Piscator

You can also see quite clearly in the video that it's only the front half that is tumbling.

Would have got that right. The rescheduling to Saturday fits my personal schedule perfectly but I hope they don't have to postpone it any further.

Or maybe they're afraid of succeeding. A starship drifting out in the ocean might be more trouble than its worth. After all you would have to scuttle it manually somehow. The thing seems to be quite resilient.

I suspect thermal radiation. Planets are slightly warmer than their surroundings due to radioactive decay, retained primordial heat etc so their infrared radiation should be detectable.

As far as I know, the charges worked immediately. It's just that it took the vessel 40 seconds to sufficiently depressurize to finally loose enough rigidity to be torn apart by aero forces.

They also explicitly mention star spots in the article which would be a fair bit cooler still.

As far as I undestand it, there is considerable overlap between both systems. The booster and launch infrastructure is always the same and a dedicated tanker starship would be needed for both mission types as well. At the point when people land on the moon in starship you're three quarters done with the Mars variant of the system as well.

If it's real, the heat shield tiles seem to have held up rather well. At least compared to the engines.

If you're talking about the featureless orange ball on page six, I'm pretty sure that's supposed to be Titan.

There was a discussion about them recently in fusion thread: Point 1) was explained in detail in the videos linked in that thread. It didn't raise any serious red flags for me at that time, but since I'm not an expert either, this probably doesn't mean very much. Basically, using pure deuterium as your source material (since you would be breeding your own He-3) would be a great advantage as you could skip dealing with the expensive and radioactive Tritium entirely. As for point 2), with any claim that seems too good to be true, there is a substantial chance that is. They wouldn't be the first to fake results, attach som blinkenlights to a spool of copper wire and call it a free energy machine. If their project is technically sound though, there's still the chance that it doesn't make economic sense. The devil is often in the detail, and maintaining your He-3 breeding infrastructure might simply be much more expensive than expected.

Pointing out that this drive would violate the third law seems a bit besides the point when the whole thing is based on the assumption that it is actually only a guideline. I think it highly unlikely that they're onto something, but it's at least nice to see their theory tested. No need to argue about it. Just let the universe be the umpire.

Well, assuming your smart cooling system works, you could just add a pair of giant stylish angel wings to your suit to increase the radiative surface. Or you could carry an equally stylish parasol.

Not really. I know that the original poster mainly uses this forum to storm his brain and our input isn't really required, but I guess I'm bored.

That's exactly what I was just thinking about. Space is big and literally contains everything. There's always a place suitable to manufacture a certain product "in space". Unless you specify an approximate region and tech level, the whole discussion is pretty meaningless.

This entirely depends on the technological limitations you are willing to accept in your scenario. All atoms found on earth can be found in space, so there's nothing fundamental keeping you from arranging them as you please. So, yes: everything.

I'm pretty sure scramjets only reach this kind of Isp because they get a large part of their reaction mass for free. After all, when calculating Isp you only have to take the propellant into account that you actually have on board. If you were carrying your own air supply, the number would drop considerably.

It's above the cabin pressure in airliners, so I guess it would be sufficient. There's not really a need to use the ISS standard, is there?

Wait, wait, wait, isn't the advantage of jet engines that you don't have to bring the air along and thus get a lot of your reaction mass for free? Making your intake air from a liquid air storage seems to defeat the purpose and would very likely result in a system massively less efficient than a dedicated rocket engine. Also "generating hydrogen in flight" is a very strange idea. The reason why you use fuel, is so that you have a nice energy storage medium without having to carry the infrastructure around that generated the energy in the first place. Or looked at it the other way round, if you had a sufficiently strong and portable energy source, you could do more efficient things with it than somehow collect water, split it and then recombine it in an engine.

Same thing, really. Whether Triton lost Pluto or Pluto lost Triton is merely a matter of perspective. The important question is whether an event strong enough to separate a hypothetical Pluto-Triton binary would leave Pluto's sub-moons untouched. Since the Plutonian system is apparently rather compact, this doesn't seem completely out of the question and as mentioned, there's always the possibility that Pluto acquired its moons in a later collision event. It doesn't make the whole idea more likely though, especially since there's little evidence pointing to Pluto in the first place. After all, there are more than a dozen objects that pretty much share Pluto's orbital characteristics and there are a whole lot more with perihelia inside Neptune's orbit which would be as likely candidates. And this doesn't even take the possibility into account that Tritons mysterious partner was simply lost or destroyed - either during the separation event itself or during a later encounter with Neptune - which seems far more likely.

At least today, Pluto doesn't come very close to Neptune due to different inclinations of their orbits. Also, Pluto would have had to acquire its current set of moons afterwards as the system wouldn't have survived the encounter. It seems more likely that Tritons hypothetical binary partner met its fate during one of the subsequent encounters with Neptune and was either ejected out of the solar system or inwards where it either disintegrated or collided with another body.

According to my very quick search, further purification involves repeated fractional distillation of volatile silicon compounds. So if you need a second step anyway, it probably doesn't matter very much where your raw silicon is coming from. Especially since this process typically uses feedstock of much lower purity. According to my somewhat more involved search, solar-grade silicon may be as impure as 99.9999%, so the cited "more than 99.999%" might actually be pretty close to being usable without further refining. Apparently, there is also some potential for getting away with even less pure silicon.

I was tempted to interpret "coolest" literally and pick Pluto, but then I chose Earth after all. It's where all the interesting biology is happenening.

Is that a crewed demo of a landing or a demo of a crewed landing? In the second case, you wouldn't necessarily have to have people on board. It would probably suffice to have life support and so on working flawlessly.

Yeah, it looked very different to me in the wide angle view as well. I guess both boosters slowing down so much before touchdown gave me a wrong impression.

I'm not a 100% sure I remember this correctly (well, actually not even 90%), but the difference in timing of the two boosters might only seem more pronounced this time, because they accidentally showed footage from the same booster on one of the previous occasions. The external footage of the two boosters coming down didn't seem much different from earlier flights.