What's NASA Up To And Other Space Stuff

[Steely Glint]

Musk reckons he can sell people tickets to go all the way to Mars for $500,000, so apparently he thinks the cost of LEO can go much lower than $1 million a head.

As for your robots, I do agree that most work in space will be done by robots but unless and until they can match the manual dexterity of a human being it will be desirable to have some people on hand, and thus organisations interested in space will do so if they're able.

[EyeKhan]

Robotics and AI are progressing incredibly fast right now. I think commercial asteroid mining is coming and it's going to be 100% robotic with mostly-autonomous machines. Maybe we'll see space energy production, but that will be robotic too. People in space will be doing research and vacationing, that's pretty much it. There might be an attempt to colonize Mars, but it will be for the sake of doing it, not for any kind of economic benefit. Bummer too, I've always really wanted humanity to become some kind of MOO-like space faring civilization.

Probably the key to the Fermi Paradox, and our future, is either self-destruction, or something like going "into the box." Once we can replace our brain's sensory input with computer generated telemetry, we'll soon lose interest in the outside world. And probably go extinct from neglect of our actual-reality needs. That scenario, if typical, would explain the lack of signals, the lack of big mega-structure projects, the lack of colonizing and terraforming in the cosmos.

- - - - - - -

In other news, KIC 8462852 (aka Tabby's Start) is even weirder. Apparently it's been dimming for the last 100 years, by like 20% -- the entire time period there are observational records. I so wish this is what all us sci-fi fans hope it is. But not very likely. Weird star, though. Really weird.

http://www.slate.com/blogs/bad_astro...t_century.html

And we just found out it’s even weirder than we thought.


Bradley Schaefer is an astronomer at Louisiana State University. He’s a clever fellow and has a habit of thinking outside the box when it comes to astronomical mysteries. When it came to Tabby’s Star, Schaefer realized there might be older observations of it that could help inform its study.


He found that Tabby’s Star has been photographed more than 1,200 times as part of a repeated all-sky survey between the years 1890 and 1989. Using two different methods, he examined those observations and measured the star’s brightness over time.



Tabby’s Star is fading over time. The blue diamonds are measurements made between 1890 and 1989. The solid line is a linear (straight-line) fit to all the data while the dashed line is just a fit to the starting and ending points. The gray points are from two other stars as controls; they don't fade over the same period.
Graph from Schaefer, 2016


What he found is rather astonishing: The star has been fading in brightness over that period, dropping by about 20 percent!


That’s … bizarre. Tabby’s Star is, by all appearances, a normal F-type star: hotter, slightly more massive, and bigger than our Sun. These stars basically just sit there and steadily turn hydrogen into helium. If they change, it’s usually on a timescale of millions of years, not centuries. Schaefer examined two other similar stars in the survey, and they remained constant in brightness over the same time period.


The long-term fading isn’t constant, either. There have been times where the star has dimmed quite a bit, then brightened up again in the following years. On average, the star is fading about 16 percent per century, but that’s hardly steady.


So it appears Tabby’s Star dims and brightens again on all kinds of timescales: hours, days, weeks, even decades and centuries.


Again. That’s bizarre. Nothing like this has ever been seen.


So what’s causing this? Well, think Occam’s razor. The simplest explanation is probably the best place to start, and in this case that means one thing is probably behind all this weird behavior. Schaefer looks into this in his paper and concludes that the comet family idea doesn’t explain all the behavior. It might explain the short-term dips (maybe, kinda) but are hugely unlikely to be behind the long-term fading. You’d need truly vast numbers of comets, and they’d have to be huge, much larger than reasonable. And they’d have to be slamming into each other just as we happen to be looking.


So, yeah. Unlikely.


Now, again, let me be clear. I am NOT saying aliens here. But, I’d be remiss if I didn’t note that this general fading is sort of what you’d expect if aliens were building a Dyson swarm. As they construct more of the panels orbiting the star, they block more of its light bit by bit, so a distant observer sees the star fade over time.


However, this doesn’t work well either. Why did the star dip so much in the 1910s, then regain brightness a few years later, for example? Also, blocking that much of the star over a century would mean they’d have to be cranking out solar panels. The star has a diameter about 1.6 times the Sun’s. To block 20 percent of its light would take solar panels equaling an area of over 750 billion square kilometers.


