Project Icarus Interstellar Spaceship Project Summary and Blog

The Project Icarus Team plan to follow on from Project Daedalus and design an interstellar spaceship. (H/T Centauri Dreams

Daedalus had three stated guidelines as follows:

1.The spacecraft must use current or near-future technology.
2.The spacecraft must reach its destination within a human lifetime.
3.The spacecraft must be designed to allow for a variety of target stars.

Following on from this historical work, the purpose of Project Icarus is as follows:

1.To design a credible interstellar probe that is a concept design for a potential mission in the coming centuries.

2. To allow a direct technology comparison with Daedalus and provide an assessment of the maturity of fusion based space propulsion for future precursor missions.
3.To generate greater interest in the real term prospects for interstellar precursor missions that are based on credible science.
4.To motivate a new generation of scientists to be interested in designing space missions that go beyond our solar system.

Similarly, the terms of reference for Project Icarus are:

1. To design an unmanned probe that is capable of delivering useful scientific data about the target star, associated planetary bodies, solar environment and the interstellar medium.

2. The spacecraft must use current or near future technology and be designed to be launched as soon as is credibly determined.

3. The spacecraft must reach its stellar destination within as fast a time as possible, not exceeding a century and ideally much sooner.

4. The spacecraft must be designed to allow for a variety of target stars.

5. The spacecraft propulsion must be mainly fusion based (i.e. Daedalus).

6. The spacecraft mission must be designed so as to allow some deceleration for increased encounter time at the destination.

Project Status
The Icarus project is divided into 10 phases.
Currently Phase 2 is on schedule: Internal publication of Project Programme Document & allocation of work programme.

Icarus Blog Summary

1. Scaling the Universe

* what possible science that could be done on such an interstellar mission to make it worthwhile?

* We can increase the accuracy of measuring distances in the universe by 272,000 times by sending a probe to the Centauri system. By using a baseline at least 272,000 times greater than the radius of the Earth‘s orbit and using equipment of similar measuring ability

A preprint provides details of the significant benefits of the interstellar mission. The benefits are identified in the fields of interstellar medium studies, stellar astrophysics, planetary science and astrobiology.

2. Using the Sun’s Gravitational Lens for Interstellar Communications

We use the Sun to focus the transmissions from the distant probe onto the receiver. This gives us an enormous antenna gain compared to what we would be able to achieve if we were trying to receive the signals directly, without using the Sun. What this means is that we can use much lower transmitter power on the probe without impacting the bandwidth that we can transmit. Like the old military saying goes: “amateurs study strategy; professionals study logistics.”

Let’s assume that we have solved the positioning accuracy problem, and we can keep the receiver exactly in line with the distant probe. Is there anything else we can do with the system to improve communications even further? Indeed there is. We can exploit two gravitational lenses: the Sun, and the distant star. So we have our receiver craft at the Sun’s gravitational focus, and the distant probe at the focus of the target star. If we can keep both the probe and the receiver exactly in line with each other, then the antenna gain we achieve is beyond enormous; it’s simply phenomenal. Using trivial amounts of power, we can achieve perfect communications between the Sun and (say) Alpha Centauri. The Sun-Alpha Cen direct radio bridge exploiting both the two gravitational lenses, this minimum transmitted power is incredibly… small! Actually it just equals less than 10-4 watts, i.e. one tenth of a milliwatt is enough to have perfect communication between the Sun and Alpha Cen through two 12-meter FOCAL spacecraft antennas.

* If somehow we could use the gravitational lens of the star in the galactic bulge as well as our own gravitational lens, we would have a workable bridge at power levels higher than 1000 watts

* a similar bridge between the Sun and a Sun-like star inside M31, using the gravitational lenses of both. We’re working here with a distance of 2.5 million light years, but a transmitted power of about 107 watts would do the trick. * Imagine the possibilities that a network of transceivers around all the local stars will open up for the next generation of probes. They will no longer need to send signals directly back to Earth. They can just “log on” to their local node which will relay data back to Earth for them.

3. The motivation behind fusion propulsion.

A re-examination of Daedalus seemed an obvious way to go. This would allow a complete re-evaluation of the original assumptions as well as hopefully improve the design. Ultimately, the aim would be to improve the Technological Readiness Level for this sort of engine design type. If other teams used the same approach, and say built upon historical projects like Vista, Longshot, TAU or Starwisp it is a personal belief that the credibility of engineering designs for interstellar missions would be vastly improved.

Of course, it is also worth pointing out that the Project Icarus Terms of Reference actually stipulate ‘mainly fusion based propulsion’. This allows for the potential for high gain enhancements such as by using Antimatter Catalyzed Fusion techniques. Similarly, the main engine can be supplemented by a secondary engine for part of the mission trajectory, such as by using a nuclear-electric engine.

It is generally the consensus within the interstellar community that the two strongest candidates for interstellar flight and which are a balance between performance and near term technology readiness is arguably solar sails and nuclear pulse propulsion.