Slashdot Mirror

GPS = global positioning system (but you knew that)

ephemeris calculation = modeling a satellite's orbit based on a handful of numbers, demonstrated by http://ssd.jpl.nasa.gov/eph_help.html

RINEX = Receiver Independent Exchange Format, http://www.ngs.noaa.gov/CORS/Rinex2.html

SLOC = source lines of code .. a simplistic and rather poor metric used to gauge the effort required to develop software. http://www.dwheeler.com/sloc/

COCOMO = an obsolete software development cost model http://www.jsc.nasa.gov/bu2/COCOMO.html

> Now, they're nowhere to be seen

Wrong.

They're moved around the planet by Saturn's magnetic field, but they're most definitely still there.

Massive oxygen appearing on Venus?

The Venera 9/10 probes rudimentary insturments were unable to detect *exoatmospheric oxygen* on Venus, which can be formed by solar radiation bombarding particles in Venus's upper atmosphere. The Keck telescope detected it (but still incredibly tiny quantities). Keck had an accuracy of over 100 times greater than the Venera probes. Seing as exoatmospheric oxygen must constantly be regenerated, this is either an issue of solar cycles changing regeneration rates or limitations in the Venera spectroscopes. Venus's atmosphere does not "glow green", as Hoagland claims - to the contrary, people had to search in incredible detail to find the green spectral line of oxygen amidst all of the other radiated energy.

Io hotter than Mercury?

Do you know what tidal heating is? Look it up some time. Io is a moon orbitting very close to massive Jupiter (Jupiter has as much mass as 1,300 Earths). It is locked in harmonic orbits with other large Gallilean moons. As they pass, they stretch Io's surface. Just as when you stretch and bend an iron bar, it heats up, the same happens when you stretch and bend a moon. Io is not hot from the sun - it is hot because it is sapping orbital energy from the large Jovian satellites, and lots of it.

Furthermore, not all of Io is hotter than Mercury. Io has extreme temperature variations (of course, so does Mercury, between day side and night side...). Io's heat is focused on "hot spots" - volcanic vents and the like. This is equivalent to Hoagland using data from volcanoes on Earth to say that Earth is hotter than Mercury. The hottest that I am aware of that has been found on such a hot spot on Io is Pele, at 1800 kelvins. The majority of Io's surface, however, is very cold - about 95 kelvins. Mercury's sun side reaches 700 kelvins; its night side reaches 100 kelvins (cold enough to freeze krypton!).

Radical new weather patterns on Neptune

Because a big storm disappeared? That's like an alien astronomer looking at the Earth a couple days ago, then looking at it a couple days from now, and saying "Wow, a huge storm just disappeared on Earth! It must be the End Times!". It is even more dramatic on Ice Giants like Neptune, which have such large quantities of gas and have precipitative heating as well.

and even Pluto

Weather on Pluto? What on Earth are you talking about?

The gas giants radiating vastly more energy than they receive from the Sun?

Precipitative heating. Gas giants are actually a lot easier to model the formation of than rocky planets - they form somewhat similarly to stars. An early protostar, which is little more than a huge, sparse gas giant radiates brightly - and yet has no fusion underway. How? For denser elements to migrate inwards (as they want to do), they have to lose energy, and this energy is lost as heat. It was actually this, before fusion was known of, that was believed to power our sun (although there were some big problems with that being the only energy source, since it would forbid the Earth being 4.5 billion years old, as geologists were insisting).

When there is enough heat and pressure in the core, Dt-Dt fusion begins; however, this isn't very powerful and has a rather limited fuel supply. At this point, the protostar is now a brown dwarf. As more heating continues, eventually the full fission/fusion processes of the star can continue, and it becomes a main sequence star.

Jupiter is not large enough to get Dt-Dt fusion, and most of its precipitative heating has already occurred. However, that is "most", not all. Jupiter's denser elements are still migrating inwards, and will continue to do so for some time to come.

Is this guy onto something big, or is he delusional

Delusional isn't a strong enough term.

