meeper
1783
Plus having a geosynchronous satellite network is just cool.
I’m confused on how to make that excel spreadsheet work, unless I’m actually doing it right. It would appear no matter what I do there will not be enough signal strength with RA-15 relay antennas to go from Duna to Kerbin when they’re furthest apart? Like it would work if I put a whole bunch of RA-15’s for when they’re orbit’s aligned closely, but other than that no communication?
Matt_W
1785
Three RA-15’s will get you there against a level 2 tracking station (Deep Space Network 2). Or just one against a level 3 tracking station (Deep Space Network 3).
A single RA-100 can reach all the way from Eeloo with DSN level 3.
I have Level 2 tracking and don’t have money to upgrade to L3 right now. So if I send a satellite up with 4 RA-15’s I will have 95% coverage at minimum distance and 14% coverage at maximum distance?
I put an antenna on every satellite I launch–often this is required by the contract anyway. It’s not the most elegant solution, but for practical purposes it basically guarantees coverage.
Matt_W
1788
Looks right. Keep in mind, it will lose coverage if Duna or Ike come in between your vessel and Kerbin.
I desperately need a big science boost so that’s why I’m looking to send a probe to Duna before I can upgrade comms or anything else.
Matt_W
1790
Have you been to Minmus? You can put a crewed vessel in a polar orbit of Minmus and collect crew reports until you’re tired of it, then return them to Kerbin for a motherlode of science.
Yep went there but did not do polar orbit. But I did land and take samples and did high/low minmus science.
OK dumb question. For Duna, do all those satellite dishes need to be on the same satellite? Or could I do 4 separate ones around Duna and get the same distance?
Pod
1792
On the same craft.
However, you could launch a few satellites into an orbit between Kerbin and Duna to act as an intermediary, I think? I’m not sure what strength you’d need between that and Duna, however.
You could always just do a Duna flyby and then return it back to Kerbin?
What’s the difference between the high gain antenna and like the Communotron antenna?
Matt_W
1794
Crew reports from low orbit are per biome, so you can orbit and collect a bunch from Kerbin, Mun, and Minmus. Kerbin gives you 5 science per biome (total 55), the Mun gives 15 science per biome (total 255), and Minmus gives you 20 per biome (total 180). That’s nearly 500 science just from crew reports in orbit, and those are 100% transmittable. You don’t have to return them.
It’s relatively easy to take an accelerometer, thermometer, and pressure sensor to Minmus and bounce around to all of its biomes (9 total) collecting science. Returning temp+press+seismic+EVA+crew+surface sample on Minmus is worth a total of 372 science per biome, for a total of 3348 science on Minmus alone.
Matt_W
1795
Range, power consumption, and relay capability. None of the Communotron antennas can relay signals to other antennas. The HG-5 and all of the relay antennas can.
So I’m making a combination relay and science satellite. Do I need anything but relay satellite dishes on this combo deal?
Matt_W
1797
Just a bunch of solar panels and batteries. Each HG-5 consumes about 50 charge/s while transmitting. The smaller extendable solar panels produce a little over 1.5 charge/s while in full sun near Kerbin’s orbit.
How much delta V should it take to get to Duna from Kerbin orbit. According to the nice chart linked further above I had calculated it would be1400 m/s. but now that I’m trying to setup my burn I am way, wayyyy short of fuel. I also used (or tried to) use transfer window planner. I put in Kerbin to Duna and fast forwarded to the day that would require the least amount of fuel.
I really messed up but I’m not sure how.
Matt_W
1799
I’m not sure what you’re seeing, but here’s an example. I’m using alexmun’s trusty online transfer planner, and I’ve set up a transfer from Kerbin 100km orbit to Duna 100km orbit at first opportunity:
Projected total delta-V for the highest efficiency transfer is 1,692 m/s. That’s about what the delta-V map up there shows. (The map shows 950 to Kerbin SOI edge+130 to intercept with Duna+250 to close the orbit+360 to circularize=1,690.) You could actually reduce that by 400-500 m/s if you use Duna’s atmosphere to capture and circularize, but that’s pretty advanced technique.
- Get into a circular, equatorial orbit at 100km (or whatever altitude you set up in the planner.)
- You’ll need to leave at about year 1, day 236 at 4:19am. You won’t be able to get the minute exactly right, but you can leave within an hour of the time it shows. Fast forward to that time.
- Set up a maneuver node with the ejection delta-V shown on the planner. In this case that’s 1027 m/s prograde, 205 m/s normal for a total (geometrically added) of 1047 m/s. (The planner shows the breakdown to prograde and normal if you click on the “i” next to the Ejection delta-V line. I think TriggerAu’s in-game planner does something similar.)
- Set Duna as your target.
- Looking straight down on Kerbin, rotate the maneuver node around your orbit until the escape vector is parallel to the terminator (the line demarcating night and day on Kerbin.) The terminator is always parallel to the direction of Kerbin’s orbit around the sun (because Kerbin’s orbit is exactly circular) and you want to escape in the direction of Kerbin’s orbit to get the maximum boost from Kerbin itself. (If you were going to Eve or Moho, you’d want to escape in the opposite direction to get the minimum boost from Kerbin.) The ejection angle on the planner shows approximately where the maneuver node should be. In this case, 162° from Kerbin’s prograde. So measuring 162° clockwise from the top of the terminator with the day side on the left. But it’s more important that the escape vector is prograde than that the maneuver node is in the right place.
- Zoom out and you should have intercept. If not, adjust the maneuver node in small steps until you do. The arrows showing closest approach should help with that.
I wrote all this up a long time ago on the KSP forums. I’m not sure how helpful it actually is anymore, but you can check it out here. (The images on that post are wrong. They don’t show the terminator correctly.)
I think you can pretty much hit the end of the tech tree with just Mun and Minimus. Duna is cool to go to as I’ve said I’ve never landed there. I always have missions going so I don’t like to warp 200 days ahead.
Another option is to set up science stations around Mun, and Min. The mobile processing lab is 160 tech, you generally get a mission to construct a station after you’ve landed on Mun and/or Min. It is basically the equivalent of the ISS in real life. I recommend putting it on a polar orbit that way you can do a EVA on all the biomes, you may have missed and then you feed the experiments into the lab for additional science. The lab generate science over time generally 5+/day or so with one over each moon you’ll easily get a 2,000 science by the time you get to Duna.
Fozzle
1801
This is easily the way to bust through any Science bottleneck you are stuck on @jpinard. Using a Science lab in orbit around Minmus is pretty cheap and if you stick a couple scientists on there, you will get a pile of science in a month or so…
The Duna transfer window is a little ways off, but I’m ready for it anyway.
On top of a 3-NERVA transfer/relay stage, there’s an orbital science satellite, a lander with drogue chutes for Duna, two landers with no chutes for the moons, and a spare relay satellite for better coverage of the Duna system.
