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[Windu]

 

[Windu]

more here

 

[Tom_Cody]

Status update of the Ares 1-X test flight:

The post of NASA administrator is still unfilled as Obama is putting other priorities ahead of the future of manned space flight. The more time passes, the more likely it seems that Bush's Vision for Space Exploration will go ahead unaltered. Nothing in NASA's future would make me happier than seeing The Vision continue. Man on Mars by 2030 here we come!

 

[Windu]

Are these things reusable? Or do they build a new one for every flight.

 

[Tom_Cody]

Are these things reusable? Or do they build a new one for every flight.

Once they become operational, the solid rocket booster (the narrow lower portion) will be reusable. The Ares I carries the Orion CEV (crew exploration vehicle) into orbit and that will be reusable as well.

The SRBs in the Ares I are actually slightly modified from the dual SRBs currently used on the space shuttle. The Ares I-X test flight will actually use an unmodified shuttle SRB.

 

[Memphis Reigns]

Status update of the Ares 1-X test flight:



The post of NASA administrator is still unfilled as Obama is putting other priorities ahead of the future of manned space flight. The more time passes, the more likely it seems that Bush's Vision for Space Exploration will go ahead unaltered. Nothing in NASA's future would make me happier than seeing The Vision continue. Man on Mars by 2030 here we come!

UGH this makes me so furious. I understand our country has issues right now but they have been constantly putting the space administration on the back burner for too long now. We are still using the same fucking propulsion technology we used when we first went to the moon! I swear once this recession is over NASA better get some attention because i'll be damned if I'm going to die without seeing a man on Mars. Not acceptable

 

[Tom_Cody]

UGH this makes me so furious. I understand our country has issues right now but they have been constantly putting the space administration on the back burner for too long now. We are still using the same fucking propulsion technology we used when we first went to the moon! I swear once this recession is over NASA better get some attention because i'll be damned if I'm going to die without seeing a man on Mars. Not acceptable

The only two near-term next generation propulsion options are thermo-nuclear and nuclear-electric ion drive. Neither are suited to sub-orbital applications. The Ares I (crew transportation) and Ares V (heavy lifter) are about as good as you could hope for in this application.

Both thermo-nuclear and nuclear-electric ion drive would be fantastic (and cost effective) options for interplanetary travel, but they have both fallen victim to politics.

Thermo-nuclear has been under development since the 50s, but it really is an inferior option compared with nuclear-electric ion drive (I can explain why if you want me to).

NASA actually uses solar-electric ion drive in some applications in unmanned close-to-the-sun missions and Russia even uses solid-state nuclear electric propulsion in some of their satellites. If we end up going to Mars, it would actually be more cost effective to use nuclear-electric ion drive, but only if we go to Mars. Unfortunately the Vision for Space Exploration calls for building a moon base first, so everything is being planned with moon operations taking top priority.

NASA actually was developing a nuclear-electric ion drive equipped unmanned mission, but it was scrapped. The mission was called JIMO (Jupiter Icy Moons Orbiter) and it was going to be a flagship mission in NASA's post-shuttle future before the Columbia tragedy happened. In the aftermath of Columbia, NASA's course was altered with a greater emphasis on manned missions so funding was diverted from JIMO and it went away.

In order to implement nuclear-electric ion drive it would take a roughly 5 billion dollar investment, but going forward every mars (or further) mission would have a faster, less expensive, and (most importantly) fuel efficient alternative.

 

[Windu]

Unusual Dusty Galaxy NGC 7049

Click For Bigger Image

How was this unusual looking galaxy created? No one is sure, especially since spiral galaxy NGC 7049 looks so strange. NGC 7049's strikingly appearance is primarily due to an unusually prominent dust ring seen mostly in silhouette. The opaque ring is much darker than the din of millions of bright stars glowing behind it. Besides the dark dust, NGC 7049 appears similar to a smooth elliptical galaxy, although featuring surprisingly few globular star clusters. NGC 7049 is pictured above as imaged recently by the Hubble Space Telescope. The bright star near the top of NGC 7049 is an unrelated foreground star in our own Galaxy. Not visible here is unusual central polar ring of gas circling out of the plane near the galaxy's center. Since NGC 7049 is the brightest galaxy in its cluster of galaxies, its formation might be fostered by several prominent and recent galaxy collisions. NGC 7049 spans about 150 thousand light years and lies about 100 million light years away toward the constellation of Indus.

