Even the relatively (pun not intended) slow speed of GSO is enough to impact measurement accuracy. Then again, KSP does do wonders for teaching orbital mechanics.

If you desire less cheese, remember sine functions are non linear. 45° gives you 70% thrust efficiency. An angle of 15° looks plenty realistic on a decently long tug and yields 96.6% thrust efficiency! Push that to 10° and you have 98.5% thrust efficiency.

Best thing to do with ailerons is to disable pitch and yaw. They offer little authority in those axis. The exception is when you combine ailerons and elevators to make a elevon (common in Delta wing designs). Even then, KSP flight control often struggles to make good use of any surface granted authority over more than one axis. Better to split into two surfaces with singular axis authority. Due to the low pitch authority, ailerons do make excellent flaps. Most of their force is applied to lift CoM instead of being applied as torque. This lowers stall speed.

I hope not. Aerospikes are a proven mechanism IRL. They even work in the hypersonic regime.

Figured I'd put my 2 cents here. My Kerbin operations always wind up being a huge time sink so 3 RL months can pass before 1 Kerbin month. KAC allows me to create a lot of overhead. I have yet to get a career mission interplanetary because I alway end the career save early. When I return from a prolonged break, there's been a patch that invalidates my career somehow. I am currently holding off starting a new game because I'm waiting on the stock communications. I fear that will cause the RUD of a working space program. I have simulated (sandbox) flying Duna mining space plane for the first transfer window of my 1.0.2 career before I abandoned it. Hopefully, my 1.2 career will try run fewer arbitrary missions. However, between contract rejection penalties and stock communications, it doesn't look good.

I definitely feel like a minority here. Since 1.0.5 I've been waiting for the new antenna features. I figure they will require space program paradigm changes that would really bork a campaign running the old system. Would rather wait longer than be tempted by an upgrade just to have a career save killed by changing core mechanics.

[quote name='Pthigrivi']These guys are correct. The 9300 m/s also counts the Kerbin's orbital velocity of 9284.5 m/s, where your reading of 2300 m/s is hiding that because it is counted relative to Kerbin. In a related question though, I've been wondered in the past how much vessels with very low TWR suffer from their inability to take advantage of oberth. I often do at least two oberth passes for transfer burns, but surely the more focused your burn is on Pe the more efficient it is. Is there an easy way to figure out what this trade-off is? Im guessing the high ISP of low TWR engines more than compensates for this deficiency but I'd been curious by how much.[/QUOTE] Long answer: Trade-off is time vs efficiency of energy transfer. The efficiency of the energy transfer is determined by the sum of your losses (cosine in some form or another plus a little from Kepler orbits). You need a good model to calculate/approximate those losses to evaluate the trade-off.

This. My most egregious contract cycling had always been to get contracts tangentially related to a planned mission (bases for miners, stations for stations/mother ships, polar sats for surveys). I'm putting something there anyway and a RNG is the only reason nobody wants it. I would also like some negotiability on contracts. Make adjustments not favor the player, but allow us some bounds to play with the particulars. Who needs a base on Eve for 20 Kerbals or a super-Munar, polar satilite?

Depends on the plane. 1000 kN of rocket power is also a lot for a plane. (Don't actually have Vector stats handy, so I'm guessing it's ¼ a Mammoth). It is the most weight and node efficient source of thrust in the 1.25 regime.

So I became intrigued by the concept of a gate orbit (https://en.m.wikipedia.org/wiki/Gate_orbit) and did some scratch work... I approximated infinite velocity of a Duna transfer orbit to be approximately 815 m/s. That puts the gate orbit at a radius of 1e7 m. Transfer window calculator verifies this. Know what else is fairly close to that radius? The Mun! (1.2e7 m). Better yet, a retrograde ejection will bring you back towards that optimal altitude. Doing this, your ejection burn only needs to add 580 m/s to Munar velocity. Under this plan, no leg (LKO -> Mun and Mun <-> Duna) needs more than 1300 km/s to complete. This allows greater mass fractions on a Duna transport. The Mun also allows for quicker rendevous because of the shorter orbit (vs the gate orbit) The obvious weakness is the requirements of Mun based fueling and the relative simplicity of Duna transfers, but it does seem like an interesting concept. Note: Duna (and possibly Eve) are the only compelling choices for a Munar way station. The higher your required infinite velocity, the smaller your gate orbit.

Only for sub .8 Mach. Go faster and shockwaves produce non-intuitive results. Rockets should go faster.

For practical purposes yes, but to be pedantic: an excess of one does reduce the minimum of another. A small portion of the dV cost to orbit (a couple hundred m/s) is gravity losses establishing a gravity turn. It well known that higher thrust ratios reduce those losses. Conversely, a lower TWR needs more dV to sink into those losses. The relationship is asymptotic though, so don't try to compensate for one with the other. TWR and dV are both derived values. They are also connected via the fuel mass. Too many variables feed into them to make them useful design parameters (though they make awesome requirements). If you are building a new ship, start with the payload. Reducing the orbiter to a bare minimum of mass ripples through your design. The rocket equation teaches us that each pound shed from the payload gives exponential savings.