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[Il Palazzo]

It can't be dark matter, as in made out of those hypothetical weakly-interacting particles, because it being dark implies not being able to clump.

[EuchreJack]

I was meaning Dark Matter more in the "Humanity is too primitive to understand" context.

[King Zultan]

Planet X sounds like the prefect place to go for vacation, let's gather all the people we hate and send them there on an all expenses payed trip!

Also why isn't Pluto show on maps of the solar system anymore, I mean even though it's a dwarf planet that doesn't stop it from being a planet, it's just a small one.

[Starver]

Also why isn't Pluto show on maps of the solar system anymore, I mean even though it's a dwarf planet that doesn't stop it from being a planet, it's just a small one.

The answer's in the question. It's not a planet because it's a dwarf planet, in the current system.

If you show Pluto at all (either for legacy reasons or possibly just pure sympathy), by all rights you should also show the near-dozen others (currently known) of its class. Or at least also Eris (larger than Pluto), and/or Ceres (the first such body discovered, being also numbered "1" in the "minor planet" listings, which includes pretty much anything identifiable orbiting the Sun (or co-orbiting the Sun with another body) that is not a definite planet or a moon or a comet or effectively just dust), and/or whatever else makes it more worthwhile to show than Pluto itself.

[jipehog]

I was meaning Dark Matter more in the "Humanity is too primitive to understand" context.

Speak for yourself, I am developing the theory of everything What is in common between the forces behind dark matter, the illusive Planet X and our bearded friends? they are all small and mysterious. And where else would they be if not in the midst of the interstellar alcohol cloud stockpile. Worst of all we don't even realize that universe is suffering from late game lag.

[EuchreJack]

... that's why yesterday's one day of work feels like two.

[jipehog]

European space agency is about to lunch a mission to Jupiter's icy moons including Europa, Ganymede and Callisto. Apparently they have one second launch window

... that's why yesterday's one day of work feels like two.

You are on to something, Mondays.. are like black holes sucking away all the energy, could be that they are the source of dark energy?

[McTraveller]

One second? That doesn't pass the plausibility smell test.  Surely there's more than one second uncertainty band in the trajectory computations.  I mean seriously, on an eight year trip, 1 second is one part per 250 million or so.  Heck if you get the winds aloft incorrect, that's going to eat up that 1 second (and more) right there. I mean even slight changes in air temperature and humidity are going to likely change the time through the atmosphere by more than 1 second due to changes in drag.

I feel like the one second window was derived by physicists or mathematicians, not engineers. 

(More likely is the media is not reporting it properly.)

[Starver]

It's punching straight into solar-orbit from take-off (no intermediate Earth-orbiting before boosting onwards), which means its increasing velocity probably renders minor fluctuations in the upper-atmosphere far less significant, and a lot of the adjustment needed is just subtle aiming (especially while the boosters are still boosting).

But it'll need to keep full throttle (staging changes aside) to have a similar sort of fuel-efficiency as an idealised suicide-burn landing hopes to achieve, to even reach the needle that it hopes to thread (the first Earth-Moon encounter, passing in exactly the right way to emerge onwards in order to thread the next needle, and the rest after that), without having to adjust too much using precious boost/manoevering fuel.

And it'll be the most massive during lift-off, from the classic "rocket-equation" of needing fuel to lift the fuel, fuel to lift the fuel to lift the fuel, etc. Making anything less than a ground-level storm (into which they wouldn't launch) a more insignificant impact upon the calculated momentum of trajectory... Or so I would think.

Can't speak for the one-second, but I could believe that they'd rather try to hit such a precise mark each day, or await an equivalent (slightly shifted) day on the day(s) after rather than submit to wasting any more of the initially lofted fuel thaj necessary by finding themselves with a subtly different intra-solar trajectory that needs to waste propellant that they could have saved for later (when other planned burns had reduced the craft-mass significantly, so even more 'sponteneity' could be achieved by the same amount of reserve).

Spoiler: My only 'practical' experience of this is by KSP (click to show/hide)

 (and an Android 'clone', more recently), where I built asparagus-like stacks that I'd launch at various times of day (local to the launch site; like midnight, noon, 6AM, 6PM, and other times) and seeing where the power to go interstellar (if launched 'outwards') would send me.

Even accounting for minor differences in the stage-separation process (not wanting to settle into an orbit, I could keep my pinkies off any yaw-controls), there could be surprising amounts of chaotic differences according to exactly when before/after 6PM (say) my launch would ultimately take the tip-top of my stack into a highly eliptical retrograde orbit. And that's without more than one gravitational influence (only actually passing through the lunar area of gravity counts, in the simplified physis model) or any actual winds (just straight and predictably procedual air-resistance).

But it was fun getting a rocket that worked consistently and then seeing where it got to for various launch-times. Which I did far too much! (When I wasn't designing my modular orbital structures, and trying to be consistent enough in reaching orbit to not need much more fuel to bring the components together. To at least top up the already launched fuel-tanks from the prior launches, then drop the latest elements back into the atmosphere again if I'd otherwise only be adding on tanks empty of all but fumes.)

[jipehog]

Looks like its going to be a fun day monday for a change, with SpaceX first test launch of its super heavy rocket, the most powerful rocket ever built

https://www.space.com/spacex-starship-first-orbital-launch-explainer

[jipehog]

another attempt today after the first launch attempt was scrubed.

Any bets on how long it will until a launch on how far will they get on their goal list? can't recall how many attempts where with flacon9 but there were many scrubs and later test flight before it made.

[Bralbaard]

another attempt today after the first launch attempt was scrubed.

Any bets on how long it will until a launch on how far will they get on their goal list? can't recall how many attempts where with flacon9 but there were many scrubs and later test flight before it made.

That was exiting to watch.

Too late for bets now, but they said beforehand that if the pad infrastructure survived, they'd consider it a success. That's putting the bar quite low, but it got close to not making that!
Quite a few engine failures at lift of, it seemed to barely have the power to clear the launch pad. Despite more engines failing during flight it somehow made it to the point were stage separation should occur. The remaining engines however did not appear to shut down, and the first stage failed to separate. The whole thing then started to tumble down untill the termination system kicked in and the thing exploded.

can't recall how many attempts where with flacon9 but there were many scrubs and later test flight before it made.

If I recall correctly the first falcon 9 launch was successful.

[Telgin]

That's a surprising number of failures.  I haven't been keeping up with these rocket systems, but even though it's a different rocket I would have expected enough engineering experience to transfer that it would have performed better.

Hopefully they got enough data to fix many of the problems for their next try, whenever that is.

[McTraveller]

It is surprising. I don't know how many engines are required for successful operation, but the more of anything you have, the more likely you are to have at least one failure.  If you have that many (5 of 33?) fail, it implicates a systematic design error not random failures.

That kind of failure rate is very concerning from an engineering standpoint if you ask me, but I don't know what their internal target for acceptable risk was.

[Bralbaard]

Well, it looks like the pad suffered very significant damage due to the power of all those engines lifting off. It left a huge crater below the pad.

link

There are videos circulating of cars parked quite far away from the launch site getting obliterated by flying debris, possibly from that crater.

link

It might well be that the root cause for those engine failures is due to damage because of debris bouncing up and destroying the rocket, so not a design flaw of the engines themselves. Nevertheless, more seemed to fail later in the flight. 
The rocket was much lower than it should be when separation should have occured, so the higher atmospheric density and different speed at that point may have been enough reason for that to fail.
It certainly was exciting to watch!