Really Rocket Science

Hovering is no easy exercise. Remember Star Wars and the X-34 landspeeder? Even the SoroSuub Corporation struggled.

But hovering isn’t just for Sci-Fi movie fans and role-players. Today’s rocket scientists may have found a new way to hover using “magnetic pinning.”

Superconductor technologies designed at Cornell aim to hold space-station modules and satellites in place without tethers or retrorockets by magnetically “pinning” them in place. Using unpowered superconductors and fixed permanent magnets, the Cornell researchers claim a new-age solution to longstanding stability and control problems in space vehicles.

Cornell hopes to prove the concept of magnetic pinning using unpowered superconductors for NASA spacecraft that must assemble themselves in orbit without the help of astronauts.. Within six months, the researchers plan to have a working test bed in place to verify that unpowered superconducting architectures can stabilize and control spacecraft.

“We believe that magnetic pinning with superconductors will enable much more stable space platforms to be constructed and held together without physical connections,” said Cornell University professor Mason Peck. “Modules that are magnetically pinned will also have a built-in bumper that prevents them from accidentally bumping into each other, potentially preventing the kind of damage that is hard to repair in space.”

This type of hovering may very well be utilized in the next year – but how will it work?

Magnetic pinning works by placing two space modules—one with an unpowered, but supercooled, superconducting coil and the other with an ordinary permanent magnet—near each other. The permanent magnet induces a current in the superconductor that is persistent and exactly opposite to the field of the magnet. In essence, one essentially “grips” the other with an invisible magnetic glove.

“When you bring a permanent magnet near a superconductor, it induces a current that stays there and exactly opposes the magnet’s own field–these are tiny current loops at the quantum level,” said Peck. “This in effect links the two objects with equal, opposing magnetic fields that keep them hovering next to each other indefinitely without supplying any external power. Even when external forces perturb them, they will maintain both their rotational and translational position.”

Of course, hovercraft are not new. Hell, Minnesota is using a much simpler version for ice rescues on Lake Minnetonka:

The department recently purchased the 16-foot vehicle that, using pressurized air power, travels above the ground, ice or water. It is perfect for when the ice is too thin to support another vehicle but too thick for a boat.

“The suits, the crawling – we were putting the victims and the firefighters in more danger,” said Dana George, assistant fire chief.

“This is not only a safer but a quicker way to reach people.”

At just $34,000, I can’t help but wonder why I can’t buy a hovercraft and go cruising. Or maybe I can:

The space shuttle Endeavour is set to liftoff tomorrow at 2:28 a.m. EDT on the STS-123 mission, which will deliver a key component of the Dextre (short for Special Purpose Dexterous Manipulator) robotic arm as well as the first section of the Japanese-built Kibo laboratory.

CTV has more on the Candian-built Dextre: 

A team of space-walking astronauts will assemble Dextre, which weighs about 1,560 kilograms, and attach it to the outside of the space station.

Dextre — 3.7 metres high and 2.4 metres wide — has two multi-jointed arms attached to its torso, a tool holder and a camera/light unit.

"Each arm has seven joints," Swanson said, adding the body can rotate. "It is a complicated arm to operate, but of course it gives you the ability to do all sorts of things with it."

Assembling Dextre will take three space walks of the five scheduled for the 16-day mission, but Swanson said it will take another two months of testing to make the robot fully operational.

Dextre is "is the third and final component of the Mobile Servicing System (MSS) developed by Canada for the International Space Station," the Canadian Space Agency writes on its website.

The Canadian Space Agency explains that:

[W]ith its two arms, Dextre will load and unload objects, use robotic tools, attach and detach covers and install various units of the Space Station. It will either be attached to the end of Canadarm2 or ride independently on the Mobile Base System and have Canadarm2 deliver equipment to it for servicing. It also has four cameras that will provide the crew inside the Station with additional views of the work areas.

Dextre is a huge accomplishment for the Canadian space industry, which has recently been embroiled in controversy over business-related changes to their prime space contractor.

Canada.com called the plans by U.S. firm Alliant Techsystems to purchase MacDonald, Dettwiler and Associates’ space and military assets for $1.325 billion "an affront," while the Ottawa Citizen and others have claimed it is vital to Canadian defence that the country maintain its own ability to launch and control its own satellites. (We’ve blogged about similar concerns about Canadian telecommunications and satellite independence.)