They've already done some analysis of the composition. The rings are apparently nicely segregated into 'rocky' and 'icy.

http://saturn.jpl.nasa.gov/cgi-bin/gs2.cgi?path=.. /multimedia/images/rings/images/PIA05076.jpg&type= image

http://saturn.jpl.nasa.gov/cgi-bin/gs2.cgi?path=.. /multimedia/images/rings/images/PIA05075.jpg&type= image

They've already done some analysis of the composition. The rings are apparently nicely segregated into 'rocky' and 'icy.

http://saturn.jpl.nasa.gov/cgi-bin/gs2.cgi?path=.. /multimedia/images/rings/images/PIA05076.jpg&type= image

http://saturn.jpl.nasa.gov/cgi-bin/gs2.cgi?path=.. /multimedia/images/rings/images/PIA05075.jpg&type= image

Maybe because the discovery was in Boulder?

Cassini Imaging Central Laboratory for Operations
Space Science Institute, Boulder, Colo.
-- http://saturn.jpl.nasa.gov/news/press-releases-04/ 20040816-pr-a.cfm

The first question that comes to mind is, does plasma research benefit from being carried out in a natural vacuum environment rather than needing apparatus to create one artificially? How does the degree of evacuation inside a fusion containment vessel compare with that in LEO, far orbit, or on the Moon?

This page states a typical pressure of 10^-7 atm for the interior of an operating fusion containment vessel. It refers to this condition as a hard vacuum, which this page defines as "a vacuum that approximates the vacuum of space." This page states an atmospheric pressure of 3*10^-9 atm at an altitude of 150 km, which isn't even LEO. (Al Shepard went more than 3x higher, and that was still a suborbital flight.) IANAHEP, but this would seem to indicate that taking advantage of the vacuum of space wouldn't be a bad idea. (The sticking point would be getting the other heavy equipment up there, along with a power supply.)

A planet which harbours intelligent life may produce night time light. A large enough telescope may be able to see it.

There are already plans for a telescope that can take a spectrum of extrasolar planets: TPF.
Yes, I know, the article is old and probably no-one reads this comment anymore. Never mind.

A planet which harbours intelligent life may produce night time light. A large enough telescope may be able to see it.

There are already plans for a telescope that can take a spectrum of extrasolar planets: TPF.
Yes, I know, the article is old and probably no-one reads this comment anymore. Never mind.

From this page:

"In November 1995, the partially completed (Russian) shuttles were dismantled at their production site. The manufacturing plant is scheduled to be converted for production of buses, syringes, and diapers."

Gotta love capitalism.

The more things change, the more they remain the same.... (see here)

The more things change, the more they remain the same.... (see here)

The more things change, the more they remain the same.... (see here)

and they can fly hundreds of kilometers. See Daedalus project here, for example.
________

It sucks that the kid died, but this should be a setback for solar-powered motor vehicle on highways. The safety problems are very probably unsolvable. Bicycles have been on the roads for over a century and motorcycles for almost as long. No technological solution for what happens when car meets bike that keeps the bike or the rider intact has been found. This suggests to me that there isn't one. If a road-safe solar vehicle can't be built, there is no point in pursuing this technology as more than a dangerous hobby any further.

More to the point, this is NOT an environmental solution. Safety issues aside, every barrel of oil that is conserved by the industrialized countries will be burned by an industrializing Third World, unless carbon-neutral solutions to replace fossil fuel cheaper than the current ones can be found. Therefore, conservation-based approaches to either global warming or running out of oil are uniformly unworkable, no matter how cool the technologies are.

We need energy replacement, not energy conservation.

The place for solar cells is in orbital solar arrays as part of a solar power satellite network. Power availablilty 24/7/365, no concerns about weather, and no SUV will ever run into a cell array and take it offline. However, this is better adapted as a solution for central station power generation facilities.

The solution for motor vehicle power? Switch to diesel engines and grow crude oil in energy farms. Even food-grain crop based biodiesel is comparable to price to bin Laden's Finest Middle East oil product, and algae-based biomass grown as part of sewage treatment promises to be quite a bit cheaper than growing it from fuel crops.

For more discussion of the implications of this, check my sig.

