Archive for the ‘Satellites’ Category

Unstoppable Flying Robots

Tuesday, May 9th, 2006

What’s that in the sky? A bird? A plane? No, it’s a flying robot. An unstoppable flying robot, according to some experts. 

The technology for remote-controlled light aircraft is now highly advanced, widely available — and, experts say, virtually unstoppable.

Models with a wingspan of five metres (16 feet), capable of carrying up to 50 kilograms (110 pounds), remain undetectable by radar.

And thanks to satellite positioning systems, they can now be programmed to hit targets some distance away with just a few metres (yards) short of pinpoint accuracy.

Security services the world over have been considering the problem for several years, but no one has yet come up with a solution.

The article quotes a number of experts who suggest flying robots may be a security threat, includes a photo of the U.S.-built "Predator" unmanned aerial vehicle, and cites development of similar technology in other countries. 

But the discussion in the blogosphere is tinged with doubt. Over on Dvorak Uncensored, at least one commenter rattles off a laundry list of pitfalls between having the technology and making it work, including everything from getting a decent engine to finding an open channel. Meanwhile, Bruce Scheiner pegs the article as tipping the" movie-threat hype meter." 

On the other hand the DefenseTech post mentioned in the article ends with the statement "How great the threat is this time remains to be seen."

Geocaching Hits Yosemite

Tuesday, May 9th, 2006

The popularity of geocaching– a high-tech scavenger hunt conducted using handheld GPS units– is not likely to be a surprise to readers of the Really Rocket Science blog. But the AP has an interesting report on how a lodge in Yosemite National Park is capitalizing on the sports’ popularity to bring visitors to its luxurious surroundings:

                                                     
 

 [T]he Tenaya Lodge, just outside Yosemite National Park near Wawona, began offering a geocaching program along with its nature hikes and horseback riding outings last year….

Built 15 years ago and renovated recently, the 244-room Tenaya Lodge is the grandest of Yosemite’s perimeter "gateway" hotels catering to the park’s overflow and visitors who prefer to put a little distance between themselves and Yosemite Valley’s bustle….

Essentially, the sport is a cross between orienteering and a treasure hunt using high-tech navigation. Someone hides a "cache" – typically a plastic or metal bucket with a lid – with a logbook and some goodies in it and publishes the precise latitude and longitude on the Web. The goal is to dial those coordinates into your handheld GPS unit and have it lead you to the stash.

Since the sport began in 2000, it has grown exponentially. According to Geocaching.com, there are currently 202,735 caches in 218 countries…..

When I switched on the unit, it locked onto four satellites in geostationary orbit – meaning they appear to hover over one point on the globe – and spat out our elevation (5,288 feet) and our exact location (37 degrees, 26.402 minutes by 119 degrees, 36.237 minutes.) Depending on how well it linked up with the satellites, it was accurate to anywhere from 25 to 100 feet. With various "waypoints" pre-programmed, the GPS unit directed my wife, Jeri, and me down a series of increasingly rough dirt roads – the last was four-wheel-drive territory _ and beeped to alert me at various junctions. Or at least it was supposed to. The hotel is still working the kinks out of the system.

Read the full report on the author’s geocaching adventure in Yosemite here.

 

GPS for Gangs

Monday, May 8th, 2006

It works for finding lost pets and kids out past curfew, so it makes perfect sense to use GPS in fighting crime. I’ll be interested to see how California’s plan to track gang members using GPS works out.

 Under an arrangement between prison officials and San Bernardino, high-risk parolees known to belong to street gangs will be released from custody on the condition that they wear a GPS bracelet on their ankles at all times.

They appear as moving dots on a map and if they try to remove the anklet or enter unauthorized areas the device sends an alert to a base station monitored by law enforcement officials. 

I suppose it’s nothing new. According to the article, it’s already used by some California counties to monitor sex offenders. But when you combine that story with the ability to track wandering teenagers (or spouses) via GPS, it starts to sound like an episode of Wild Kingdom. It’s just that the tag is on a tasteful bracelet instead of being fastened to an ear. 