The Endeavour flight is commanded by Dominic Gorie, with Gregory H. Johnson serving as Pilot. The crew also includes Mission Specialists Rick Linnehan, Robert L. Behnken, Mike Foreman, Garrett Reisman and Japanese astronaut Takao Doi.

Doi is aboard to help with the Kibo Japanese experiment module — and word has it that he will be comfortably dressed: 

 [A] team from Japan Women’s University has developed "everyday spacewear," to make things more comfortable for astronaut Takao Doi during his stay on the station…

The team… has spent three years developing practical spacewear suited to a weightless environment.

They developed eight items, including long- and short-sleeved polo shirts, shorts, trousers, socks, underwear and a tracksuit top and bottoms….

Perhaps surprisingly, there is a lot of dirt on the space station, which means clothes get grubby easily.

The group created a polyester fiber-cotton blend fabric that allows sweat to be quickly absorbed and dried, which prevents dirt sticking to the garments.

The team also came up with ways to prevent the clothes interfering with electronic instruments onboard, such as interweaving them with a metallic fiber to prevent the buildup of static electricity.

Many of the everyday clothes worn by astronauts staying on the International Space Station are personal items bought from normal stores. But in a weightless environment, the hems and cuffs rise making them uncomfortable to wear–another problem overcome by the new items.

Kibo (meaning "hope" in Japanese) is the first manned facility made by Japan to be added to the ISS. The Pressurized Module of Kibo will be primarily used for experiments in a microgravity environment. 

As always, the launch will be webcast on NASA TV — with an additional live stream provided from Japan.

Great image from the Astronomy Picture of the Day:

The Keck Interferometer — two linked observatories in Hawaii (above, with Pu’u Poliahu in the background), located on the highest point in the Pacific — give astronomers a new view of novae:

First results from a new NASA-funded scientific instrument at the W. M. Keck Observatory at Mauna Kea, Hawaii, are helping scientists overturn long-standing assumptions about powerful explosions called novae and have produced specific information about one nearby nova.

This sophisticated new system, called the Keck Interferometer, combines the observing power of the two 10-meter (33 feet) Keck telescopes into a single mega-telescope. Using the interferometer’s "nulling" mode, data were taken by the Keck Interferometer team on a nearby nova called RS Ophiuchi.

In "nulling" mode, the Keck Interferometer suppresses the blinding light of a star so researchers can study the surrounding environment. The instrument helps them observe very faint objects near bright sources and produces 10 times more resolving power than a single Keck telescope working alone. It is the only instrument of its kind in operation.

The nulling mode was developed to search for dust regions around nearby stars, where planets might be forming, but the bright starlight poses a great challenge. "Because a star is so much brighter than the dust, something has to block the light, which is what the nuller does," said Rachel L. Akeson, Keck Interferometer project scientist at the California Institute of Technology’s Michelson Science Center. "This technique turns out to be useful for lots of other kinds of objects, including this one, where dust is near a star that just went nova."

These nova data were taken by a team led by Wes Traub of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., and the data analysis and unified model for the nova were produced by a team led by Richard Barry and William Danchi of the Goddard Space Flight Center, Greenbelt, Md.

The star in the constellation Ophiuchus went nova at the perfect time for the team, on Feb. 12, 2006. "We were extremely lucky, because we had astronomers in place at two mountain-top interferometers, Keck in Hawaii and Infrared Optical Telescope Array in Arizona. Within minutes of hearing about the discovery of the nova, we alerted both teams to start observing it that night," said Traub, a senior research scientist at JPL.

The nova system, known as RS Oph consists of a white dwarf and a red giant. The red giant is gradually shedding its massive gaseous outer layers, and the white dwarf is sweeping up much of this wind, growing in mass over time. As the matter builds up on the white dwarf’s surface, it eventually reaches a critical temperature that ignites a thermonuclear explosion that causes the system to brighten 600-fold. RS Oph was previously observed blowing its stack in 1898, 1933, 1958, 1967 and 1985, so astronomers were eagerly anticipating the 2006 eruption.

About three-and-a-half days after the nova was detected, the group observed the explosion with the Keck nuller. They set the instrument to cancel the nova’s light, allowing them to see the much fainter surrounding material, and then the extremely bright blast zone.

The instrument’s versatility was key to a surprising discovery. The nuller saw no dust in the bright zone, presumably because the nova’s blast wave vaporized dust particles. But farther from the white dwarf, at distances starting around 20 times the Earth-sun distance, the nuller recorded the spectral chemical signature of silicate dust. The blast wave had not yet reached this zone, so the dust must have pre-dated the explosion.

