When I was a kid, interstellar destinations were sharply defined. It seemed obvious that you didn't even consider Alpha Centauri, because a double-star primary system surely wouldn't allow stable planetary orbits. So you looked around for single stars. Moreover, these should be stars a lot like the Sun, so that when Frank Drake began SETI with Project Ozma, it made all the sense in the world to focus on Tau Ceti and Epsilon Eridani. Both were similar enough to our own star to suggest that they would have planets, and maybe one like ours. For that matter, we had no idea in those distant days whether the Sun was a statistical fluke in having planets or simply a garden-variety star with a system that was all but inevitable. These days we keep finding interesting planets, but so far (other than perhaps in the Gliese 581 system) we haven't found anything enough like the Earth to consider any nearby system an obvious target for an interstellar probe. All that may change, and swiftly, when...

One of the most useful technologies the Project Daedalus team lacked when designing its interstellar probe back in the 1970s was the personal computer. Today's effort to re-visit Project Daedalus can draw on the strength of intercontinental networking for fast communications and widespread computer availability to design a probe differently. It's exciting to hear that the Project Icarus team plans vIcarus, a 'virtual' interstellar mission drawing on the completed Icarus design and 'flown' through ongoing computer simulation. Spun out in real time, vIcarus will give designers and the public a chance to follow the mission step by step. Andreas Tziolas (Variance Dynamical Corporation) discussed the idea on the Project Icarus blog recently, noting that over the next few years, the Icarus team will be creating computational models for propulsion, fault repair, communications, flight through the interstellar medium and all the factors impinging upon the behavior and stability of the...

Two versions of Icarus are on my mind today. Well, actually three. The first is the Japanese solar sail/solar cell hybrid called IKAROS, scheduled for launch today but scrubbed because of the weather at Tanegashima. The new launch date is Thursday May 20 at 2158 UTC (1758 EDT). IKAROS will piggyback aboard the JAXA H-2A booster with the Venus Climate Orbiter (AKATSUKI), and will be a ground-breaking shakedown of solar sail technologies in interplanetary space. Needless to say, we'll follow this one with interest as solar sails move to the next level of testing. Meanwhile, Kelvin Long reports that Project Icarus, the joint-undertaking between the British Interplanetary Society and the Tau Zero Foundation, made the pages of the London Metro newspaper recently. Be sure to click 'This Week's Graphic' at the bottom of the article to view the whole story. Icarus, often discussed in these pages, is the successor to the BIS Project Daedalus starship study, and seeks to examine fusion...

The fastest moving spacecraft in our Solar System is currently Voyager 1, which is moving at 61,419 kilometers per hour, a figure that works out to 17.06 kilometers per second. It's always interesting to weigh such speeds against the hypothetical upper limits we would get from certain kinds of propulsion. Geoffrey Landis told me years ago, when we were talking in his office at Glenn Research Center in Cleveland, that a reasonable Sun-diver maneuver (a close pass by the Sun to get the ultimate gravitational boost) might result in a properly designed solar sail getting up to 500 kilometers per second. Quite a jump from Voyager 1. On the other hand, contrast it to a journey to the nearest stars. Moving at 500 kilometers per second (assuming they could withstand the acceleration of the maneuver), the occupants of our solar sail starship would travel some 2580 years before reaching Centauri A and B. I've seen some extrapolations that get travel time to the Centauri stars down to about...

Is Jupiter the best place to collect massive amounts of helium-3? The Project Daedalus designers thought so. Back in the 1970s, members of the British Interplanetary Society set out to design a starship that would use pulsed fusion propulsion, with deuterium and helium-3 as fuel. Daedalus had mind-bending requirements, for the plan was to drive it to 12 percent of lightspeed on a flyby mission to Barnard's Star that would take fifty years to arrive. 250 pellets of deuterium and helium-3 would be detonated every second in its combustion chamber over a thrust period of four years. That calls for a lot of fuel, and therein lies the problem. Fueling Up the Probe We can find deuterium (an isotope of hydrogen) right here on Earth, but helium-3 is a rarity. The Daedalus team figured it needed some 30,000 tons of helium-3, so it envisioned mining Jupiter's atmosphere, where the stuff is plentiful. Imagine floating factories in the atmosphere of the giant planet using waste heat to generate...

I love what Dan Wertheimer, a Berkeley astronomer and one of the powers behind the SETI@Home distributed computing project, told a session at the recent AAAS meeting in San Diego. Wertheimer was talking about the possibility of using the Sun's gravitational lens for SETI purposes, and as quoted by Alan Boyle, said that such an observatory could "read the license plates on an extrasolar planet." That reminded me of Claudio Maccone's whimsical but mind-boggling remark at the interstellar conference in Aosta last July, which went in much the same direction. What could lensing do? "We could see the roads of their cities. We could see the cars they are driving." Drake has made the case for using the Sun's gravitational lens for SETI purposes for a long time now, and he repeated it at the TED 2010 conference in Long Beach. As to Maccone, he has long championed the FOCAL mission to the gravitational lens that would exploit the fantastic magnifications available at 550 AU and beyond. But it...

