sevenperforce

If the planet is rotating, you have to factor in the Coriolis effect. The tangential velocity of the surface of the spherical planet is larger than the velocity halfway down, which is larger than the velocity 2/3 of the way down, and so forth. If dropped, the ball will maintain its tangential velocity, and it will strike the side of the tunnel at a point which can be trivially calculated by the diameter of the tunnel, the diameter of the planet, and the rate of rotation. Side note: if the Earth were suddenly to be collapsed into a black hole (which, FYI, would have an event horizon slightly smaller than a dime), all the objects on the surface would find themselves at the apoapses of highly eccentric orbits around that black hole. Don't recall exactly what the periapse would be, but I'm guessing about 50-100 miles from the center, for observers at the equator. Observers at higher and lower latitudes than the equator would be in more eccentric orbits. But @Green Baron is right; IF the planet is not rotating, then the moment the ball drops into the shaft, it begins to accelerate at a decreasing acceleration. The further it falls, the less planet there is below it and the more there is above, so the magnitude of the acceleration vector decreases. Once it passes the center, where the forces on it are momentarily zero but its speed is at a maximum, it begins to slow down because the acceleration vector has reversed and started to go up again. Its oscillations will continue indefinitely unless an additional force, like friction, comes into play.

Pretty sure it is allowed; I think several people have done that.

STATIC FIRE DAAAAAAAAAAAAAAAAAAAAAAAAAAAY

Confirmation of a 15 second static fire.

I've been working on this as well. A couple of things to consider: For optimal drag characteristics, your prop should be able to deploy between a minimum and maximum pitch so you can light up your engines while you're still in-atmo. The Dart has only 6.3% better ISP than the Skipper, but the Skipper has 20% better TWR and gimbaling, so the Skipper (perhaps paired with a couple of LV-Ns) might be a better option for main propulsion. The Rhino beats both, but it may be too big for your purposes, depending on the size of your propeller. If possible, your propeller should use a bearing mechanism that can be reattached in orbit, so you don't warp and lose it, and so that it can be refueled and sent back down for another trip. A pair of small docking ports might work if you fire a pair of Spiders to push the ports back together.

It would have to be on/off.

Oh, I understand that his first sentence was fiction.

Oh god what a lovely quote.

@Ultimate Steve's scoring system automatically works in points for returning to Kerbin. It awards one set of points for orbiting, one set of points for landing, one set of points for getting back to orbit after landing, and one set of points for getting back to Kerbin. So under his system, allowing double points for a double (non-sequential) visit to the Mun, I'd score 160.

Do I get credit for landing on and reorbiting the Mun twice? Also, I DID land back on Kerbin without difficulty; my computer just glitched and I don't have the screenshots.

Ridiculously impressive!

Shoot, I should have caught that. You should ask @Ultimate Steve if you can borrow his scoring from the One Life challenge. It's closer. Speaking of which, he still needs to put me at the top of the leaderboard. Speaking of leaderboards, how would you score it if, perhaps, I went to Duna, Eeloo, and Moho, in one launch, without decouplers?

The part which landed got into a suborbital spaceflight by itself, but it was not a single-stage-to-orbit. As it turns out, @Kergarin HAS demonstrated an Eve SSTO, albeit made possible only by ISRU and pinpoint landing on the very highest peak of Eve. But that required spending a tremendous amount of fuel just to slow down and land. I would be truly, ridiculously shocked and flabbergasted if someone managed to go from Eve orbit to the surface, and back, without staging, docking, or ISRU. Let alone having enough fuel to land anywhere else. But hey, if you can do it....

Uses ISRU, and not an SSTO.

How's this for unconventional staging? All decouplers are replaced with cubic octagonal struts. For "decouplers" with engines on top, no additional help is necessary. For decouplers not topped by engines, like my single-seat ion lander and the final staging, three Sepratrons with only a tiny bit of fuel fire to blow up the strut and break off the part. For side-mounted stages, decouplers are still cubic octagonal struts, but the Sepratron is clipped into the discarded booster; it thus also acts as a sep assist motor. Took this bad boy to Munar orbit, "decoupled" my ion lander, EVA'd over, hopped on the ion lander and went down to the Mun and back up again, EVA'd over to the mothership, went to Minmus, came back to the Mun with a Kerbin gravity assist, did a rendezvous with the ion lander, went BACK down to the Mun with the remaining xenon, ran out of fuel 30 m/s before impact and bounced to safety after lithobraking my engine, EVA'd into a suborbital trajectory, did a suborbital catch with the mothership, and came back home to Kerbin. Individual staging events are not particularly easy to see, but here's what it looks like. Decoupling my lander. Coming down to the Mun. Who indeed? Landing on Minmus. Wise words. Rendezvous with the waiting lander. Landing. The suborbital catch. Then it was homeward bound!

NTR releases potentially radioactive exhaust. Even if it's just a few irradiated hydrogen atoms turning into tritium by neutron capture, it's still a release of radioactive material. A reactor does not release anything, and I do believe the reactor flew before the test ban treaty anyway.

Go for it.

Can you post a more specific scoring system? Because I can go really, really far.

NTR potentially violates the Nuclear Test Ban Treaty. But yeah, there's no reason to keep it secret and we don't need it anyway. Note that she didn't say Zuma was a success, only that F9 did everything right.

Someone is still going to find out about it at some point.

Save early and often!

Then you should re-read the OP: "At no point can any parts explode, break off, or otherwise leave your ship."

One visit per celestial body; no one wants to see a ship land on Gilly 400 times. And no, ISRU would be refueling; no refueling allowed. Doing it without refueling is the really challenging part, here; how do you budget, and what order do you travel in? If you're using bipropellant auxiliary engines for extra thrust at Tylo, for example, you'd want to visit Tylo first so as not to lug that heavy oxidizer all around to all the other worlds...yet if you visit the other worlds first, your Tylo vehicle will be lower-mass and so you don't need to have as much dry mass. I don't doubt people can land on Eve. I doubt people can leave in an SSTO. Added new bonuses!

If the sat carried its own kick stage for GTO insertion, it could go do eavesdropping spysat stuff. But if it launched with a sharp inclination, this is unlikely.

Testbed NTR would be in violation of treaties. An orbital weapons platform would be in violation of even more treaties. The US government does not have a need for an nuclear thermal rocket which would be sufficiently significant to violate treaties in pursuit of it.