There are fundamental problems with all of these types of devices-- they 1) don't let the body handle momentum naturally and 2) don't stimulate the vestibular system in a way that is consistent with the visual or proprioceptive (the body's sense of where its limbs are) cues.

1) Momentum: On a 2-D treadmill, the omni-directional treadmill is supposedly fast enough that it allows for running. But when you are running and then change direction quickly, your body will lean into the turn to counter its momentum. Doing this on the treadmill will make you fall over. Someone once described it as "running on a slippery ice cube".

2) Vestibular cues: Our body can sense motion even without visuals or body movements. This is why some flight simulators have motion platforms [://www.simlabs.arc.nasa.gov/vms/motionb.html]. One post above said that the treadmill should reduce motion sickness because it provides body motions as well as visuals. But a treadmill doesn't cue the vestibular system. One theory of motion sickness is that it results from a mismatch of visual and vestibular cues. In the back seat of a car, your visual cues say you are still (relative to the inside of the car) but the vestibular system says you are moving. Similarly in a IMAX theater or while playing an FPS on a big screen, your visuals say you are moving but your vestibular system says you are still. Knowing how you are moving is critical for maintain balance and even surviving. The mismatch in visual and vestibular cues interferes with your ability to balance, and that's why dizziness results.

Luckily, one can fool the vestibular system, much as we can fool the visual system. Techniques include "wash-out" on motion platforms, electrical stimulation, and Redirection. Wash-out is where the motion platform moves the user to simulate the virtual motion, but then sneaks her back to the center of the room at an acceleration that is below what her vestibular system can detect. The shifting tiles look like a fabulous idea, and I wonder if one could implement a form of wash-out on those tiles.

Links

• Nasa Ames VMS motion simulator
• http://www.simlabs.arc.nasa.gov/vms/motionb.html

  Sphere http://www.vr-systems.ndtilda.co.uk/sphere1.htm2-D treadmills

  Omni directional treadmill http://www.movesinstitute.org/darken/publications/ ODT-UIST97.pdf

  Torus treadmill (great video) http://intron.kz.tsukuba.ac.jp/vrlab_web/torustrea dmill/torustreadmill_e.html

  Redirection http://www.cs.unc.edu/~eve/rdw/

One more thing, the problem with, as one post suggested, implementing VR in a huge wide open space (like a desert) is tracking. The computer needs to know where your head is and in which direction you are looking, very accurately and quickly, so it can draw the virtual scene from your perspective. By accurately, I mean with millimeter precision, and by quickly I mean it must update the images within tens of milliseconds of your head moving. If you focus your eyes on your figure at arms length, then rotate your head right and left, the reflex that moves your eyes to keep them locked on your finger is called the VOR (vestibular ocular reflex). It can react to head movements in 10 milliseconds.

The NASA website has a Fluxtimator that predicts the meteor flux (meteors per hour) for various cities around the world during the night of August 11-12. It will also work for the Leonid shower in November. It looks like the peak is fairly sharp, and drops off quickly thereafter.

NASA should just get a waiver from the CAIB requirements and go ahead and do the mission. Why a mission profile that's been successfully accomplished dozens of times is suddenly too risky even to consider is beyond me.

Replacing the instruments is the easiest part of the mission, since it's just a matter of pulling out one refrigerator-sized box and replacing it with another one. Dealing with the gyros and the other stuff planned for the mission is going to be a lot harder.

I continue to gasp at Slashdot posts that sound so authoritative but yet are so wrong, and this is another one. Hubble's defective mirror was not replaced; it's right where it's always been. The initial fix for the defect was a device called COSTAR, which was put in an onboard instrument slot (with ease, since Hubble was designed to allow astronauts to change out instruments) and used small mirrors to correct the aberrations for each of the other instruments.

All later instruments have been designed with the necessary optical corrections built in, hence COSTAR is no longer necessary and was to be removed with the next servicing mission.

Because some people still have romantic scifi notions of humans laboring in the new space frontier like heroic cowboys, when the reality is that increasing robotic/ai capability will be replacing many jobs starting with the most dangerous.

