Archive for July, 2008

First Storm of the Season

Monday, July 7th, 2008

 

It’s officially hurricane season and Bertha is gearing up to be the year’s first storm.

Whether you might find yourself in the eye of the storm or you’re just intrigued by extreme weather, you’re sure to appreciate the fun tools that the National Weather Service puts out for the public. This one lets you track the storm’s movements. And this one shows wind speeds.

How do they get all the data for these cool images? Why satellites, of course. And the NOAA has a full arsenal. But how does all the information coming from those satellites turn into something we can understand, like this animation of the season’s first hurricane?

With Giovanni it’s simple. And no, that isn’t the name of an Italian tropical storm guru…

Giovanni is actually an acronym for the GES-DISC (Goddard Earth Sciences Data and Information Services Center) Interactive Online Visualization ANd aNalysis Infrastructure.

In other words, it’s a web-based application developed by NASA that is available to anyone with a computer and a bit of spare time. But beware, for those of us who’ve lost hours tooling around on Google Earth, this can become a bit addictive…

Ariane 5 Launch Update

Monday, July 7th, 2008

 

Conveniently for the American rocket scientists, Arianespace postponed the Ariane 5 ECA launch from Friday, 4 July 2008, to today. The launch window opens at 21:47 GMT and closes at 22:21. More about the payload:

The Ariane 5 ECA will deliver a payload performance of 8,639 kg. – which includes 7,537 kg. for the mission’s ProtoStar I and BADR-6 spacecraft passengers, along with their integration hardware and the SYLDA 5 multiple satellite dispenser system.

ProtoStar I is the first in a fleet of relay platforms that Asian satellite services company ProtoStar will deploy for advanced satellite television services and powerful two-way broadband communications access. It is based on Space Systems/Loral’s 1300 spacecraft bus, and will provide K-band/C-band relay capacity over Asia for the needs of both emerging and existing direct-to-home (DTH) operators, as well as other broadband communication requirements in the region.

Arabsat’s BADR-6 satellite will open up new video broadcasting and telecommunications services for the entire Middle East and North Africa region, along with a large part of sub-Saharan Africa. Built by EADS Astrium, the Ku/C-band relay platform is designed for a lifetime of about 15 years, and will operate from Arabsat’s 26 deg. E geostationary orbital location.

Voir la vidéo ici. Watch the video here, too.

DIY Friday: Sky Show

Friday, July 4th, 2008

No, not your own fireworks — playing with chemistry at home is dangerous. We’re talking dazzling astronomic observation, as this "image of the day" from NASA:

 

Stars and a Stripe in Celestial Fireworks

A delicate ribbon of gas floats eerily in our galaxy. A contrail from an alien spaceship? A jet from a black-hole? Actually this image, taken by NASA’s Hubble Space Telescope, is a very thin section of a supernova remnant caused by a stellar explosion that occurred more than 1,000 years ago.

Around May 1, 1006 A.D., observers from Africa to Europe to the Far East witnessed and recorded the arrival of light from what is now called SN 1006, a tremendous supernova explosion caused by the final death throes of a white dwarf star nearly 7,000 light-years away. The supernova was probably the brightest star ever seen by humans, and surpassed Venus as the brightest object in the night time sky, only to be surpassed by the moon. It was visible even during the day for weeks, and remained visible to the naked eye for at least two and a half years before fading away.

It wasn’t until the mid-1960s that radio astronomers first detected a nearly circular ring of material at the recorded position of the supernova. The ring was almost 30 arcminutes across, the same angular diameter as the full moon. The size of the remnant implied that the blast wave from the supernova had expanded at nearly 20 million miles per hour over the nearly 1,000 years since the explosion occurred.

Today, SN 1006 has a diameter of nearly 60 light-years, and it is still expanding at roughly 6 million miles per hour. Even at this tremendous speed, however, it takes observations typically separated by years to see significant outward motion of the shock wave against the grid of background stars. In the Hubble image as displayed, the supernova would have occurred far off the lower right corner of the image, and the motion would be toward the upper left.

Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) 

 

 

But NASA is predicting a planetary alignment for today and this weekend, via PhysOrg.com:

The show gets going on Friday, July 4th. Red Mars and ringed Saturn converge just to the left of the bright star Regulus. The three lights make a pretty 1st-magnitude line in the heavens.