 

[Calculon]

That picture with the backlit panels is crazy.

 

[Tom_Cody]

http://www.youtube.com/watch?v=yJ1jyneFWeU

The Soyuz undocked from the station at 11:55 p.m. for a landing in Kazakhstan at 3:16 a.m. Wednesday. Russian recovery teams and NASA personnel are prepared to reach the crew by helicopter shortly afterwards, even in the event of a ballistic landing.

A Soyuz eye view of an undocking from the ISS complete with a cyryllic-filled HUD. You probably won't want to watch the entire video, but it's worth checking it out.

After this undocking occurred, the Soyuz just landed in Kazakhstan 3 hours ago.

http://www.cbsnews.com/stories/2009/04/08/tech/main4927948.shtml

 

[Twig]

In order to implement nuclear-electric ion drive it would take a roughly 5 billion dollar investment, but going forward every mars (or further) mission would have a faster, less expensive, and (most importantly) fuel efficient alternative.

Now I don't actually know anything about this stuff, but this topic came up in a conversation I was having today and I brought up the nuclear-electric ion drive.

I was told ion drives would take years to actually power up or something? Wouldn't that be a huge downside? Was duder just an idiot or what?

Color me inquisitive.

 

[Tom_Cody]

Now I don't actually know anything about this stuff, but this topic came up in a conversation I was having today and I brought up the nuclear-electric ion drive.

I was told ion drives would take years to actually power up or something? Wouldn't that be a huge downside? Was duder just an idiot or what?

Color me inquisitive.

The short answer is "days, not years". This is sort of difficult to explain without getting too technical, but I'll try.

Rocket propulsion is governed by the conservation of momentum equation, MV=MV. In order to accelerate a rocket you need to expel mass at a high velocity. The higher the velocity the mass is expelled at, the more acceleration you will get from a unit weight of fuel.

Relative to nuclear-electric ion drive, chemical rockets expel their mass of fuel much more quickly, but at a lower velocity. When you see all that exhaust from a rocket engine, that is the mass that is being expelled that accelerates the rocket.

Nuclear-electric ion drive expels it's fuel at a much higher velocity, but the mass does not come out at as high a rate.

You can accelerate a rocket in space to as a high a velocity you want, but you are limited by the amount of fuel you want to send into orbit. The acceleration per unit/weight of fuel (referred to as specific impulse) is much greater for nuclear-electric ion drive.

Essentially what your friend is referring to it the characteristic of nuclear-electric ion drive that the initial acceleration is slower, but it can continue for an extended period of time, thus producing a higher eventual velocity. This is the reason that the technology is only suited to mars-and-farther missions and not our near-future activities on the moon (as I mentioned in my previous post).

 

[Twig]

Roger. Thanks for the explanation. I understand that perfectly.

 

[Tom_Cody]

Roger. Thanks for the explanation. I understand that perfectly.

I'm glad. At a certain point while I was writing I started to fear that it would come out as babble.

 

[DaCocoBrova]

I'm glad. At a certain point while I was writing I started to fear that it would come out as babble.

So...are you a rocket scientist?

 

[DarkJediKnight]

Some awesome pictures in here. Keep it up guys.

 

[Windu]

So...are you a rocket scientist?

He probably just stayed at a Holiday Inn.

 

[Windu]

What was the worst disaster in the history of space travel? - question from Marcus​

If you are referring to manned space exploration, the two tragedies that resulted in the greatest loss of life were the destruction of the American space shuttles Challenger and Columbia. Each accident claimed the lives of seven astronauts.

