Image: Mag-beam system
University of Washington
An artist's conception shows a space station, at left, firing a stream of magnetized ions at a transport spacecraft with Jupiter in the background.

Oct. 15, 2004 | 8:15 p.m. ET
Mag-beam musings: Could a magnetized particle beam really propel a manned spaceship to Mars, or would the beam-generating system cause more problems than it was worth? Thursday's item on the mag-beam scheme, which University of Washington planetary scientist Robert Winglee believes could provide a rapid-transit system for interplanetary explorers, sparked an equal and opposite reaction from some Cosmic Log correspondents:

Randy Wickers, a retired Air Force pilot who is now a Lockheed Martin engineer living in Gig Harbor, Wash., had two concerns about the idea:

"First, for every action there is an opposite and equal reaction. What would be done to prevent the 'beam firing' platform from going in the opposite direction?" he wrote. "Second, what sort of radiation effects are emitted from a mag-beam?  If it's strong enough to push a sail, would there not be a need for some shielding for the human occupants of the taxi?"

Several other readers echoed Wickers' first question, which relates to Newton's laws of motion. In response, Winglee acknowledged the problem and said Newton's laws could help overcome it as well.

"The space station would be pushed," he told me today, "but it would be way more massive than the object you would be pushing."

A key part of the concept is that the space taxi would be quite small -- much smaller than it would have to be if it had an interplanetary propulsion system on board. Thus, the effect of the beam on the taxi would be much greater than the effect on the beam-generating space station itself, because acceleration equals force divided by mass.

Winglee said the mag-beam would be emitted in bursts rather than continuously. After one beam burst, the space station would have to correct its orbital course before firing off the next burst.

As for the radiation risk for the taxi riders, Winglee said the deflector sail on the taxi would "stop all the particles." Nevertheless, it seems to me that the crew would have to have some shielding, not only against the beam particles, but against the natural radiation environment of deep space as well.

Some readers wondered whether a fast-moving space taxi would face an increased impact risk from meteoroids: Again, Winglee acknowledged the risk, but said "the fact that you have a smaller spacecraft means that the hazard is less" than it would be for a conventional rocket ship.

For much, much more discussion of the mag-beam concept, check out Slashdot's thread.

Meanwhile, another reader had a question about a different type of ion propulsion. "Whatever happened to the continuous-thrust 'ion engine' thruster developed back in the '70s?" Joe asked. "If we weren't being held back with the totally obsolete shuttle program and were allowed to use the advanced space technology the military keeps their thumb on, we could have been to Mars and back before now."

I don't know about that, but ion engines are definitely back in vogue: NASA's Deep Space 1 mission was considered a wildly successful test of the ion thruster concept, and the European Space Agency's SMART-1 spacecraft is even now being pushed toward the moon by an ion engine. Ion engines are slow starters, as the mag-beam is likely to be, but they can build up velocity over a sustained period. SMART-1 has been in transit for a year, and next month it's due to enter lunar orbit.

NASA's Dawn spacecraft, due for launch in 2006 to study the asteroids Ceres and Vesta, also will use an ion propulsion system. Don't miss NASA's cool tutorial that lets you practice building your own virtual ion engine, as well as our own interactive graphic on Deep Space 1's ion engine.

Oct. 15, 2004 | 8:15 p.m. ET
X Prize party time! The $10 million X Prize for private spaceflight may have been won , but the winners won't get their check until Nov. 6, during a ceremony at the St. Louis Science Center. The party should be a doozy: There'll be rounds of public educational events on the 5th and the 6th, and scores of space team members will attend a Saturday night black-tie gala, with SpaceShipOne creator Burt Rutan, financial backer Paul Allen and perhaps Virgin Galactic chief Richard Branson among the headliners. Stay tuned for details early next week.