But that is just the beginning. On Saturday, July 5th, with weekend fireworks at fever pitch, a lovely crescent Moon joins the show. Saturn, Mars, and the Moon trace an even brighter line than the night before.

Scan a small telescope along the line. You’ll see Saturn’s rings, the little red disk of Mars, a grand sweep of lunar mountains and craters, and just maybe—flash!—a manmade incendiary. How often do you see fireworks through a telescope?

This is, however, more than just a flashy gathering of planets—it is also a gathering of spaceships and robots.

Each of the three worlds is orbited or inhabited by probes from Earth. Saturn has the Cassini spacecraft, studying the gas giant’s storms, moons and rings. The Moon has two probes in orbit: Kaguya from Japan and Chang’e-1 from China. The pair, operating independently, are mapping the Moon and scanning for resources in advance of future human landings. NASA’s Lunar Reconnaissance Orbiter will join them later this year.

Mars has more probes than the others combined. Three active satellites orbit the red planet: Europe’s Mars Express and NASA’s Mars Odyssey and Mars Reconnaissance Orbiter. The three not only study Mars with their own instruments, but also form a satellite network in support of NASA’s Mars rovers Spirit and Opportunity and Mars lander Phoenix.

None of these mechanical specks are visible in a backyard telescope, but they are there, heralds of a growing human presence in the solar system. Tell that to your buddy at the fireworks show!

During the short night of July 5th, the Moon glides past Mars and Saturn so that nightfall on Sunday, July 6th, brings a different arrangement—a scalene triangle. The triad is easy to find in the hours after sunset. Look west and let the Moon be your guide.

In the nights that follow, the Moon exits stage left, leaving the others behind. Don’t stop watching, though. Saturn and Mars are converging for their closest encounter of the next 14 years. After nightfall on Thursday, July 10th, the two planets will be just ¾ of a degree apart, snug enough to fit behind the tip of your pinky finger held at arm’s length.

Now that’s spectacular—no fireworks required.

 

Cool. No smoke, fire or noise. There’s more than enough of that going on around you. To all the rocket scientist in the U.S., have a great 4th of July. 

This Solar System is Lopsided

Thursday, July 3rd, 2008

If you ever felt things were a little off-kilter, now we know why:

 The Voyager 2 spacecraft, which has been traveling outward from the Sun for 31 years, has made the first direct observations of the solar wind termination shock, according to a paper published in the July 3 issue of the journal Nature.

At the termination shock the solar wind, which continuously expands outward from the sun at over a million miles per hour, is abruptly slowed to a subsonic speed by the interstellar gas.

Shock waves in the thin, ionized gas — called plasma — that exists in space are similar in some respects to the shock waves produced by an airplane in supersonic flight. Shock waves in space are believed to play an important role in the acceleration of cosmic rays, which are very energetic atomic particles that continually bombard Earth.

The most energetic cosmic rays, which are potentially hazardous to astronauts, are believed to be produced in intense shock waves caused by supernova explosions — immense stellar explosions that occur in massive stars toward the end of their lives.

The termination shock is believed to be responsible for the origin of less energetic cosmic rays called "anomalous cosmic rays." The recent observations at the termination shock are expected to help physicists understand how cosmic rays are produced by the turbulent fields that exist in such shocks.

Gurnett said,"There is no way for us to make direct measure of a super nova shock, so the Voyager 2 measurements at the termination shock provide us the best opportunity in the foreseeable future to understand how cosmic rays are produced by supernova cosmic shocks."

Here’s a summary of the electric field amplitudes in the Voyager-1 1.78 kHz and 3.11 kHz PWS spectrum analyzer channels from 1992 to present: 

 

So what does all that mean?

You can dig into the scientific analysis here. Or, NASA’s Jet Propulsion Laboratory provides a lay explanation, as well as a much better picture:

 

This artist’s rendering depicts NASAs Voyager 2 spacecraft as it studies the outer limits of the heliosphere – a magnetic ‘bubble’ around the solar system that is created by the solar wind. Scientists observed the magnetic bubble is not spherical, but pressed inward in the southern hemisphere, according to recent data published as part of a series of papers in this week’s (July 3, 2008) Nature. These findings help build up a picture of how the sun interacts with the surrounding interstellar medium.

Having crossed the termination shock and the edge of our solar system, Voyager now continues on; in five to seven years, it may have something equally profound to tell us about deep space.