Timmy: "Mommy, when I grow up I want to be a RoboNaut"
Mom: "Ah... how cute - and your sister wants to be a 'My Little Pony' when she grows up."

--

Its replacement also isn't scheduled to go up for another 7 years...

So why not push this project a bit more? I'm all for not rushing things, but surely there are priority considerations that could be improved here.

...And doesn't factor in the cost to get it up there yet. Or the labour to build the thing. Or the cost of fixing it when the inevitable problems crop up.

Are you sure? What costs would you assume are in that number, just design costs? I don't see a break down, so my assumption is that is a mission cost estimate.

Also, lets look at the JWST FAQ to get some more cost details:
" JWST is projected to cost one-fourth to one-third the cost of Hubble, one of the most successful science instruments ever, yet JWST will be more capable than Hubble in many ways. The JWST will realize these cost savings primarily through advanced technology. JWST has a shorter lifetime, and since it will not be serviced in space, there are no costs for servicing. "

So, no, there will not be costly service missions. Kind of hard to service something at the second Lagrange point.

I'll give you a freaking break right away.

You must feel sooo cool.

Also too bad everything in space isn't floating along next to each other. You can't exactly see Hubble out the window of the ISS and walk over to fix it. For one the ISS is at around 230 miles while Hubble orbits at 375. You might notice another minor problem if you look at the two orbits here http://hubble.nasa.gov/hubble-operations/tracking. html and here http://spaceflight.nasa.gov/realdata/tracking/.

Also too bad everything in space isn't floating along next to each other. You can't exactly see Hubble out the window of the ISS and walk over to fix it. For one the ISS is at around 230 miles while Hubble orbits at 375. You might notice another minor problem if you look at the two orbits here http://hubble.nasa.gov/hubble-operations/tracking. html and here http://spaceflight.nasa.gov/realdata/tracking/.

I'm just happy that they decided not to ditch the Hubble.

Ditching it may be stupid, but this is crazy. 1.6 billion for what? It's replacement is only slated to cost $824.8 million

Gimmy a freaking break.

Actually, NASA already has a working prototype/model of a robot.

I was able to see the robot at NASA's Community Day at the Goddard Space Flight Center (GSFC). (NASA opened up the campus of GSFC to the public in July for one day. I submitted a story about this to /., but it was rejected.)

The "sophisticated camera" that the original article referred to is the Wide Field Camera 3. At NASA's Community Day I was able to talk to the lead electrical engineer for the Wide Field Camera 3, and he has been succesfully been using the robot for the past couple of months to work with the camera installation.

Considering that NASA already has a working prototype/model, I'm sure that finalzing the design can be accomplished in the next year.

Actually, NASA already has a working prototype/model of a robot.

I was able to see the robot at NASA's Community Day at the Goddard Space Flight Center (GSFC). (NASA opened up the campus of GSFC to the public in July for one day. I submitted a story about this to /., but it was rejected.)

The "sophisticated camera" that the original article referred to is the Wide Field Camera 3. At NASA's Community Day I was able to talk to the lead electrical engineer for the Wide Field Camera 3, and he has been succesfully been using the robot for the past couple of months to work with the camera installation.

Considering that NASA already has a working prototype/model, I'm sure that finalzing the design can be accomplished in the next year.

It will be interesting to see which one can be made clear first. A single-pane window that insulates like a tightly-sealed glass window with 10-20 panes would be nice. Although I'm a bit surprised that aerogel isn't being used in more applications today. (NASA only recently licensed the technology to a company, so perhaps we'll see more of it soon.)

If we could have just tried Orion, we could have landed full-scale bases on the moon, mars, and wherever else we wanted them with only a handful of launches. And we would have done this more than 20 years ago.

We've lost the tooling now to even make more of the Saturn V rockets we used to have. The only reason NASA can even do as much as it does anymore is because they can take advantage of miniturization to fit more in their tiny payloads. That and having Russia save our butts on the station.

It makes me sick.

They need more Astronauts like Story to gain interest. Am I the only one who remembers their kickass EVA on STS-61 ? Of course, adding in a Zero-G sex act would probably increase viewership way more than the intellectual challenge.

