12-04, 17:20–17:30 (Europe/Luxembourg), Banquet Room
Background
Previous rocket concepts for interstellar missions using such propulsion, which the mankind might be able to develop during the next 100 years, like projects Orion, Daedalus and Longshot have suggested travel times around 50-100 years to our nearest star systems. For example Project Daedalus had 2-stage rocket using inertial confinement fusion, which managed to reach 50-year travel time to the Barnard's star for a flyby-mission.
Objective
This feasibility study evaluates the concept of using groups of co-operating fuel-carrying rockets for reducing travel times. The payload rocket doesn't have to carry all fuel it needs for the mission. Instead it shall meet other fuel-carrying rockets at crucial points along the way. These fuel-carrying rockets shall likewise meet other fuel-carrying rockets and use their fuel. Vessels of similar speed, direction and place can rendezvous and exchange fuel. This is especially useful for the deceleration phase of the journey, because all the fuel for deceleration don't have to be costly accelerated to very high speeds.
Methods
Using performance metrics of Project Daedalus like similar fuel / empty mass ratios of rockets and the same effective exhaust velocity some example configurations of fuel and payload carrying rockets are created. Travel times and resource requirements for a mission to Alpha Centauri system are calculated for different configurations using established science like the ideal rocket equation.
Results
With the example rocket configurations used travel time for a one-way, decelerating mission to the nearest star system is reduced from 50 - 100 years to 10 - 20 years. The resource requirements are huge, 500 - 300 000 expendable fuel carrying rockets with total masses 12 000 000 - 6 000 000 000 tons. However, the resource requirements are related to travel time: the quicker we want to go the more resources we need. Rockets needed for deceleration require tens of years of lead time before payload rocket.
Conclusions
Using the described methodology a human colonization mission to our nearest star system is possible without sleeper or freezer or hibernation ships or generation arks.
Aapo Puhakka has Master of Science degree in computer science and engineering from Helsinki University of Technology / Aalto University. He has participated in various rocketry and space activities of Finnish Astronautical Society. He works professionally as CEO of software company Vetokonsultit Oy in Finland.