Futuristic Interstellar Space Probe Idea Revisited

New technologies and the growing number of alien planets being discovered are fueling a new look at a plans for a futuristic interstellar probe into deep space.

A dedicated study team has formed Project Icarus, an international initiative established by the Tau Zero Foundation in the United States and the British Interplanetary Society (BIS).

The multi-talented group is delving into everything under our the sun to develop designs for the interstellar spaceship, from inertial confinement fusion to reviewing the latest in nanotechnology, computing, and electronics, as well as identifying target star destinations.

Today?s Project Icarus signals a bit of a baton-passing from a BIS-backed star ship appraisal called Daedalus that was done in the late 1970s.

?The Project Daedalus theoretical engineering design study took place over three decades ago. In the time since, there have been many advances in science and technology,? said Kelvin Long, a key Icarus designer.

?There is a need to maintain interest in and the capability to design interstellar probes,? Long told SPACE.com. ?With many of the historical leaders in this field now nearing retirement or deceased, the Project Icarus study group wants to take up the baton and keep alive the long term vision that travel to the stars will one day be possible. This is one of the reasons why over half of the team is relatively fresh out of their university studies.?

Think outside the box

Designing an unpiloted Project Icarus space probe is requiring the time and energy of some 20 volunteer designers. Taking on interstellar travel this 21st century go-round is estimated to consume around 30,000 man/woman hours of effort, with submission of the final study reports due for 2014.

Many of the original Project Daedalus study participants are providing guidance.

Long said that Project Icarus is an exercise in theoretical engineering to the extreme. Project Icarus, he said, will take another look at several of the Daedalus assumptions and systems. Furthermore, an objective of the initiative is to continue to inspire the next generation.

?Icarus may not be the blueprint for how we first reach the stars, but it is hoped that it will be an important contribution towards this long term goal. Another purpose of Project Icarus is to remind space agency mission planners to think outside of the box,? he said.

Long-haul roadmap

The intellectual thrust behind Project Icarus will measure, for one, the technological maturity of fusion-based propulsion schemes. Key technological stepping stones are to be identified. In short, a long-haul roadmap to the stars is on the group?s to-do list to make such a mission possible.

?This would provide an estimate for the earliest time upon which such a mission could be launched. This may be in the latter part of this century, sometime in the 22nd century or even later,? Long observed.

The Project Daedalus effort of decades ago proposed mining Helium-3 (He3) from the gas giant Jupiter which necessitated a massive space based infrastructure.

Fast forward to today means that the Project Icarus group will re-evaluate this fuel acquisition tactic and consider alternatives - such as mining He3 from Earth?s moon or exhume deuterium from objects in the Oort cloud. Moreover, the assumed Daedalus propellant combination of deuterium and He3 will also be re-examined, as will implosion-driving schemes.

Fusion of ideas

Long said that the choice of mainly fusion-based propulsion for the project was made because it is believed to be one of the strong candidates for how the first interstellar missions will be achieved in future decades or centuries hence.

?There are other proposals which are credible, such as solar sails...but fusion certainly offers the required performance for an interstellar mission, provided you can make the technology work,? Long noted. Project Icarus aims to build on the first-rate work of Project Daedalus, by refining the design with updated knowledge in science and technology, he said.

?Primarily, we have over thirty years of new data on experimental fusion, and thus have a deeper understanding of the process,? said Richard Obousy, primary propulsion lead of the study group. Possibly one of the most exciting advances, he said, is the suggestion that antimatter itself, in very small quantities, could be used as a catalyst for fusion ignition.

?All these technologies could certainly optimize the original Daedalus design, meaning less mass for the propulsion system and more possibilities for the payload. We hope our study will result in a faster and less massive design,? Obousy said.

Most suitable target?

Given the gulf between our solar system and another star system, long distance data transmission from the Icarus probe is a tricky issue.

According to the team?s communications lead, Pat Galea, solutions range from examining the potential for powerful lasers to broadcast data back to Earth, to more exotic ? but physically plausible ? mechanisms, such as using the sun as a gravitational lens to focus the distant transmissions onto a deep-space receiver craft.

?We are aiming for a technically credible solution for Icarus,? Galea added, ?so there?s a lot of model building and number crunching ahead before we can decide on the optimum solution.?

With the onslaught of exoplanet detections, with far more to come, what?s the most suitable target for the first mission of an interstellar probe?

Long responded that Epsilon Eridani, 10.7 light-years away, is a good candidate as infrared observations have detected dust rings suggestive of a planetary system.

?Ideally, we would like to identify Earth-like worlds in the habitable zone and this is an ongoing research program in the astronomical community,? Long pointed out. ?However, the choice must be balanced with engineering design constraints and what is realistically possible within a 100 year mission, one of the requirements for Project Icarus.?

Renewed spirit of adventure

?It is about time to put some systematic work into assessing to what degree the advances since Daedalus have made interstellar flight easier ? and to recheck where we stand today ... and what we need to do to make progress,? said Marc Millis, President of the Tau Zero Foundation, based in Fairview Park, Ohio.

Millis is an Icarus consultant and former project manager of the NASA Breakthrough Propulsion Physics Project at the space agency?s Glenn Research Center in Cleveland, Ohio.

?Consider what will happen when the first Earth-like exoplanet is discovered. We cannot reach such a place with the technology and science we have today. That discovery will likely spur a renewed spirit of adventure to push the edge of knowledge to create such transportation abilities,? Millis said. ?And that is where my cohorts and I are?looking beyond the obvious next-steps for the huge gains that will change everything ? and having the patience to teach the lessons along the way.?

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Leonard David has been reporting on the space industry for more than five decades. He is past editor-in-chief of the National Space Society's Ad Astra and Space World magazines and has written for SPACE.com since 1999.