Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Starver]

Titan has smaller gravity (by ~7x) but a denser atmosphere (by ~1.5x). Which makes me wonder if you could fly there by flapping your arms hard enough.

With a few square meters of wing, yes. Though, you would get tired pretty quickly. Some Titan analogue of hang gliding would be pretty awesome.

You remind me (fondly... I think I'll read through a few of the other old ones there) of the WhatIf..? A you tried to fly a cessna out there on other solar system bodies, and its punchline. A bit out of date (there are actual electric planes, designed as such, and they got the Inginuity helicopter... both things that weren't anywhere near happening/imagined when it was written), but otherwise still very factual+funny (do check the hovertext of the images). And the punchline paragraphs near the end deal with Titanic human-flight in a bit more detail.

[Magmacube_tr]

Titan has smaller gravity (by ~7x) but a denser atmosphere (by ~1.5x). Which makes me wonder if you could fly there by flapping your arms hard enough.

With a few square meters of wing, yes. Though, you would get tired pretty quickly. Some Titan analogue of hang gliding would be pretty awesome.

Forget the flying. We all know that everyone actually just wants to swim in the fart lakes.

[MonkeyHead]

Titan has smaller gravity (by ~7x) but a denser atmosphere (by ~1.5x). Which makes me wonder if you could fly there by flapping your arms hard enough.

With a few square meters of wing, yes. Though, you would get tired pretty quickly. Some Titan analogue of hang gliding would be pretty awesome.

Forget the flying. We all know that everyone actually just wants to swim in the fart lakes.

Good luck: the low densities of hydrocarbons mean this would be a cold and smelly way to drown in toxic alien ass juice.

No doubt thats probably someones ideal way to die, though. *Shrug*

[bloop_bleep]

I present

https://youtu.be/yrc632oilWo

SpinLaunch.

I really like the approach. It excites me. I have a few (untrained layman) ideas pertaining to what was laid out in the video.

Firstly, for the rebalancing of the centrifugal arm after releasing the spacecraft. I was wondering whether you could have the arm slide along its center of rotation, so immediately after the launch vehicle is released it can rapidly rebalance the arm by sliding it in the direction of the spacecraft -- the counterweight just needs to get close to the center of rotation. The question then becomes if you can do it without punching a hole in the side of the vacuum chamber. To get it to have to travel less you need a counterweight closer to the center of rotation, which means a heavier counterweight, which means denser materials. Then there's also the problem where if the center of rotation can move, it will tend to move in the direction of greater imbalance, since the heavier side will pull the arm towards it by its inertia exacerbating the imbalance. This, however, stops occurring if the rotating object is placed in a denser medium, because then the whole thing becomes essentially a centrifuge and the less dense rotating object will like to move back to the center if it goes out of alignment. They can't put some dense fluid in the vacuum chamber, though, of course, but I think they can simulate this self-correcting effect by having rollers running along the circumference of the vacuum chamber attached to the arm via springs, which can apply this correcting force. I'm just coming up with ideas here, I'm not sure if they make sense or are practical. Feel free to let me know your thoughts.

The second piece which I had ideas about is the airlock doors. They say they have a major engineering challenge in getting them to rapidly open to let the spacecraft out then rapidly close to preserve the vacuum. They apparently have hinged doors. I was wondering, what if they have a sliding door, a solid piece 3x1 relative to the dimensions of the opening with a 1x1 hole in the middle, such that the closed section is obscuring the opening when the spacecraft is spinning up, so that when it starts sliding in the release sequence it first becomes open, then keeps moving at the same velocity, in the same direction to rapidly close again after? No need for massive forces to reverse the door velocity in milliseconds, no need to fight atmospheric pressure, and no need to have it slam against a bumper in such a way that it bouncing would compromise the vacuum. Let me know what you think of this too.

[Madman198237]

It wouldn't be a 1:1 size hole in the sliding portion; it'd have to be an oval to account for the size of the spacecraft and the finite (though large) speed with which it is moving. And at least one, and I think several, of the doors are going to be open at start and just close behind the spacecraft. The only one that opens in front of the spacecraft is the outermost door. Getting a seal on a sliding door would, I think, be trickier than a good seal on a swinging door, so swinging doors it is.

