Icarus and Daedalus

Previously I talked about the original state of Project Orion and its first life as an attempt to develop an atomic bomb-propelled spacecraft.  Now I will talk about later so-called "post-Orion" theoretical studies in nuclear pulse propulsion from which lay the groundwork for the new propulsion system for Project Orion.  Starting in the late 1960s and early 1970s, researchers started banning the bomb from nuclear pulse propulsion studies.

One famous study was a five-year study done by the British Interplanetary Society in the 1970s called Project Daedalus.  Daedalus was a concept for an interstellar probe flyby mission to Barnard's Star.  The 190m long and about 175m wide Daedalus spacecraft was designed to be two stages and to accelerate a 450 tonne payload to 12% of the speed of light.  Daedalus was the first concept designed to utilize deuterium-helium3 fusion and was planned to have its helium3 mined from the atmosphere of Jupiter.  A Daedalus spacecraft would have a total departure mass of 54,000 tonnes counting 50,000 tonnes of propellent alone with only 4,000 tonnes of dry mass and that includes the 450 tonne payload.  Daedalus would not decelerate to the destination and instead fly by it at 12%c.  Plus there would be dispatch probes stored in the top of the payload bay just beneath the erosion shied and and astronomy deck with telescopes right below.  Daedalus is too massive for humanity's first interstellar spacecraft and that is where a Project Icarus and Project Orion will later come in.  Orion borrows its second primary propulsion system, dispatch probes, and astronomy deck all from Project Daedalus even before Icarus was started.  Below is a blueprint of Daedalus drawn by Rick Sternbeck and and computer generated model of the Daedalus spacecraft.

Project Icarus is a current five-year joint study between the aforementioned British Interplanetary Society and the Tau Zero Foundation and starts from where Daedalus left off.  Unlike Daedalus, Icarus is designed to decelerate to its target star system to explore it in far more detail than its predecessor.  Icarus will also have a secondary propulsion system such as a light sail or a magsail for deceleration to save propellent and make it less massive than Daedalus.  Icarus my even use antimatter to assist in its D-He3 fusion.  Also unlike Daedalus, Icarus will not have its helium3 mined from Jupiter and instead it will be mind elsewhere in our solar system such as on Uranus.  Icarus Started on September 30, 2009 and will conclude in 2014.  Below are three computer generated illustrations of three designs for Project Icarus.

Even before Icarus, I considered using a secondary propulsion system for Orion such as a magsail to decelerate to its destination and to make it less massive than Daedalus.  In light of Icarus, Orion may even use a little antimatter for an anti-matter assisted D-He3 fusion pulse propulsion system in its return.

So I will discuss the possible interstellar destinations for Project Orion in the future under its refit of a Daedalus/Icarus-style propulsion system.