TL,DR; use 'tonnage payload in orbit' as a kind of checkpoint or progress unlock. Hi KSP community, I would guess this could be implemented as a mod, but it's been something I've felt is missing from the stock game ever since I started playing career mode and think it would make an awesome addition. Your thoughts and feedback most welcome - and if you know of something similar already in the works, I'd appreciate a link as I haven't found anything. Sometimes launching a new rocket design is fun and exciting (for reasons we all know and love) but other times I find it tedious and boring, especially if the whole thing gets krakened for no good reason, or I have to launch 5 almost-identical things in to orbit for a construction project. Also we are currently bound to something like 100,000x speedup which is pretty super, but still boring to wait through. In addition we have to deal with the orbit altitude restrictions to apply this kind of speedup, especially as this only applies when there is an active craft rather than anything that would be accepted as 'on rails' as in the map view. So to start with the basics: If I get 60t in to orbit around Kerbin, save a state Where orbit is as defined in career mode, possibly quantised (e.g. rounded to 0* equatorial orbit, 45*, -180*) as these take different amounts of dv The 'payload' is the remaining vehicle minus the current stage ('launch remnant') The save would include the launch remnant parts and resources state The save also includes (for career mode) the cost of the launch so far, minus the cost of parts in the payload If I get 90t in to orbit around Kerbin, save another new state If I get 90t in to orbit around Kerbin (where something like the value of the parts discarded minus the value of the current stage) is less than the current 90t Kerbin orbit, update that save state. i.e. if you find a way to build it cheaper, or have a better launch procedure and end up with more fuel onboard in orbit, use this rocket instead! Of course, some quantisation, possibly non-linear, may be needed here as well e.g. 5-10t, 10-20t, 30-50t etc... Alternative is, for simplicity, the new 90t save also overwrites the 60t save, but this would mean as you build bigger rockets it becomes very expensive to launch a tiny probe, for example, so I would keep the quantisation. [*]When I go in to the launch window (runway or launchpad) I can pick from a list of unlocked planetary bodies, and from them an orbit and payload. This filters the remaining vehicles by tonnage. At this point I can launch without the remnant, i.e. spawn my craft in the saved orbit. I perhaps lost some dv, but save a lot of time and effort. The payload is a limit, so anything less is acceptable (e.g. if I can launch 90t, I can put say 60t on that rocket. If I had a 60t rocket save, it may be more efficient money-wise to use that instead). The launch costs at least as much as recorded by the save [*]Alternatively, when building in the SPH or VAB, I can select (much like submodules) an existing launch remnant on which to start building, for a particular orbit/payload. The remnant cannot be modified in any way The total mass of parts/resources attached to it cannot exceed the existing payload limit Launching this rocket is locked to the orbit/payload as in 4 (i.e. lower payloads are allowed) Extra things: Aero fairings vs non-aero fairings and payloads - this could be accounted for e.g. by only allowing modification of stages contained within fairings, though is a bit of a fun/realism tradeoff. Potentially use the mission duration to forward time. Store current mission duration on save, and then skip time forward to deploy the new vehicle. Or perhaps store a future, such that when that time is evenutally reached, your vehicle arrives. Another fun/realism tradeoff. Durations and timings etc mean that for optimal DV usage often one might wait for perfect planetary alignment etc, such that a later deployment *should* cost more dv. I don't think it is worth enforcing anything regarding alignment or distance etc on load as this would somewhat limit the usefulness. Duna orbit implies Kerbin orbit, and we can infer this knowing the DV map for the solar system. Fun/realism again, I think it's reasonable to have to make at least one complete mission to each planetary body before being able to spawn stuff there. Career mode could pick a sprinkling of orbits and payloads as paid contracts. I would be content with ignoring points 5 and 1.3 since they add a lot more work relative to the functionality, but it would increase realism somewhat and makes more sense if you have to stage just before making orbit (i.e. you have loads of fuel left in your launch remnant ... also makes more sense for SSTOs etc). Perhaps for some kind of hard mode, variations could be applied, e.g. your remnant may randomly have slightly less fuel, or maybe the whole thing occasionally blows up, or maybe the launch cost is scaled by some amount so it's usually more expensive than flying it yourself. This checkpoint system actually encourages further attempts to better your progress, whether through better piloting or by using newly unlocked parts, without making it a necessity. So, will this idea burn up on entry? - Solderflux