"This flies in the face of what we expected. Astronomers had previously thought that nova explosions actually create dust," said Richard Barry of Goddard, lead author of the paper on the observations that will appear in the Astrophysical Journal. The team thinks the dust is created as the white dwarf plows through the red giant’s wind, creating a pinwheel pattern of higher-density regions that is reminiscent of galaxy spiral arms. Inside these arms, atoms become cool enough and dense enough to allow atoms to stick together to form dust particles. The nova’s blast wave has since destroyed RS Oph’s pinwheel pattern, but it should re-form over the next few years, and future observations by NASA’s Spitzer Space Telescope could see it. Barry is also coauthor of a paper based on Spitzer observations of RS Oph.

Most studies of RS Oph have relied on spectroscopic models, which have not been able to distinguish various nova components with as much detail as the interferometer. The Keck nuller measured one component of the RS Oph system to an accuracy of just 4 milliarcseconds, or about the size of a basketball seen 7,500 miles away.

With all the space debris out there, especially in the lower orbits, its a wonder we don’t hear about this type of news more often. Big news a year ago was the Chinese missile taking out one of its own weather satellites, causing a space junk controversy (watch the video simulation here). You can track this debris yourself.

But I reckon it’s called "space" for a reason — there lots of it up there.

The news, via the Daily Press in Virginia:

An unknown object apparently collided with a satellite with NASA Langley Research Center connections in November, sending several broken pieces flying into orbit.

The satellite was decommissioned in December 2005, but was one of NASA’s largest and brightest in low-Earth orbit, and popular among amateur sky watchers. Called UARS, Upper Atmosphere Research Satellite, it was launched in 1991 and carried a NASA Langley instrument called HALOE that captured data about the chemistry of the atmosphere.

On Nov. 10, something apparently hit the school bus-sized orbiter. It could have been one of the many pieces in a growing field of "space junk." It could have been a meteoroid. Space debris often leaves pings and dents in satellites and even the space shuttle, and aging satellites decay over time. But a collision that actually creates new pieces of debris is more rare.

"When I heard this, I was shocked," said Jim Russell, a Hampton University professor who was the project lead for HALOE. "This is very unexpected. That’s not normal decay."

Nicholas L. Johnson, chief scientist for NASA’s Orbital Debris Program, said it remains unclear what happened to UARS. Four pieces bigger than 4 inches in diameter — roughly the size of a trackable piece of space junk — were sent into orbit, but it is unclear how large those pieces are.

A collision from a meteoroid or another piece of debris is the best hypothesis, Johnson said. The core of the spacecraft appears to still be intact.

"Unfortunately, we might not ever learn what caused the event," Johnson said.

Mark Matney, who works with Johnson in the Orbital Debris Program, said satellites with still-functioning pressurized systems sometimes eject new debris if a tank explodes. But UARS had no such systems, so a collision is the best explanation.

Only three known collisions between two satellites have ever occurred, Matney said. But these "anomalous" events, where it’s not clear what one of the colliding objects was, do happen occasionally, he said.

"It’s very hard to determine," what might have hit UARS, Matney said.

Decommissioned satellites typically continue to orbit for years before losing energy and falling toward Earth, usually to burn up. UARS was expected to fall out of orbit around 2011, Russell said.

UARS weighed about 13,000 pounds and measured 35 feet long and 15 feet wide, perhaps making it a better target than most.

The U.S. Space Surveillance Network, run by the Air Force, estimates there are about 10,000 objects in low-Earth orbit that are larger than 4 inches. The network’s sensitive ground-based instruments can track those objects. The objects range from communication satellites to the International Space Station to junk — pieces of decaying satellites and the remnants of rocket boosters.

The field of debris has become an increasing concern as the number of pieces continues to increase. The debris field was also significantly expanded in January of this year, when China angered the U.S. and other nations by testing an anti-satellite missile. The Chinese destroyed their FY-1C satellite, an aging weather observer.

The missile test exploded the satellite into more than 1,000 pieces of debris, and U.S. intelligence and defense analysts almost immediately deduced what had happened, before the Chinese government admitted it a few weeks later.

The UARS collision created only a handful of new pieces of debris, but still, "You hope it’s not anything sinister," said Ellis Remsberg, a Langley scientist who worked on HALOE with Russell.