Oct. 15, 2004 | 8:15 p.m. ET
Feedback on the dinosaur-killer: This week's dueling reports on what caused the demise of the dinosaurs stirred up a lot of introspection over how conflicting scientific findings are reported. l came in for a share of constructive criticism as well on the Cambridge Conference Network's discussion forum.

Oklahoma State University's Hermann Burchard observed that "even the redoubtable Alan Boyle's Cosmic Log on MSNBC is not infallible" — and pointed out that I had referred to the object behind the catastrophic Chicxulub impact 65 million years ago exclusively as an asteroid. The redoubtable Professor Burchard is quite correct in saying that scientists aren't certain whether the object was an asteroid or a comet. I've corrected the item to reflect that.

Ryan Norris, a graduate student in the University of Vermont's biology department, provided some scholarly feedback expanding on the research that argued against blaming the dinosaurs' extinction solely on the asteroid or comet. It's well worth quoting at length, for the benefit of those who are turned on by this sort of thing (those who aren't are free to leave the classroom):

"Penny and Philips do a very nice job of establishing the alternative possibilities and the lines of evidence that might lead to different conclusions. Their article is also an important reminder that such major events are rarely caused by a single factor, but usually involve many components. The mass extinction of non-avian dinosaurs was probably not exclusively the result of the Chicxulub asteroid, but was also likely influenced by other factors such as the rise of flowering plants, global drying and perhaps competition with other vertebrates.

"The figure in their paper showing the relative decline of small dinosaurs makes a particularly convincing case that either:

  1. Dinosaurs were, on average, getting consistently bigger during the Cretaceous (an idea not mentioned); or
  2. Some factor was driving small dinosaurs extinct.

"The authors suggest option 2, and suggest that this factor was competition with warm-blooded birds and mammals. As an aside, some dinosaurs (i.e., many thecodonts) were almost certainly warm-blooded (as shown by the presence of insulating feathers), and the warm-blooded factor may require a second look. The success of warm-blooded birds and mammals when pitted against small dinosaurs does not translate to success against their bigger relatives. Large animals (even 'cold-blooded' ones) maintain a fairly constant body temperature due to the geometric properties of surface area to volume ratios. Even if birds and mammals were able to wipe out all small dinosaurs, they would not be able to use their warm-blooded advantage against big dinosaurs.

"The bulk of their argument is based on a host of recent genetic studies that strongly suggest that most modern placental mammal orders had split from one another well before the end of the Cretaceous. The problem with this approach is that splitting into different lines (as recorded in the genes) is not the same thing as diversifying into a wide range of ecological niches. In fact, a look at the family tree of mammals shows that there are animals on many branches that have changed very little from the nocturnal insectivores that were running around alongside dinosaurs through much of the Mesozoic. (See Springer et al.'s 2004 article in TREE 19:430-438 for a nice overview of the placental family tree.) Tree shrews, elephant shrews, tenrecs, true shrews, and hedgehogs were once placed in the same group and all look like the mammal ancestors. It's been shown, however, that tree shrews are related to mice and humans, elephant shrews and tenrecs are related to aardvarks and manatees, whereas true shrews and hedgehogs are related to bats, dogs and whales.

"Meanwhile, the old definitions of what's actually in an order (except the primitive insectivore group and what to do with whales) have been supported by genetics. Basically, what an animal looks like will give you a pretty good idea of what order it belongs to, but is a terrible indicator of how those orders are related. How an animal looks is closely tied to the type of lifestyle it lives.

"The evolution of families within placental orders seems to have almost exclusively happened after the Tertiary. This really suggests that several (perhaps many) different varieties of small shrewlike animals (just like what had been living alongside dinosaurs for tens of millions of years) survived the end of the Cretaceous and didn't evolve into bats, elephants, manatees, monkeys, pigs and aardvarks until after the dinosaurs were gone and their ecological niches were free. Essentially, something wiped out the dinosaurs at the end of the Cretaceous, and, though they may have given a nudge, it probably wasn't mammals."

