The Solar Sail Technology and Applications Conference, organized by NASA Goddard Space Flight Center, has begun in Greenbelt MD and will run through tomorrow. Complete agenda here. Colin McInnes gave the keynote this morning. His book Solar Sailing: Technology, Dynamics and Mission Applications is as indispensable as it is hard to find, though Amazon now seems to have some used copies.
On the left is the cover of the first paperback edition of Poul Anderson's Tau Zero, published in 1970 (a shorter version called "To Outlive Eternity" appeared in 1967 in Galaxy Science Fiction, though unseen by me, as I was getting ready to leave for college). The first hardcover edition is below. Many of the scientists I talked to in doing the research for Centauri Dreams told me they read science fiction, and most favored the 'hard' SF, scrupulously accurate to science as understood at the time, favored by writers like Anderson. And several said that it had been Tau Zero that got them into physics or engineering in the first place. Here's Anderson's look at a Bussard ramjet as it consumes interstellar hydrogen on a runaway journey that will never end: The ship was not small. Yet she was the barest glint of metal in that vast web of forces which surrounded her. She herself no longer generated them. She had initiated the process when she attained minimum ramjet speed; but it became...
Even as NASA announced the head of the Genesis Mishap Investigation Board (Dr. Michael Ryschkewitsch, Director of the Applied Engineering and Technology Directorate at NASA's Goddard Space Flight Center), unexpectedly good news from the mission continued to mount. At least two of the four segments of the solar wind concentrator Genesis carried seem to be intact, and the gold foils used to analyze nitrogen isotopes have also survived. Even the hexagonal wafers that collected solar wind particles may yield good data, despite the fact that all or nearly all are broken. ""We won't really know how many can be recovered for some time, but we are far more hopeful important science can be conducted than we were on Wednesday," said Dr. Roger Wiens of the Los Alamos National Laboratory, a member of the Genesis science team. "We are very encouraged." This is astoundingly good news to anyone who watched Genesis hit the ground at the Utah Test & Training Range at close to 200 mph on September 8....
Well, David Brin wrote a novel called Sundiver, which wouldn't have been a bad name for the end of this mission. Genesis may still have some salvageable science on-board, but it's hard to see how much of the solar wind experiment could have survived its crash. Here's a link to the BBC's coverage. No deployment on the drogue chute!
Use NASA's Genesis mission page to monitor the progress of the first sample return mission since Apollo 17. Coverage will be broadcast live and on the Internet (links available at the NASA site). Although snagging the Genesis return capsule in mid-air (using helicopters piloted by stunt flyers) should be spectacular, what interests interstellar theorists is what we may learn about the solar wind. This stream of charged particles and magnetic fields moving up to 500 kilometers per second may eventually be used to push a magnetic sail like M2P2 (Mini-Magnetospheric Plasma Propulsion), which the University of Washington's Robert Winglee designed in a study for NASA's Institute for Advanced Concepts. A NASA page on the Winglee design can be found here. From the article: There is enough power in the solar wind to accelerate a 136 kg (300 lb) spacecraft to speeds of up to 288,000 km/h (180,000 mph) or 6.9 million km (4.3 million mi) a day. By contrast, the space shuttle travels at about...
Here is a press release first seen on Science Blog that details NASA's latest work on solar sails, and that of two key subcontractors. L'Garde's solar sail deployment occurred in July, using a 100-foot in diameter vacuum chamber at NASA's Glenn Research Center in Ohio. The test included temperatures of minus 112 Fahrenheit to mimic actual space conditions, and used inflatable booms that become rigid once deployed. Able Engineering has also tested a solar sail deployment at NASA's Langley Research Center in Hampton, VA using a graphite boom that is extended by remote control. Able's boom supports a sail made of an aluminized material called CP-1, produced by SRS Technologies of Huntsville. Deploying a solar sail is an enormous challenge, particularly when you start talking about sails considerably larger than these test models (we'll need sails kilometers in diameter when and if we start talking about interstellar missions). Moktar Salama of the Jet Propulsion Laboratory, who has been...
The Japanese Institute of Space Astronautical Science has tested a ' reflective polyimide resin only 0.0075 millimetres thick' in space, deploying two sails at an altitude of 150 kilometers (93 miles) and 170 kilometers (106 miles). This article in New Scientist provides the details, noting that this is the first time a solar sail has ever been deployed in space (I assume they mean the first 'free-flying' solar sail, since Russia's Znamya space mirror tested deployment technologies on February 4, 1993). The Planetary Society's Cosmos 1 sail would have been the first space-based deployment of a free-flying sail, but the sail was destroyed in 2001 along with its booster rocket. The second test for Cosmos 1 may occur as early as this year. Deployment of thin films in space is dicey stuff, as a later Znamya experiment made all too clear in February of 1999. Attempting to spin the sail, engineers controlling the Progress supply ship to which it was attached accidentally extended an...
Cosmos 1, the privately-funded solar sail experiment funded largely by Ann Druyan's Cosmos Studios and run by The Planetary Society, has passed an important milestone. All electronic systems for the spacecraft have been thoroughly tested at the Space Research Institute in Moscow, and have been sent to nearby Lavochkin for assembly in the vehicle. Although there have been previous experiments with photon propulsion (through Russia's Znamya space mirror deployment), Cosmos 1 would be the first spacecraft to demonstrate solar sail technologies in free flight. The goal is to launch the sail from a Russian nuclear submarine in the Barents Sea, perhaps as early as the end of this year. One fascinating experiment to watch in addition to the demonstration of photon propulsion will be an attempt to use beamed microwaves to move the sail. The microwave experiment is in the hands of James Benford of Microwave Sciences, Inc. of Lafayette, CA; Benford plans to use a large radio dish in Goldstone,...
The Hubble Space Telescope has given us no end of gorgeous astronomical photographs. This one is of an enormous cavity of gas carved out by the stellar wind from the nebula N44f; the image comes from the ESA/Hubble Information Centre. You're looking at what happens when a cloud of gas is inflated by fast-moving particles from a hot young star. This stellar wind is moving at about 7 million kilometers per hour, far faster than the Sun's (a sedate 1.5 million kilometers per hour). Keep this image in mind when thinking about new propulsion concepts like Robert Winglee's M2P2, which uses the solar wind to push a magnetic sail. You can read about Winglee's work at this Web site at the University of Washington. And note that when we talk about the solar wind pushing a magnetic sail, we are discussing something different than a solar sail, which gets its push solely from the momentum imparted by photons. They are two entirely different concepts.
