Icarus: Revisiting the Daedalus Starship

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 of an interstellar probe ever attempted. The 54,000 ton two-stage vehicle was to be powered by inertial confinement fusion using electron beams to compress deuterium/helium-3 fusion capsules to ignition.

Daedalus was to have obtained an eventual cruise velocity of 36,000 km/s or 12% of light speed from over 700 kN of thrust, burning at a specific impulse of 1 million seconds. Travel time to flyby at destination would be approximately 50 years.

Daedalus had three stated guidelines:

The spacecraft must use current or near-future technology.

The spacecraft must reach its destination within a human lifetime.

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

Announcing Project Icarus

Project Icarus: Son of Daedalus – flying closer to another star. This is the full name of the new study, a Tau Zero Foundation initiative in collaboration with the British Interplanetary Society (BIS). Over three decades have passed since the Daedalus work, making this a good time to revisit the design study in light of scientific and technological advancements.

The purpose of Project Icarus is as follows:

To design a credible interstellar probe that is a concept design for a potential mission this century.

To allow a direct technology comparison with Daedalus and provide an assessment of the maturity of fusion based space propulsion for future precursor missions.

To generate greater interest in the real term prospects for interstellar precursor missions that are based on credible science.

To motivate a new generation of scientists to be interested in designing space missions that go beyond our solar system.

Certain reference points follow on from the original Daedalus study, modified to reflect changes of time and circumstance. Thus the spacecraft design must use current or near-future technology so that it could be credibly launched by 2050. It must be designed to reach its destination as quickly as possible, in a time-frame not exceeding sixty years but, hopefully, much sooner. The propulsion system must be mainly fusion-based. Assuming realistic maximum cruise speeds of 0.3 c and a sixty year flight duration, this places approximately forty-eight stars within an 18 light year distance within range of Icarus.

Genesis of a New Starship Study

In the introduction to the Daedalus study report Alan Bond states that:

“…it is hoped that these ‘cunningly wrought’ designs of Daedalus will be tested by modern day equivalents of Icarus, who will hopefully survive to suggest better methods and techniques which will work where those of Daedalus may fail, and that the results of this study will bring the day when mankind will reach out to the stars a step nearer.”

So in essence, the naming of the successor project as Icarus was suggested by the original study group.

Daedalus and Icarus were characters from ancient Greek mythology. In an attempt to escape the labyrinthine prison of King Minos, Icarus’ father Daedalus fashioned a pair of wings made of feathers and wax for both himself and his son. But soaring joyfully through the sky, Icarus flew too close to the sun, melting the wax on his wings. He fell into the sea and died after having ‘touched’ the sky. Project Icarus aims to ‘touch’ the stars and escape from the bounds of mother Earth.

Toward an Evolving Design

An assessment of the many dozens of propulsion concepts for interstellar flight made it clear that one way to advance the prospects for interstellar travel would be to focus on a specific design proposal. This way, a concept design could be derived, iterated and improved. Over time, the concept would be worked upon by future generations and could ultimately lead to a design blueprint for an interstellar probe. As the Daedalus study was performed three decades ago, it seemed appropriate to start by re-designing the Daedalus probe with updated scientific knowledge.

Thus the genesis of Project Icarus. It is hoped that other teams around the world will eventually be assembled, working on specific propulsion proposals that have been investigated in the past, such as Starwisp, VISTA, AIMStar or one of the many others. In this way, the technological maturity of different propulsion schemes can be improved over time, drawing on a common background of study rather than diverse and uncoordinated research efforts.

Needless to say, Centauri Dreams will provide regular updates on the progress of the Icarus design team, which will also be developing its own Web site in conjunction with the September symposium.