Oct. 15, 2004 | 8:15 p.m. ET
Weekend field trips on the World Wide Web:
'Nova' on PBS: 'Neanderthals on trial'
The Economist: Pictures as passwords
Science News: Bad science on the movie screen
TLC on Discovery.com: Which Medici are you?

Oct. 14, 2004 | 6:20 p.m. ET
Ride the mag-beam to Mars: A novel propulsion system, involving a beam of magnetized ions, could reduce the round-trip travel time for a trip to Mars from more than two years to as little as 90 days, the project's leader says.

The "mag-beam" concept, advanced by a team at the University of Washington, envisions establishing beam-generating space stations near Earth and Mars. At the start of the trip, the Earth station would focus its particle beam on the magnetic sail of a Mars-bound space taxi, pushing it to speeds of tens of thousands of miles an hour. During the approach to Mars, the Red Planet station would fire its own beam to decelerate the spacecraft.

"We're trying to get to Mars and back in 90 days. Our philosophy is that, if it's going to take two and a half years, the chances of a successful mission are pretty low," said Robert Winglee, an Earth and space sciences professor who is leading the university's project.

Two and a half years or so is the standard estimate for the length of a human mission to Mars — but that time frame raises concerns about the health effects of long-duration spaceflight, such as bone loss, muscle loss, radiation exposure and psychological isolation. Anything that can reduce the travel time would make Mars missions much more doable.

The mag-beam system would eliminate the need for a transit vehicle to carry its own interplanetary propulsion system. "Rather than a spacecraft having to carry these big powerful propulsion units, you can have much smaller payloads," Winglee said.

The space stations themselves would have to carry megawatt-scale beam generators, however. "It can be nuclear-powered, or it could be solar electric with some fuel cells attached," Winglee told me.

The concept is a spin-off of an earlier scheme Winglee was investigating, known as mini-magnetosphere plasma propulsion, or M2P2. The earlier concept called for creating a magnetic bubble around the transit spacecraft, which would then be pushed outward by the solar wind.

The mag-beam idea is an improvement, Winglee said, because M2P2 "was considered too passive, and it was problematic as to how you could provide a test in the laboratory that you could easily scale."

Winglee said mag-beams would work better than light-based space-sail systems because of the issue of beam divergence over the vast distances of space. "What mag-beam offers, compared with the other methods, is an amount of self-focusing," he said. The space station's emitter would be magnetically linked to the space taxi's sail, providing a built-in guide for the ion beam.

If it works, the mag-beam approach would open up "a lot of new trajectories," and could make quick trips to other parts of the solar system routine, Winglee said. Mag-beam units could be installed on space probes going to deep-space destinations for other purposes — for example, the Jupiter Icy Moons Orbiter . Those probes could then serve as the remote robotic space stations for the first wave of taxi-borne explorers.

The mag-beam system is one of 12 proposals that has just received a $75,000, six-month grant from the NASA Institute for Advanced Concepts, or NIAC. If the idea is validated at the end of those six months, the team could receive as much as $400,000 more over two years.

Winglee said the first outer-space tests of a mag-beam system could be conducted within five years, using suborbital sounding rockets. But what about Mars? NASA officials have said the first humans could be sent to the Red Planet in 20 or 30 years . Winglee says the mag-beam can be ready by then.

"We could easily do it by 2020, if we were continuously funded," he said.

The mag-beam concept — along with the other NIAC-funded proposals for projects ranging from an extrasolar-planet imager to a lunar space elevator — will be discussed next week at a meeting in Seattle. Check out the University of Washington's news release as well as Winglee's Web page — then let me know whether you think the mag-beam idea, or any of other NIAC concepts, will actually fly.

Oct. 14, 2004 | 7:30 p.m. ET
Space TV renewal: Rumblings about space-based TV projects are on the upswing: Even before SpaceShipOne's successful X Prize bid , TV executives were taking a fresh look at concepts that had to be shelved in the wake of the Columbia tragedy. Now networks are said to be interested. Peter Diamandis, chairman and founder of the X Prize Foundation, said half-jokingly that camera crews could follow around rocket teams for a TV series he dubbed "Monster Hangar," modeled on the Discovery Channel's "Monster Garage."

