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I posted this yesterday in another article, but it didn't escape the science section.

What does this remind you off?

If you visit APOD (Astronomy Picture Of the Day) they link to a huge 7.2 megapixel version of this picture. So, unless your desktop is bigger than 2700x2700 anyone can scale it down and make a cool desktop from this.

The APOD also has a good picture of this today.

Check out this Hubble picture

Don't worry, kids, it's a NASA site!

Who is this interstellar gas cloud gesturing too, and what is it ordering?

...and just in time for me to go home, too.

Here's a NASA page on Project Prometheus.

Have a good weekend, all.

-Carolyn

And did the presence of humans help with Columbia or Challenger?

As cool as the shuttle program is, I'm afraid it's turned out to be another example of overengineering: so heavily dependent on supposedly failsafe systems that a single failure (O-ring, foam strike) destroys the entire system.

Contrast with the comparatively simple Soyuz launch system. It may seem primitive, but by golly, the thing usually works. And when it doesn't, you can still survive (though "15-17 Gs" doesn't sound like a picnic in the Russian countryside).

And the reference to Cook's terrestrial explorations has another parallel with space exploration: sailors on his ships (or any ship of the time) had no guarantee that they'd make it back home. They don't call it a "widow's walk" for nothing. I'm not sure we can get anywhere on the "new frontier" until we're able to accept the sort of losses that were common on the "old frontier".

Of course, this is easy to say, sitting in a comfy chair in an air-conditioned office, listening for the boss' footsteps so I can minimize my browser when she walks by...

It seems that the failure to apply the thermodynamic limitations to radiation physics has shown up in many experiments involving radiation pressure. Thus Crookes' radiometer has invariably rotated in the opposite sense to the expected one. The black side of the paddles invariably recedes from the light, and many explanations have been offered, but not including that which would seem the most obvious: the absence of radiation pressure on the bright side. Similarly all attempts to observe a steady deflection of a pendulum exposed to a light beam have always only shown a brief effect following the sudden beginning of the illumination. Experimental evidence has been ignored and "explained away" each time as some unexpected artifact, because of the widespread belief that the conventional momentum conservation law must be correct. But this law was recognized by Newton only for material bodies, and he had no information about radiation effects. But the momentum conservation law can be shown not to apply to the interaction of radiation with any material objects.

I also note that it is common to see people who have to control spacecraft (especially those not in earth orbit) say that you cannot neglect the effects of solar radiation pressure on the spacecraft's attitude and trajectory. For example NASA's Microwave Anisotropy Probe plans to use solar radiation pressure for backup attitude control (see page 8) and at the very least, cannot neglect this force on the spacecraft.

I would tend to conclude that this guy doesn't really know what he's talking about.

via:

article

"Indeed, a small "kite" or solar sail (31 cm x 76 cm in area) was actually added to the Mariner series of spacecraft to balance the solar pressure on the solar cells. However, it wasn't until the Mariner 10 mission that solar sailing techniques were used for maneuvering by using the pressure of sunlight reflecting off of the solar panels for attitude control. By using the ballast solar sail for attitude control manuevering, the project was able to extend the planned life of the mission to get more data."

M2P2 is a much more viable alternative -- no massive sheets to drag around, low power consumption, and a clever way of doing things. More on it here and here and here and here and here.

Nope. They could maneuver in a way similar to that sailing ships use to go upwind. By angling the sails correctly and using the sun's gravity field, a solar sail vessel can fly "upwind" toward the sun. See this NASA reference for a basic primer.

When you have a cool concepy like a solar sail, why let little things like laws of physics get the in the way?

This guy is wrong. Period. The solar sail would not be a heat engine -- it's not an engine of any kind -- so Carnot's analysis does not apply. Radiation pressure does exist and can be used to blow objects away from the Sun. Don't believe me? Too bad, because we have photographic evidence: The tails of comets always point away from the Sun (during the approach and departure of the comet), in part due to the radiation pressure on the dust that makes up the tail.

Very good points. There are also many other galactic objects that block our view, like Bok Globules, and large nebulae like the Eagle Nebula.

And as far as commercial entities go, don't forget IBM's find back in September of 2002, which was making nanotubes with carbon instead of metal.

I should hope it has built hypersonic aircraft. Otherwise there's been a huge conspiracy to mislead the public, and that concorde thing must be a hoax too.