Meanwhile, NASA’s Stereo Mission (which we blogged about here and here) has created its first images of the edge of the solar system, and its findings are equally interesting and helpful in understanding what happens at the point where the solar system meets interstellar gas:

 

 NASA’s sun-focused Solar Terrestrial Relations Observatory, or STEREO, twin spacecraft unexpectedly detected particles from the edge of the solar system last year. …

From June to October 2007, sensors aboard both STEREO spacecraft detected energetic neutral atoms originating from the same spot in the sky, where the sun plunges through the interstellar medium.

Mapping the region by means of neutral, or uncharged, atoms instead of light "heralds a new kind of astronomy using neutral atoms," said Dr. Robert Lin, professor of physics at the University of California, Berkeley and lead for the suprathermal electron sensor aboard the STEREO spacecraft…..

The results, reported in the July 3 issue of the journal Nature, clear up a discrepancy in the amount of energy dumped into space by the decelerating solar wind. The solar wind was detected when Voyager 2 entered the heliosheath.

Researchers determined that the newly discovered population of ions in the heliosheath contains about 70 percent of the dissipated energy from the solar wind, exactly the amount unaccounted for by Voyager 2’s instruments. The Voyager 2 results also are reported in the July 3 issue of Nature.

The Berkeley team concluded that these energetic neutral atoms were originally ions heated up in the termination shock area that lost their charge to cold atoms in the interstellar medium and, no longer hindered by magnetic fields, flowed back toward the sun and into the sensors aboard STEREO.

Would it be a bad holiday pun to call all of this a shocking discovery?

Indeed it would be a bad pun. But now it’s done.

Enjoy the Fourth!

Mobile TV Olympics

Wednesday, July 2nd, 2008

 

Bèibei, Jīngjing, Huānhuan, Yíngying, Nīni — the Fuwa, official mascots of the Beijing 2008 Olympiad. Each represents one of the five Chinese elements: Water, Wood, Fire, Earth, Air, respectively. Colored for the five Olympic rings, we can expect a lot of them over the course of this summer, with the Beijing 2008 opening ceremony on Friday, 8 August 2008.

The swirling stories around the 3.5 hour show are getting interesting — from a giant winking panda to fantastic fireworks. According to one of the producers,  "The world can expect, of course, to be gobsmacked…"

Imagine a 100-m-wide red flower opening up its petals; picture 10,000 bicycles circling the Olympic stadium and transforming into hi-tech robots; then envisage Peking Opera performers morphing into hip-hop dancers and singing in English.

Finally, picture a 50-m-tall giant inflatable panda, which turns its head and winks at the world.

These powerful images of rapid change and spectacular icons are the possible eye-candy in the Middle Kingdom’s biggest ever ceremony.     

China’s record-breaking social and economic changes over the past 20 years will become one of the major themes of the Olympic opening ceremony, according to one of the key members of the team.

Although opening ceremony organizers are sworn to secrecy, Games ceremonies guru Ric Birch has hinted that China’s great changes will be a dominant theme.

"The fact China has achieved so much in one generation is so extraordinary, we can’t compute it," he told China Daily.

"There has never been an equivalent, so we don’t have benchmarks.

"All these issues will come together for me in Beijing for the opening ceremony."

Australian Birch is a key adviser to Zhang Yimou, who wields full creative control over the ceremonies.

I still like Jack Black’s arrival in Cannes last month…

 

The Olympics are an immense undertaking and China will be under an intense global media spotlight. TV news crews from all over the world will need to coordinate their RF transmit-receive equipment like never before.

What we might expect to see unveiled is which mobile TV standard will be selected as the national standard in China. EE Times did a piece on this a month ago:

"We used to joke that there are as many standards in China as there are universities, but it looks like CMMB is pulling ahead," said Azzedine Boubguira, vice president of business development for DiBcom, which designs demodulators.

DiBcom, Siano and Beijing-based Innofidei Inc. will all have CMMB silicon ready by the end of this year or early next. Innofidei already has a chip out, having released a first-generation demodulator in March, and hopes to have a smaller, lower-power version by October. Around that time, two satellites will be launched in preparation for network trials in the spring and modest commercial services targeted at the Olympics.

