Geometrian

Something Is Very Wrong With This Picture

After a series of incredibly dumb failures exploring the Jool system in career mode (ranging from not executing landing burn soon enough, aerobraking too hard, running out of fuel, time warping fails . . .) I finally decided to get it right. I was at my first destination, Bop, and had lowered my orbit nice and low--so low that it required 1x time warp (I believe this is significant). However, it was in a perfectly reasonable, stable orbit. I had to orbit just a half orbit more, and figured I'd switch to the KSC and warp ahead. But when I looked in the planetarium, I couldn't find my beautiful spaceship. It had been eaten! --- I believe the relevant factor is the altitude. The orbit didn't intersect Bop (and the ship disappeared exactly when I loaded the KSC), but I had been switching around just fine at higher altitudes before.

I have discovered something interesting: if you enable infinite fuel, jets work in space. They have around 1kN to 3kN thrust.

The important thing here is that the jet is at full thottle. It's relatively simple to get low thrust just by setting everything lower (for example see the spoiler). I have clarified this in an edit.

Challenge: Using only jet/turbojet power, what is the highest apogee from Kerbin you can get (stock parts and stock aerodynamics)? My current record . However, I'm kinda betting that it might be possible to get escape velocity by using more jets.Because of this, I'd like to split this challenge into two categories: Using only one jet/turbojet Using any number of jets/turbojets Your craft does not have to be an SSTO, but all power in each stage should derive from jets. Bonus: if escape velocity is indeed possible, can you get interplanetary travel using only jet propulsion? A one-way trip would be impressive enough, if only for the required precision alone--but maybe you can, for example, get to Laythe and back using only jet power?

Challenge: achieve the lowest possible thrust from a turbojet without flameout (stock parts only and stock aerodynamics). Here's my record 3.9kN: Additional rules: Thrust must be computed on the upward part of the trajectory (+/- maybe a few seconds). This is because when reentering, thrust can be made arbitrarily low without flameout Your craft should use only the turbojet (or turbojets) to reach altitude and speed. This is mainly for a similar reason. Obviously, throttle must be full open.

I've noticed that KSPInterstellar exaggerates the problem. Here's an attempted SSTO burning blue: I've noticed that in this case, the engines power off automatically. I believe this is KSPInterstellar's doing. The exact same aircraft without it doesn't overheat. Though, it doesn't get to orbit; for that you need this:

Landing on Minmus with a jetpack is a . Get a ship in low orbit, then jump out and thrust backward. Minmus's low gravity (0.491 ms^-2) and relatively fast rotation (11h 13m 20s) mean that the relative velocity of landing on the surface isn't much. Getting back into orbit is easy if you time the rendezvous intelligently. I've contemplated going twice in one run.Landing on Ike, though . . . They said it was impossible. Technically, it is. Ike has well over twice stronger gravity (1.10 ms^-2) and a slower relative rotation (18h 11m 58s). The lowest energy stable orbit I got was 325m/s relative to the surface. Since a jetpack only has 600m/s dv and crashing a Kerbal at >50m/s to make up the difference doesn't sound survivable, well . . . This all occurred in my Duna mission, whereupon it was realized that fulfilling both contracts (Duna and Ike) at once wouldn't work with a one-time lander. After getting into orbit around Ike I got an idea: stop the ship. Just bring the ship to a dead stop over the surface, drop the kerbal out, and then accelerate back up to orbit. Switch to the falling kerbal and use the jetpack to break the fall. Land and do all the science. Getting back to the ship is much harder. You need to jetpack upward, and simultaneously stop the ship exactly so that the altitude, speed, and position all match. Stopping the ship means of course that as soon as you switch to the kerbal, the ship will start falling. In practice, though you can boost upward periodically to compensate, the timing tolerances are too tight to also control the kerbal to a rendezvous--and altitude loss is unavoidable. So, you'll get a hair-raising near-surface rendezvous, after which you immediately blast off back into orbit, just seconds before slamming into the ground. The difficulty here is managing the actions of two different vessels, one without a HUD to tell you where to go. I succeeded after several tries, although it could be easier with a different ship. Also, I lost all the science due to a bug

Eh? Actually, since the thing rides close tolerances all the way up, it takes both a lot of skill and concentration to power the ascent, which, since the gravity turn doesn't happen in atmo, is briefer than a chemical rocket. Good question. I meant monopropellant-power only. It has lower specific impulse, which is why it's difficult. Compare the O-10 (290s) and the RV-105 (260s) best case versus e.g. Mainsail (320s) worst case. Generally the difference is more like 50%-100%, which starts hurting a lot for a SSTO.

It could be either. The body need not completely occlude the other. For example, annular solar eclipses. At the scales dealt with on Earth, people tend to use "eclipse" for sun/earth/moon events and "transit" for sun/other-planet/Earth events. Speaking as someone who knew the difference IRL, but still screwed up, I think it's just that "Lunar Eclipse" makes sense as an event involving the moon, so it's the first thing people think of. "Solar eclipse" IMO is sortof an unfortunate name.

Gack. Yes. I said "Munar Eclipse" to differentiate it from a "Minmusar Eclipse". It's not a problem on Earth since we only have one moon. I suppose such a culture would have to find new terminology. I think "Kerbolar eclipse of the Mun" is the best solution.

I was just about to launch a 100% ion SSTO (which on further examination, actually wasn't). When dawn came, I got the most picturesque Munar eclipse ever:

Nope. My install is entirely stock. Not even MechJeb. Put three Rockomax 24-77 engines spaced around a turbojet output, angled two "SHIFT+W"s inward. That makes a fairly stable example for a turbojet.It's also possible with a standard jet engine:

After a SSTO was destroyed at a critical moment, I reproduced the problem: overheating. It turns out that overheating jet engines glow blue (which makes some kind of sense, but I didn't realize was implemented): I hadn't seen anyone notice this before, but I thought it was kindof pretty. The small rockets are angled toward the jet; the screenshot was taken a few milliseconds before the jet exploded.

I had a goal of making a SSTO using only RCS thrusters. No rockets. No jets. No ion engines or sepratons for a boost even. I failed miserably, but today I decided to have another go. I succeeded, and the result is essentially just some on the larger RCS tanks stacked on top of each other. This seems to be semi-identical to the very few other success stories out there. Here's the .craft file, in case anyone's interested. Directions included. The title is a bit of an exaggeration; this one can get to over a 200K orbit, so it could do a 100K orbit and deorbit easily; early versions were not so lucky. Bob, you will be missed. Anyone make an actually elegant RCS SSTO?