That’s 1,500 times the area of the entire Earth. Yikes.


And that’s only if they happened to place those panels perfectly between their star and us. More likely they would be in a ring or a sphere, so the actual area would be far, far larger. Several trillion square kilometers at least for a ring, and much more than that for a sphere.


That’s a heckuva long-term project.

[Aimless]

Aliens or no, I'm always happy to see you're still alive and geeking Choobs

[Wraith]

1.6 mile tall towers of ice in Saturn's rings:

[Veldan Rath]

Well, if EK is correct in that machines will do the space mining, we could let them create the habitats on Mars first then send folks?

[Aimless]

http://arstechnica.com/science/2016/...-wave-finding/

Remember those rumors from a few weeks ago?

[Aimless]

http://arstechnica.com/science/2016/...ational-waves/

BOOM

[Steely Glint]

Can't get that bloody 'wave after wave' song out my head now either

[earthJoker]

Upgraded LIGO detectors spot gravitational waves

Now all we need is a LEGO detector that finds missing pieces.

[Ominous Gamer]

Bare feet seem to work just fine for that

[EyeKhan]

Well, if EK is correct in that machines will do the space mining, we could let them create the habitats on Mars first then send folks?

Seems like a reasonable plan. It will be interesting to see how far robotics and AI can go. Still have to justify the expense to a very short-sighted wallet, though. The big X against Mars colonization is the cost/ benefit. All the costs are high, economic and right now. The benefits will be far down the road and probably not directly related to the investment. With our current economic thinking, it's hard to see how a Mars colony could ever happen. I'd be very surprised to see any boots on Mars in my life-time.

[EyeKhan]

1.6 mile tall towers of ice in Saturn's rings:

Where did you find this pic? I occasionally drop by NASA's Cassini page and I've never seen anything like that. I've always thought the bits in the rings were relatively small - certainly not mile high spikes. Are you sure it's not a fake?

EDIT: Hmmm.... from Wikipedia:

B Ring[edit]

A location at the outer edge of the B Ring, viewed shortly before equinox, where shadows are cast by vertical structures up to 2.5 km high, probably created by unseen embedded moonlets. The Cassini Division is at top.

The B Ring is the largest, brightest, and most massive of the rings. Its thickness is estimated as 5 to 15 metres and its optical depth varies from 0.4 to greater than 5,^[55] meaning that >99% of the light passing through some parts of the B Ring is blocked. The B Ring contains a great deal of variation in its density and brightness, nearly all of it unexplained. These are concentric, appearing as narrow ringlets, though the B Ring does not contain any gaps.^{[citation needed]}. In places, the outer edge of the B Ring contains vertical structures deviating up to 2.5 kilometers from the main ring plane.
A 2016 study of spiral density waves using stellar occultations indicated that the B Ring's surface density is in the range of 40 to 140 g/cm², lower than previously believed, and that the ring's optical depth has little correlation with its mass density (a finding previously reported for the A and C rings).^[56][55] The total mass of the B Ring was estimated to be somewhere in the range of 7 to 24×10¹⁸ kg. This compares to a mass forMimas of 37.5×10¹⁸ kg.<sup>[55]

EDIT 2:</sup>

In this image, Cassini's narrow angle camera captured a 1,200-kilometer-long (750-mile-long) section arcing along the outer edge of the B ring. Here, vertical structures tower as high as 2.5 kilometers (1.6 miles) above the plane of the rings -- a significant deviation from the vertical thickness of the main A, B and C rings, which is generally only about 10 meters (about 30 feet).

Cassini scientists believe that this is one prominent region at the outer edge of the B ring where large bodies, or moonlets, up to a kilometer or more in size, are found. It is possible that these bodies significantly affect the ring material streaming past them and force the particles upward, in a "splashing" manner.

So they aren't 1.5 mile long solid structures, it's the smaller ring material grouping in splash like structures...

[Steely Glint]

they done landed one on a barge

[Timbuk2]

Juno successfully enters Jupiter orbit

The US space agency has successfully put a new probe in orbit around Jupiter.

The Juno satellite, which left Earth five years ago, had to fire a rocket engine to slow its approach to the planet and get caught by its gravity.