As for springs and counter-moving masses and whatnot...the double-spacecraft or "just throw something at the wall" options definitely seem simpler and probably better than messing with that sort of stuff.

[LordBaal]

Didn't we talked about this a while ago?

[Starver]

One Hundred and EIGHTY!!!!

(...another bit of coverage, headed up by a nosecam view (trigger warning?)...)

[Starver]

Just to insert other news... I wonder if this is a prelude to not needing the Russian bits (as well as the earlier switching to visiting Dragon thusters instead of Soyuz ones).

But, back to that asteroid... ...it has apparently worked, and hence we probably won't die from a sufficiently predicted car-crash.

[martinuzz]

Quite the accomplishment. With a significant impact on the target's orbital velocity. Very nice shot.

[Starver]

Talking of the Russian bits (well, not really, but they do feature in the posts immediately before this mild necro), what with the existing Soyuz MS-22 craft apparently having leaked coolant (and not because of micrometeroid damage, apparently[1]), it might be that Russia sends MS-23 up empty, in February, to act as the ride home for those that would otherwise have come back in 22 in March.

I hope things don't get much more interesting, because there's already more than enough precarious situations just about keeping the ISS going...


[1] But whether it's more akin to the "mysteriously drilled holes", from a year or three back, I have no idea. Only heard third-hand conclusions.

[Starver]

If you're bothered about it, you'll already have heard that the UK's first home-based (rather than Australian, etc) satellite launch, courtesy of Virgin Orbit's plane-launched LauncherOne, went awry. Currently seems to be a second-stage 'anomaly'.

It's still a maturing technology, so the occasional glitch is not unexpected. Still, an inauspicious start. If at least safely away from all the actual human-driven bits of the launch.


Additionally funny is the political revisionism (nearly necroed the UK thread, just for this) surrounding the attempt. The hilarity being in the obvious photoshopping-style artefacts in the revised photo (I think too much clone/smear use, and too little tidying up after that.

[Starver]

Everybody duck!

_{(So, there's always seems to be a lot of Space-stuff to talk about (like stacking of Spaceships, etc) but this aint an irregularly updated LiveJournal thing, so I've been resisting double-/triple-posting with everything I've been keeping track of. Until now, just because. But please forgive me. ...I shall now go off to hibernate again. At least once the minibus has safely passed by.)}

[JoshuaFH]

That was quite the dramatic article for a minibus-sized meteor. A meteor that size might be able to survive entry and actually hit the ground, but it wouldn't do much damage most likely. There is the nigh-infinitely small chance it could hit-and-run a satellite though, and the astronomers couldn't see a license plate on it so there's no chance the space police could track it down after it gets slingshotted away.

[Ziusudra]

Scientists find first evidence that black holes are the source of dark energy

The researchers looked at a particular type of galaxy called giant elliptical galaxies, which evolved early in the universe and then became dormant. Dormant galaxies have finished forming stars, leaving little material for the black hole at their center to accrete, meaning any further growth cannot be explained by these normal astrophysical processes.

Comparing observations of distant galaxies (when they were young) with local elliptical galaxies (which are old and dead) showed growth much larger than predicted by accretion or mergers: the black holes of today are 7—20 times larger than they were nine billion years ago.
...
This is the first observational evidence that black holes actually contain vacuum energy and that they are 'coupled' to the expansion of the universe, increasing in mass as the universe expands

[Starver]

Odd final phrasing. Given the headline, I would have expected "the universe expanding as they increase in mass". Which rather calls into question the true causation/correlation they're trying to put forward.

(Also, they will stop/slow forming stars because of less remaining material available to, it won't be that the lowered star formation means a reduced amount of "new mass" to feed the holes, in any meaningful way.)

I shall read the full article later ("larger" is in size/extent, not mass, I assume, and they ruled out other reasons why later populations could be seen to be shifted up the scale a bit), when I have the time, but you'd have thought even the summaryised language on a science site wouldn't be so... confusing.