Hypersonic is five times the speed of sound. The Concorde is supersonic only. Although the x-15 has been acknowledged as a hypersonic test platform it was:
A. A rocket
B. A test aircraft flown by NASA

To date there are no known flying hypersonic aircraft. Although there are a few test platforms for various airframes and engines (ramjets, wedge shapes, waveriders, etc) I know of no flying hypersonic aircraft that is public.

Are they? If so, are they planning cooperation with land-based or other space telescopes?

P.S. Has anyone noticed that NASA/JPL switched the labels of Earth and Jupiter in this picture on the "What is TPF?" page?

Are they? If so, are they planning cooperation with land-based or other space telescopes?

P.S. Has anyone noticed that NASA/JPL switched the labels of Earth and Jupiter in this picture on the "What is TPF?" page?

a whacking great bolt of lightning should just about do it. The characteristics match across the board. The only issue being that conventional science admits of no source for such a bolt.

It's the Phirst Phuck You Nebula!

Right here.

In the next decade we will see the first of a totally new class of orbiting space telescopes - large arrays of sensors spanning many tens of miles across. These will be true orbiting interferometers which will bring amazing optical resolution to "near-earth" explorers.

The ramifications for earth-based planetary exploration are huge. Currently, work is being performed on how to keep such a satellite array in perfect alignment. Low-thrust ion engines and tide-stabilizing configurations are flying as we speak.

NASA has plans to launch the first Space-Based Interferometer in 2009. Taking into account the inevitable schedule slide, we should start seeing some really cool pictures in about 2012. AND, since the array will live relatively close to our "Big Blue Marble," it might also be a reason to keep the ISS and the manned space program in general running for another decade. All it takes is $$$$$$$$$$$$$$$$$$$.

Good call! I can have one for you by next Thursday!

No, but seriously, I absolutely agree. At first, I thought that the ISS was supposed to be that starting point, but either I misunderstood, or NASA got sidetracked... again. I just want them to do SOMETHING worthwhile. It seems like forever since any good news from them.

What are the main requirements for a manned space flight to Mars? Oxygen, fuel, and (duh) people (if I'm missing any, let me know). Oxygen seems like a no-brainer. Just have a bunch of plants, and there ya go (yes, I know it's SLIGHTLY more complicated than that, but this is a generalization). Fuel doesn't seem like a major concern either. I'd be glad to volunteer for the first manned mission to Mars, so I'm guessing "people" would be easy to come by... just pick up a bunch of homeless people and ship them up. The next step is landing the ship, and setting up a base camp. No problem. We can already do landings, and as far as a base camp, how about a relatively small half-sphere of glass with the necessary supports? Doesn't seem too difficult to me, all in all. I've seen it in lots of movies...

Probably off topic, so Mod me as you will,

However, there is a great picture on the
Astronomy Picture of the Day that looks like its flipping you off.

This article discusses how astronauts get lots of useful pictures that we would not get from satellites.

And I've seen lots of articles like this one explaining how an astronaut discovered something unexpected and that would have been missed without the astronaut there.

I've also seen articles (sorry, no links handy) where on-the-ground scientists talk about how they can execute much richer experiments in space because there are people up there.

You might not think these are great examples, and it's true that given enough time, technology could do most of the things that astronauts are doing. Plus the claims that most experiments are autonomous seems true enough. But even with the autonomous experiments, there have been reports back about the people on board being able to see something unexpected, to make calibrations in ways that could not have been anticipated, to make unexpected (and otherwise impossible) repairs to important and pricey equipment.

The common thread here seems to be that having real people on the ISS has generated lots of ideas, with respect to both science and experimentation, that might not have been thought up for some time by ground-based researchers, and certainly not by robots. In other words, they seem to speed up the efficiency of our learning and research up there. And it's possible that having real people on board something like the ISS will help guide researchers in this way for a long time, no matter how far out that research and learning curve goes. What we might look for is the point of diminishing returns on that curve - the time when having astronauts on board, while still adding value, doesn't add enough value to justify their cost or the risk to their lives. From what I've read, we aren't very close to that situation yet.

This article discusses how astronauts get lots of useful pictures that we would not get from satellites.

And I've seen lots of articles like this one explaining how an astronaut discovered something unexpected and that would have been missed without the astronaut there.

I've also seen articles (sorry, no links handy) where on-the-ground scientists talk about how they can execute much richer experiments in space because there are people up there.

You might not think these are great examples, and it's true that given enough time, technology could do most of the things that astronauts are doing. Plus the claims that most experiments are autonomous seems true enough. But even with the autonomous experiments, there have been reports back about the people on board being able to see something unexpected, to make calibrations in ways that could not have been anticipated, to make unexpected (and otherwise impossible) repairs to important and pricey equipment.