A sequence of tones transmitted from the spacecraft confirmed the braking manoeuvre had gone as planned.

Receipt of the radio messages prompted wild cheering at Nasa's Jet Propulsion Laboratory in Pasadena, California.

"All stations on Juno co-ord, we have the tone for burn cut-off on Delta B," Juno Mission Control had announced. "Roger Juno, welcome to Jupiter."

Scientists plan to use the spacecraft to sense the planet's deep interior. They think the structure and the chemistry of its insides hold clues to how this giant world formed some four-and-a-half-billion years ago.



Engineers had warned in advance that the engine firing was fraught with danger.

No previous spacecraft has dared pass so close to Jupiter; its intense radiation belts can destroy unprotected electronics.

One calculation even suggested the orbit insertion would have subjected Juno to a dose equivalent to a million dental X-rays.

But the probe is built like a tank with titanium shielding, and the 35-minute rocket burn appeared to go off without a hitch.

"Nasa did it again," said an elated Scott Bolton, Juno's principal investigator. "That says it all to me. And I'm so happy to be part of the team that did that. I mean this team has worked so hard and we have such great people. And it's almost like a dream coming true right here."

While the radiation dangers have not gone away, the probe should now be able to prepare its instruments to start sensing what lies beneath Jupiter's opaque clouds.

Tuesday's orbit insertion has put Juno in a large ellipse around the planet that takes just over 53 days to complete.

A second burn of the rocket engine in mid-October will tighten this orbit to just 14 days. It is then that the science can really start.

This will involve repeat passes just a few thousand kilometres above the cloudtops.

At each close approach, Juno will use its eight remote sensing instruments - plus its camera - to peer down through the gas planet's many layers, to measure their composition, temperature, motion and other properties.

A priority will be to determine the abundance of oxygen at Jupiter. This will be bound up in its water.

"How much water Jupiter has tells us a lot about where the planet formed early in the Solar System," explained team-member Candy Hansen.

"We think that Jupiter may not have formed where it is today, and if it formed further away or closer in - that tells us a lot about how the Solar System in general formed. Because when we look at planets around other stars we see quite a menagerie of possibilities."



The probe will also try to settle old arguments over whether the planet hosts a solid core or whether its gases go all the way down to the centre in an ever more compressed state.

And it will look for the deep swirling sea of liquid metallic hydrogen that theory suggests is the driver behind Jupiter's immense magnetic field and its spectacular auroras.

Scott Bolton said he wanted particularly to understand more about the Great Red Spot - a long-lived, giant storm.

"I love that Great Red Spot. We see it evolving, and it's been getting smaller ever since I first got amazed by it, which was when I was a child," he told reporters.

"The fact that it's lasted so long - there are records of it going back hundreds of years - means that it must have fairly deep roots.

"It looks a little like a hurricane on the Earth but we know it can't be working exactly like that because hurricanes on the Earth need an ocean underneath and feed off the liquid and then change when they go on land. At Jupiter, it's all gas."

Nasa plans to run Juno through to February 2018, assuming any radiation damage has not made it inoperable by then. The performance of the camera, for example, is expected to degrade rapidly within a few months.

In line with the practice on many previous planetary missions, the probe will be commanded to end its days by ditching into the atmosphere of Jupiter.

This ensures there is no possibility of Juno crashing into and contaminating the gas giant's large moons, at least one of which, Europa, is considered to have the potential to host microbial life.


For scale: No solar-powered spacecraft has worked so far from the Sun, hence its huge panels.

Well done NASA. Incredible acheivement.

[EyeKhan]

they done landed one on a barge

I thought this was pretty sweet, though apparently the rockets they've so far successfully landed were in poor condition -- not about to be turned around and re-flown to get that reusable booster cost savings. But the data collected will likely point the way to more robust designs to enable true re-usability.

Interestingly, these booster landings are doubling as development for similar landings on Mars. Up to now NASA has used chutes, bubble wraps and 'sky cranes' to get landers on the Martian surface (though I think the Viking landers may have gone down on rockets - have to check that). But they've more or less reached the weight limit for those strategies, owing to the thin Martian atmosphere, and to get anything much heavier safely down, they'll need to land using rocket engines. Space-X is planning to send a Dragon capsule to Mars in 2018 and land it via rockets, which I believe will be the heaviest spacecraft ever landed there -- and the first private mission to Mars. That capability will enable landing the equipment and cargo needed for a manned mission to the surface. Details are supposed to be announced this September.

