Wednesday, March 30, 2011

Rocket Wednesday

     In a curse of irony, last time I had a rocket Wednesday I mentioned that I would cover nuclear powered rockets and at the time of this writing, the future nuclear landscape has changed drastically due to the events in Japan (which I covered in an earlier post). Still as an important possibility in propelling starships, nuclear still is an important option to consider and is worth looking in to.
     While there are many different varieties of nuclear propulsion available to starships, one of the more fascinating is nuclear pulse propulsion. The concept of driving a ship with nuclear based technology is not new and dates back into the WWII era, but by far one of the more interesting ideas came out of the 70's. Project Daedalus was a British plan to build the first interstellar ship with the intent of reaching the stars within a life time.

  
     By feeding nuclear pellets into a laser reactor, a plasma explosion could be generated which could slowly accelerate a ship. While there was no plan to slow down Project Daedalus, it would be theoretically capable of reachin other stars. The intended target of the project was the fast-moving Bernard's star (since we know its speed precisely and over the lightyears of travel, all stars would also move due to time) and though the original speeds would be comparatively small, after 50 years of accelerating slowly, it would be moving quite fast.
     One major problem that would be encountered by an astronaut on such a vessel would be acceleration. While it is feasible to build such a ship, the human body can only withstand a certain amount of force and it could get quite tedious to live an entire lifetime feeling several G's of force always pulling on you. A nuclear derived thrust system could be designed to accelerate only at a moderate amount, and though it would take longer for a ship to get to its destination, the astronauts on board would be feeling significantly better about their situation.
     Next week we will look at other options for exploration and the ships that could be used to get there.
May the stars shine bright in your skies!
tip of the hat to the wikipedia spacecraft propulsion page and also to whoever finds flaws in this, I am not the best at nuclear technology

Tuesday, March 29, 2011

A Perspective From Kepler

     First off I am going to make a recommendation. If you like all this cool space stuff and you like seeing a cool new space picture every day make Astronomy Picture of the Day (APOD) one of your bookmarks. Not only does it have a cool new image every day it generally gives a little bit of the history and science behind the picture.
     Today's picture was quite a surprise especially for an aspiring planetary scientist like myself.



     The above image is a comparison of a number of the stars that Kepler found possible planets around. Each disc is of course a star while the little black dots are the approximate size of the planets found around each star. That smaller disc slightly below the right side of the first row is our sun with the black dot representing Jupiter though if you want to go and see the image on the APOD site, you can see a very small dot representing Earth, its very cool.
     The remarkable insight gained from this picture is the shear number of planets that have been found. these of course are mostly the larger planets, smaller ones may be hiding in their systems and would be too small to detect with our current level of technology. Also remember that this is just a small sample size in comparison to our own galaxy; there are many more stars with planets around them in our grasp. Who knows, one of these little black dots may hold life, its a distinct possibility.
     Even as our own planet loses its uniqueness in the universe, the universe itself, of which we are a distinct part, grows grater and greater with every passing moment.



May the stars shine brightly in your skies!

Tuesday, March 22, 2011

The Universe Is Truly Beautiful

     By far the coolest part about studying the space sciences are the images that come out of our vast array of satellites. The following picture is from the Spitzer Space Telescope and is of the center of our home galaxy in the infrared spectrum.

tip of the hat to NASA on this one
     As humans we are used to perceiving objects in the visible light spectrum. While this is a handy realm of light, visible light has a very hard time passing through the immense dust clouds that dot the galaxy and thus, we have a hard time capturing images of the densest parts of the universe. Thanks to Spitzer, we can image some of these places outside the realm of visible light and thus can see through these unfortunate dust clouds.

Thursday, March 17, 2011

I Have A New Tool!

     So to better improve certain elements of this blog I have obtained a new tool to better attempt to illustrate some of the basic concepts of extra-solar activity along with other fun stuff such as asteroid impacts and satellite paths. There is a wonderful program called Universe Sandbox (which you can download the demo of here). the system acts as a modeling program for gravitational situations such as planetary orbits and collisions.
     A program like this can be extremely useful in illustrating certain concepts such as how a large body on the outside of our solar system would wreck havoc on certain inner system features (its not pretty) or what would happen if you put another Earth on the other side of our orbit (fun stuff, but generally little to no consequence). It also has some fun additions such as seeing how certain rings would act in orbit around Earth. currently I am working on a way of illustrating these models in case the sources I have don't have good images or display the system poorly from the perspective of a amateur to the field.