Two of the "large" pieces that broke off UARS have apparently already burned up in the atmosphere, Johnson said. The other two pieces will likely do the same.

What remains of the craft’s core will continue to orbit for some time — barring another collision.

NASA’s been busy at the White Sands Test Facility in New Mexico. Just last week, they unveiled their new 18-meter Ka Band Antenna Network: 

 “Ka band” refers to a section within the microwave portion of the electromagnetic spectrum. Much like how listeners can’t pick up FM waves on AM radios and vice-versa, Ka band signals require special equipment to receive them.

The three new dishes help meet the growing demand for ground stations to handle high volumes of science data generated by today’s new satellites. The Ka band system allows satellites to transmit more data to the ground than ever before, in the area of 45 terabytes a month. That’s about the equivalent of 1,152 fully loaded 40-gigabyte iPods!…

The network makes use of a two-part epoxy developed at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Tests have shown the glue and the dishes will last for decades, according to Raymond Pages, chief of Goddard’s Ground System Development Office.

The first missions to use the network will be the Solar Dynamics Observatory (SDO) and the Lunar Reconnaissance Orbiter (LRO). SDO will study solar variations that affect life on Earth. LRO will focus on selecting landing sites, identifying lunar resources and studying how the moon’s environment will affect humans. Both probes are slated for launch in late 2008.

And today, NASA is breaking ground on a new Orion Test Pad at White Sands: 

The pad will be the site of a series of tests of a launch abort system that will help ensure the safety of astronauts aboard the new Orion spacecraft.

NASA’s Constellation Program is developing Orion to carry astronauts to the International Space Station, the moon and beyond. Engineers will use the test results to help design Orion’s launch abort system.

The first of five planned abort tests is scheduled from the new pad on Sept. 23, 2008. Two of the tests will evaluate the performance of the launch abort system at ground level. Three more tests will evaluate its performance at different altitudes.

Although a strong advocate for the space industry in New Mexico, Governor Bill Richardson won’t be attending the groundbreaking today, as he’s having pizza with caucus-goers in Nevada as part of his bid for the presidency. 

In addition to White Sands National Monument (pictured above), the area is home to the U.S. Army’s White Sands Missle Range. Unlike at the Monument, however, visitors to the Missle Range should learn about UXOs before wandering around this beautiful and stunning desert landscape.

Describing their mission as a “triple home run,” Discovery’s Commander, Pam Melroy, must have been pretty relieved. From NASA:

The crew of space shuttle Discovery left its mark on the International Space Station during two weeks in space that included adding a new piece, moving another and conducting an unprecedented spacewalk successfully.

“This is truly a triumphant moment for NASA,” Scott Parazynski said. “I think we obtained the summit and then some.”

“When I look back at our mission, it seems like we kind of hit a triple home run,” Commander Pam Melroy said a few hours after landing Discovery at NASA’s Kennedy Space Center on Nov. 7.

The seven astronauts connected a segment called Harmony that will serve as an attachment point for European and Japanese laboratory modules in the next several months. They also moved a tower of electricity producing solar arrays to the far end of the station’s central truss.

The group noticed a tear in one of the blankets as the arrays unfurled, and it took a concerted effort in space and at NASA centers to plan a spacewalk to repair the damage.

“It was an amazing thing to watch a large organization like NASA pivot so easily” to tackle the problem, Melroy said.

Parazynski made the repairs during a spacewalk that called for him to be perched on the end of the long boom normally used to inspect shuttle tiles.

“I had more butterflies than I normally do before an EVA,” Parazynski said. “It was just different than the prior spacewalks that I had done.”

With the repairs completed, the crew was cleared to return to Earth a day later than scheduled, but confident they left the station and its three crew members in good shape for future additions.

“It really was a beautiful moment for NASA,” Melroy said. “What you saw is who we are at NASA.”

Check out NASA’s site for more videos and behind-the-scenes info.

And if you missed the heroics of the spacewalk, watch this news report:

The original prop used as Luke Skywalker’s lightsaber in "Return of the Jedi" (watch the trailer from 1983) is aboard the International Space Station, marking 30 years since the release of the first Star Wars movie in 1977. It’s not the first time historical items have made the trip into space, according to NASA (podcast):

The Wright Flyer got only a few feet off the ground during its maiden flight in 1903, but traveled to the moon 66 years later.