Fun stuff!

[Tylor]

I managed to get a Juno pin last week - a couple of employees no longer working at JPL weren't there to pick theirs up

[Aimless]

http://arstechnica.com/science/2016/...xas-for-tests/

[EyeKhan]

http://arstechnica.com/science/2016/...xas-for-tests/

Given the US government's general movement to dis-invest in the country these days, I'd say NASA has a snowball's chance in Arizona summer to get people to Mars, ever. But SpaceX seems serious about it. And not just visiting, but setting up a colony.

[wiggin]

Given the US government's general movement to dis-invest in the country these days, I'd say NASA has a snowball's chance in Arizona summer to get people to Mars, ever. But SpaceX seems serious about it. And not just visiting, but setting up a colony.

To be fair, I don't think that setting up a colony on Mars even remotely qualifies as investing in the United States.

[EyeKhan]

To be fair, I don't think that setting up a colony on Mars even remotely qualifies as investing in the United States.

Building and supporting a real colony on Mars would require a very large investment in space-related industries on Earth. Maybe Musk plans to make those investments outside the US, but right now it seems SpaceX is doing its thing here.

[wiggin]

Building and supporting a real colony on Mars would require a very large investment in space-related industries on Earth. Maybe Musk plans to make those investments outside the US, but right now it seems SpaceX is doing its thing here.

Oh, please. I'm sure that some modest infrastructure will be created for the Mars shot (which counts as 'investing in America') but spending for the sake of spending is hardly an investment. There will be the usual knock-on effects from demand creation and the like but the multiplier for Mars exploration is likely to be quite low compared to, say, investing in more useful R&D or building bridges and ports.

[Steely Glint]

Mars shot != mars colony

[EyeKhan]

Oh, please. I'm sure that some modest infrastructure will be created for the Mars shot (which counts as 'investing in America') but spending for the sake of spending is hardly an investment. There will be the usual knock-on effects from demand creation and the like but the multiplier for Mars exploration is likely to be quite low compared to, say, investing in more useful R&D or building bridges and ports.

As Steely noted, we're not talking about a Mars "shot." Musk intends to build a colony, which would require lots and lots of rockets, equipment, supplies - space logistics infrastructure here on Earth, in orbit, maybe on the moon. And if the engineering and development of that infrastructure is done here in the US, and if the Earth-bound elements are built in the US, then yeah, that's investment. If a real space industry can get off the ground, the dream of a true space-faring humanity that Musk is attempting to get started, and its based in the US, that is potentially big investment in the US.

[wiggin]

I am deeply skeptical that this will be any more of a colony than the ISS is a space station. I agree that if - if some science fiction future you envision comes to pass, it will be beneficial to the US to have the technology and space infrastructure. In reality I suspect this will be substantially more limited in scope and other than providing a few thousand high paying jobs in the aerospace industry and building a few more factories, the impact on the US economy will be muted. It'll make us look good, sure, and I have no doubt it will be exciting and scientifically interesting. But on a dollar for dollar basis it seems far more likely that an investment in much more prosaic needs would have a far bigger payoff in both the short and long term.

Essentially this comes down to a matter of scale. The world has spent somewhere in the ballpark of $150 billion on the ISS; a somewhat smaller amount on the Apollo program. Both are impressive engineering feats and have provided some level of scientific payoff (though likely far less than could have been achieved through a similar investment in e.g. robotic exploration or non-space R&D), but they have hardly paid off from an economic (i.e. 'investment') perspective. I posit that a limited Mars colonization effort - at substantial expense - will likely be similar in scope. Yes, I imagine that a more ambitious plan could be put forth that would involve, say, regular capture of asteroids for mining and construction in orbit, and development of the technologies and capital equipment necessary to sustain a human presence on Mars indefinitely. This would likely have massive effects on the global economy, including potentially some positive ones for the US. But the price tag is likely prohibitive - even a huge government like the US would be hard-pressed to support such an effort, and a relative minnow like SpaceX simply doesn't have the capital. We're probably talking well into the 12 figures, if not 13.