The common thread here seems to be that having real people on the ISS has generated lots of ideas, with respect to both science and experimentation, that might not have been thought up for some time by ground-based researchers, and certainly not by robots. In other words, they seem to speed up the efficiency of our learning and research up there. And it's possible that having real people on board something like the ISS will help guide researchers in this way for a long time, no matter how far out that research and learning curve goes. What we might look for is the point of diminishing returns on that curve - the time when having astronauts on board, while still adding value, doesn't add enough value to justify their cost or the risk to their lives. From what I've read, we aren't very close to that situation yet.

And those handy dandy batteries that power portable power tools.

"The entire computer industry was driven to micro-miniaturization and 'chips' by the huge costs per pound of putting computers into space."

And the cost per pound comes from flinging people into space. (Astronauts were really freaking heavy in those days.)

Mmmmm... Tang."

Too bad the ISS is far from complete, and I recall they were looking to mothball the project not too long ago (I can't seem to find any info about whether they did or not)

So maybe it's a less than perfect analogy.

Then let's consider the quality of workmanship and engineering that typically come out of china... those aging, rickety shuttles look pretty appealing!
=Smidge=

The Helios unmanned high altitude vehicle was developed cooperatively by NASA's Dryden flight Research and SkyTower Communications A division of Aerovironment These can help you learn more about their research into 3G and broadband deployment over Japan. Also, you can view the press release on the crash here.

The Helios unmanned high altitude vehicle was developed cooperatively by NASA's Dryden flight Research and SkyTower Communications A division of Aerovironment These can help you learn more about their research into 3G and broadband deployment over Japan. Also, you can view the press release on the crash here.

IANARS, but just look at the problem: to keep a solar-powered airplane flying for 4 days. Given this, I can see why the engineers would have tried to pare this thing down to the bone. Each extra gram (or ounce, pick your units) matters. You are at the absolute edge of the performance figures for each of the components. The slightest flaw can break things (as it obviously did).

You are exactly correct. Back when they were working on Daedalus, the mantra was, "If its never broken, its not light enough; if it breaks too often its too light." Basic background available here.

Posted AC because I do not have a /. account.

IAARS. (I Am A Rocket Scientist.)

One question that has plagued me since the destruction of Columbia: If there wouldn't have been extreme heat going into the wing, would the crew still be alive? I'm no aerodynamics expert, but isn't it possible, at the point of entry into the atmosphere, when temperatures start to rise, that the shuttle release some liquid nitrogen or some other super-coolant in some manner as to keep homeostasis of the vehicle?

Upon reentry, the Orbiter (the white and black plane-lookin' portion of the Shuttle), is carrying no cryofuels. They are stored in the large red-orange External Tank, and used up during launch. The Shuttle uses LOX and LH2, both of which are f'nasty to deal with and are economical only to generate the immense thrust necessary to achieve orbit. While in orbit, the Orbiter maneuvers using (relatively) small hydrazine thrusters. N2H4 is also f'nasty, but somewhat less so than either LOX or LH2. NASA's Shuttle Basics website provides a good nontechnical overview of mission stages.

The Orbiter doesn't maintain homeostasis during reentry. The bottom gets really, really, really hot. Because the Orbiter is essentially falling back to Earth, the crew wants to bleed off as much speed as possible. By taking advantage of friction with the air, the Orbiter can slow down, and not be travelling at Mach 20 or so when it lands. It is a tricky balancing act among speed, attitude, and heat--the tiles can only absorb so much thermal energy, the crew has only aerodynamic control of the Orbiter's attitude, and there is a whole lot of kinetic energy that needs somewhere to go.

From my understanding of the physics of reentry, and the information available about the Columbia breakup, I do not think that the only factor was heat. The speeds at which spacecraft travel during reentry are so far beyond the speed of sound that aerodynamicists classify them not as supersonic, but hypersonic. The hypersonic regime (generally > M5) is somewhat counterintuitive. Friction with air generates enough heat at reentry speeds (M20 and up) to vaporize graphite and cause dissociation in N2 and O2 molecules, creating an ion cloud around the spacecraft.

