PakledHostage

Thanks. Good suggestion to test only those objects in orbit around the same body. It does that for the old method of seeking satellites with some GNSS acronym in their vessel name, but I don't think I remembered to do it in the new case. I wonder, though, if the bug is as simple as some funny interaction between Figaro and other mods like MechJeb? As I mentioned before, it doesn't bog down on my machine and I am only running it on a very slow little netbook... Another possibility is that it bogs down when none of the orbiting vessels have a Figaro Transmitter part installed. I never actually tested that case. I will look into it in the next few days. @AviatorDSB: Your game's persistence files are located in the "Saves" directory of the KSP game's folder. They are the files that the game uses to store data about all of your active missions. Don't worry about it if you can't find it. I wouldn't want you to screw up your game's save file.

I used the method that Edmund Halley proposed in 1716. It works by timing the passage of Eve across Kerbol's disk from two locations on Kerbin. A bit of trigonometry is then all that's required to calculate the Kerbal AU. I found the image below to illustrate how it works: The difficult part is accurately determining the lengths of the transits. As shown in the images that I posted above, Eve transits Kerbol starting late in the day on UT = 162 days. I never bothered to figure out how often it transits, because I only needed one transit for my experiment. I will dig up my calculations and post them, but it might take a few days. I have it on my computer at home, but I plan to be playing outside for the next few days rather than sitting in front of a computer...

I posted a thread a few months ago detailing how I tried to calculate the size of the Kerbol system by observing a transit of Eve. The thread was destroyed when the forum database was corrupted in April, but I've included a link below to an album of screen shots. My result was about 30% larger than the actual value, but I am not sure if that was due to a math error on my part or some quirk of Unity's 3D rendering. Maybe someone who's keen would like to take it on to compare results? I can dig up my actual calculations. If that is too much effort, then another idea is to calculate the mass and size of a celestial object by placing a spacecraft in orbit around it.

Sounds like you're well on your way... Have a look at the orbital characteristics in the Wiki. They should get you started with planning your intercepts. And I think the ocean liner analogy is quite apt. A cycler only saves resources if you maintain it for long enough to offset the cost of building it/maintaining it against the cost of flying all of your life support and habitation infrastructure on every mission.

Yes. It would not have intercepted Duna at all on the next pass. Depending on the type of cycler trajectory that you're trying to set up, an intercept may not occur every orbit. I think only an Aldrin Cycler trajectory will intercept every orbit. In this case, the trajectory merely demonstrated that it was possible to set up a transfer with sufficient accuracy to intercept Duna and Kerbin on the same orbit, with very little in the way of orbital trim manoeuvres required to return to Kerbin. A true cycler would have to use a gravitational assist from Duna to set up the next intercept with Kerbin, and the gravitational assist from Kerbin would then set up the next intercept with Duna. Your craft may have to orbit for several years between each set of intercepts, however.

a) I think it should be possible, but you'd need to be very precise with your trim manoeuvres. I did a "proof of concept cycler" trajectory about 9 months ago. It wasn't a true cycler trajectory because it wouldn't have continued to cycle, but it did originate at Kerbin then intercept Duna before returning to Kerbin on the same orbit. I would have had to move my Duna flyby periapsis closer to Duna to set up a true cycler. c) Unlikely. I did it by patching together the orbital conics in a MathCAD spreadsheet (we didn't have manoeuvre nodes yet at that time). I can't think of an easier way than that other than to try using the manoeuvre nodes. I'll see if I can find my notes for that mission but it might take a few days. Edit: Here's a video showing the trajectory intercepting both Duna and Kerbin. The trajectory in the map view was flicking back and forth between them.