However, another event that occurred in the Soviet Union in 1960 is generally recognized as the single greatest disaster in the history of rocketry. The event was not directly related to manned space flight, but to the development of an intercontinental ballistic missile (ICBM). In the early days of space flight, both the US and Soviet space programs were very much intertwined with the development of ICBMs. These vehicles were designed to launch nuclear warheads over great distances, leaving no part of the world safe from the threat of nuclear destruction. However, the technologies pioneered for these weapons of war served a secondary purpose of providing the first generation of rockets for space exploration.

Sputnik on the launch pad being prepared for liftoff

In fact, the early flights of Sputnik and Yuri Gagarin in the USSR as well as those of Explorer I and John Glenn in the US were all conducted using modified ballistic missiles. The primary Soviet launch vehicle of the period was the R-7 rocket, modified versions of which are still used even today for most Russian space flights. The R-7 was originally developed as an ICBM under the direction of Sergei Korolev, the Soviet Union's pre-eminent rocket designer of the day. The R-7 successfully completed a number of test flights between 1957 and 1959, including launching the first two artificial satellites. While only four examples of the R-7 were ever deployed as ballistic missiles from 1960 to 1968, the same basic design has remained in use throughout the Russian space program. Modern variants of the R-7 continue to launch satellites as well as manned Soyuz flights, and the type had achieved a success rate of nearly 98% in over 1,600 launches by the year 2000.

R-7 rocket

However, a competing rocket designed by Korolev's former assistant Mikhail Yangel was also under development in the late 1950s. This new rocket, the R-16, was a more powerful ICBM intended to supersede the R-7. The R-7 had been deemed impractical for military use because it needed cryogenically cooled liquid oxygen as a propellant, which necessitated complex storage and fueling systems. The R-16 ICBM was instead designed to use fuels that were easier to store, giving the missile a much faster response time. Since the R-16 was considered a top priority by Soviet leadership, oversight of the project was given to Marshal of Artillery Mitrofan Nedelin, the commander of the Soviet Strategic Rocket Forces (or nuclear missile forces).

Marshal Mitrofan Nedelin and Mikhail Yangel

Under Marshal Nedelin's prodding, the design team worked furiously to complete the first R-16 rocket as soon as possible. Although the development was hampered by numerous unsolved technical problems, chief designer Yangel reluctantly agreed to deliver the first missile to the test range at what is now the Baikonur Cosmodrome in September 1960. Both Nedelin and Yangel hoped to please Premier Nikita Khrushchev by demonstrating a successful launch of the R-16 prior to November 7, the anniversary of the Bolshevik Revolution.

Nevertheless, technical problem with the flight control system continued to plague the test preparations. Despite these obstacles, the rocket was moved from the assembly building to the launch pad at a location called Site 41 on October 21. At this point, fueling of the rocket with its toxic and highly corrosive propellants began. Proper safety protocols insisted that all non-essential personnel evacuate the area during fueling operations in case of an accident. However, Nedelin ignored these regulations and reportedly set up a chair at the pad from which he could oversee the arrangments. Approximately 150 other civilian and military personnel also stayed at the site under his direction.

As preparations for the launch continued, increasingly more fuel leaks and electrical problems began to emerge. On October 23, a number of electrical faults occurred that prevented the propellant pumps from working properly. The rocket would have to be drained of fuel before beginning repairs, but Marshal Nedelin refused to do so since it would delay the launch by at least several hours. He instead ordered workers to perform their repairs on the rocket while its dangerous propellants were still aboard.

R-16 intercontinental ballistic missile

Repairs continued to drag on the next day prompting Nedelin to demand to be taken to the pad "to figure out what's going on." In addition to Nedelin and his subordinates, Yangel and a number of visiting dignitaries were also taken to the pad to personally direct the pre-launch operations. The presence of so many powerful figures put great stress on the workers, and the situation was only made worse by pressure from Moscow to launch as soon as possible. Many tests and other operations were being conducted simultaneously, and safety procedures were neglected to save time.

The most significant oversight involved a device called the Programming Current Distributor (PTR) that activates various systems on the rocket. Following a test, the PTR was accidentally set to the wrong position. This mistake caused the batteries and propellant lines on the rocket to be activated, meaning that only a single valve prevented the rocket engines from being ignited prematurely. When a technician accidentally reset the PTR, that last safeguard was removed, and a horrible sequence of events was set into motion.