Saturday, March 12, 2011

Hyping Up The Science

     Following the recent earthquake and resulting tsunami and then resulting nuclear emergency in Japan these last few days I have noticed quite a bit about how different organizations portray the state of crisis in an emergency. To set the tone of this post, I began watching the BBC live feed about one hour after the earthquake hit, though I was aware of it slightly after the tsunami hit.
     For the most part the BBC did not get very sensationalist about the disaster, and while they sure did love showing the footage of the tsunami rushing over the farmland, so did every other news network. What shocked me was the downplay of the deathtoll. Unlike other networks the BBC clearly stated how many were known to be dead and specifically separated that from the amount missing. Also shocking for me personally as an American viewer was the presence of a science correspondent who directly interacted with the anchor of the news program and informed of the science and geology behind the quake; they were unafraid to wake up a geophysicist here and there and did not restrict their sources to UK based organizations.
     While I did not observe much in the way of CNN, Fox, or MSNBC, I did also keep up with the Al Jazeera feed which was reliable as it moves into the realm of globally respected news networks. From my understanding the American networks did not have as much of the science adequately portrayed and focused more on the shock and the disaster at hand while more estimating a death toll, it was only after a few hours in that the BBC began to ask for estimated deaths and as of 1:07 PM on the 12th, they still have yet to estimate an economic loss.
     The best example of hype has focused more around the Fukushima nuclear facility. It is known that the cooling system failed and the Japanese government was forced to vent gas from the facility to prevent a meltdown. Beyond that different sources put it in varying lights. I personally was woken up this morning to be told that the entire facility had exploded including the containment, though I am unsure of where my personal source had got their fears. I quickly jumped on the web and was regaled with articles stating one of the reactors had experienced meltdown, that Japan was at a true risk of a Chernobyl style disaster, or as it really is, a building had exploded, but mostly everything would turn up alright, less than a Three-Mile Island.
     At this point I am still seeing these sensationalist phrases such as "Japanese Nuclear Reactor Explodes" which have half-truths in them and are baiting everybody. I watched a basic social media post turn into an all out verbal brawl over nuclear power's safety with the person against power citing articles at this point have been deem to solely be sensationalist without a fact around. Even my grand scientific network of BBC has been running sensational claims in the ticker, though the main stories are generally reliable.
     My personal fear about these sensational claims is though they do attract the world to this remarkable disaster, they also polarize people before they can make their decisions themselves. This disaster has happened at an interesting time in the energy community. Nuclear power has begun to regain stride as a possible alternative and it would be unfortunate to see it quelled again. We must remember this plant is mostly under control, it is better than Three-Mile was and not to mention it was an 8.9 earthquake followed immediately by a tsunami. The other plants in the network have been fine, they worked as they were meant to and they still have a strong future ahead of them. Lets not chicken out now.

Wednesday, March 9, 2011

Rocket Wednesday

     Though today is the final landing of Space Shuttle Discovery, I will not be focusing on it other than saying that it landed safely and cutting off the program here is halting an expensive but extremely useful asset in space research.
     No, what I am going to discuss is propulsion methods, or more precisely, Solar Sails. There are a variety of different propulsion methods in space from the currently used chemical propellants, to the more futuristic electrical, to the somewhat controversial nuclear option, and a variety of strange methods including the innovative solar sails.

We have come full circle in a way

     Contrary to what logic would dictate, space has wind, its just not exactly as it is here on Earth. When you are around a star, there is generally a very strong supply of photons heading out from the star (and by generally I mean always.) We observe this stream as light, but strangely enough though these particles theoretically have no mass, they hold a momentum and if they run up against an object, they can impart that momentum into the object. With enough photons bombarding a surface, especially if it is made to catch that momentum, and object should be able to theoretically move in space and gain up momentum, kinda like a sail on a sailing vessel would catch the winds momentum (physicists I know this isn't exactly true, it just works out).
      The sail will of course be attached to a satellite or a ship and will be retracted when the ship moves out of the path of the photon movement, thus it keeps up the momentum. The pros of the propulsion method is that it  requires no fuel and it can work over a fairly extensive range. The cons on the other hand are that it only works going outwards, for now at least, and that it is extremely delicate. Recently the first one was tried out and their main concern was that it wouldn't unfurl without tearing. Luckily it worked out.




May the stars shine brightly in your skies and check back next week for the nuclear option!

Tuesday, March 8, 2011

Is There Life Out There Or Are We Just The Stars Of A Lonely Party

     First off I would like to apologize for a lack of updates recently, some personal issues came up and I have had a hard time keeping a regular schedule.
     Nonetheless I had to poke my head up when the blogosphere erupted over news from the Journal of Cosmology. According to the Journal, Dr. Richard Hoover of NASA has stated that there is a chance that a meteorite that he was looking at has fossilized alien life. Pretty cool eh?

