Published articles on space exploration in print media

Book chapter

• “When Will Voyager 1 Leave the Solar System?”, in Kelvin F. Long (ed.), Beyond the Boundary: Exploring the science and culture of interstellar spaceflight (Initiative for Interstellar Studies, 2014), p.63-75.

Technical papers

• “Self-Replicating Interstellar Probes and Runaway Growth Reconsidered”, JBIS, vol.75 no.8 (August 2022), p.283-292.


• “SETI and Evolutionary Population Dynamics”, JBIS, vol.74 no.11 (November 2021), p.401-408.


• “From Earth-Orbit Space Colonies to Deep-Space and Interstellar Habitats and Worldships: Solving the Economics”, JBIS, vol.73 no.10 (October 2020), p.382-384.


• “Cycler Links Between Earth and the Gas Giant Planets, 2: Station Design Concepts”, JBIS, vol.73 no.10 (October 2020), p.363-371.


• “Cycler Links Between Earth and the Gas Giant Planets, 1: Trajectories”, JBIS, vol.73 no.4 (April 2020), p.142-152.


• “Scenario Block Diagram Analysis of the Galactic Evolution of Life”, JBIS, vol.71 no.6 (June 2018), p.212-215.


• “An Earth-Moon-Mars Passenger Transport Pyramid”, JBIS, vol.71 no.5 (May 2018), p.165-177.


• “Quantifying the Assumptions Behind the METI Debate”, JBIS, vol.69 no.12 (December 2016), p.419-428.


• “Staggered Launch Sequences for Fleets of Interstellar Worldships”, JBIS, vol.69 no.9/10 (September/October 2016), p.326-330.


• “The Bottleneck Effect on Interplanetary and Interstellar Growth over the Coming Millennium”, JBIS, vol.69 no.1 (January 2016), p.20-26.


• “The Starship Philosophy: Its Heritage and Competitors”, JBIS, vol.67 no.11/12 (Nov./Dec. 2014), p.447-459.


• “A Parameter Space as an Improved Tool for Investigating Extraterrestrial Intelligence”, JBIS, vol.67 no.6 (June 2014), p.224-231.


• “The Long-Term Growth Prospects for Planetary and Space Colonies”, JBIS, vol.65 no.6 (June 2012), p.200-217.


• “The Emergence of the Worldship (II): A Development Scenario”, JBIS, vol.65 no.4/5 (April/May 2012), p.155-175.


• “The Emergence of the Worldship (I): The Shift from Planet-Based to Space-Based Civilisation”, JBIS (Journal of the British Interplanetary Society), vol.65 no.4/5 (April/May 2012), p.140-154.

All these papers used to be found by going to the archives of the Journal of the British Interplanetary Society and searching on author “Ashworth”. Needless to say, the website has now been changed so that you can’t do this any more.

Technical correspondence

• Correspondence concerning the paper by James Schwartz, “Worldship Ethics: Obligations to the Crew”, JBIS, vol.71 no.10 (October 2018), p.358-359, with response by James Schwartz on p.359-360.


• Correspondence concerning the paper by Mark Hempsell, “Skyfarm: Feeding a Large Space Population”, JBIS, vol.70 no.7 (July 2017), p.256-257, with response by Mark Hempsell on p.257-259.


• “The Kennedy Wait Calculation Reconsidered”, JBIS, vol.70 no.1 (January 2017), p.36-38, with response by Andrew Kennedy on p.38-39.


• “Von Neumann Probes, Errors and the Absence of Evidence for Extraterrestrial Civilisations”, JBIS, vol.69 no.4 (April 2016), p.148-150, with response by Axel Kowald on p.150-152.


• “Embryo Space Colonization: A Reconsideration”, JBIS, vol.67 no.3 (March 2014), p.127-128.


• “Comments on ‘First Interstellar Missions, Considering Energy and Incessant Obsolescence’ by Marc Millis, JBIS, 63, pp.434-443, 2010”, JBIS, vol.64 no.9/10 (Sept./Oct. 2011), p.341-342, with response by Marc Millis on p.343.

Popular articles

• “Missed mission”, Spaceflight, vol.65 no.8 (August 2023), p.43.