A lead cargo tag that took months to cross the Atlantic Ocean from England to the nascent colony at Jamestown recently made the same crossing in minutes.

Now a plastic handle whose sole role was to make the fictional world of Star Wars look realistic is ready to take a real trip to the stars aboard space shuttle Discovery for mission STS-120.

From pieces of history to articles of pop culture, the assortment of items astronauts have taken with them into space is as varied as the world the artifacts represent.

Most of the objects find esteemed homes when they return, such as a stuffed teddy bear that STS-116 Commander Mark Polansky took into orbit. The bear was a replica of one owned by a Holocaust survivor. The astronaut returned the replica to a museum after the flight for its collection.

For the Star Wars prop, a lightsaber handle that was used by Luke Skywalker, even the send-off was celebrated. Actors dressed as characters including Chewbacca and X-wing pilots escorted the item to an airport in California for the flight to NASA’s Johnson Space Center in Houston, where it was packed into a shuttle locker and taken to NASA’s Kennedy Space Center in Florida for loading aboard Discovery.

Astronaut Jim Reilly, who flew three missions and has conducted eight spacewalks, said there is a symbolic tie between the lightsaber and the real-life work NASA does in space.

"There’s a kind of a fine line between science fiction and reality as far as what we do and it’s only just time really because a lot of what we’re doing right now was science fiction when I was growing up," he said. "I think it’s a neat link because it combines two space themes all at one time."

The lightsaber will spend 14 days in orbit on mission STS-120, but is not expected to leave the locker during the flight. It will be returned to Star Wars creator George Lucas’ film company after the mission.

It will not be the first time a Star Wars-related item has gone into orbit, though. Reilly said astronauts have taken small Star Wars toys into space with them when asked.

"Toy mementos, things like a Star Wars toy that might have meant something in their life, so there are any number of things that might be just a little out of the ordinary," he said.

More solemn markers have also accompanied astronauts. For example, Reilly’s STS-117 mission carried a medal earned by a World War II pilot who died in the war.

Patches, flags and medallions are routinely carried by the dozens or more on each flight, with some going on display and many going as awards to shuttle workers and VIPs.

"I think it makes it real," astronaut Rick Arnold said. "I lived in several countries and I think it’s nice to be able to present one of the flags that flew on our mission to those host countries as a thank you."

Arnold has been picked to fly aboard STS-119 in 2008, and is just starting to contemplate what to take with him to mark the occasion.

"There’s not a lot of room for personal items," he said.

Wedding rings and other small tokens are often taken into orbit. They are small enough to fit and large enough to have meaning. Each crew member is allowed to take about two pounds of mementos on their flight, but they must fit in a comparatively tiny area.

Astronaut Stephanie Wilson is taking a sheet of music from the Boston Symphony Orchestra onboard Discovery for mission STS-120. The music comes from Beethoven’s "Ode to Joy," a favorite in the orchestra’s extensive repertoire. Wilson worked at one time in a music store in Tanglewood, Mass., which is the summer home of the orchestra.

Some items never leave space, notably mission emblems like those stuck to the walls inside the International Space Station.

Another example is a golf ball astronaut Alan Shepard carried to the moon on Apollo 14 and hit with an improvised club.

Moonwalker Charles Duke left a portrait of his family on the lunar surface.

Thousands of signatures have also gone into the solar system in the form of computer codes imprinted on compact discs.

Whether they go into space to stay or to be appreciated anew back on Earth, the artifacts manage to find a unique home.

"When you get the chance to deliver that stuff back to your family and friends, they’re really excited about it," Reilly said.

Our favorite bring-along was the dried elk, crispbread and gingerbread by Swedish astronaut Crister Fuglesang.

Here’s the memorable lightsaber duel from that movie:

The Chandra X-Ray Observatory, run by the Smithsonian Astrophysical Observatory in Cambridge, MA, helped astronomers find a huge black hole orbiting a buddy star. Image above: artist’s representation of M33 X-7, a binary system in the nearby galaxy M33 (Credit: Illustration: NASA/CXC/M.Weiss; X-ray: NASA/CXC/CfA/ P.Plucinsky et al.; Optical: NASA/STScI/SDSU/J.Orosz et al.). Check out the Chandra blog, too.

Here’s the NASA release:

Astronomers have located an exceptionally massive black hole in orbit around a huge companion star. This result has intriguing implications for the evolution and ultimate fate of massive stars.