Great news that NASA will seek to keep the Hubble up and working. Sounds like NASA will be able to schedule a service mission in about 3 years (with one of those years just planning). However, I am a little worried that there is not a lot of press covering its replacement - the James Webb Space Telescope. This isn't scheduled to be launched until 2011. The extension of Hubble closes the gap between current and future platforms. Interestingly Webb has a mission life of 5 - 10 years. In contrast Hubble was launched in 1990 and will be in use for at least another 3-4 years. Let's hope NASA is being conservative in their estimate of the duration of the Webb...

I'm not really sure I want to be looking to make contact with aliens who are pointing FRICKEN LASERS at us.

Why not? After all, we point lasers at other planets too.

There is an even better way to do it. It's called Chemical Vapor Deposition. Basically, you pump gaseous material(precursor) into a furnace. The molecules break down, depositing the desired material onto a base surface(substrate) and the leftover gases are pumped out. There are a variety of uses for CVD in semiconductor manufacturing(metal,amorphous silicon,silicon dioxide deposition) as well as astronautical uses(complex shape production where casting and forging isn't possible).

CVD is incredibly useful for creating free-standing thin films. You take your substrate, CVD your desired chemicals onto it, and then chemically remove the substrate.

A little about CVD

A PDF about rocket combustion chambers and nozzles of Iridium/Rhenium by NASA/assorted US military

Personally, if it were me, I would investigate the posibility of using a CVD thin-film of polished amorphous silicon on a organic polymer substrate. It has a lot of advantages in strength and rigidity as well as the silicon CVD process being a thoroughly tested process. It would also present an anvantageous surface area/weight metric.

Erm, are you SURE about that?

Ignoring the real nearest star, Sol, the next nearest star is Proxima Centauri which is 4.22 light-years away... i.e. its light only takes 4.22 years to get here, not the 25 you claim.

There are 25 known stars within 13 lightyears. Their light won't take 25 years to get to us either.

Seriously. You wanna check your random information before presenting it as a fact!

Erm, are you SURE about that?

Ignoring the real nearest star, Sol, the next nearest star is Proxima Centauri which is 4.22 light-years away... i.e. its light only takes 4.22 years to get here, not the 25 you claim.

There are 25 known stars within 13 lightyears. Their light won't take 25 years to get to us either.

Seriously. You wanna check your random information before presenting it as a fact!

Ugh, too much wrong with your post to even break it down and comment. Read this.

These solar sails are pretty useless. Here http://solarsails.jpl.nasa.gov/introduction/design -construction.html are calculations from NASA guys. It looks like this Japanese sail has acceleration of few mm/s^2 and is not able to get out of sun gravitational field (and, of course, the Earth's one). It would take solar sail 100 years to get to alpha centauri if it had acceleration 10 m/s^2 (table 3 in the above link, there is "-" in the table for 5 m/s^2 and less , that is it will never get away from sun ). There was a good idea though to build a huge mirror to focus sunlight on such sail. This would effectivly increase surface area of a sail and pressure would not drop as square of the distanse from the sun.

But when it comes to interplanetary distances, 25KMPH is ... barely pokey.

Closest star to us is Proxima Centaury -- about 4.2 light years, or 2.5 * 10^13 miles.

Well, this explains it much better than I can. Basically, the Japanese mission is using 7.5um film; the NASA document posits that, if we were able to use sail of only a few nanometers (actually, a few thousand times lower areal density than we can currently achieve), we could see acceleration of up to .3m/s/s, and terminal velocity of around 671KPH. Estimated trip to closest star: About 2693 years.

Don't hold your breath.

Orion starship that could get to Alpha Centauri in 130 years [..]. Thats much faster than a solar sail could ever hope to do.

But a laser pumped solar sail could be faster. Those big laser will be a big investment, though... and the "misuse" applications should be about the same as for lots megaton bombs! (It's mentioned e.g. here.)

Did anybody else look at that video and immediately remember the montage sequence from The Right Stuff with archival footage of NASA's rockets blowing up?

Wow... am I with you on this one. Remember people... these are ENGINEERS. They are developing something new...