I get the argument put forth by space junkies that Musk's plan is to dramatically reduce launch costs, thereby substantially cutting the capital required for developing substantial industry in orbit or extraterrestrially. And as far as it goes, that's a great idea. Unfortunately, the cost is still astronomical - you'd need orders of magnitude reductions to really make things feasible, and SpaceX - transformative as they may be - does not have that level of cost savings in mind. There's a certain amount of energy required to get a given payload into orbit (let alone to Mars), and it's a crapload. Without fundamental changes in how we get things to orbit - as well as in propulsion methods in space - the cost for any substantial engineering effort in space is simply too high. Can we put a dozen people on Mars and keep them supplied indefinitely? Sure, albeit at substantial cost. But to do what you're envisioning requires more than some regular payloads shipped to Mars - and the capital required is daunting.

[EyeKhan]

So you agree with me after all. Good.

[wiggin]

I agree that if your wildly optimistic assumptions end up being valid, you might have a point. I haven't a clue where Elon Musk will get, say, $500 billion-$1 trillion to get started, but it's at least theoretically possible.

Look, I love the idea of space travel as much as the next guy. I think it's super cool. I just don't think it's currently economically feasible or desirable given the available technology. The occasional manned mission just to make a point? Sure! Want to set up a little group of scientists somewhere on a semi-permanent basis at significant cost? Probably a waste, but if you can find the money go for it. But setting up a spacefaring industrial and life support basis that is broadly self-sustaining? Not in the cards anytime soon.

For now, robots are likely to do the vast majority of the work in space, for good reason. There is precious little justification for the expenditures necessary to do anything else.

[Steely Glint]

And as far as it goes, that's a great idea. Unfortunately, the cost is still astronomical - you'd need orders of magnitude reductions to really make things feasible, and SpaceX - transformative as they may be - does not have that level of cost savings in mind.

Oh, but they do:

"If one can figure out how to effectively reuse rockets just like airplanes, the cost of access to space will be reduced by as much as a factor of a hundred." - Musk

I believe 'a factor of a hundred' is two orders of magnitude?

There's a certain amount of energy required to get a given payload into orbit (let alone to Mars), and it's a crapload.

It's not exactly the propellant that makes going to space such an expensive business.

[wiggin]

Oh, but they do:

"If one can figure out how to effectively reuse rockets just like airplanes, the cost of access to space will be reduced by as much as a factor of a hundred." - Musk

I believe 'a factor of a hundred' is two orders of magnitude?


It's not exactly the propellant that makes going to space such an expensive business.

Musk is wrong. I mean technically not wrong. In the sense that yes, in terms of the actual rocket fuel required, that's dramatically cheaper than the current per-pound launch costs. So if the only think you need to keep a rocket going like an airplane is to refuel it, it's super cheap - all of your capital cost is tied up in the hardware, which is almost entirely reusable in a commercial jet (there are some quibbles here - the mass ratio of a rocket might not be as favorable for reusable systems requiring high fuel costs, but it's still likely to be substantially cheaper than getting new hardware). But rockets are not planes: they have multiple stages and have fairly expensive retrieval, refurbishing, and assembly costs. No way you'll be able to get two orders of magnitude reduction in costs, even if you recover all of the stages.

The big problem that I alluded to early talking about energy costs to get into orbit isn't the rocket fuel itself; it's the costs that using such high energies impose on your launch system. There are very high stresses involved in a typical rocket launch, let alone during the recovery process, and that necessitates a fairly expensive refurbishing of the hardware. That's why the Space Shuttle was so expensive, and I doubt that SpaceX has solved this problem in a satisfactory manner. Sure, I imagine that by clever design and really good organization they'll be able to reduce refurbishment time and costs to a minimum, but it's not going to be easy. Things will get pricier if you try recovering a second stage given the bigger reentry/etc. issues... not to mention recovery of much bigger launch vehicles to throw the really heavy payloads into orbit (which you'll need to be doing a lot of if you're trying to develop orbital infrastructure).