At about 6:45 PM, with some 250 personnel and visitors crowded around the launch pad, the second stage rocket engine of the R-16 ignited. The exhaust immediately ripped through the fuel tank in the first stage, creating a massive explosion that sprayed acidic chemicals across the launch complex. The luckiest were those who were instantly incinerated in the ensuing fireball that engulfed the rocket. Others died more slowly as they were burned while trying to escape through the raging inferno. Still more were able to evacuate the immediate vicinity only to be suffocated by the poisonous gases created by the burning propellants.

Catastrophic explosion of the R-16

Massive explosions continued to rock the launch pad for about 20 seconds, and the subsequent fires lasted for two hours. The blast was reportedly visible as far as 30 miles (50 km) away. Below are quoted some descriptions of the disaster from witnesses to the dreadful events:

"At the moment of the explosion I was about 30 meters from the base of the rocket. A thick stream of fire unexpectedly burst forth, covering everyone around. Part of the military contingent and testers instinctively tried to flee from the danger zone, people ran to the side of the other pad, toward the bunker...but on this route was a strip of new-laid tar, which immediately melted. Many got stuck in the hot sticky mass and became victims of the fire...The most terrible fate befell those located on the upper levels of the gantry: the people were wrapped in fire and burst into flame like candles blazing in mid-air. The temperature at the center of the fire was about 3,000 degrees. Those who had run away tried while moving to tear off their burning clothing, their coats and overalls. Alas, many did not succeed in doing this."

"...automatic cameras had been triggered along with the engines, and they recorded the scene. The men on the scaffolding dashed about in the fire and smoke; many jumped off and vanished into the flames. One man momentarily escaped from the fire but got tangled up in the barbed wire surrounding the launch pad. The next moment he too was engulfed in flames."

"Above the pad erupted a column of fire. In a daze we watched the flames burst forth again and again until all was silent...(After the fires had been extinguished,) all the bodies were in unique poses, all were without clothes or hair. It was impossible to recognize anybody. Under the light of the moon they seemed the color of ivory."​

The lives of Yangel and a few other high ranking officials were spared since they had stepped into a bunker to take a break mere minutes before the explosion. Many others, including some of the most prestigious pioneers of the Soviet space program, were not so lucky. Among those killed were:

• Marshal Mitrofan Nedelin, commander of Soviet Strategic Rocket Forces
• Boris Konoplev, chief designer of the R-16 control system
• Lev Grishin, deputy chairman of State Committee for Defense Technology
• Colonel A. Nosov, chief of the Baikonur launch command who had personally launched Sputnik in 1957
• Colonel Nikolai Prokopov, deputy chief of the directorate of missile troops and equipment
• Tyuratam Grigoryants, chief of the directorate responsible for R-16 testing
• Evgeniy Ostashev, chief of the directorate responsible for R-7 testing who had developed the booster rocket for Sputnik
• V. Kontsevskoi and Lev Berlin, two of Yangel's deputies and chiefs of test directorates

An investigation into the tragedy was immediately ordered by Nikita Khrushchev and headed by Leonid Brezhnev, future leader of the Soviet Union. The commission set the official death toll at 90. This tally included 74 who perished in the initial explosion, 57 of them military personnel and another 17 civilians. A further 49 were injured, and 16 of these later died of their wounds. An additional two bodies of suffocated soldiers were found after the official report was completed, raising the official toll to 92 (74 military and 18 civilians).

However, the true casualty list has always remained a mystery. More recent investigations have estimated the death toll as high as 200. The best estimate, however, appears to be around 122 fatalities. This value includes 74 killed in the blast and 48 who died over subsequent weeks from injuries due to burns or exposure to toxic chemicals. Of those killed, 84 were military officers or enlisted technicians while 38 were civilian engineers.

