Stories tagged space

Dec
26
2009

GOCE Satellite: The Gravity field and steady-state Ocean Circulation Explorer
GOCE Satellite: The Gravity field and steady-state Ocean Circulation ExplorerCourtesy ESA
Can it be true? Yes, for a mere $5,544 dollars round-trip airfare to Greenland! In March 2009, the European Space Agency launched the Gravity field and steady-state Ocean Circulation Explorer (GOCE) into orbit around our planet, which is now transmitting detailed data about the Earth’s gravity. The GOCE satellite uses a gradiometer to map tiny variations in the Earth’s gravity caused by the planet’s rotation, mountains, ocean trenches, and interior density. New maps illustrating gravity gradients on the Earth are being produced from the information beamed back from GOCE. Preliminary data suggests that there is a negative shift in gravity in the northeastern region of Greenland where the Earth’s tug is a little less, which means you might weigh a fraction of a pound lighter there (a very small fraction, so it may not be worth the plane fare)!

In America, NASA and Stanford University are also working on the gravity issue. Gravity Probe B (GP-B) is a satellite orbiting 642 km (400 miles) above the Earth and uses four gyroscopes and a telescope to measure two physical effects of Einstein’s Theory of General Relativity on the Earth: the Geodetic Effect, which is the amount the earth warps its spacetime, and the Frame-Dragging Effect, the amount of spacetime the earth drags with it as it rotates. (Spacetime is the combination of the three dimensions of space with the one dimension of time into a mathematical model.)

Quick overview time. The Theory of General Relativity is simply defined as: matter telling spacetime how to curve, and curved spacetime telling matter how to move. Imagine that the Earth (matter) is a bowling ball and spacetime is a trampoline. If you place the bowling ball in the center of the trampoline it stretches the trampoline down. Matter (the bowling ball) curves or distorts the spacetime (trampoline). Now toss a smaller ball, like a marble, onto the trampoline. Naturally, it will roll towards the bowling ball, but the bowling ball isn’t ‘attracting’ the marble, the path or movement of the marble towards the center is affected by the deformed shape of the trampoline. The spacetime (trampoline) is telling the matter (marble) how to move. This is different than Newton’s theory of gravity, which implies that the earth is attracting or pulling objects towards it in a straight line. Of course, this is just a simplified explanation; the real physics can be more complicated because of other factors like acceleration.

Albert Einstein
Albert EinsteinCourtesy none
So what is the point of all this high-tech gravity testing? First of all, our current understanding of the structure of the universe and the motion of matter is based on Albert Einstein’s Theory of General Relativity; elaborate concepts and mathematical equations conceived by a genius long before we had the technology to directly test them for accuracy. The Theory of General Relativity is the cornerstone of modern physics, used to describe the universe and everything in it, and yet it is the least tested of Einstein’s amazing theories. Testing the Frame-Dragging Effect is particularly exciting for physicists because they can use the data about the Earth’s influence on spacetime to measure the properties of black holes and quasars.

Second, the data from the GOCE satellite will help accurately measure the real acceleration due to gravity on the earth, which can vary from 9.78 to 9.83 meters per second squared around the planet. This will help scientists analyze ocean circulation and sea level changes, which are influenced by our climate and climate change. The information that the GOCE beams back will also assist researchers studying geological processes such as earthquakes and volcanoes.

So, as I gobble down another mouthful of leftover turkey and mashed potatoes, I can feel confident that my holiday weight gain and the structure of the universe are of grave importance to the physicists of the world!

Popular Mechanics summarizes how our knowledge of planets in the Solar System has changed over the last 30 years of space exploration.

Diviner Observes LCROSS Impact: The locations of the Diviner LCROSS impact swaths overlain on a grayscale daytime thermal map of the Moon’s south polar region.
Diviner Observes LCROSS Impact: The locations of the Diviner LCROSS impact swaths overlain on a grayscale daytime thermal map of the Moon’s south polar region.Courtesy NASA/GSFC/UCLA
So I totally missed that they crashed a probe on the moon last Friday? Where was I? I love this stuff, I can't believe I missed it! Not everyone was impressed.

Nov
08
2009

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LaserMotive wins $900,000 power beaming space elevator prize

An 11-pound contraption built by LaserMotive of Kent, Wash., successfully climbed up a kilometer high cable suspended from a helicopter in 4 minutes 2 seconds. This qualified them for $900,000. If they had done it in 3 minutes the prize would have been 1.1 million dollars. In four years of the power-beaming competition, LaserMotive is the only competitor to qualify for a cash prize.