Oct. 14, 2004 | 7:30 p.m. ET
Profiles in science and technology on the Web:
AutoWeek: Burt Rutan takes latest Lotus out for a spin
The 15th Annual Discover Awards for Innovation
Scientific American: Science's political bulldog
Discovery.com: Michelangelo's David missing a muscle

Oct. 13, 2004 | 7 p.m. ET
How did dinosaurs die? What led to the extinction of the dinosaurs and many other species 65 million years ago? Over the past 20 years, most scientists have come to favor the theory that the Cretaceous-Tertiary extinction, one of the "Big Five" global die-offs, was caused by a catastrophic asteroid or comet impact centered on Mexico's Yucatan Peninsula.

But every once in a while, skeptical scientists cast doubt on that claim, contending that the dinosaur tribe was fading away even before the space rock hit. In this scenario, other factors — perhaps global climate change, or a gamma-ray burst, or just plain mammalian know-how — had already put the dinosaurs into decline, and the Chicxulub impact was just the final blow.

The latest burst of skepticism was sparked this week by a paper appearing in the journal Trends in Ecology & Evolution. David Penny of New Zealand's Massey University and Matthew Phillips of England's Oxford University say their genetic sleuthing led them to the conclusion that mammals were becoming more diverse tens of millions of years before the cosmic impact, and that dinosaur diversity was shrinking.

"So far, this evidence contradicts the popular theory," Penny told Agence France-Presse in a report carried by Australia's ABC Online.

A similar report appears in the New Zealand Herald. Penny is quoted as saying, "We agree completely with the geophysicists that an extraterrestrial impact marks the end of the Cretaceous. But after 25 years they have still not provided a single piece of evidence that this was the primary reason for the decline of the dinosaurs and pterosaurs."

That claim was quickly disputed by Benny Peiser, an anthropology professor at Liverpool John Moores University who specializes in chronicling the debate over past (and perhaps future) global catastrophes.

"The hard facts point in exactly the other direction," Peiser told me in an e-mail. "According to the latest analysis of a new dinosaur database, the K/T [Cretaceous-Tertiary] impact hit the dinosaurs at their peak."

He pointed to a report posted on Wissenschaft.de (in German) that in turn refers to the database analysis, published in this month's issue of the journal Geology. The researchers behind that analysis say dinosaur species were actually on an upswing when the impact occurred — lending credence to the view that those poor giant reptiles were cut down in their prime.

Data: The rise and fall of Earth's species Based on that research, the claim that there's no evidence supporting the killer-asteroid hypothesis "turns out to be a lot of hot air and theoretical nonsense — and poor science reporting, too," Peiser wrote.

The back-and-forth sheds light on something even more important than figuring out what killed off the dinosaurs: the scientific process itself. Over the decades, theories rise or fall depending on how well they stand up to the assaults from skeptics, and how well they explain fresh information. Few scientific theories are beyond doubt — but the mere persistence of skepticism doesn't mean a theory is on shaky ground. That goes for evolution as well as relativity and quantum physics.

To keep up with the debate over impact threats, global climate change and other catastrophe theories, check in with Peiser's Cambridge Conference Network.

Update for Oct. 15: References to the Chicxulub asteroid were amended to leave open the possibility it might have been a comet instead.

Oct. 13, 2004 | Updated 7:45 p.m. ET
The rocket report: SpaceX says its first low-cost Falcon rocket has been set up on the launch pad at California's Vandenburg Air Force Base in preparation for putting the TacSat-1 military communications satellite into orbit.