People attempting to escape the R-16 fire

In determing the origin of the disaster, the commission ultimately concluded that,

"The direct cause of the accident was the shortcomings in the design of the control system, which allowed unscheduled operation of the of the EPK V-08 valve controlling the ignition of the main engine of the second stage during pre-launch processing. This problem was not discovered during all previous tests. The fire on the vehicle...could have been avoided if the reconfiguration of the current distributor into a zero position was conducted before the activation of the onboard power supply."​

The report went on to blame the massive death toll on the actions of those who ignored or did not enforce proper safety procedures. Those responsible put too much confidence in the safe performance of the R-16 rocket under extreme conditions without proper analysis to justify their decisions.

Before proceeding with the R-16 program, the commission recommended more extensive testing of the control system and a re-evaluation of the pre-launch sequence to improve safety procedures. Even so, the willingness of the Soviet leadership to risk sacrificing more lives in pursuit of their political goals is rather shocking. The commission went on to recommend repairing the launch pad within two weeks and resuming the test program as soon as November!

Remains of the R-16 rocket after the fire

Despite this optimism, the next launch attempt was not made until February 1961, and it too ended in failure when the rocket crashed during flight. The R-16 program continued to suffer after the loss of so many of the nation's most experienced rocket engineers, and it was not until June 1963 that the missile was finally accepted for military service. The R-16 and improved R-16U remained in use until 1974 when the type was eliminated under the first Strategic Arms Limitation Treaty (SALT-1).

Perhaps one of the most remarkable aspects of what has commonly become known as the Nedelin Disaster or Nedelin Catastrophe is how successful the Soviet Union was in covering up the event. Marshal Nedelin is still regarded as a hero to the Russian people for his service during World War II, and his untimely death was explained away as an aircraft accident. Families of those killed in the disaster were never told the truth, though rumors of an accident did spread as people realized that so many rocket experts had died around the same time. Western observers occasionally heard some of these rumors from defectors, but the stories became mixed with other unrelated events and were never taken seriously. It was only after the fall of communism in 1990 that the true scope of the Nedelin Disaster finally became public.

Today, the location of the explosion at Site 41 is an empty and abandoned lot at the edge of the Baikonur Cosmodrome. The site is marked only by a small monument containing the names of those who perished and a map illustrating the layout of the old launch complex. Elsewhere on the base is a single coffin containing the remains of those who could not be identified. The coffin was buried in Leninsk Park and is now covered by a small grassy mound and fenced in. It was not until three years after the disaster that local officials were allowed to erect a memorial obelisk over the site. The memorial lists the names of 54 victims of the blast who were never identified. It is because of their needless sacrifice that 24 October 1960 will forever be remembered as one of the darkest days of the space race.

Few sources have definitively documented the events that led up to the Nedelin Disaster, but it is discussed in other excellent books about Soviet rocketry. Among them is Korolev: How One Man Masterminded the Soviet Drive to Beat America to the Moon that describes many of the political battles waged between Sergei Korolev and Marshall Nedelin or Mikhail Yangel. Additional information can be found in Asif Siddiqi's Sputnik and the Soviet Space Challenge.
- answer by Joe Yoon, 6 June 2004

http://www.aerospaceweb.org/question/spacecraft/q0179.shtml

 

[Memphis Reigns]

Tom Cody post

Awesome post thanks for that information. I did not know about the cancellation of the JIMO project. The Moon is going to be the gateway to interplanetary space travel, and I do believe the plans for a Moon base are in the works, are they not? By 2020 or so? Once that happens it will open it up for possible advances in propulsion tech since it will be so much cheaper even to launch from the moon (less fuel and force needed since gravity is so low). But ultimately the answer is going to be in the Ion drive. I am just bitter that I won't get to see the big jumps in space travel: wormholes, near lightspeed flight, etc.

I'm 24 and healthy and will probably make it to my 80s or 90s. That will be the year 2075. If by that time we have not made it to Mars or even beyond, our planet is in trouble. Because if we don't develop the tech now, sooner or later we will need it for when humans are forced to leave.

 

[DarkJediKnight]

Tom Cody post

I'm 24 and healthy and will probably make it to my 80s or 90s. That will be the year 2075. If by that time we have not made it to Mars or even beyond, our planet is in trouble. Because if we don't develop the tech now, sooner or later we will need it for when humans are forced to leave.

