Two talks at the 100 Year Starship conference held the key to the future, in the opinion of Adam Crowl. Adam Crowl is a designer on the Icarus Project. Project Icarus is a theoretical design study with the aim of designing a credible interstellar probe that will serve as a concept design for a potential mission that could be launched before then end of the 21st century
James Benford, Ph.D, discussed the economics of developing beamed-energy propulsion to propel high-speed sail-probes out of the solar system. His discussion demonstrated that the infrastructure required to launch sail-probes can also be used to develop the solar system for the benefit of all humanity. An incremental pathway to the stars, performing useful , profitable tasks at each step, can be carried out using technology we have now. The architecture might not be as Dr.Benford sketched out, but there is a road to the stars, which Icarus Interstellar is a part of.
Jim and Gregory Benford think the most likely first unmanned “ship” will be a beam driven sail that makes a sundiver fall to get a boost from maybe 1/100th of our orbital radius, then gets pushed by beamed laser or microwave beams to very high speeds. The physics of that we now understand; Jim and I worked on the basics in the early 2000s—stability, steering, high acceleration. We even lifted a carbon fiber sail against gravity at JPL. With the basic physics done, it’s merely engineering… but what fascinating prospects! The sail papers were all promising.
What about larger payloads? We’ve hit the engineering wall, going as far as we can with chemical propulsion systems. If we’re going to make it to Mars in any sort of reasonable timeframe or with healthy transit durations, nuclear is the obvious next step.
Indeed, if NASA doesn’t show the world it has a goal—which should be Mars, certainly–and will develop the means to go there, it will be deeply cut in the budget battles soon to come. The Webb space telescope, now projected to cost $9 billion (ten times the initial supposed cost), is the only good project they have on hand. If we put it into the L2 point at Earth’s shadow as planned, we’d better be able to service it, to get long term performance from such a huge expense. That’s hard and expensive to do with chemical rockets.
Nuclear thermal rockets are the sole economical way we have to reach such places, four times further away than the moon. The outlines of an emerging interplanetary transport system are clear. At the Symposium Geoff Landis reported on the NASA Glenn nuclear thermal rocket program, the third generation of development (after the NERVA program of the 1960s-70s and Timberwind, a still classified program of the 1980s-90s). Stan Borowski of NASA Glenn projects a manned Mars expedition by 2033!
NBF comment – Spacex should be able to take chemical rockets further to 130 to 150 ton payloads and to reusable systems. If Spacex can achieve their goal then they could do it with affordability that rivals advanced nuclear thermal rockets. Skylon might also take chemical rockets and hypersonics spaceplanes further. All of those approaches should be pursued.
The other talk [that Adam Crowl picked as his top two] was given by Ariel Waldman, founder of Space Hack, an organization devoted to getting ordinary, but space-minded, people involved in space exploration in whatever way possible. That can range from attending workshops on how to make your own Cube-sat, to joining a planetary Rover team, to scanning distant galaxies and categorizing them (a job computers still struggle to do.) If Icarus Interstellar, and the 100 Year Starship Organization, can mobilize everyone who longs for the stars, then the task will be achieved, and everyone will have had a hand in it.
Adam Crowl is Lead designer on important parts of the Icarus Project
Research Module 6.0 Fuel and Fuel Acquisition
Lead: Adam Crowl
Definition: This includes what fuels are used for the primary and secondary propulsion as well as the availability and acquisition of those fuels (i.e. from Jupiter atmosphere) and an assessment of the technology and infrastructure required to obtain them. Fuel storage issues, during boost-phase, cruise and braking phases should also be considered.
Scope: During this work many options for fusion based fuels should be identified. Acquisition and mining techniques should also be discussed. These should include novel fuels such as ultradense Deuterium or antiprotons and their storage. Recommendations for several preferred fuel and mining options should be made. Possibility for refuelling in the target system and the minimum requirements for useful ISRU should be examined. Specific research topics for the concept design phase are described in the project programme document (PPD).
Research Module 7.0 Structures and Materials
Lead: Adam Crowl
Definition: This includes a description of all of the materials used in the vehicle, their mechanical properties and response to the exposed internal and external environment (i.e. pressure). Some consideration should be given to the manufacture of novel materials and the in-situ acquisition and manufacture of replacement materials by the probe.
Scope: A thorough review of historical, modern and future materials technologies should be conducted. The requirements for deep space missions of decades long duration should be identified. Several candidate materials for the different structures used in the Daedalus configuration should be given. Specific research topics for the concept design phase are described in the project programme document (PPD).