We would not be able to travel at hypersonic speeds if not for a quirk of geometry. If you look at a supersonic vehicle, such as the X-1, you will notice that the leading edges of the wings and fuselage are pointed and form very sharp angles. This causes the shockwave formed by supersonic speed to break cleanly around the vehicle, which is good for aerodynamics. If you look at a hypersonic vehicle, like the Orbiter, you will notice a blunt, rounded leading edge and nosecone, which causes the shockwave to separate from the craft, forming a cushion of air. This insulates the Orbiter somewhat from the heat of reentry.

If that rounded profile is compromised, in Columbia's case by loss of tiles on the leading edge, the shock will break as in a supersonic craft, allowing both heat to transfer to the wing, and also subjecting the Orbiter to the considerable kinetic forces generated by air resistance. Heat did not tear Columbia apart. Her own speed did.

-Carolyn Lachance

Posted AC because I do not have a /. account.

IAARS. (I Am A Rocket Scientist.)

One question that has plagued me since the destruction of Columbia: If there wouldn't have been extreme heat going into the wing, would the crew still be alive? I'm no aerodynamics expert, but isn't it possible, at the point of entry into the atmosphere, when temperatures start to rise, that the shuttle release some liquid nitrogen or some other super-coolant in some manner as to keep homeostasis of the vehicle?

Upon reentry, the Orbiter (the white and black plane-lookin' portion of the Shuttle), is carrying no cryofuels. They are stored in the large red-orange External Tank, and used up during launch. The Shuttle uses LOX and LH2, both of which are f'nasty to deal with and are economical only to generate the immense thrust necessary to achieve orbit. While in orbit, the Orbiter maneuvers using (relatively) small hydrazine thrusters. N2H4 is also f'nasty, but somewhat less so than either LOX or LH2. NASA's Shuttle Basics website provides a good nontechnical overview of mission stages.

The Orbiter doesn't maintain homeostasis during reentry. The bottom gets really, really, really hot. Because the Orbiter is essentially falling back to Earth, the crew wants to bleed off as much speed as possible. By taking advantage of friction with the air, the Orbiter can slow down, and not be travelling at Mach 20 or so when it lands. It is a tricky balancing act among speed, attitude, and heat--the tiles can only absorb so much thermal energy, the crew has only aerodynamic control of the Orbiter's attitude, and there is a whole lot of kinetic energy that needs somewhere to go.

From my understanding of the physics of reentry, and the information available about the Columbia breakup, I do not think that the only factor was heat. The speeds at which spacecraft travel during reentry are so far beyond the speed of sound that aerodynamicists classify them not as supersonic, but hypersonic. The hypersonic regime (generally > M5) is somewhat counterintuitive. Friction with air generates enough heat at reentry speeds (M20 and up) to vaporize graphite and cause dissociation in N2 and O2 molecules, creating an ion cloud around the spacecraft.

We would not be able to travel at hypersonic speeds if not for a quirk of geometry. If you look at a supersonic vehicle, such as the X-1, you will notice that the leading edges of the wings and fuselage are pointed and form very sharp angles. This causes the shockwave formed by supersonic speed to break cleanly around the vehicle, which is good for aerodynamics. If you look at a hypersonic vehicle, like the Orbiter, you will notice a blunt, rounded leading edge and nosecone, which causes the shockwave to separate from the craft, forming a cushion of air. This insulates the Orbiter somewhat from the heat of reentry.

If that rounded profile is compromised, in Columbia's case by loss of tiles on the leading edge, the shock will break as in a supersonic craft, allowing both heat to transfer to the wing, and also subjecting the Orbiter to the considerable kinetic forces generated by air resistance. Heat did not tear Columbia apart. Her own speed did.

-Carolyn Lachance

Inventions developed because of the space program, are (among others): sat dishes, barcoding, ear thermometers, vision screening, fire fighter equipment, invisible braces, advanced plastics, and more.

It's a very flimsy looking aeroplane. A 247 foot wingspan (a longer wingspan than the 747) that bends into a shallow U when aloft, with an all up weight of 1323 pounds (about the same as a light aircraft with no fuel or people in it) it looks like it wouldn't take too much to exceed its structural limits - some heavy wind shear or possibly a control surface stuck out of true.

Website here if you want to learn more.

Oh yeah, and how about a new moderation category?
"-999 Oh my god not those tired old chestnuts AGAIN" for all the fuckwits who have nothing better to do than drag out the tired old jokes every time someone mentions NASA here, as well as all the other pathetic unfunny crap that you losers repeat over and over and over again!

I wonder how much that thing weighed. Anyone have a link somewhere to specifications on the Helios?