I think we'll be a dead duck until another race brings us jump gate technology. :lol

 

[Rindain]

Tom Cody post

I think we'll be a dead duck until another race brings us jump gate technology. :lol

When we have no choice but to leave Earth, humanity will put its entire effort behind space travel research, and we'd have starships in a matter of decades.

Imagine if we put as much effort and money into interstellar space travel as we did into winning WW2.

 

[camineet]

Oh look at all the galaxies. I've never felt so unspecial, but in a good way.

There is a God!

 

[Tom_Cody]

So...are you a rocket scientist?

I just like dorking around on NASA's websites.

Awesome post thanks for that information. I did not know about the cancellation of the JIMO project. The Moon is going to be the gateway to interplanetary space travel, and I do believe the plans for a Moon base are in the works, are they not? By 2020 or so? Once that happens it will open it up for possible advances in propulsion tech since it will be so much cheaper even to launch from the moon (less fuel and force needed since gravity is so low). But ultimately the answer is going to be in the Ion drive. I am just bitter that I won't get to see the big jumps in space travel: wormholes, near lightspeed flight, etc.

The idea of a spaceport has never really materialized. The ISS went through numerous design iterations before they arrived at it's current form and at one point it was going to serve as a refueling station of sorts to support activities on the moon and mars. This idea has been largely abandoned in the past 15-20 simply because it would require a major long-term commitment to justify itself. Instead our activities on the moon are going to be more similar to what we did with the ISS: a base constructed of modular components that will serve to teach us more about long duration stays in space.

The first manned moon mission of Project Constellation is scheduled for 2019. Wikipedia has a great listing of currently planned Constellation missions:

http://en.wikipedia.org/wiki/List_of_Constellation_missions

 

[Windu]

50th Anniversary of the Mercury 7 Press Announcement

Wikipedia Page

 

[Tom_Cody]

50th Anniversary of the Mercury 7 Press Announcement

Wikipedia Page

click for high res



Slightly cleaned up version. I just printed this out for framing yesterday by total coincidence (I hadn't seen Windu's post). I was going to post this a few days ago, but GAF was acting up and I never got back to it.

In the scope of the history of space travel, the assembly of the 'Mercury Seven' group is probably not that significant, but that image always stirs up something inside of me.

Here's an excerpt from The Right Stuff, the popular book made into the popular movie about the Mercury Seven:

As to just what this ineffable quality was. . .well, it obviously involved bravery. But it was not bravery in the simple sense of being willing to risk your life... any fool could do that... No, the idea... seemed to be that a man should have the ability to go up in a hurtling piece of machinery and put his hide on the line and then have the moxie, the reflexes, the experience, the coolness, to pull back in the last yawning moment – and then to go up again the next day, and the next day, and every next day... There was ... a seemingly infinite series of tests. ... a dizzy progression of steps and ledges, a ziggurat, a pyramid extraordinarily high and steep; and the idea was to prove at every foot of the way up that pyramid that you were one of the elected and anointed ones who had the right stuff and could move higher and higher and even – ultimately, God willing, one day – that you might be able to join that special few at the very top, that elite who had the capacity to bring tears to men's eyes, the very Brotherhood of the Right Stuff itself.

I'm going to write a longer post about this in a few days. I love this topic.

 

[Lost Fragment]

Random physics question: why is it that planets tend to have their axes going in the same general direction?

 

[Scrow]

Random physics question: why is it that planets tend to have their axes going in the same general direction?

i didn't think they did? don't their axes vary greatly?

in any case... if they DO have a similar axis i imagine it has something to do with their orbit around the sun and the effect its gravity has on it.

 

[Lost Fragment]

i didn't think they did? don't their axes vary greatly?

in any case... if they DO have a similar axis i imagine it has something to do with their orbit around the sun and the effect its gravity has on it.

The tilt, I mean. Uranus is the only planet with a horizontal tilt IIRC.

 

[fallout]

EDIT: Yikes! That's what I get for leaving a tab open at work for so long.