Hello there neighbor?
     Still, there are problems with this and I will lay them down:

  1. There is always risk of contamination, according to the article it is not a solid chunk of meteor, its fractured, and on top of that it didn't fall in some desolate wasteland, like Antarctica, where there is little in the way of life to crawl in, it fell in Africa, which is teeming with life.
  2. There is a chance that it isn't even life at all, there is much in the universe that looks like life but really isn't. I have looked at rocks which look like it has tracks, but these were just results of wind or tides. While these have a high carbon content which is promising, carbon is not solely unique to the kingdom of life.
  3. SPACE IS BIG and life is small. If you took a sample of Earth right now, yes it would likely have something like a piece of pollen, but go back a couple hundred million years, which is the maximum extent that life in our Solar system has got if it were to exist, and your probability of finding something drops down to around zero.
  4. Its happened before. We are constantly looking for life and getting duped. See 3 for why
     Do I hope that this is actually life? I do, I really do, it would just about be the most important scientific discovery of my lifetime were it to happen, this is my Higgs boson. I am not on the other hand holding any expectations of these claims, there is just too low a chance and too large a contamination ability.
     It would be cool though eh?

May the stars shine brightly in your skies.

Wednesday, March 2, 2011

Astro Fact: The Truth About Shooting Stars

     Once upon a time a wise animated cricket said something to do about dreams coming true and shooting stars, or maybe those were just immobile stars, oh well. Still when a shooting star passes overhead there is a mix of awe and fascination which is shocking for an event that lasts less than a second.
     If I were to ask how large a shooting star is, I image from experience that the range of size would be between the size of a small washing machine and a decent car; the truth on the other hand is significantly more brilliant given the effect. for the most part a normal shooting star is between the size of a letter in this article to at most the size of a golf ball. Shocking then is it that such a small object can give off such a large amount of light? Not really...
     When an object begins to fall into the atmosphere, it begins rubbing against atmospheric particles and while there aren't many atmospheric particles, the objects are moving very fast. Incredibly fast! That speed equals friction and that friction brings about heat and that heat messes with the external skin of the falling rock and that in turn emits a whole lot of light, for a second at least.
     For the most part these dust bits fall to Earth like snow but every once in a while one will fall down and impact, or at least get close to impacting. For the most part these rocks are fairly loose and they explode before they hit the ground, hence blast craters. Occasionally one will be harder and thus we get meteorites which can unveil the history of the solar system.
     Sometimes they also just pass through, say hello and go on their merry way, like the famous Grand Tetons Meteor of 1972.



May the stars shine brightly in your skies!

The One Where I Start Talking About Rockets

     Scientists can hypothesize as much as they want about what planets may lay outside our home, we can dream of lush worlds like Pandora from Avatar, desert wastelands like Tatooine from Star Wars, or intellectual paradises like Gallifrey from Dr. Who; none of it really matters much though if we have no means of making it to those places. While the news media is filled with talk of nearly Earth-sized planets being found, very few reports focus on the future of rocketry and space transport.
     Don't get me wrong, we have made some huge strides in how we get from the surface world up to space, the Saturn V rocket was a spectacular feat of human engineering. Still these can get us to the Moon, our nearest neighbor with a small price tag of 40 or so billion dollars for development and launch, 50-80 if you include everything to do with the program. Currently our main workhorse for human transport is the Space Shuttle, which as of writing, is nearly done with. While the Space Shuttle is advanced, its the equivalent of a shallow water barge when compared to the technology required for deep space travel.

pretty, yes, meant to handle the tortures of deep space, not at all
     On the other hand we have a vast array of launch vehicles not compatible with human flight. While most of these push small satellites up to the edge of space, a few of them have delivered payloads that are well outside the bounds of the traditional solar system. These, while fast, are impractical for humans, they are too small and they accelerate fast enough to turn your average astronaut into a splatter. So we need something that is reliable, like a Space Shuttle or Saturn V, or dare I say it, Buran Shuttle, but also meant for deep space, like one of Lockheed's army of rockets.

yes, the Russians had a shuttle, and admittedly, it was significantly cooler than ours
     There have been many designs proposed, such as attachments to the now cancelled Constellation program, but none have come to an actual building phase, which is unfortunate.
     So now comes my opinion; I feel we need space docks, we will never be able to make a ship that can truly efficiently and safely cross the vast distances (and times, see last astro fact) here on Earth, it will just waste too much material to leave the planet and theres a large risk at that point, especially with the cost and complexity of a ship like that. So we make a port in space where we can build ships from materials sent up from the Earth (or the moon, it costs less fuel) and we have no risk of a problem on launch, we use cheaper rockets to transport, and then when we take off, we send the astronauts up and board them in space, sure there is now crowning launch moment like what defined the Apollo program, but it is a significantly smaller risk.
     To keep people coming back, I will add a cliff hanger. Next time around on Rocket Wednesday I will discuss some rocket types that we could use efficiently in space and some of the problems associated with human space travel. See you back here then.

May the stars shine brightly in your skies!