Every few weekends as we move toward the March 5 deadline for submission of abstracts to the next International Astronautical Congress, I'll re-run this call for papers that I originally published in December. The Tau Zero Foundation hopes to energize discussion of FOCAL in the astronautical community and create a growing set of papers analyzing aspects of the mission from propulsion to communications, leading to a formal mission proposal. We hope anyone interested in furthering this work at the coming IAC in Prague will consider submitting a paper. The Tau Zero Foundation is announcing a call for papers related to the FOCAL mission. The venue: The 61st International Astronautical Congress in Prague, which convenes on the 27th of September, 2010 and runs to October 1. Specifically, we are looking for papers for session D4.2, "Interstellar Precursor Missions," whose focus is "...missions that significantly expand science -- using existing and emerging power and propulsion...

Every few weekends as we move toward the March 5 deadline for submission of abstracts to the next International Astronautical Congress, I'll re-run this call for papers that I originally published in December. The Tau Zero Foundation hopes to energize discussion of FOCAL in the astronautical community and create a growing set of papers analyzing aspects of the mission from propulsion to communications, leading to a formal mission proposal. We hope anyone interested in furthering this work at the coming IAC in Prague will consider submitting a paper. The Tau Zero Foundation is announcing a call for papers related to the FOCAL mission. The venue: The 61st International Astronautical Congress in Prague, which convenes on the 27th of September, 2010 and runs to October 1. Specifically, we are looking for papers for session D4.2, "Interstellar Precursor Missions," whose focus is "...missions that significantly expand science -- using existing and emerging power and propulsion...

If you haven't read George Dyson's fascinating history of Project Orion, let me recommend it to you highly. Project Orion: The True Story of the Atomic Spaceship (Henry Holt, 2002) fires the imagination with the audacity of the project, a nuclear pulse rocket that would have exploded atomic bombs behind the vehicle, using the world's ultimate shock absorbers to ride the wave to the outer planets. There was talk of going to Saturn (to Enceladus, no less) in the late 1960's, but those dreams were quickly quashed by treaties forbidding nuclear testing. The Problem with Orion Kelvin Long, who heads up the ambitious Project Icarus attempt to revisit and extend Project Daedalus, notes in a recent post on the Icarus blog that Freeman Dyson (George's father) ultimately gave up on Orion (a fact that surprised me when I did a telephone interview with him on the prospects for interstellar propulsion back in 2003). Here's what Dyson says about the subject in his book Disturbing the Universe...

Every few weekends as we move toward the March 5 deadline for submission of abstracts to the next International Astronautical Congress, I'll re-run this call for papers that I originally published in December. The Tau Zero Foundation hopes to energize discussion of FOCAL in the astronautical community and create a growing set of papers analyzing aspects of the mission from propulsion to communications, leading to a formal mission proposal. We hope anyone interested in furthering this work at the coming IAC in Prague will consider submitting a paper. The Tau Zero Foundation is announcing a call for papers related to the FOCAL mission. The venue: The 61st International Astronautical Congress in Prague, which convenes on the 27th of September, 2010 and runs to October 1. Specifically, we are looking for papers for session D4.2, "Interstellar Precursor Missions," whose focus is "...missions that significantly expand science -- using existing and emerging power and propulsion...

The Tau Zero Foundation is announcing a call for papers related to the FOCAL mission. The venue: The 61st International Astronautical Congress in Prague, which convenes on the 27th of September, 2010 and runs to October 1. Specifically, we are looking for papers for session D4.2, "Interstellar Precursor Missions," whose focus is "...missions that significantly expand science -- using existing and emerging power and propulsion technologies." Long-time Centauri Dreams readers are well aware of Claudio Maccone's FOCAL concept, a mission to the Sun's gravitational lens at 550 AU and beyond. FOCAL would make possible studies of astronomical objects at unprecedented magnifications. The electromagnetic radiation from an object occulted by the Sun at 550 AU (i.e., on the other side of the Sun from the spacecraft), would be amplified by 108. Moreover, whereas with an optical lens light diverges after the focus, light focused by the Sun's gravitational lens stays fixed along the focal axis....