• “Space travel and environmental sustainability”, Room, Winter 2022 (30) (published January 2022), p.59-63.


• “Planetopolis”, Spaceflight, vol.63 no.7 (July 2021), p.30-31.


• “On Mars as it is on Earth – preparing for settlement”, Room, Spring 2021 (27), p.86-91.


• A response to Dr Geoffrey Briggs (on p.32) in “Earth first or on to Mars?”, Spaceflight, vol.63 no.2 (February 2021), p.33.


• “Ein neues Zeitalter der Aufklärung? Eine kulturphilosophisch-theologische Betrachtung für Marskolonialisten”, Raumfahrt Concret, Heft 111 (2020), p.40-44 (Deutsche Bearbeitung: Jacqueline Myrrhe).


• “Above & beyond” (report on the second Foundations of Interstellar Studies Workshop, June 2019), Spaceflight, vol.61 no.9 (September 2019), p.40-42.


• “A new age of Enlightenment [on Mars?]”, Spaceflight, vol.60 no.12 (December 2018), p.26-33.


• “Evaluating Mars Programme Designs”, Spaceflight, vol.59 no.9 (September 2017), p.336-342.


• “Aridopolis: Project for a Sustainable Earth/Mars Desert Settlement”, Principium: The Newsletter of the Initiative for Interstellar Studies, issue 18 (August 2017), p.4-11.


• “Elon Musk and Mars – looking for a snowball effect”, Room, #4 (10) Winter 2017, p.10-15.


• “Von der Raumstation zum Mond und dem Mars”, Raumfahrt Concret, Heft 92 (2016), p.29-31 (Deutsche Bearbeitung: Silvia Mutterer).


• “Settlement of Mars: is it possible?”, Spaceflight, vol.58 no.4 (April 2016), p.136-137.


• “From Space Station to the Moon and Mars”, Spaceflight, vol.57 no.11 (November 2015), p.432-433.


• “Zu den Sternenräumen – Interstellare Raumfahrt von Übermorgen”, Raumfahrt Concret, Heft 84/85 (4/5/2014), p.18-21.


• “The future of space flight: the case for growth”, Spaceflight, vol.55 no.9 (September 2013), p.351.


• “Opening the final frontier”, Spaceflight, vol.55 no.2 (February 2013), p.57-59.


• “America needs strategy for space settlement”, Spaceflight, vol.53 no.8 (August 2011), p.295.


• “Strategic role of asteroid mining”, Spaceflight, vol.53 no.4 (April 2011), p.137-138.


• “The Moon – an important place in human affairs”, Spaceflight, vol.53 no.2 (February 2011), p.46.


• “Battle between old and new: Time for commercial development – or back to the Moon?”, Spaceflight, vol.52 no.7 (July 2010), p.252-256.


• “Projekt Ikarus – Sohn des Dädalus”, translated by Jacqueline Myrrhe, Raumfahrt Concret, Heft 64/65 (4/5/2010), p.36-39.


• “Project Icarus – son of Daedalus: BIS symposium report”, Spaceflight, vol.51 no.12 (December 2009), p.454-455.


• “Lost promise of the Space Shuttle: The quest for more efficient access to space”, Spaceflight, vol.51 no.9 (September 2009), p.330-334.


• “Can space save planet Earth? BIS symposium report”, Spaceflight, vol.51 no.6 (June 2009), p.236-237.


• “A visionary British engineer: Reaction Engines’ chief talks to Spaceflight”, Spaceflight, vol.50 no.11 (November 2008), p.420-424.


• “Space for the mass market: BIS conference – European developments in space tourism”, Spaceflight, vol.49 no.3 (March 2007), p.92-95.


• “A growth-oriented UK space strategy: Leading the way to a profitable future”, Spaceflight, vol.49 no.1 (January 2007), p.20-23.


• “Space tourism: The key to low-cost access to space”, Spaceflight, vol.48 no.6 (June 2006), p.212-215.


• “Europe’s Martian dream: ESA’s first design study for sending astronauts to Mars”, Spaceflight, vol.48 no.4 (April 2006), p.136-139.


• “Space: Philosophy of the Future”, Spaceflight, vol.37 no.12 (December 1995), p.426.