Thanks for the feedback. Sounds like it is getting bogged down while searching for the transmitter part on your satellites. It doesn't do that step if you set GNSSacronym to something other than "NONE". It only develops the list of GPS SVs once when you first load your flight (and then again if the number of vessels ever changes), but it sounds like it is struggling to find SVs in the first place. It uses a bit of a kludge to find the SVs because I don't have access to the guts of the game, but obviously I'll have to come up with a more efficient method. Can you maybe PM me with a link to your Persistence file so that I can trouble shoot? It doesn't do what you're describing on my computer, so it must be something peculiar to your Persistence file.

I have been trying to resist responding to your post, but I've lost the battle... With all due respect, I get tired of the accusations of elitism. You are in a forum with an above average percentage of people with strong physics and math backgrounds. Why is it "elitist" if those people want to do a little math or engineer a solution to a problem using only the limited tools available in the stock game? Nobody would accuse artists (such as those who make the parts we all enjoy) of being elitist for practicing their passion. Nobody would accuse actors or writers of elitism for doing the same. Why then, is it acceptable to criticise people who are talented in mathematics or the sciences in general for enjoying their passion? There will always be some in any area of talent who really are elitist, but the vast majority of posts I read on these forums are just "sciency" people doing what they love.

Amen! ten characters

Isn't it a bit absurd to complain about potential devision in the community and then fuel it with such obvious bias? This community has always been divided along those lines. Nothing is going to change when career mode is added.

True. Magellan sailed to the Spice Islands via the Straight of Magellan because they believed that it was shorter to go that way than via the Cape of Good Hope. That belief was based on Ptolemy's estimate of the size of the Earth from the time of the ancient Greeks. They were surprised by the true size of the Pacific when they sailed across it, because Ptolemy's estimate was about 30% smaller than the Earth's true size.

Yes, when calculating whether or not a satellite is visible above the receiver's horizon, it assumes planets are perfect spheres. Let's just assume that trace amounts of handwavium in the Kerbal universe refract GNSS and pseudolite signals around obstacles like mountains... UPDATE I believe I have fixed the bug that was reported by spacerodent and billeinstein. I have rebuilt the plugin as v1.0.21.02 and posted it to SpacePort.

You are probably referring to the NASA announcement of the discovery of the microbe strain GFAJ-1. The microbe was believed to use arsenic in place of phosphorous, but there has been plenty of further research since that first announcement questioning the validity of the discovery.

You are absolutely right, which is why the feature would be optional if I were to add it. (And I am not sure that I will add it.) As you point out, there is plenty that the game "hand-waves", like having precise position information available without requiring the infrastructure to support it. The beauty of mods, however, is that they give players the option to customize gameplay. An optional "hardcore" mode within an optional mod only adds a layer of challenge for those who want to take it on. I'll do some work later today on the bug that billeinstein and spacerodent identified and will post back with an updated version once I have it fixed. The fix will not require players to relaunch their GNSS constellations, so... as you were.

Clearly there is a bug. It sounds to me like it isn't always updating or renewing the list of SVs. It only searches for SVs when it first loads and whenever there's a change in the number of spacecraft. I'll have to look for an oversight in the logic... Please give me a day or so. (If someone can PM me with a link to download a persistence file, that would be great.) In the meantime, billeinstein and spacerodent, you should be able to make it work reliably by reverting to the old method of identifying SVs in your constellation. In your case, billeinstein, I see that all of your satellites are called "gps launcher". You can change the "GNSSAcronym" parameter in the Figaro Receiver part's part.cfg file from NONE to gps and it will work more reliably. Same is true for you, spacerodent. Just use any acronym that is unique to your constellation. And Kimberly is correct about the need for real GPS satellites to be updated from ground stations from time to Time. I had actually considered adding an advanced mode where the SVs would have to orbit within view of KSC's tracking station every so often, but I haven't gotten around to it yet...

Star Trek, The Crystalline Entity?

Sounds like an interesting idea. Especially the idea of a two stage rocket. It would be fun to see how different the optimal ascent profile is, if at all.