At least, that’s the plan. "It will be a rush job for sure. I don’t see it happening by then," said Duncan Clark, managing director of telecom consultancy BDA China. Others are also doubtful, including the chip makers themselves.

It has become increasingly clear that CMMB’s benefactor, the State Administration for Radio, Film and Television (Sarft), is willing to use its power over frequency allocation and content licensing to see that CMMB wins out over competing standards, including established international formats such as Europe’s DVB-H and South Korea’s T-DMB. But the CMMB effort’s estimated $3 billion price tag may not fly with government bean counters. And China’s track record for implementing homegrown technologies is spotty. Its highest-profile case thus far is a 3G technology, TD-SCDMA, whose ascendancy has easily set back the rollout of 3G services for at least a year as engineers rush to make it reliable.

Sarft introduced CMMB last October. The spec is based on a homegrown transport technology known as STiMi (short for "satellite and terrestrial interactive multiservice infrastructure"). The service operates in the 2.6-GHz frequency, using 25 MHz of bandwidth to offer 25 video and 30 radio channels, plus some data channels. STiMi supports the S- and UHF/VHF bands and will use both satellites and terrestrial relays to implement coverage. The technology bears some resemblance to Europe’s DVB-SH (for satellite service to handheld devices).

Competitive and regulatory challenges could impede CMMB’s progress. A chip maker associated with the development of China’s free-to-air transmission standard, DMB-T, is trying to field a low-power chip set for portable media players (PMPs), automotive displays and notebook PCs (via USB dongles). The company, Legend Silicon, believes those uses will trump handsets as the early market for mobile TV in China.

"There’s enough money to be made in USB and PMPs, plus we have the larger market of set-top boxes and TVs," said Hong Dong, a co-founder of Legend.

Interestingly, the USB and PMP market is also the initial target of CMMB backer Innofidei. By sidestepping the handset, at least for now, these companies are waiting to see the outcome of a potential showdown among CMMB, DMB-T and another, little-known standard that has been floated by a rival bureaucracy, the Ministry of Information Industry (MII).

The spec, T-MMB (Terrestrial-Mobile Multimedia Broadcasting), is a T-DMB derivative developed by Beijing software firm Nufrontsoft in conjunction with two local universities. The MII-backed format supports frequencies from 30 MHz to 3 GHz. Like T-DMB, which is based on the Digital Audio Broadcasting spec, it uses bandwidth of 1.536 MHz and can support four to seven video channels and two audio channels.

At the moment, it’s uncertain how committed MII is to backing T-MMB and instigating a turf battle. Insiders said T-MMB seems to have the least support.

The minutiae of bureaucratic maneuvers may have a profound impact on the way the mobile-TV industry develops in China. If CMMB is to be successful, it needs the backing of telecom regular MII, which approves handsets for distribution to operators. On the other hand, if MII wants to push T-MMB, it would have to get Sarft to approve frequencies and content licenses.

"They need each other to be successful, but they need telecom convergence to see this happen. So they are kind of stuck," said BDA’s Clark.

 

All this uncertainty greatly influenced EchoStars decision (10-Q Statement) to suspend their S-band payload plans:

We are suspending construction of the CMBStar satellite and may record an impairment charge. During April 2008, we notified the State Administration of Radio, Film and Television of China that we were suspending construction of the CMBStar satellite pending, among other things, further analysis relating to efforts to meet the satellite performance criteria and/or confirmation that alternative performance criteria would be acceptable. We are also currently evaluating potential alternative uses for the CMBStar satellite. Therefore, we could be required to record an impairment charge relating to the CMBStar satellite. We currently estimate that this potential charge could be as much as $100 million, which would have a material adverse effect on our results of operations and financial position.

Good of EE Times to pick up on that one, too, and concluding no satellite capacity exists to launch a new national standard in China:

When the Beijing Olympic Games start in August, China’s much-touted mobile TV broadcast service will have to crawl before it can walk–because it’s missing one leg.

The homegrown Chinese system has been designed to operate by picking up two signals: a 2.6-GHz satellite signal and a 700-MHz terrestrial signal. (see: Satellite mobile-TV spec gains influential backers in China)

However, no satellite will be operating in time to realize the full promise of the China Multimedia Mobile Broadcasting (CMMB) standard — technology also known as STiMi (satellite and terrestrial interactive multiservice infrastructure).

