I was going to be all pissy about how there are more problems than just using maneuver nodes can solve, since there are so friggin’ many different parameters when it comes to planets (particularly if you’re trying to get to Eve, which is off-axis), but I decided to give it another try instead, and I made it to Eve! And then it turned out the landing gear on my probe had disappeared somewhere along the way, so I decided to give it another try with another ship, and that worked, too. And then it struck me that a rover might be a nice thing to have if you’re going all the way to another planet, so then I landed a rover down. In other words, it was awesome.
And thanks for the suggestions. I used the site recommended by Scott Manley to optimize the journey. It’s not a panacea or anything, since there’s no way to measure most of the values they give you with the vanilla version of the game. I ended up doing an awful lot of correction burns en route (as in, anywhere from 400m/s to 1500m/s just to get an encounter, then maybe another 1500m/s to get into orbit and land). But that’s actually fine — like I said before, I’m very generous with my rocket designs.
In preparation for my first interplanetary voyage, I’m rebuilding the mothership I was working on in 0.20. So far I’ve got the forty ton command module in orbit and an extra fifteen tons of rocket fuel. Next is a couple of habitat modules, and then a lander with its own complement of rovers. All up, I expect the vessel to weigh over two hundred tons fully fueled.
How difficult is it to meet in space? It would seem to be very difficult.
How do you catch up to what you’re going after since altering your speed will alter your altitude as well? I read about the first real space dockings being messed up because of the counterintuitive dynamics at play.
I just successfully docked two asymmetrical spacecraft with unbalanced RCS starting in identical orbits on opposite sides of the planet, so if you can do that you can do anything. My method is very simple:
Match destination.
Match Velocity.
Repeat.
Match Destination
Select the other ship as your target and create a maneuver node. Check the estimated intercept. Tinker with the maneuver node until you know what will reduce the distance at intercept. Try to get it within 50 kilometers, then perform the burn. Create a new maneuver node, and try to get the intercept within twenty kilometers, then perform the burn. Keep doing this until you’re down to around one kilometer.
Match Velocity
Once you’re close to the intercept, find the retrograde relative velocity marker on the navball. Burn until your relative velocity is close to zero.
Repeat
Find the prograde direction marker. Burn or use RCS until you’re moving (slowly) towards the other ship. Continue making small burns between the prograde direction marker and retrograde velocity marker until you’re just about touching the other ship. Rotate your ship so that it’s aligned with the docking port and use RCS to dock the same way you’d maneuver a Kerbal on EVA.
For me, meeting another craft in orbit got a lot easier when I ditched maneuver nodes.
If my target is behind me, I put myself into an an orbit that’s around 20km higher. If it’s in front of me, one that’s about that much lower. Each orbit, the distance between my craft and the target at the closest encounter shrinks by the same amount. When the distance between them on the next approach is less than how much that distance will change on the next orbit, I match orbits. Then it’s just a matter of barely raising or lowering me Ap or Pe as appropriate to make that next encounter close enough to begin the actual approach (matching velocities, burning prograde and retrograde, etc.).
Anybody else tried to come up with hyper speed air-breathers? I found that with a proper design and manoeuvering, I could get a speed over land of a bit more than 1880m/s within the atmosphere and be able to skip across Kerbin rather fast.
So I’m rebuilding the space station I was working on in 0.20. I’m trying ways to stop wobble. Last time I tried quantum struts but those introduced some phantom thrust which was probably my fault. So now I’m going to try having multiple docking ports connecting the segments. Last night I sent up a small test vehicle which could split in two, flip over and then dock onto itself using 2 docking ports in each piece. It worked as a proof of concept, but it wasn’t big enough to have any significant wobble. This weekend I’ll send up a couple of large station parts and see how it works on the real thing.