Hi Sidfu! Glad to read you're interested in my mod. For what it is worth, I prefer my online handle to "this guy", but suit yourself... About your suggestion, that was the idea behind adding the FigaroTransmitter part to the mod distribution. You can add the Figaro GNSS antenna array to any satellite you build, just like you would any other part. That way your remotetech satellites can carry a GNSS payload. Alternatively, you could do as KhaosCorp suggests and edit the FigaroTransmitter part's part.cfg file to incorporate the remotetech module. Hi Kimberly! I am afraid I don't understand your suggestion? Can you please clarify?

@Custard Donut (In Space): That sounds like the aforementioned Rama series...

No, I made it backwards compatible for people like yourself. Just look in the FigaroReceiver part's part.cfg file for the "GNSSacronym" parameter. Change it from "NONE" to whatever acronym you use for your constellation.

I just read the paragraph you referenced, and if I understood it correctly, they used exactly the same method that the Apollo capsules did. The thruster's primary function was to orient the entry vehicle heat shield first prior to entry, to stop the cruise phase spin and to orient the re-entry vehicle about its roll axis during atmospheric entry. Precise orientation of the aeroshell about its roll axis was important because it allowed the guidance computer to keep the lift force pointed somewhere useful. The article says that two 75 kg ejectable tungsten ballast masses were jettisoned minutes before atmospheric entry. Presumably it was necessary for the C of G to be on the axis of symmetry during the launch and cruise phases of the mission, and offset from the axis of symmetry during the EDL phase. As I mentioned previously, the offset C of G makes the entry vehicle stable in the blunt-end-forward orientation and causes the aeroshell to maintain a lift generating angle of attack.

The Apollo capsules had their centre of mass offset from the axis of symmetry, as shown in the image below. This prevented them from re-entering upside down because the capsule could only be in one stable orientation (right side up) when the drag on the capsule was aligned with the centre of mass. The slight offset would also give the capsule a small angle of attack such that it would create a bit of lift during the re-entry. The lift to drag ratio wasn't very good (about 0.3), but it was enough to allow for some guidance. Depending on which way the re-entry vehicle was positioned about its roll axis, the re-entry trajectory could be steepened (higher g's, higher heat flux, shorter heat exposure) or flattened (lower g's, lower heat flux, longer heat exposure). Some cross-range deflection was also possible. The "hardcore mode" in my old Re-entry Heat Module and Mk-1 Pod Heat Shields mod used to simulate these effects on the command pods, including the Apollo style "skip re-entry". I retired the mod when v0.19 came out because I didn't have the time to support it anymore and the new Deadly Re-entry mod gave me a convenient exit, but it was kind of fun to play with. Edit: I see that the original Re-entry heating physics model discussion thread still exists. I used the equations that I posted in that thread in my old re-entry heat mod. The discussion may still be interesting to some readers. Note that I eventually incorporated radiative heat transfer effects into the mod's re-entry physics, but as a cooling effect not as a heating effect.

Coincidentally, I watched it last night. Here's the link: Garik Israelian: How spectroscopy could reveal alien life

Just FYI: I was able to upload the latest version of the Figaro GNSS mod (V 1.0.21.01) to SpacePort this morning after N3X15 kindly reset my SpacePort password.

UPDATE OK, so N3X15 got back to me last night. He kindly reset my SpacePort password and I was able to upload the latest version of the mod (V 1.0.21.01) this morning. CHANGES INCLUDE: - Added a new Figaro Transmitter part, created by MrPwner. The transmitter part resembles an array of helical antennas, as shown in the picture below. Add the part to your dedicated GNSS satellites, or to multi-purpose satellites. The Figaro receiver will detect satellites in orbit that contain the transmitter part and will use those satellites to calculate a navigation solution. - Added a "Here" button to the Figaro Receiver's UI. This allows users to set the current location as the navigation waypoint. Users might appreciate this feature when they set out on EVA's that will take them out of sight of their base. - Fixed a bug in the UI that resulted in bad formatting on some computers.