August 17, 2010
Japanese Spacecraft Approaches Venus
For the next few months, Venus will be softly resplendent in the evening sky, a treat for stargazers – but looks can be deceiving. Consider this: The Venusian surface is hot enough to melt lead. The planet's 96% carbon dioxide atmosphere is thick and steamy with a corrosive mist of sulfuric acid floating through it. The terrain is forbidding, strewn with craters and volcanic calderas – and bone dry.
Takeshi Imamura can't wait to get there.
Imamura is the project scientist for Akatsuki, a Japanese mission also called the Venus Climate Orbiter. The spacecraft is approaching Venus and will enter orbit on December 7, 2010. Imamura believes a close-up look at Venus could teach us a lot about our own planet.
Takeshi Imamura can't wait to get there.
Imamura is the project scientist for Akatsuki, a Japanese mission also called the Venus Climate Orbiter. The spacecraft is approaching Venus and will enter orbit on December 7, 2010. Imamura believes a close-up look at Venus could teach us a lot about our own planet.
August 8, 2010
Cooling System Malfunction Highlights Space Station's Complexity
The recent cooling system malfunction aboard the International Space Station has underscored the intricacies of keeping the enormous orbiting complex properly functioning. The weekend glitch, which has not endangered the crew members currently living aboard the station, highlights the scope and challenge of maintaining the football field-size outpost.
"The ISS is probably the most complex engineering feat ever performed," NASA spokesman Kelly Humphries said in a telephone interview Monday.
Late Saturday, a pump module failed in one of the station's liquid ammonia cooling loops, forcing the astronaut crew aboard the ISS to power down some of the station's vital systems while engineers on Earth addressed the problem.
"The ISS is probably the most complex engineering feat ever performed," NASA spokesman Kelly Humphries said in a telephone interview Monday.
Late Saturday, a pump module failed in one of the station's liquid ammonia cooling loops, forcing the astronaut crew aboard the ISS to power down some of the station's vital systems while engineers on Earth addressed the problem.
July 31, 2010
James Webb Space Telescope completes cryogenic mirror test
Recently, six James Webb Space Telescope beryllium mirror segments completed a series of cryogenic tests at the X-ray & Cryogenic Facility at NASA's Marshall Space Flight Center in Huntsville, Alabama.
During testing, the mirrors were subjected to extreme temperatures dipping to -415° Fahrenheit (-248° Celsius), permitting NASA engineers to measure in detail how the shape of the mirror changes as it cools.
The mirrors will be shipped to Tinsley Corp. in Redmond, California, for final surface polishing at room temperature. Using "surface error" measurements, each mirror will then be polished in the opposite of the surface error values observed, so when the mirror goes through the next round of cryogenic testing, at Marshall, it should "distort" into a perfect shape.
During testing, the mirrors were subjected to extreme temperatures dipping to -415° Fahrenheit (-248° Celsius), permitting NASA engineers to measure in detail how the shape of the mirror changes as it cools.
The mirrors will be shipped to Tinsley Corp. in Redmond, California, for final surface polishing at room temperature. Using "surface error" measurements, each mirror will then be polished in the opposite of the surface error values observed, so when the mirror goes through the next round of cryogenic testing, at Marshall, it should "distort" into a perfect shape.
July 28, 2010
Will We Ever Travel At The Speed Of Light?
It would be terribly convenient to circumnavigate the Earth in a fraction of a second, to make a round trip to the Sun in just over a quarter of an hour, to go to Neptune and back in a workday. Modern life is too busy to waste time getting from here to there, and moving around at the speed of light--about 300000 kilometers per second--would take a lot of the labor out of travel.
Forget it, though. You'll never go that fast. Albert Einstein said so. His special theory of relativity had at its heart an astonishing claim: the speed of light in a vacuum is always the same, for all observers. This strange idea leads to even stranger consequences, including the fact that as an object goes faster, its mass increases (the reasons are very very complex, but it's been verified in particle accelerators). The faster you go, the harder it is to get yourself going faster still. As you near the speed of light, your weight heads for infinity, which makes it infinitely hard to go faster. So while we might reach 99% of light-speed, or even 99.99999%, the last little bit will forever lie just beyond our grasp.
So it seems unlikely we will be able to build a spacecraft capable of interstellar travel anytime soon. But just how fast can we go with today's technology? Speed records for spacecrafts have to be carefully defined. If we say, for example, that a spacecraft is traveling at 20,000 km/h, what is this relative to – the Earth, the Sun, or some other body?
Let's take for example conventional rockets. Any rocket can achieve a very high speed if it accelerates for a long time. A conventional rocket has a hard time doing this because a huge amount of fuel must be carried into space in order for this to happen. This may make the rocket too heavy to lift off. Conventional rockets are generally designed to meet the speeds necessary for them to go where they need to go, and not go much faster. Generally, a conventional rocket has to be going about 17,000 mph (27358 km/h) for it to achieve orbit; otherwise known as LEO -- Low Earth Orbit. This is the minimum speed for a spacegoing rocket. The farther from the Earth, the faster it needs to go. With increasing speed it becomes harder and harder to gain another mile per hour. This is because the amount of fuel one has to carry becomes really big, and it becomes difficult and expensive to lift that much fuel into space. Solar escape velocity (about 58741 km/h) is near the practical limit of how fast one can move with conventional rockets.