EchoStar, the primary provider of S-band satellite capacity for China’s mobile video project, quietly revealed in its 10-Q form filed with the U.S. Securities and Exchange Commission in late May that it is suspending construction of the CMBStar satellite.

China Satellite Mobile Broadcast (CSM), a company overseen by the Wireless Bureau of China’s State Administration of Radio, Film and TV (Sarft), last year selected China Mobile Broadcasting Satellite (CMBSat), a Hong Kong-based affiliate of EchoStar, as its partner.

EchoStar claimed that it already notified the Sarft of its intentions in April. But the U.S. firm has not explained why it suspended activities in China, other than saying that its decision is "pending, among other things, further analysis relating to efforts to meet the satellite performance criteria and/or confirmation that alternative performance criteria would be acceptable."

It remains unclear if any technical problems have surfaced, or if the delay is purely a negotiating ploy by EchoStar or CSM.

Although EchoStar remains a viable candidate to deliver a satellite to China, a growing likelihood is that China will turn to its own satellite companies to launch a satellite in the first quarter of 2009.

 

 

Satcom in Uganda

Tuesday, July 1st, 2008

We’ve written extensively about efforts to connect Africa with the digital world (see Com in Africa: A Changing Marketplace, A Pan-African E-Network, With India’s Technology, and Which Satellites Aid Oil Exploration in Africa?, for examples).

Now, East and Southern Africa are about to be connected to the global internet pipeline by undersea cable, and terrestrial networks are rapidly expanding in major towns.

But what about the more remote nations of Africa, such as Uganda, home of the Bwindi Impenetrable National Park?

 

Like Nigeria, Uganda relies upon satellite for its principle mode of digital communications

Satellite transmission remains the most apt mode of digital communication in Uganda and much of Africa where spotty infrastructure and geographical isolation still pose a formidable challenge to the deployment of fibre optic cables, according to an official from Afsat Communications ltd.
 
Afsat is Africa’s largest provider of Very Small Aperture Terminal, (VSAT) based internet services. At a June 19th media presentation in Kampala on the potential of satellite technology in bringing internet access, Afsat’s General Manager Job Ndege said VSATs were still the best and cost efficient means of bringing the Ugandan masses access to internet.

Currently Afsat is marketing its services in Uganda under the brand name iWay Africa and connects its clients to: “fast, reliable, efficient and cost effective broadband intenrt” and “Tailor designed and highly available intra-corporate connectivity solutions.”

The company is present in 28 sub-Saharan African countries and has installed about 5200 VSATs on both the broadband and intra-corporate platforms. Lately there has been a lively debate among the ICT industry analysts, policy makers and academics on the relevance of VSATs in the wake of efforts, now in advanced stages, to connect East and Southern Africa to the word’s fibre optic network.

Monitor Online has a good interview with Afsat’s Job Ndege, who notes that VSAT is immune to the problems of poor infrastructure "because it is possible to have a VSAT system that completely bypasses the local infrastructure.
This is a key advantage of VSAT as compared to other technologies."

For delivery of the digital connection, Afsat’s iWay Broadband utilizes the Intelsat 10 (IS-10) and NSS-7 satellites. 

Space Weddings

Tuesday, July 1st, 2008

Last month, we read on Pink Tentacle about a company in Japan offering weddings in space via Kistler’s RocketPlane.

Today we read in The Australian they’re accepting reservations:

Each happy couple will spend 240 million yen ($A2.4 million) for the ceremony in a small space vessel, which will shoot up 100km into the sky.

During the hour-long flight, the couple will spend several minutes in zero gravity during which they will exchange their vows with up to three guests present, said Taro Katsura, a spokesman for Japanese firm First Advantage.

The couple would perform most of the ceremony before takeoff "so that they can say their vows and look out the window," Mr Katsura said.

The firm is offering the space marriages in a tie-up with US-based Rocket Plane, which will conduct the flights from a private airport in Oklahoma. From the spaceship, the couple would probably be able to see the outline of the Earth although they will not be far enough into space to allow complete floating, Mr Katsura said.

Despite launching the offer in Japan, the company said it expected most of its customers to be from China or Arab Gulf nations. There are currently no plans to start the space weddings in the United States, Mr Katsura said.

Sure, I’ll look out the window for a few minutes. Other newlywed activities may be more interesting for most people — especially rocket scientists.

I can almost hear Frank Sinatra singing the song now…