One question arises in my mind, however. How secure is this tracking system? In the cases of people who might be subject to retaliation or other attacks if identified — like sex offenders and gang memvers — how easy would it be for someone with enough technical knowledge, and an intent to do harm, to hone in on their tracking device and  locate them?

Fermi’s Paradox: Why We Haven’t Met Any Aliens

Wednesday, May 3rd, 2006

Seed Magazine takes a look at Fermi’s Paradox:

Sometime in the 1940s, Enrico Fermi was talking about the possibility of extra-terrestrial intelligence with some other physicists. They were impressed that life had evolved quickly and progressively on Earth. They figured our galaxy holds about 100 billion stars, and that an intelligent, exponentially-reproducing species could colonize the galaxy in just a few million years. They reasoned that extra-terrestrial intelligence should be common by now. Fermi listened patiently, then asked, simply, "So, where is everybody?" That is, if extra-terrestrial intelligence is common, why haven’t we met any bright aliens yet? This conundrum became known as Fermi’s Paradox.

"The Paradox has become even more baffling" in the past 60 years, as the technology to conduct the search for intelligence has improved dramatically with no results, according to the article’s author, Professor Geoffrey Miller of the University of New Mexico. Miller posits a radical hypothesis:

I suggest a different, even darker solution to the Paradox. Basically, I think the aliens don’t blow themselves up; they just get addicted to computer games. They forget to send radio signals or colonize space because they’re too busy with runaway consumerism and virtual-reality narcissism. They don’t need Sentinels to enslave them in a Matrix; they do it to themselves, just as we are doing today. Once they turn inwards to chase their shiny pennies of pleasure, they lose the cosmic plot. They become like a self-stimulating rat, pressing a bar to deliver electricity to its brain’s ventral tegmental area, which stimulates its nucleus accumbens to release dopamine, which feels…ever so good.

It’s an interesting theory. Perhaps ET is too busy playing Pac Man (does that reveal I’m a Gen Xer or what?) to care about reaching out to explore our solar system. Zoning out takes precedence over homing in for alien species, says Miller:

This is the Great Temptation for any technological species—to shape their subjective reality to provide the cues of survival and reproductive success without the substance. Most bright alien species probably go extinct gradually, allocating more time and resources to their pleasures, and less to their children. They eventually die out when the game behind all games—the Game of Life—says "Game Over; you are out of lives and you forgot to reproduce."

 The full entertaining article can be found here

Science Mythbusting

Monday, May 1st, 2006

Over on Newsvine, I came across an interesting post by someone who claims to be busting the myths about science, and found a couple of interesting items on the list.

Myth 2. The Great Wall of China is the only manmade structure visible from space

There are several variations on this folkloric statement, and they’re all quantifiably false. Astronauts can spot the Great Wall from low-Earth orbit, along with plenty of other things like the Giza pyramids and even airport runways. But they can’t see the Wall from the Moon. 

Myth 12. There is no gravity in space

Blame the term "zero-gravity" for this common misconception. Gravity is everywhere, even in space. Astronauts look weightless because they are in continuous freefall towards the Earth, staying aloft because of their horizontal motion. The effect of gravity diminishes with distance, but it never truly goes away. It is also untrue that space is a vacuum. There are all kinds of atoms out there, albeit sometimes far apart. 

I don’t know about the gravity question (any physicists out there?), but apparently our mythbuster is dead on about the Great Wall.

“You can see the Great Wall,” Lu says. But it’s less visible than a lot of other objects. And you have to know where to look.

In fact stretches of the wall aren’t even visible from China. They’ve been buried by sand for centuries. NASA has used space-based radar to map out hidden parts of the ancient structure. [Astronaut Ed] Lu is trying to get a picture of it, too, with a digital camera. 

I don’t know if Lu every got his picture, but I did track down the pictures NASA took with its "space-based radar." 

The mythbuster also takes on some common myths about asteroids.