by Pat Galea Project Icarus will update the Project Daedalus starship designed by the British Interplanetary Society in the 1970s. As we saw yesterday, developments in technology allow new options in a number of areas, but also raise questions about the mission's scope and choice of targets. Pat Galea now concludes his discussion of the recent Project Icarus symposium in London, after which the terms of reference for the project, now frozen, are listed. Propulsion Options Richard Obousy tackled the part of the system that is the most obvious, the most important and probably the most difficult: the engine. As I've noted above, the Daedalus propulsion system uses pulsed nuclear fusion to accelerate the craft to about 12% of the speed of light. Even at such an immense speed, the mission time to Barnard's Star (5.9 light years from Sol) is about fifty years. Obousy took us through different methods of propulsion that have been proposed, such as chemical rockets, electric ion engines and...

by Pat Galea The Tau Zero Foundation has been working with the British Interplanetary Society on Project Icarus, a starship study that updates the famous Project Daedalus work from the 1970s. Pat Galea, a software engineer with a lively interest in the physics of interstellar flight, attended the recent symposium that launched the project, and here provides us with a report that I will publish in two parts, concluding tomorrow. Just over thirty years ago, British Interplanetary Society (BIS) members carried out one of the most complete studies of an interstellar vehicle ever made. Even today, Project Daedalus retains its status as an outstandingly comprehensive reference design. Its final report sits on the shelf of many a starship enthusiast. In the intervening years, technology and science have advanced in many of the areas that are crucial to the Daedalus mission plan and design. The time has come to re-examine Daedalus in light of the progress that has been made, so Kelvin Long...

NASA has made its choices, and TESS is not one of them. The Transiting Exoplanet Survey Satellite would have used six telescopes to observe the brightest stars in the sky, a remarkable 2.5 million of them, hoping to find more than 1,000 transiting planets ranging in size from Jupiter-mass down to rocky worlds like our own. An entrant in the agency's Small Explorer program, TESS could have accelerated the time-frame for discovering another habitable world, assuming all went well. Not that we don't have Kepler at work on 100,000 distant stars, looking for transits that can give us some solid statistical knowledge of how often terrestrial (and other) planets occur. And, of course, the CoRoT mission is actively in the hunt. But TESS would have complemented both, looking at a wide variety of stars, many of which would have been M-dwarfs. Not long ago I referred to a Greg Laughlin post that noted a 98 percent probability that TESS would locate a potentially habitable transiting planet...

EGR, standing for Embryo/Gestation/Rearing, is the name of a mission presented by John Hunt on Tibor Pacher's PI Club site, where Tibor encourages the development of what he calls 'crazy ideas.' Crazy, that is, in terms of brainstorming, getting concepts out there for comment and growth. Hunt's is likely to be controversial on several levels, although its goal -- an insurance policy for the species -- is one this site can endorse. Why an insurance policy? As we've discussed recently, the number of existential threats facing our species makes the Fermi question pointed. Self-destruction would be an ignominious end for any culture, but one not inconsistent with factors as diverse as incoming asteroids, nuclear war or biological weaponry run amok. Hunt prefers to focus on a specific threat: Advances in the area of biotech, nanotech, and artificial intelligence are accelerating. Molecular manufacturing will also bring us the ability to produce chemicals which are entirely novel and...

Imagine frozen pellets of deuterium and helium-3 being ignited by electron beams to produce fusion, all this occurring in a combustion chamber fully 330 feet in diameter. Such was one early concept for Project Daedalus, the British Interplanetary Society's starship design that would evolve into a two-stage mission with an engine burn -- for each stage -- of two years, driving an instrumented payload to Barnard's Star at twelve percent of the speed of light. We've been kicking the Daedalus concept around here recently because the BIS is developing, in conjunction with the Tau Zero Foundation, Project Icarus, a revisiting of the original Daedalus concept. The Daedalus propulsion system required fifty billion fuel pellets, thirty thousand tons of helium-3 and 20,000 tons of deuterium, as massive an undertaking as our species has ever attempted, given that the helium-3 would have to come from the atmosphere of a gas giant like Jupiter. Icarus will study what Daedalus might look like with...

by Kelvin Long Project Daedalus was the first thoroughly detailed study of an interstellar vehicle, producing a report that has become legendary among interstellar researchers. But Daedalus wasn't intended to be an end in itself. Tau Zero practitioner Kelvin Long here offers news of Project Icarus, a follow-up that will re-examine Daedalus in light of current technologies. A scientist in the plasma physics industry and an aerospace engineer, Long is assembling the team that will begin this work in 2010, following a 'Daedalus After 30 Years' symposium scheduled for September at the headquarters of the British Interplanetary Society. Can we improve Daedalus' propulsion systems, change its targets, modify its shielding? Numerous theoretical studies await. During the period 1973-1978 members of the British Interplanetary Society undertook a theoretical study of a flyby mission to Barnard's star, some 5.9 light years away. This was Project Daedalus, which remains the most detailed study...