Random physics question: why is it that planets tend to have their axes going in the same general direction?

Little unsure what you mean by this (i.e. rotational direction of planet or the tilt), but it's bound by the same properties that govern a spinning top ... good old angular momentum. There's obviously more to it than just "angular momentum", but that's about the best reason I can give without reviewing a bunch of physics. Generally speaking, everything was spinning in the same direction before the solar system was formed, and that's how everything continues to spin.

Related trivia: Uranus rotates perpendicular to us. The only theory I've seen proposed for this is that it was related to a massive collision that knocked it off-axis.

 

[Scrow]

Little unsure what you mean by this (i.e. rotational direction of planet or the tilt), but it's bound by the same properties that govern a spinning top ... good old angular momentum. There's obviously more to it than just "angular momentum", but that's about the best reason I can give without reviewing a bunch of physics. Generally speaking, everything was spinning in the same direction before the solar system was formed, and that's how everything continues to spin.

Related trivia: Uranus rotates perpendicular to us. The only theory I've seen proposed for this is that it was related to a massive collision that knocked it off-axis.

why does the moon not spin?

 

[fallout]

why does the moon not spin?

It does spin. It just happens that it takes the same amount of time to rotate on its own axis as it does to rotate around the Earth.

 

[shortstop]

It does spin. It just happens that it takes the same amount of time to rotate on its own axis as it does to rotate around the Earth.

not only that, it also wobbles a little (an effect called libration). See the following animation:

http://apod.nasa.gov/apod/image/9911/lunation_ajc.gif

 

[bone idle]

EDIT: Yikes! That's what I get for leaving a tab open at work for so long.

Little unsure what you mean by this (i.e. rotational direction of planet or the tilt), but it's bound by the same properties that govern a spinning top ... good old angular momentum. There's obviously more to it than just "angular momentum", but that's about the best reason I can give without reviewing a bunch of physics. Generally speaking, everything was spinning in the same direction before the solar system was formed, and that's how everything continues to spin.

Related trivia: Uranus rotates perpendicular to us. The only theory I've seen proposed for this is that it was related to a massive collision that knocked it off-axis.

I've read that collisions between large planetary bodies were common during the early (first few 100 MYs) life of our solar system. Possibly responsible for the Uranus tilt, Earth's tectonics and large moon, the eccentricity of the orbit of Mars, Venus having such a long year, Saturn's rings, the asteroid belt, and so on. It seems the characteristics/quirks of a particular solar system are dependent on what happened during these early years. We'll know a lot more when Kepler and other orbital telescopes come online. Can't wait!

 

[speedpop]

Since the discussion is slightly on the moon, I figured I'd search up a decent image of the side that we never see.

 

[xBerserker]

Since the discussion is slightly on the moon, I figured I'd search up a decent image of the side that we never see.

Interesting, never thought about that.

 

[fallout]

http://en.wikipedia.org/wiki/Far_side_of_the_Moon

Little bit more at the Wiki there for anyone that's interested.

 

[Windu]

Behind the Scenes of Designing Lunar Living Spaces

Also, you can find more Nasa Youtube videos here.

 

[Windu]

NASA Names Node on "Colbert Report"

 

[Anticitizen One]

Does anyone know what happened to Bush's "Vision for space exploration" that involved setting up permanent colonies on Moon and Mars? It sounded awsome.

What is Obama's stance on space travel? I hope hes not one of those "hur no need" kind of people like Bill Clinton was.

 

[fallout]

What is Obama's stance on space travel? I hope hes not one of those "hur no need" kind of people like Bill Clinton was.

Obama was going to cut NASA funding, but thankfully backed down on that. Still, I don't think he's too keen on exploring space.