Weather Satellites Launch After Weather Delays

Monday, May 1st, 2006

Seventh time’s the charm, right?

                                                             

After six tries over eight days, NASA launched a Delta 2 rocket Friday and a pair of satellites that will give planet Earth its newest health checkup by examining the secrets of clouds.

The 12-story-tall rocket built by Boeing rumbled off Space Launch Complex-2 at 3:02 a.m. into foggy skies at Vandenberg Air Force Base.

The approximately $515 million mission placed two satellites into orbit: CloudSat and CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations). About 90 minutes later, officials confirmed that the satellites had arrived in space.

“With the successful launch of CloudSat and CALIPSO we take a giant step forward in our ability to study the global atmosphere," said David Winker, CALIPSO principal investigator from NASA’s Langley Research Center, Va. "In the years to come, we expect these missions to spark many new insights into the workings of Earth’s climate and improve our abilities to forecast weather and predict climate change."

 We wrote about the launch in anticipation on the 20th of April; Rocco kept us updated in the comment threads ("CloudSat can’t launch because of clouds. Go figure."); but now the wait is over, and you can view Friday’s successful launch here.

The Big Break-Up

Friday, April 28th, 2006

Everybody’s talking about the big break-up. No, I don’t mean Nick and Jessica. I’m talking about Schwassmann-Wachmann, a comet that supposed to swung by earth next month, after it — according to one report — broke up for no apparent reason ten years ago. 

In 1995, Comet 73P/Schwassmann-Wachmann 3 did something unexpected: it fell apart. For no apparent reason, the comet’s nucleus split into at least three "mini-comets" flying single file through space. Astronomers watched with interest, but the view was blurry even through large telescopes. "73P" was a hundred and fifty million miles away.

No apparent reason? Not exactly. 

Naturally, I’m not the guy with the answers on this. (Again, I refer you to the screen name.) But Phil over at Bad Astronomy has what seems like a reasonable explanation to me. 

The exact cause is a mystery, though there are plenty of reason why a comet would fall apart. Comets are made of rock and ice. When they get near the Sun, the ice sublimates– turns directly into a gas — and flows into space, which is why comets look fuzzy in pictures. The actual nucleus, the solid part, is very small, but the coma, the fuzzy part, can be thousands of miles across.

It makes sense that after repeated passes of the Sun, enough ice is lost to venting that the structure of the comet can be fragile, since the ice in a way is holding the comet nucleus together. Once enough ice is gone, a breakup could occur if the sublimating ice builds up enough pressure to disrupt the structure. But that is just one explanation. The famous comet Shoemaker-Levy 9 broke apart because of the immense tidal forces of Jupiter’s gravity. Most comets don’t break apart; look at comet Halley, which has been circling the Sun for a long, long time (it was seen in ancient times). It goes to show that some comets are very fragile, and some are not.

OK, so it’s just one possible explanation, but it’s one more than I could come up with on my own. But just for the sake of argument, what other explanations could there be? Unless Bruce Willis or Morgan Freeman had an hand in it, I’ll take Phil’s explanation for now. (HubbleSite has the pics.)

European Hams Hear Signals from the Edge of Space

Thursday, April 27th, 2006

This one gets filed under "cool stuff," for sure:

Hams in Germany received signals from American spacecraft Voyager 1 March 31 using a 20 meter parabolic antenna of a radio telescope on a frequency of 8.4 GHz….

A team of hams at AMSAT-DL/IUZ Bochum (The Institute for Environmental and Future Research at Bochum Observatory) using Doppler shift and sky positioning, received the signal from a distance of 8.82 billion miles (14.7 billion km). That’s roughly 98 AUs, or 98 times the distance from the Sun to Earth. This is the first recorded reception of signals from Voyager 1 by radio amateurs….

Voyager 1 was launched in September 1977 to conduct close-up studies of Jupiter and Saturn, Saturn’s rings and the larger moons of the two planets. Originally built to last only five years, the probe will continue to send back astronomical information to NASA and the JPL until at least 2020. Voyager 1 will continue to study ultraviolet sources among the stars, and the fields and particles instruments aboard will continue to search for the boundary between the Sun’s influence and interstellar space. Communications will be maintained until the nuclear power sources can no longer supply enough electrical energy to power critical subsystems. 