"We will be doing a hold-down test firing in December (pending range availability), and our first launch is slated for late January 2005," Dianne Molina, marketing manager at SpaceX, reported in an e-mail. "Vandenberg will be closing down from Thanksgiving through mid-January, so the last week of January is the earliest we can get in there to launch."

On another topic, I was curious whether SpaceX founder Elon Musk was interested in pursuing the $50 million orbital spaceflight prize announced last week by hotel magnate Robert Bigelow. "According to Elon, we are waiting to see the final details of the prize before making a decision," Molina said.

Meanwhile ...

  • SpaceShipOne designer Burt Rutan is hoping to go to the moon in 10 years, according to a report from last weekend's Space Frontier Conference passed along by Armadillo Aerospace's John Carr. "He is not known for making wild statements," Carr wrote in an e-mail. "I wouldn’t be surprised if he gets the support from the industry to do it!"
  • Armadillo's latest video about its own rocket program was reportedly a hit at the conference, and is now posted on the Armadillo home page.
  • An Associated Press story about the private-spaceflight legislation bottled up in Congress says efforts to hammer out a more palatable compromise will continue next week, with the aim of getting something passed during next month's lame-duck session.

For more about SpaceX, SpaceShipOne, Armadillo and all the other usual suspects, click on over to Clark Lindsey's RLV News. And for more on space politics, check out Jeff Foust's aptly named Space Politics blog.

Oct. 14, 2004 | Updated 2:15 a.m. ET
Scientific stops on the World Wide Web:
Defense Tech: Pentagon wants mini-killers in space
New Scientist: Are you listening, America?
Scientific American: Sci-Tech Web Awards 2004
Popular Science: The worst jobs in science, Vol. II
National Geographic: Why do fall leaves change color?

Oct. 12, 2004 | 7:15 p.m. ET
Galactic fossil unearthed: NASA's Spitzer Space Telescope has used its infrared eyes to pick out a previously unnoticed "fossil" of unearthly origin. The globular star cluster, about 9,000 light-years away in the constellation Aquila, is thought to rank among the oldest objects in our Milky Way galaxy.

About 150 of these ancient star bundles are sprinkled around the Milky Way's center, "like seeds in a pumpkin," Spitzer researchers said in today's advisory. They date back as far as the birth of the Milky Way, about 13 billion years ago, and thus can be used as tools for studying our galaxy's age and formation.

Astronomers thought they had already spotted just about all of our galaxy's globular clusters, but University of Wyoming graduate student Andrew Monson found one more while going through observations from a Spitzer project known as GLIMPSE — Galactic Legacy Infrared Mid-Plane Survey Extraordinaire. He confirmed the cluster's existence by checking data from an earlier infrared survey, the Two Micron All-Sky Survey.

"The cluster was there in the data, but nobody had found it," Monson said.

Image: Globular cluster
NASA / JPL / Caltech / U.Wyo.
The newfound globular cluster is the bright spot in the middle of this image, surrounded by the reddish signature of interstellar dust.
University of Wyoming astronomer Chip Kobulnicky, the lead author of a report accepted for publication in an upcoming issue of the Astronomical Journal, said the discovery was "like finding a long-lost cousin." The star cluster can't be seen at all in visible-light imagery of that region of the sky, because visible wavelengths are blocked by galactic dust. However, Spitzer's infrared vision can see right through the haze.

"This discovery demonstrates why Spitzer is so powerful — it can see objects that are completely hidden in visible light. This is particularly relevant to the study of the plane of our galaxy, where dust blocks most visible light," said Spitzer project scientist Michael Werner of NASA's Jet Propulsion Laboratory.

Check out the Spitzer Web site and our Spitzer slideshow for more infrared wonders.

Oct. 12, 2004 | 7:15 p.m. ET
The geography games: How well do you know the globe? If you're a geography whiz, you might want to try boosting your country's score in the Geography Olympics, sponsored by the folks behind the Global Puzzle. Right now, New Zealand is leading in the standings, followed by Israel and Gambia. The United States isn't even in the top 40.