 

[Windu]

• Space shuttle Discovery STS-119 launch
• First Space Shuttle Launch - STS-1
• Space Shuttle STS-119 Launch 3-15-09
• Space Shuttle Launch (doesn't say which one)
• STS-119 Space Shuttle Landing
• Space Shuttle Discovery Sunset Launch....while skydiving.
• Space Shuttle STS117 Launch
• International Space Station and Discovery Space Shuttle Flybys 3-16-09
• Nasa shuttle launch Atlantis
• Space Shuttle carried on 747 on low approach
• STS 127 Endeavour Rollover
• STS 119 HD ISS Fly Around Sped Up
• Earth view from ISS window
• Earth view from spinning Space Shuttle
• Constellation Animation
• STS 119 HD Flight Day 3 Highlights
• Bruce McCandless in Orbit (from the When we left Earth Series)
• Space Shuttle HD
• Live Video Interview from the ISS

• 
  [*]NASAtelevision
• ReelNASA

 

[Tom_Cody]

Does anyone know what happened to Bush's "Vision for space exploration" that involved setting up permanent colonies on Moon and Mars? It sounded awsome.

What is Obama's stance on space travel? I hope hes not one of those "hur no need" kind of people like Bill Clinton was.

Obama took multiple contradictory stances during his campaign but he has made no changes since getting elected. He actually hasn't even chosen his NASA administrator yet (Bush's associate administrator is now acting administrator).

As a firm supported of The Vision for Space Exploration, I say no news is good news. The first test flight of the Ares-IX, NASA's next generation human rocket, is taking place in July. The closer we get to that date without hearing from Obama, the greater the chance The Vision will continue. I've made periodic updates on the Ares-IX in this thread. If you're interested you can check out the past few pages.

 

[Windu]

• Tour the International Space Station
• Hubble Operations Control Room
• International Space station - Life in Orbit
• Views of Earth from Space Station
• STS 119 Hatch Opening

 

[Windu]

Flowing Barchan Sand Dunes on Mars

Click For Bigger Image:

When does Mars act like a liquid? Although liquids freeze and evaporate quickly into the thin atmosphere of Mars, persistent winds may make large sand dunes appear to flow and even drip like a liquid. Visible on the above image right are two flat top mesas in southern Mars, where the season is changing from Spring to Summer. A light dome topped hill is also visible on the far left of the image. As winds blow from right to left, flowing sand on and around the hills leaves picturesque streaks. The dark arc-shaped droplets of fine sand are called barchans, and are the interplanetary cousins of similar Earth-based sand forms. Barchans can move intact downwind and can even appear to pass through each other. Over the past few weeks, winds on southern Mars have been kicking up dust and are being watched to see if they escalate into another of Mars' famous planet-scale sand storms.

 

[Scrow]

Not sure if this series of documentaries has been mentioned in this thread yet, but I highly recommend them.

http://en.wikipedia.org/wiki/When_We_Left_Earth

When We Left Earth: The NASA Missions is a Discovery Channel HD documentary miniseries consisting of six episodes documenting human space exploration of the past 50 years, spanning from the first Mercury flights through the Gemini program to the Apollo moon landings, the Space Shuttle, and the construction of the International Space Station. It was created in association with NASA to commemorate the agency's fiftieth anniversary in 2008.

Totally awesome and very informative. I learnt lots I didn't know about the early days of journeying to space.

 

[Windu]

Yeah I have seen the last couple episodes of that series. I set my DVR to record the series but they don't air it much any more. I guess I will have to go out and get it because I liked the episodes I saw.

 

[fallout]

Totally awesome and very informative. I learnt lots I didn't know about the early days of journeying to space.

I really recommend checking out From the Earth to the Moon. You can find it just anywhere at a decent price.

 

[Windu]

I tried this Tineye.com (I just found out about it from another post on GAF.) thingy out on some of the pictures in this thread.

Anyway, not sure if anyone posted a bigger picture of the The Orion Nebula which I posted in the OP, but here it is:

http://esamultimedia.esa.int/images/hubble/heic0601a_H.jpg

Just wanted to test the website out, pretty easy to find bigger images this way.

 

[Darklord]

Whats the blue glow around it? It's huge.

 

[Memphis Reigns]

I was playing around on the Kepler website and found this neat calculation game that finds hypothetical Earth-like planets. I did it a few times and got 1 habitable planet.

http://kepler.nasa.gov/ed/xo/