Tag Archives: space exploration

Sailing, sailing, over the bounding interplanetary main

solar sailI’ve always loved the idea of the solar sail, giant glistening sails that use solar radiation to propel a ship through the solar system (as in the image at left).

But the Finnish Meterological Institute has come up with a better way to utilize that radiation for spacecraft propulsion, “by using long metallic tethers and a solar-powered electron gun to create an ‘electric sail.'” (Via Gizmag.)

Invented in 2006 at the Kumpula Space Centre, the electric solar wind sail, alas, loses some of the romance of the traditional solar sail: it looks more like an antenna (view an animation here):

A full-scale version would consist of up to 100 thin conducting wires as long as 20 km that are kept in a high positive potential by the spacecraft’s on-board solar-powered electron gun. This electric field effectively turns the wires into 50 meter wide sails that can then make use of solar wind. It’s estimated that a 20km long electric sail wire (which weighs only a few hundred grams and fits in a small reel) is equivalent to a one square kilometer solar wind sail when deployed in this way.

Planning for a test mission has begun, and the researchers note that the same technology could also assist in the development of solar power satellites.

In 2004 NASA’s Solar Sail Propulsion Team successfully deployed two 10-meter solar sails made of reflective material 40 to 100 times thinner than a piece of writing paper in a laboratory vacuum environment. But the first solar sail spacecraft, Cosmos 1, failed to enter orbit after its 2005 launch.  (UPDATE: Not, as commentator Anthony points out, due to any fault of the solar sails, but due to a rocket booster failure.)

(Image: John Ballentine.)

[tags]space exploration, solar sails, space travel, solar power[/tags]

The search for life on Europa begins here on Earth


Although the search for extraterrestrial life in our solar system has focused on Mars for many years (and it still might be found there), increasing attention is now being paid to Jupiter’s moon Europa. That’s because the scientific consensus now is that Europa almost certainly boasts an ocean, hidden beneath a shell of ice.

Life on Earth originated in the ocean. Could life have similarly arisen in Europa’s ocean?

We’ll have to go there to find out. Both NASA and the European Space Agency are actively studying launching a mission to Europa within the next decade, but even before that happens, technologies that could help us explore beneath the ice shell are being tested here on Earth. (Via Universe Today.)

This week–February 11 to 15–researchers are testing the NASA-funded ENDURANCE (Environmentally Non-Disturbing Under-ice Robotic Antarctic Explorer), a robotic probe designed to swim on its own under ice, creating 3D maps of the underwater environment, collecting data on environmental conditions, and taking samples of microbial life. The testing is taking place in Lake Mendota on the campus of the University of Wisconsin, Madison; later this year, the probe will be shipped to Antarctica for tests in permanently frozen Lake Bonney.

Manwhile, a team of U.S., Russian and Asutrian scientists are already heading to Australia to look for life in another Antarctic lake, Lake Untersee. Always covered in ice, Lake Untersee has a pH level closer to that of bleach than regular lake water. It’s also the planet’s single largest natural source of methane. All of these things mean conditions there may well resemble conditions in Europa’s ocean and other locations in the outer solar system.

One question: is life found on Europa European, or Europaen? Copy editors want to know!

(Image: Courtesy NASA/JPL-Caltech.)

[tags]solar system, NASA, space exploration, extraterrestrial life, Europa[/tags]

Freakonomics asks – Is Space Exploration Worth the Cost?

Freakonomics has an excellent quorum of space experts and economists talking about a very interesting question – Is Space Exploration Worth The Cost? There are some interesting points made although all of the participants are in the field of space science, so naturally they all agree it’s a good thing! It would have been nice to have a few dissenting views but even so there are some good quotes here.

G. Scott Hubbard: “We explore space and create important new technologies to advance our economy. It is true that, for every dollar we spend on the space program, the U.S. economy receives about $8 of economic benefit. Space exploration can also serve as a stimulus for children to enter the fields of science and engineering.”

Keith Cowing: “Right now, all of America’s human space flight programs cost around $7 billion a year. That’s pennies per person per day. In 2006, according to the USDA, Americans spent more than $154 billion on alcohol. We spend around $10 billion a month in Iraq. And so on. Are these things more important than human spaceflight because we spend more money on them? Is space exploration less important?”

John M. Logsdon: “In the longer run, I believe that human exploration is needed to answer two questions. One is: “Are there activities in other places in the solar system of such economic value that they justify high costs in performing them?” The other is: “Can humans living away from Earth obtain at least a major portion of what they need to survive from local resources?” If the answer to both questions is “yes,” then I believe that eventually some number of people in the future will establish permanent settlements away from Earth.”

Personally I agree with Charles Stross that living away from Earth has so many things to overcome that it’s unlikely without huge discoveries but the value of space exploration in our lifetimes may be in asteroid mining – with many new technologies like solar cells rapidly using up some of Earth’s more scarce elements.