Piscator

According to Wikipedia there seem to have been at least four distinct periods of mountain-building (and subsequent erosion). So while some of the rock formations are indeed over a billion years old, the process that created the actual mountains (as in something that can be seen rising above the surrounding area) happend only some tens of millions of years ago. At least, that's how I understand it from my casual read.

Not in a hurry, indeed. The ISS's solar panels have a power output of about 240 kW in direct sunlight. 50 Starlink Gen 2 ion thrusters (you can of course choose any brand you like, but I thought I go with something you might have 50 spares lying around somewhere) need about 210 kW and have a combined thrust of 6.5N (according to Wikipedia). For a mass of 450 metric tons, this translates to an acceleration of whopping 14.4 µm/s² or 1.25 m/s per day (so no worries about structural integrity, yay!). Since a trip to the moon requires a delta-V budget of about 4000 m/s you'd arrive in somewhat less than 9 years. This obviously ignores the mass of the required fuel and the fact that you would only get about half of the power output while still being in earth's shadow periodically. So better assume a decade, I guess. Speaking of fuel, with a mass-specific impulse of about 25000m/s for the engine of choice, we get a wet to dry mass ratio of ~1.17 for this trip, by the way. This translates to 78 metric tons of - in this case - argon, which doesn't sound that bad actually.

I was doing some quick back of the envelope math, fully expecting to kill the international space zeppelin idea right there, but the basics seem to check out. The ISS has a mass of about 450 metric tons. Helium has a buoyancy of about one kilogram per cubic meter at standard conditions. Therefore, you need about half a million cubic meters of helium to balance the mass of the ISS. This is equivalent to a sphere with a diameter of about 100 meters, which fits the dimensions of the ISS nicely. It's also well within the available helium budget of the world and would just cost about 10-20 million dollars (if I read the pricing information correctly). So absolutely doable. Right? Right ..?

That's gross.

Would the FTS even work while not in flight? I was under the impression that the aero forces do much of the actual destruction when it's triggered. (But then again, they might have installed a 'float termination system' as well ;).) That said, I would assume they have to send out a crew anyway. If not to make a visual inspection of the hardware before scuttling it, then at least to check if the self destruct worked properly and it is indeed sunk.

Seeing how little the flaps were used (and how little of the flaps was used at times), I wonder if you could get away with just using attitude control or some kind of grid flaps.

Not quite sure what you are referring to, but there's a nice shot of what remains of the heat tiles along the edge of the flap at 01:05:52. PS For context: replying to JoeSchmuckatelli

It will be interesting to see how accurate the predictions will turn out to be. Apparently we only have good observational data for the last two events, which is surprisingly little to go on.

Well, no "giant dot in the sky" then if you prefer to be needlessly specific. The point I was trying to make is that, while the event is certainly rare, cool and something to watch out for, it's still something you might very well overlook if you wouldn't know it was there.

It's also not exactly expected to be giant. More like something of the magnitude of Polaris. Which is a lot, considering it's usually about magnitude 10, but not quite enough to put the sunglasses on.

I would love to see missions like these. Your timeline might not work out though. I have no idea when Jupiter would actually be in a suitable position for a gravity assist, but to launch probes in two opposite directions you would presumably also need Jupiter in two roughly opposite spots along its orbit. So it would seem more realistic for your "second" mission to launch in 2036 (assuming your launch date in 2030 for the first mission works out), three years after the "third" mission.

Let's try to avoid steering into ad hominem territory, but so far problems with the Raptor engine seem to either originate from side effects of being struck by debris, likely issues with the fuel supply or not being started up at all due to faulty attitude control. I don't see how testing the engine for minutes instead of seconds would solve these issues, since Raptor seems to be quite reliable once it's running.

Repeating that something is a mistake over and over again doesn't make it a mistake though.

In fact, the main form of propellant you lose is the bombs. Which, as has been pointed out, are used very inefficiently.

I guess they could try it, but they would end up with a bunch of satellites with reduced life-expectancy (very reduced if they don't dispense properly). I'm not sure that's a good deal.