Oct. 12, 2004 | 7:35 p.m. ET
Rocket launch rescheduled: Space Transport Corp., the Washington state X Prize team that made a fiery splash with its August rocket launch, now says it's planning to fire off its Rubicon 2 rocket on Oct. 24 — a week later than previously planned. Check the STC Web site for updates.

Oct. 12, 2004 | 7:15 p.m. ET
Scientific spin on the World Wide Web:
The Economist: The men in the white coats are winning
Nature: Molecular clock tied to fossil record
Archaeology Magazine: Malta's monumental mandate
Western Mail: Nurse documents near-death experiences

Oct. 11, 2004 | 7:15 p.m. ET
Celebrity spaceflights: Remember 'N Sync pop singer Lance Bass and his dream of flying in space? Well, the dream is still alive, two years after Bass was taken off a crew bound for the international space station due to a lack of sponsorship.

Bass said he's still planning to fly someday, during an appearance at last weekend's Space Frontier Conference in Long Beach, Calif.  "I have several experiments I want to perform on a spaceflight, and bring more excitement to kids about space," he told the crowd.

He is staying involved in the space scene by serving as youth spokesman for World Space Week — and it was in that capacity that he toured a number of Los Angeles-area schools last week.

With the space shuttle fleet still grounded and Russian Soyuz flights at capacity for the next year or so, it might seem as if Bass will have to wait a good while longer for his ride. However, Michael Mealling's RocketForge blog quotes the 25-year-old heartthrob as saying "something is in the works to make it pretty soon."

There are other rumblings about passenger rides, though they may not be related to Bass' plans: Eric Anderson of Virginia-based Space Adventures, the company that put millionaires Dennis Tito and Mark Shuttleworth in space, hinted last week amid the X Prize festivities in Mojave, Calif., that a significant announcement was being readied for mid-October. Anderson  said New Jersey scientist/entrepreneur Greg Olsen , who is missing out on this week's Soyuz launch due to medical concerns, was still hoping to get to the space station on a later flight.

Lori Garver, a former NASA associate administrator who is now serving as a science adviser to John Kerry's presidential campaign, was in Mojave as well — and she said she'd also like to get into space. Like Bass, "Astromom" Garver received cosmonaut training in Russia in hopes of getting a future Soyuz ride, but her sponsorship deal never came together.

Oct. 11, 2004 | 7:15 p.m. ET
No women allowed: NBC News space analyst James Oberg notes with interest that Russia's 500-day Mars mission simulation , planned for 2006, will be for men only. In an e-mail, Oberg sheds light on a possible reason why:

"A similar ground simulation wound up wracked by international and transgender tensions when the Russians couldn't keep their hands (and lips) off the foreign women, and couldn't understand why they should have objected," he writes. The full story from four years ago is archived on Oberg's Web site.

Oct. 11, 2004 | 7:15 p.m. ET
Stem cells in the spotlight: The passing of "Superman" quadriplegic Christopher Reeve comes just as Reeve's cause celebre, embryonic stem-cell research, is heating up as a presidential campaign issue. To learn more about the controversy, you can check out our special report on stem cells ... pick up "The Proteus Effect," a newly published book on stem cells and their promise ... and tune in over the Web on Tuesday and Wednesday for a timely workshop on the guidelines governing stem-cell research.

Oct. 11, 2004 | 7:15 p.m. ET
Your daily dose of science on the Web:
Discovery.com: Robot tongue sounds out sweet and sour
N.Y. Times (reg. req.): Genome in black and white (and gray)
New Scientist: Nanoparticles hunt down harmful bacteria
The Independent: Space race of the 17th century

The fine print: Looking for older items? Check the Cosmic Log archive. Share your perspective on cosmic subjects with Alan Boyle. If you link to this page, you can use http://cosmiclog.msnbc.com or http://www.cosmiclog.com as the address. MSNBC is not responsible for the content of Internet links.

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