 The achievement by the German hams makes Satellite Radio seem déclasse.

ER on the Moon?

Friday, April 21st, 2006

Back to robots for just a minute. I mentioned the pregnant robot earlier, the one used to help train medical students without the need for human guinea pigs. I also blogged about the challenge of meeting medical needs in space. Well, those topics have come together in a pretty interesting way. With help of a NASA robot, emergency surgery in space may have just gotten a lot easier. 

Using a cramped undersea laboratory off Florida’s Atlantic coast, NASA astronauts and medical experts have teamed with an experimental robot to demonstrate long-distance surgical procedures that might one day save the life of a critically injured explorer on the moon or Mars.

The mission to evaluate a new branch of health care called telemedicine and the use of robots in surgery will draw to a close today when the three-man, one-woman crew leaves the research facility 62 feet below the water’s surface where they have lived since early this month.

During their stay aboard the 43-foot-long Aquarius, submerged among the coral reefs off Key Largo, Fla., physician Tim Broderick and three astronauts — Dave Williams, Ron Garan and Nicole Stott — assisted as Canadian surgical researchers 1,250 miles away sent commands to a robot inside the laboratory.

Responding to those commands, the portable robot sutured a badly damaged vein in the wounded arm of a patient simulator, a lifelike medical teaching aide constructed of rubber and fabrics that mimic human tissue and contain bloodlike fluid.

"Patient simulator"? "Lifelike medical teaching aide"? Is it me or does that sound like a robot doing surgery on a robot? I guess it’s better that way, as long as they’re experimenting, but I supsect they won’t get any notes about cold hands or bedside manner from a "lifelike medical teaching aide."  

Via Mars Blog.

The Kon-Tiki Sails Again!

Friday, April 21st, 2006

"Nearly 60 years after Thor Heyerdahl’s Pacific Ocean crossing aboard the balsa raft Kon-Tiki, a Norwegian team is in Peru putting final touches on a new vessel to repeat the journey," the AP reports.

 

                                    

                                                    The original Kon-Tiki in 1947.

"I think we are mentally prepared and we are really, really anxious to put this raft in the ocean," said Olav Heyerdahl, 28, the adventurer’s grandson and one of the six-member crew.

Behind him in a dry-dock in Lima’s port of Callao loomed the balsa raft Tangaroa — named for the Polynesian god of the ocean — which is scheduled to set sail April 28.

The expedition had been set for last year, but was postponed after key sponsors diverted funds to help victims of the 2004 Southeast Asian tsunami.

In 1947, Thor Heyerdahl and his team sailed their primitive raft 5,000 miles from Peru to Polynesia in 101 days to support Heyerdahl’s theory that the South Sea Islands were settled by ancient mariners from South America. Heyerdahl, who died in 2002 at age 87, documented his voyage in the best-selling book "Kon-Tiki" and in an Oscar-winning documentary film.

The adverturer’s 67-year-old son, Thor Heyerdahl Jr., came to Peru to see the new vessel and cheer on his own son. "I’m very happy for him that he gets this opportunity," he said.

The new 56-foot vessel is larger than the Kon-Tiki, with eight crossbeams lashed to 11 balsa logs from Ecuador and covered by a bamboo deck. Atop a hardwood cabin, the crew fitted a thatched-reed roof made by Aymara Indians.

The Kon-Tiki carried only the most basic equipment, even by 1947 standards. But the Tangaroa features abundant modern technology, including solar panels to generate electricity and satellite navigation and communications gear.

We’re not sure if the expedition has Internet access while adrift in the South Pacific, but it is possible if they contacted Connexion by Boeing, which uses SES-Americom’s AMC-23 satellite, which is the only satellite that they can use for Internet based on their route.

Consider that a modern factoid for an ancient journey.