The Great Ongoing Space Exploration Thread

So it looks like a new interstellar object has been detected. I think we’re going to see a lot more of these now that detection technologies are progressing so quickly. This thing is moving FAST - the sun barely makes a dent on its trajectory.

As long as it doesn’t go through the Sun largely undisturbed we’ll be ok.

Anything able to do that undisturbed pretty well guarantees the Sun will be massively disturbed. Sux to be us.

I’d be interested to know what such an event would look like. A11pl3Z is minuscule compared to the sun.

~20km diameter @ ~68km/s sun-relative speed. A teeny drop in a big bucket.

Assuming a direct straight line path to impact, it’ll spend about 12 days inside the orbit of Mercury. Whether rocky or iron, it’s gonna lose a lot of mass to melting & outgassing. If instead it’s a cometary iceball, it’ll be nothing but rapidly slowing gas long before it gets to the photosphere.

I was making allusion to a magical maybe black hole sorta thing that kicked off Seven Eves. But this version would have a much shorter story arc.

Sorta depends on what you think of as “through”. Passing just inside the photosphere wouldn’t be a big deal. Successfully passing through the center of mass would be more interesting.

Yeah.

Anything with the 'nads to pass through the core of the Sun at ludicrous speed & come out the other side in recognizable condition is going to leave a very disrupted star in its wake.

Interesting indeed.

I’m reminded of the ST: TNG novel “Vendetta”. A second Doomsday Machine planet eater turns up. At one point it flies into a star and everyone aboard the Enterprise presumes it has been destroyed– until it flies out the other side.

I hate it when that happens. :wink:

It would probably be ok if a small enough black hole passed through the Sun at a high enough speed. Getting trapped would be bad. And a large black hole would obviously be bad. But it’s possible there are primordial black holes (ones formed in the early universe) that could be small enough to not cause much damage and fast enough to pass through completely. Wouldn’t want to bet on that, though…

Red sprite seen from orbit:
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Imgur

There’s now a dedicated thread …

Any news out of SpaceX on what they’re going to do about Starship? They can’t simply keep launching vehicle after vehicle only for it to always end with upper stage fire, loss of attitude control and RUD. Anything publicly available yet on how they expect to solve this?

It’s different issues each time, so there isn’t going to be one magic solution. The latest was a COPV (pressurized tank) failure. No real news on that except that it failed at much lower than its rating. Somewhat reminiscent of the AMOS-6 failure except that the tank wasn’t immersed in a cryogen.

The question, to my mind, is whether this is genuinely just a string of bad luck, or symptoms of lax management at Starbase. There were some rumors of COPVs being mishandled there, with complaints to management being ignored, but it’s hard to know what to make of those. The reality is usually more complex than what you get on the outside.

Regardless, they can in fact keep this up for quite some time. The Falcon 9 still has a tremendous record, and Starlink/Starshield bring in plenty of cash.

I’d hope that the new factory also helps with the quality control. Maybe some of their quick-and-dirty approaches are catching up with them as the design becomes more sophisticated.

Raptor 3 should help as well, but it’s not in full production yet.

An interesting question. Who actually came up with the reusable starship concept… was it actually Musk or some engineer behind the scenes?

And who decided that stainless steel was the appropriate material to use?

One begins to wonder if they will have to eventually concede that the concept was overambitious?
I really hope not… only time will tell…

They were originally going to use graphite composite, but switched to stainless steel. Stainless steel is a very mature technology with very well understood engineering properties. It’s more heat resistant than aluminum and conducts heat less, reducing cryogenic boil-off. It’s stronger by absolute cross section, which for a large enough rocket when the tankage has to be thick and strong anyway doesn’t impose an unworkable weight penalty.

Early 20th century science fiction.

May well have been a good decision. I just wonder who made it?
As you say though, is even stainless steel going to get us through the re-entry problem?

True, Heinlein et al had tail-landing spaceships.
But it’s not called science fiction for nothing.

That’s the billion-dollar question. Reentry from orbit has been the single biggest hurdle facing reusable rockets since the very dawn of the space age. It doesn’t help that SpaceX hasn’t even gotten to test its thermal protection lately because few of the upper stages have made it that far. The ones that did slashed down in one piece but too damaged to have ever been reused.

Impossible to really answer coherently. Musk has been talking about some kind of BFR since before the Falcon 1 even flew. It would have been a sort of scaled-up Falcon 9, with kerolox Merlin 2 engines. They moved on from that to various hydrogen-based designs (predecessor to Raptor engine) before deciding on methane. They went through several major design changes, going from a 12 m diameter down to 9 m, and of course changing from composite to stainless steel.

The various changes undoubtedly came from a variety of sources. Musk would have made the final decision on all the major ones but only after engineering discussion. He’s mentioned a couple of examples where he started off skeptical on something or other but the team convinced him otherwise.

If we start seeing stripped-down upper stages, with no tiles, no flaps, etc., that might be a sign that they were too ambitious. Not seeing any evidence of that yet, though.