If they manage better than a single order of magnitude anytime soon I'd be astonished. That will drop costs, yes - you might be able to set up a modest Mars colony for 'only' a few hundred billion dollars, with substantial ongoing costs for its support.

Of course launch costs are only part of a much bigger story. A lot of what has been suggested in this thread is much more ambitious than just 'cheapish' launches leading to a moderately cheaper Mars shot using relatively conventional technologies (e.g. the Dragon capsule or a variant). If we really want to develop this 'infrastructure' that Choobs is suggesting we're going to need to develop a lot of complex and unprecedented technologies - how to gather resources and manufacture in space, how to design relatively self-sufficient (rarely, if ever, breaking) systems for extended use in a hostile environment, etc. I read The Martian a while back, and despite all of my complaints about the book, it was right about one thing: it's reasonably doable for a sufficiently well-funded effort by NASA or another player to set up robust systems that will keep people alive for weeks. Doing it for years or decades is a hell of a lot harder. The kind of thing you're talking about happening is wildly expensive given currently technology. Maybe someday it will be feasible, but in the meantime I think the reality is going to be far short of the starry-eyed ideal we all have about Martian colonies and orbital factories. Space is hard.

edit: I don't want to diss SpaceX here. I think the it's fantastic what Musk is doing, and I think the broader move by the US towards commercial competition in the space market is a smart one. I think that reduced launch costs - even if it's only, say, a 70% reduction - will have a dramatic effect on what we consider feasible to put into orbit, and that will open up a lot of new and interesting applications in LEO. I like the ambition of trying to get people onto Mars, even if the reality will be far short of 'Red Mars' or similar fiction. I just think that the hype about opening up space is just that - hype. It reminds me a lot of future-looking pieces in the 50s and 60s - during the dawn of the space age and nuclear energy and all sorts of other cool technologies, it looked inevitable that we'd have lunar bases before the end of the 20th century, and that series like 2001 et al were only mildly far-fetched. Exciting, yes, but reality - and economics - get in the way.

[EyeKhan]

I agree that if your wildly optimistic assumptions end up being valid, you might have a point. I haven't a clue where Elon Musk will get, say, $500 billion-$1 trillion to get started, but it's at least theoretically possible.

Look, I love the idea of space travel as much as the next guy. I think it's super cool. I just don't think it's currently economically feasible or desirable given the available technology. The occasional manned mission just to make a point? Sure! Want to set up a little group of scientists somewhere on a semi-permanent basis at significant cost? Probably a waste, but if you can find the money go for it. But setting up a spacefaring industrial and life support basis that is broadly self-sustaining? Not in the cards anytime soon.

For now, robots are likely to do the vast majority of the work in space, for good reason. There is precious little justification for the expenditures necessary to do anything else.

Quoting myself from earlier in this thread:

It will be interesting to see how far robotics and AI can go. Still have to justify the expense to a very short-sighted wallet, though. The big X against Mars colonization is the cost/ benefit. All the costs are high, economic and right now. The benefits will be far down the road and probably not directly related to the investment. With our current economic thinking, it's hard to see how a Mars colony could ever happen. I'd be very surprised to see any boots on Mars in my life-time.

And

Robotics and AI are progressing incredibly fast right now. I think commercial asteroid mining is coming and it's going to be 100% robotic with mostly-autonomous machines. Maybe we'll see space energy production, but that will be robotic too. People in space will be doing research and vacationing, that's pretty much it. There might be an attempt to colonize Mars, but it will be for the sake of doing it, not for any kind of economic benefit.

You can see, again, we more or less agree. I get the realities enough that your somewhat condescending tutuoring isn't needed. That said, NASA doesn't get nearly enough funding to do even the anemic things they have planned now. SpaceX, on the other hand, appears to be actually pushing ahead in a, comparatively, quick and substantial way. I don't know what Musk's long term plan is, how he expects to fund a real Mars colony. But he's doing some nifty stuff and, in a time when I see NASA being starved, it's great that somebody is pushing ahead in a meaningful way and it's good fun to watch. So stop pouring water all over it.

[wiggin]

Dude, I never thought you didn't get this. I just don't get why you think it counts as investment in America. The same capital could be put to much better use.

You implied that not funding a Mars trip and/or limited colony amounts to 'disinvesting' in the United States. That's my only complaint.