Gryphon

I just completed my toughest rescue in KSP. I am very proud of managing to get this screenshot with Bill alive and well on the surface of Kerbin: Here's how he got there: I started a new Hard career mode game for the new version of KSP, 0.25. I am using multiple mods including, but not limited to: TAC Life Support Deadly Reentry Remote Tech 2 FAR Kerbal Engineer Redux No Mechjeb So, I sent Bill Kerman on the first mission to the Mun. It's early, so I don't have solar panels or fuel cells, but I do have batteries, so I packed a bunch on his ship. My mistake was counting on using the rocket engine to charge the battery each time I burned. I overestimated how much it would charge. A lot. I believe I needed about 3X the battery capacity on board. So there I am, with Bill 90% of the way to the Mun, and that's when I figure out that I won't be able to charge the batteries enough with the remaining fuel to do the mission. The ship was close to a free return trajectory, but then I figured out that it would take far too long to get back home that way. So, I refigured for a direct abort. It would be close, but Bill would go about an hour and a half without power, reenter, land, and recover with a few minutes to spare. On the way back, I burned all the fuel, both to return faster and to build up charge to keep the heater running. Then I ran into another problem. I realized the trajectory was not deep enough in the atmosphere to slow him down enough to reenter in a single pass. Normally, this would be OK; the trajectory would just take him around one orbit and drop back down, so he could just go around and reenter successfully the second time. In this case, though, he would have been out of power for over two hours and be dead. OOPS! The good news was that his flight path would pass over KSP before he would run out of time. RESCUE MISSION! I quickly modified an existing ship with a probe core and an antenna, and launched it to rendezvous with Bill's dead ship. Of course, I needed to make rendezvous while the rescue ship still had line of sight to KSC, since I don't have any relay satellites yet. (As Bill's time ran down, I may have sent Bill on an EVA to make sure he would survive, since it appears that TACLS has a different countdown for power loss when you go EVA, even from a ship that is without power.) I launched, made several quick orbital adjustments, and I made the rendezvous, just as the rescue ship went over the horizon from KSC. (Using RemoteTech, remember?) Bill transferred over, and all was well...OR WAS IT? (I realized a little too late that Bill didn't grab the science data when leaving the dead ship. As I maneuvered the rescue ship for another rendezvous, both ships started reentering the atmosphere and were losing altitude pretty quickly, so I dropped that plan.) As Bill's rescue ship was heating up on reentry, I realized another problem known as NO PARACHUTE!! See, the ship I had QUICKLY modified had a nosecone parachute, which I removed to place the Stayputnik (the only probe core I have available). When I removed the parachute, I hadn't added a replacement. Bill wasn't doomed yet, though. I set up the rescue ship with both a high TWR and a lot of delta V, to ensure it could make orbit and the rendezvous quickly and sloppily if necessary. At this point, it still had a fair amount of fuel left. So, I just waited out the heat, let air resistance slow down the ship as much as I dared, then I started burning to kill the last 200 m/s of delta v. and... BILL MADE IT! It was a clean landing and nothing broke. What I didn't realize until AFTER he landed was that the ship had juuust a smidge of fuel left when he set down; just 38 m/s of delta v. So, that's what made this my Toughest Rescue.

Yes, that's what he is talking about.

Return all the waste to KSC, of course! (possibly at high velocity)

Hey, just a note, I just got freaked out a bit: In the first post, there's a big red link, "v1.2 release notes, please read before installing." So, I follow it, and I read the following, also in big red text: "...Also please note that this will break all currently in flight vessels..." I was freaking out - until I finally realized that the link points at a post from the release of v1.2, way back in July, and that the v1.2.5 release post (from 7 Oct) doesn't have that big red scary text. If I am correct in understanding that v1.2.5 won't break in-flight vessels from a v1.2.4 install, then perhaps that could be made clearer somehow? (I understand there still might be someone who is just now upgrading from a pre-v1.2 install, but for the rest of us, perhaps something updated is in order?) Thanks!

Um. I may not have fully tested the electrical consumption without a charge from the panels, and I forgot that KSP doesn't spend electric when you are not focusing on that vessel, so when it looked OK, I thought it was OK. I'd rather pretend that it works the way it should, so I checked it out: The good news is that it's only 20 minutes of Kerbin shadow at keosynchronous equatorial orbit. The bad news is that with the full 210 EC available, the satellite batteries last about 1 minute with all antennae active. In the dark, the sat with all antennas up drains the 210 EC in about 1 minute. HOWEVER, with the dishes turned off and just the omni antenna active, the sat has enough power for continuous operation without input from the solar panels. The Kerbals COULD keep re-aiming dishes to different parts of the network as sats go in and out of shadow, and it would work OK. I'd rather have enough power to get through shadow periods, though; in my mind, constant switching is a recipe for losing unmanned craft, when you forget to retarget in the correct order and lose control of the satellite. (In the version more real than RemoteTech, you could just use a really large dish like Arecibo and still contact the satellite, like they did, for instance, with ISEE-3. But I digress.) If my math is right, then I need more power or more battery for that shadow: 5 more PB-NUK's or 4300+ EC of batteries. BUT WAIT, THERE'S MORE! There are also Munar shadows to contend with. A craft will stay in the Munar shadow the longest while it is out on the limbs of the orbit, going directly toward or away from the Mun. This could be 8+ minutes. At those points of the orbit, the batteries should be recharged sufficient to handle that amount of time (I think). However, if the craft encounters the Munar shadow just before or after the Kerbin shadow, it will still be an additional 4 minutes or so of discharge time. That adds up to 5200+ EC required. So, thanks for the heads-up; now I get to fly ANOTHER mission to each satellite! Edit: Oh, hey, the Universal Storage guy made a spreadsheet for figuring this stuff: http://www.kingtiger.co.uk/kingtiger/wordpress/2013/11/20/kasa-power-requirements/

(I am using RT2, TAC life support, FAR aerodynamics, and Procedural Fairings, among other mods not relevant to this.) Here is my keostationary equatorial orbit comsat network: I named each satellite in the network based on the position of the sun from KSC towards its location: Sunset, Twilight, Midnight, Predawn, and Sunrise. The apparent gap in the network is intentional; the ground-based antennae at KSC cover that part of the sky. Note my pre-positioned Kerbal retrieval ship in LKO. While it is on the opposite side of the planet from KSC, it has a short window when all the KEO Comsats are simultaneously visible, as shown here. The links going offscreen are to the Munar comm network, currently being deployed. KEO Comsat, first wave of deployment (2 sats). Each sat has an interplanetary-range dish, a shorter range dish for long links in the Kerbin SOI, and the largest omni available, intended for links to Kerbin, LKO, and the rest of the KEO Comsat net. I also included a Clamp-o-tron jr. on the aft end for refueling or expansion. After it was in operation, I decided it the sats needed an RTG for auxiliary power, so I brought extras along for the first wave sats when I was deploying my second wave of KEO Comsats. KEO Comsat, second wave of deployment (3 sats). Similar to the first wave, but I unlocked the biggest dish, and more is better, right? These also included the PB-NUK on initial deployment. MSEO Comsat (3 sats). I am currently deploying three equidistant comsats to semi-synchronous equatorial orbit around the Mun. Each has two dishes to link back to two separate KEO Comsats, and an omni to support Munar ops.