Did anybody else look at that video and immediately remember the montage sequence from The Right Stuff with archival footage of NASA's rockets blowing up?

Wow... am I with you on this one. Remember people... these are ENGINEERS. They are developing something new...

Ironically, this technology can take us to 'the stars' but not toward our own.

And, why not?

Sailing ships have sailed "upwind" for many centuries.

In outer space, you are either in orbit, or falling directly towards the nearest large body. A solar sail can be used to slow down or accellerate lateral speed simply by rotating it 45 degrees.

A simple google search turned up this in case you are curious.

Although they are right, in that solar sails do accelerate the entire trip and carry no fuel, I don't think that sails are "the way to go" unless we're talking about a ten thousand year multi-generational ship.

I consider the Bussard RamJet the "only way to fly". It carries no fuel, but is powered by carving a planet-sized swath out of the ambient hydrogen atoms out of interstellar space and fusing them.

With interstellar distances, the real issue is: how quickly can you get to relativistic speeds? Because, at .5 C, it'd take thousands to millions of years to get anywhere. But, at relativistic speeds, it'd still take thousands of years, but to the crew on board, it'd be like mere hundreds or even tens of years.

You need power to get you there in less than hundreds of years - thus the RamJet.

This takes you to the Kuyper belt. From there, ion drive takes you the rest of the way.

For display, I'd rather have something in a pair of glasses, preferably in true stereo-vision. If it can do HD-resolution or higher, on a virtual 50" screen at an appropriate distance away, that would be just fine with me. Audio from the earpieces from the glasses.

Virtual projected keyboard is fine, but a data glove interface might work well too. Give it tactile feedback, and use the glasses for the keyboard overlay, and you wouldn't even need a flat surface to project it onto. Another input device might be recent developments in picking up sub-vocal nerve impulses. People on a train, sitting back, typing in midair or sub-vocalizing, might become a very common sight.

The only satellite retrieval mission that immediately comes to my mind was the LDEF recovery. This was no ordinary satellite, it was basically a long term expirement to see what happens to different materials when they are left out in orbit for a long time.

Although not possessing a wide variety of observing modes, COS will outperform STIS in the key areas for which it was designed, and in many others will provide limited back-up capabilities should the STIS Side 2 electronics (and hence the instrument itself) fail in the future.

How is the James Webb Space Telescope, which will launch in 2011, an empty promise?

Why must a replacement be in place before we let the disintegrating old one die, when it will take enormous costs in time and resources to "bandage" until then?

Especially when advances in adaptive optics have allowed ground-based observatories to compete with Hubble in terms of clarity?

Isn't it true that yours, and most other Hubble-rejuvenators' positions are largely based on sentimentality and emotionalism? This is science, not religion...

• NASA Press Release
• Space.com

The technique usually used for this I understand is conformal mapping. There's a little spiel and animation about it here. The calculation itself isn't really that fun, at least from what I remember from my homework assignments, but its pretty cool that it can be done systematically for all these airfoils.

If you are into the details, from the the Riemann theorem quoted in the wikipedia link, any simply connected subset of the complex plane can be mapped onto a disk, and since it's easy to conformally map from a disk to the complex plane minus that disk - like in the figure on the second linked page - then once you know that first mapping for whatever shape your airfoil is (the hard part) you can figure out all the fluid flows around that shape. Of course, this entire technique only works for infinitely long airfoils, since the complex plane just represents a cross-section. If you dislike math and want the actual figure you can just stick it into an air-tunnel and skip the calculation. But you get the idea.

Of the 100+ systems currently known to contain planets, all contain seemingly only gas giants. However, this may be a case of current technology and techniques being unable to detect planets similar to Earth.

I can end this question right now.

It is because current technology can only detect said planets.

Time to read up for the journalist?

It's kinda sad to see them going these lengths to write these stories when he hasn't even done basic research.

Oh, I also forgot Vega as a candidate. NASA and the JPL thinks so.

Seems your hypothosis is crumbling... :)

State is a function of temperature. For example: dry ice is solid CO2. Liquid O2 is used in rockets