Contests are getting the job done

Million dollar prizes are motivating research and development in areas that probably wouldn’t be done otherwise, said Andrew Petro, manager of NASA’s Centennial Challenges program. Many of these challenges have just finished.

Learn more about other Centennial challenges

Source
Winner in Contest Involving Space Elevator New York Times

Oct
25
2009

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$750,000 prize for moving dirt

NASA is using prize money to create innovative solutions to building a base on the moon. The Regolith Excavation Challenge promotes the development of new technologies to excavate lunar regolith (moving moon dirt). In order to qualify, a team must excavate at least 150kg (330 lbs) of lunar regolith simulant (JSC-1A) within 30 minutes. For the first time in three years, teams took home the prize money.

  • 1st Place, $500,000: Paul's Robotics, Moonraker Robot
    = 439 kg excavated
  • 2nd Place, $150,000: Terra Engineering
    = 270.6 kg excavated
  • 3rd Place, $100,000: Team Braundo
    = 263.75 kg excavated

To learn more use the links on the California Space Education and Workforce Institute website.

$2 million Lunar Lander Challenge finish this week

Stay tuned for more from the NASA Centennial Challenges as the Northrop Grumman Lunar Lander Challenge wraps up this week (Oct. 26 - 31). The Astronaut Glove Challenge will also take place on November 18-19 in Florida.

Armadillo Aerospace is winning again

Armadillo Aerospace took home $350,000 last year and has already qualified for a million dollars this year. Check out this FAQ page to learn how Armadillo was founded by DOOM and Quake computer game developer, John Carmack. Click this link to see videos, photos, and more about Armadillo Aerospace.

Water on the Moon

by Anonymous on Sep. 28th, 2009

The lunar surface: The Sea of Rains (lower plain) and Sea of Cold (upper plain) on the Moon's surface. Early astronomers may not have been completely wrong thinking the Moon's mare were oceans of water.
The lunar surface: The Sea of Rains (lower plain) and Sea of Cold (upper plain) on the Moon's surface. Early astronomers may not have been completely wrong thinking the Moon's mare were oceans of water.Courtesy NASA
Three separate sources have confirmed finding water on our Moon, according to a report in the journal Science. Although the Moon is still much dryer than any desert on Earth, the possibility of extracting water from the lunar surface could provide astronauts with a source of drinking water and fuel.

Well, Japan probably doesn't say "Go" exactly, because I don't think it means the same thing in Japanese. But the country is prepared to shell out $21 billion for a space-based, energy-beaming solar power plant.

The same sort of thing was talked about in this post, but that project was being lead by an upstart company, which kinda makes me think that their satellite power plant is a long way off. Japan wants the technology ready inside of four years. (They don't expect the plant to be operating until about twenty or thirty years from now, though.)

The plan is for the satellite to produce about 1 gigawatt. From my super-lazy internet searches, it looks like that's about the same output as a nuclear power plant. Nuclear power plants are cheaper to build (this site says the cost can be around $10 or $15 billion per station), and you don't have to go into space to fix them. But then there's also the cost of obtaining and processing nuclear fuel, and then dealing with it afterwards. Apples and oranges, maybe.

But it's kind of an interesting project, I think.

Aug
30
2009

Chandrayaan-1 lunar image: Taken over the equatorial region of the Moon by Chandrayaan-1, the picture shows the uneven surface of the Moon with numerous craters. On the lower left, part of the crater Torricelli is seen.
Chandrayaan-1 lunar image: Taken over the equatorial region of the Moon by Chandrayaan-1, the picture shows the uneven surface of the Moon with numerous craters. On the lower left, part of the crater Torricelli is seen.Courtesy Indian Space Research Organisation
Indian space scientists lost contact with the Chandrayaan-I lunar orbiter today, and as a result were forced to declare the mission over. Chandrayaan-I operated for only 312 days, less than half of the intended two-year mission.

Chandrayaan-I was India’s first lunar probe and carried payloads from the United States, the European Union and Bulgaria. Chandrayaan-I’s primary missions were to take high-resolution images of the lunar surface, to search for water or ice and to identify the chemical composition of certain lunar rocks.

Even with the shortened mission, officials say that Chandrayaan-I met most of these scientific objectives during its more than 3,400 orbits of the moon.

Chandrayaan's imagery will be used to aid in identifying regions that will be explored in detail later by NASA's Lunar Reconnaissance Orbiter (currently in orbit around the moon) in establishing a future potential lunar base.

Interested in lunar research? Here’s a list of all current and planned lunar missions.