On the other hand the highest speed at which any spacecraft has ever escaped from the Earth is 35,800 mph (57,600 km/h) in the case of the New Horizons probe, which was launched in January 2006 and is now heading towards Pluto. This beats the 32,400 mph (52,100 km/h) Earth escape speed of the Jupiter probe Pioneer 10, launched in 1972, and the 34,450 mph (55,400 km/h) Earth escape speed of the solar probe Ulysses, launched in 1990. New Horizon's speed is so fast that the probe reached the distance of the Moon in only nine hours (compared to three days for the Apollo missions) and then reached Jupiter in just 13 months. However, as fast as that is, we are still a long long way from the unreachable 300000 km/s!!
Rami B.
Forget it, though. You'll never go that fast. Albert Einstein said so. His special theory of relativity had at its heart an astonishing claim: the speed of light in a vacuum is always the same, for all observers. This strange idea leads to even stranger consequences, including the fact that as an object goes faster, its mass increases (the reasons are very very complex, but it's been verified in particle accelerators). The faster you go, the harder it is to get yourself going faster still. As you near the speed of light, your weight heads for infinity, which makes it infinitely hard to go faster. So while we might reach 99% of light-speed, or even 99.99999%, the last little bit will forever lie just beyond our grasp.
So it seems unlikely we will be able to build a spacecraft capable of interstellar travel anytime soon. But just how fast can we go with today's technology? Speed records for spacecrafts have to be carefully defined. If we say, for example, that a spacecraft is traveling at 20,000 km/h, what is this relative to – the Earth, the Sun, or some other body?
Let's take for example conventional rockets. Any rocket can achieve a very high speed if it accelerates for a long time. A conventional rocket has a hard time doing this because a huge amount of fuel must be carried into space in order for this to happen. This may make the rocket too heavy to lift off. Conventional rockets are generally designed to meet the speeds necessary for them to go where they need to go, and not go much faster. Generally, a conventional rocket has to be going about 17,000 mph (27358 km/h) for it to achieve orbit; otherwise known as LEO -- Low Earth Orbit. This is the minimum speed for a spacegoing rocket. The farther from the Earth, the faster it needs to go. With increasing speed it becomes harder and harder to gain another mile per hour. This is because the amount of fuel one has to carry becomes really big, and it becomes difficult and expensive to lift that much fuel into space. Solar escape velocity (about 58741 km/h) is near the practical limit of how fast one can move with conventional rockets.
On the other hand the highest speed at which any spacecraft has ever escaped from the Earth is 35,800 mph (57,600 km/h) in the case of the New Horizons probe, which was launched in January 2006 and is now heading towards Pluto. This beats the 32,400 mph (52,100 km/h) Earth escape speed of the Jupiter probe Pioneer 10, launched in 1972, and the 34,450 mph (55,400 km/h) Earth escape speed of the solar probe Ulysses, launched in 1990. New Horizon's speed is so fast that the probe reached the distance of the Moon in only nine hours (compared to three days for the Apollo missions) and then reached Jupiter in just 13 months. However, as fast as that is, we are still a long long way from the unreachable 300000 km/s!!
Rami B.
July 24, 2010
Japanese Solar Sail Successfully Rides Sunlight
An unmanned probe riding a solar sail through space has felt its first accelerating push from sunlight in a successful test of its novel propulsion system, Japan's space agency has announced.
Observations of the Ikaros solar sail built by the Japan Aerospace Exploration Agency (JAXA) confirmed that the spacecraft has received a growing speed boost from light radiated by the sun, the space agency said.
Observations of the Ikaros solar sail built by the Japan Aerospace Exploration Agency (JAXA) confirmed that the spacecraft has received a growing speed boost from light radiated by the sun, the space agency said.
July 24, 2010
John Glenn: Keep US space shuttles flying
CAPE CANAVERAL, Florida--Mercury astronaut John Glenn wants NASA's space shuttles to keep flying until a reliable replacement is ready, no matter how long it takes.
Glenn joined the national debate last month over America's future in space and became the latest ex-astronaut to speak out on the matter. He issued a nine-page statement in which he questioned the decision to retire the shuttle fleet and rely on Russia to take astronauts to the International Space Station.
Glenn joined the national debate last month over America's future in space and became the latest ex-astronaut to speak out on the matter. He issued a nine-page statement in which he questioned the decision to retire the shuttle fleet and rely on Russia to take astronauts to the International Space Station.
July 21, 2010
Robot Blimps Could Soar on Other Worlds
Blimps and balloons are routinely used on Earth for aerial surveillance or to conduct research in hard-to-reach places. Similar unmanned flying vehicles, or aerobots, could open up new vistas in planetary exploration, providing an inexpensive way to observe large swaths of alien terrain without ever touching the ground.
July 13, 2010
Computer Program Learns to Sort Galaxies Like a Human
A computer algorithm modeled after the human brain has learned how to recognize different galaxy types ranging from spiral to elliptical, and can now help flesh-and-blood stargazers with the daunting task of classifying billions of galaxies.