In mean, sheesh, I’m proud of finally having designed an vessel that will get three kerbals to Duna and back (we shall see … mission in progress), and Macey Dean has been launching freaking capital ships to Jool and staging an entirely plausible interplanetary war! :eek:
Started a new save, where I’ll be using the skills I learned instead of randomly flinging crap into space. I put two satellites into orbit so far, one around the home planet and one around the Mun. Going to try to send a probe to the Mun now…
My second Munar orbiter got into LKO more efficiently than the first (I finally managed to do asparagus staging without toppling the rocket - I used the sixfold symmetry tool to position the tanks then connected each one individually), but I misjudged my burn to intercept the Mun, chased it half way around Kerbin and achieved Munar orbit at the cost of 2580 units of fuel.
My first Munar orbiter has returned to Kerbin with a total of 2659.7 units of fuel spent. Still got a way to go before I can try a kerbed mission.
The Mk2 Mun Lander made it into orbit, but I realized I wouldn’t have enough fuel so I came back down. The Mk3 was a revolutionary design (for me): I used 3 stages of engines. First came 5 basic liquid fuel engines to get the rocket into space; then the outer 4 rockets would be shed along with their fuel tanks, leaving the last engine (which had been drawing fuel from them instead of using its own) to get the Mk3 into a proper orbit. Next, the bottom engine would be shed, leaving a much smaller rocket powered by a nuclear engine. The highly efficient nuclear engine uses a small fuel tank to make any corrections to the orbit and then launch the lander towards the Mun. The nuclear engine would then bring the lander into orbit and begin slowing it down; it runs out of fuel about half way down. Then it is shed as well, leaving the final, smallest engine to guide the lander safely onto the Mun. That engine is also used to bring the lander straight up, eventually escaping the Mun’s sphere of influence and being caught by Kerbal; at that point a little bit of slowing action allows the lander to fall back into atmospheric orbit where it can aerobrake and come to a stop.
Sadly, the Mk3 had a fatal flaw: I messed up the staging, so that the nuclear engine fired along with all the other engines. This caused the rocket to explode, killing poor Jebediah. The Mk3.5 made it all the way to the Mun on its first run, though!
I reached Minmus! Huzzah! My Jumbo Lander Mk2 managed to put 3 Kerbals on Minmus. I had an enormous surplus of fuel, too; I dropped the nuclear rocket I use to aim a few thousand meters above Minmus when it was 3/4ths full so that I could get my landing rocket out, and returned home with half a tank of fuel left in my landing gear. I think that the Jumbo Lander Mk2 might make a run for the next planet over as well.
MichaelEMouse, how are those jets working for you? When I try to use jets on my rockets, they spin around and don’t move it at all. How are you able to take off with such a huge ship using those jets? (My Jumbo Lander, for example, uses 5 Mainsail rockets).
They’re working pretty well. I either 1) shoot straight up, ditch the jet engines and coast until I fire the rockets or 2) go straight up to 10K, start picking up horizontal speed up to 1000-2000m/s at an altitude of 20-40K then ditch the jet engine(s) and shoot straight up with rocket(s) until my apoapsis is comfortably above the atmosphere.
I make sure the jet engines are linked to a jet fuel-only tank. Then I give them plenty of air intakes. The spinning can usually be dealt with the SAS computer and gently-ish handling.
As for how I’m able to take off: There are 16 engines with a theoretical power output of 225 Kn. In practice, on take-off, they usually output something like 110 Kn each. That means 1760 Kn total thrust.
If we divide that by the speed of gravity on Kerbin and the weight of the ship, we get a power to weight ratio of more than 2.50 which is amply sufficient to take off and results in rather fast vertical acceleration. I’ve made ships of a little more than 11 tons take off vertically with just 1 jet engine. It would be possible to cut down the number of jet engines to 5 or 6 and still make the same non-jet engine stages take off.
I used the site recommended by Scott Manley to optimize the journey. It’s not a panacea or anything, since there’s no way to measure most of the values they give you with the vanilla version of the game. I ended up doing an awful lot of correction burns en route (as in, anywhere from 400m/s to 1500m/s just to get an encounter, then maybe another 1500m/s to get into orbit and land). But that’s actually fine — like I said before, I’m very generous with my rocket designs.