The specs of Helios are one click away from the article to which slashdot links to. Maybe next time you could check the story before you start posting.

http://www.dfrc.nasa.gov/Newsroom/FactSheets/FS-06 8-DFRC.html

Remember the poor Mars Polar Lander? Thing crashed and mission failed miserably. Live and on the Internet three years ago.

http://mars.jpl.nasa.gov/msp98/

Um, we've landed stuff on Venus and an asteroid called Eros

Jeff

Um, we've landed stuff on Venus and an asteroid called Eros

Jeff

Is mars far enough from earth that this would indicate life is probably "all over" the universe, or might that mars life have a common source with our own?

While going into space on top of a roman candle is a horrible inefficent way of doing things, it's the technology we master today. What technology we master when we are setting up a launchfacility on Mars we can only speculate about, but lets assume that the elsewheredrive isn't yet avilable and we have to make do with LH and LOX (liquid hydrogen and liquid oxygen).

However, it'll cost far less, energywise, to launch something from Mars than from the earth. Mars has a escape velocity of just 5.03 km/s^2, compared to earths 11.19 km/s^2. And as we all know that Ek = m*v^2, the energy needed to deliver something into interplanitary space from Mars will be roughtly 1/5th of what it'll cost us to launch it from the surface of the earth (launching from the moon will cost under 1/20th of launching from the earth - but there is no readily avilable supply of water on the moon as far as I know).

Having seen that there is indeed some sence in building and launching oldfashion chemical rockets from the surface of the red planet, lets consider just how to split the water into oxygen and hydrogen, before we compress/freeze it. This takes, as pointed out, a whole lot of energy. Fortunatly however, bang smack in the middle of our solar system we got a gigantic nuclear furnace pumping out more energy than even the western civilisation can waste. True, Mars is somewhat farther from the earth, and the Solar irradiance is just 589.2 W/m^2 (or about 43.1% of earths), but Mars contains large open deserts and has less problems with clouds than earth do. Large solar farms should solve the problem, and I'm fairly sure that Mars itself can provide the necesary materials to construct them.

All information about Mars in this reply is taken from Nasa's Mars Fact Sheet.

Seesh, did you read the proper answer?

A) Mercury does rotate. However, your "proper answer" got it wrong; while Mercury rotates on its axis every 58.6 days, it's moved a long way around the sun in that same time. As a result, it's day (period between one sunrise and the next) takes longer than its rotation period. In fact, it takes about 3 rotations to get one 'day'. Also, because of the elliptical orbit and long rotation period, you can get a funky double-sunset effect, when the sun sets, then rises again in reverse before setting again.

B) Mercury does so have an atmosphere. The atmosphere is, on average, about 440K; quite hot enough. The night side is cold, not because there is no atmosphere, but because the atmosphere is so thin it radiates the heat away into space very fast. Mercury actually has a very turbulent convenction system, especially around the terminator line.

Most notably, 19 times from space.

Anyway a space race is coming, the US will certainly be involved, because China is the last great evil. These mideastern conflicts are tiny compared to what would happen if China were feeling froggy, and that fear will drive us just as it did in our space race against Russia.

Anyway a space race is coming, the US will certainly be involved, because China is the last great evil. These mideastern conflicts are tiny compared to what would happen if China were feeling froggy, and that fear will drive us just as it did in our space race against Russia.

Anyway a space race is coming, the US will certainly be involved, because China is the last great evil. These mideastern conflicts are tiny compared to what would happen if China were feeling froggy, and that fear will drive us just as it did in our space race against Russia.

Anyway a space race is coming, the US will certainly be involved, because China is the last great evil. These mideastern conflicts are tiny compared to what would happen if China were feeling froggy, and that fear will drive us just as it did in our space race against Russia.

From an earlier experiment it is clear that there are forces that will wreak havoc on most equipment. Travelling that fast through even the thinnest atmosphere or magnetic field will do some serious stress on things.

No, jafuser pointed directly to the archive of The Hubble Deep Field shot. Had he pointed here, it would have been a different picture every day.

The Russians have done a lot of thought about this subject, and the general conclusion is that it's not practical or ethical. Besides which, it'd be damn hard to do. It takes about 30 minutes just to use the toilet up there, because of the lack of gravity-induced friction (traction) forces. Sex is all about friction. You'd need to strap one party down, and the other one would need hand- and foot-holds just to maintain contact. It would take 10 minutes just to get into position, not to mention the fact that if I were another crew member and I saw ejaculate floating around or stuck in the air filters (or heaven forbid, any of the flight controls) I'd probably kick your ass... it just doesn't seem worth it.