The black hole is part of a binary system in M33, a nearby galaxy about 3 million light years from Earth. By combining data from NASA’s Chandra X-ray Observatory and the Gemini telescope on Mauna Kea, Hawaii, the mass of the black hole, known as M33 X-7, was determined to be 15.7 times that of the Sun. This makes M33 X-7 the most massive stellar black hole known. A stellar black hole is formed from the collapse of the core of a massive star at the end of its life.

"This discovery raises all sorts of questions about how such a big black hole could have been formed,” said Jerome Orosz of San Diego State University, lead author of the paper appearing in the October 18th issue of the journal Nature.

M33 X-7 orbits a companion star that eclipses the black hole every three and a half days. The companion star also has an unusually large mass, 70 times that of the Sun. This makes it the most massive companion star in a binary system containing a black hole.

"This is a huge star that is partnered with a huge black hole," said coauthor Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "Eventually, the companion will also go supernova and then we’ll have a pair of black holes."

The properties of the M33 X-7 binary system – a massive black hole in a close orbit around a massive companion star – are difficult to explain using conventional models for the evolution of massive stars. The parent star for the black hole must have had a mass greater than the existing companion in order to have formed a black hole before the companion star. Such a massive star would have had a radius larger than the present separation between the stars, so the stars must have been brought closer while sharing a common outer atmosphere. This process typically results in a large amount of mass being lost from the system, so much that the parent star should not have been able to form a 15.7 solar-mass black hole.

The black hole’s progenitor must have shed gas at a rate about 10 times less than predicted by models before it exploded. If even more massive stars also lose very little material, it could explain the incredibly luminous supernova seen recently as SN 2006gy. The progenitor for SN 2006gy is thought to have been about 150 times the mass of the Sun when it exploded.

"Massive stars can be much less extravagant than people think by hanging onto a lot more of their mass toward the end of their lives," said Orosz. “This can have a big effect on the black holes that these stellar time-bombs make."

Coauthor Wolfgang Pietsch was also the lead author of an article in the Astrophysical Journal that used Chandra observations to report that M33 X-7 is the first black hole in a binary system observed to undergo eclipses. The eclipsing nature enables unusually accurate estimates for the mass of the black hole and its companion.

"Because it’s eclipsing and because it has such extreme properties, this black hole is an incredible test-bed for studying astrophysics," said Pietsch.

The length of the eclipse seen by Chandra gives information about the size of the companion. The scale of the companion’s motion, as inferred from the Gemini observations, gives information about the mass of the black hole and its companion. Other observed properties of the binary were used to constrain the mass estimates.

This animation sequence begins with a wide-field optical image from Kitt Peak of M33, a spiral galaxy about 3 million light years from Earth, and then zooms into a view from the Gemini telescope on Mauna Kea, Hawaii. Next, the view zooms into an even smaller field, from the Hubble Space Telescope, that includes M33 X-7, the most massive known black hole to be formed from the collapse of a star. The final image is a composite of the region around M33 X-7 that contains both the Chandra and Hubble data.
(Credit: Kitt Peak: NOAO/AURA/NSF/T.A.Rector; Gemini: AURA/Gemini Obs./SDSU/J.Orosz et al.; HST: NASA/STScI/SDSU/J.Orosz et al.; Chandra: NASA/CXC/CfA/P.Plucinsky et al.)

Here’s an interesting proposal to meet our future energy needs, perfectly timed with Al Gore’s receipt of the Nobel Peace Prize and the heightened awareness that brings to the need for clean, non-carbon energy:

A futuristic scheme to collect solar energy on satellites and beam it to Earth has gained a large supporter in the US military. A report released yesterday by the National Security Space Office recommends that the US government sponsor projects to demonstrate solar-power-generating satellites and provide financial incentives for further private development of the technology.

Space-based solar power would use kilometre-sized solar panel arrays to gather sunlight in orbit. It would then beam power down to Earth in the form of microwaves or a laser, which would be collected in antennas on the ground and then converted to electricity. Unlike solar panels based on the ground, solar power satellites placed in geostationary orbit above the Earth could operate at night and during cloudy conditions.

"We think we can be a catalyst to make this technology advance," said US Marine Corps lieutenant colonel Paul Damphousse of the NSSO at a press conference yesterday in Washington, DC, US.

The NSSO report recommends that the US government spend $10 billion over the next 10 years to build a test satellite capable of beaming 10 megawatts of electric power down to Earth.

The NSSO report can be found here.