A second paper has now been published on the concept of the SunVoyager spacecraft. This is a robotic probe mission to 500 - 1000 AU propelled by inertial confinement fusion engines. Its main purpose is to deliver a large astronomical observatory to the solar gravitational lens focal point so as to image exoplanets around nearby stars in the opposite direction of the Sun.
In the redesign the vehicle would use 5.76 mg ICF pellets fuelled with a mixture of deuterium and helium-3, but this would be augmented with 10 mg of expellant propellant for the purpose of increasing the mass flow rate and therefore the thrust.
The spacecraft would travel at a speed of 720 km/s reaching its destination in a trip time of 6-10 years. Although such a mission has much potential, it is not without its problems. In particular, the laser drivers required for the mission would have to be highly efficient, and for this model they were calculated assuming 24% efficiency which is beyond the current state of art.
Yet such a mission may be possible in future decades and this is especially since in the last two years the National Ignition Facility in San Francisco has achieved ignition and energy gain within a laboratory experiment. This is an exciting time to be alive and once we have figured out the physics all that remains is the engineering and economics to build a better machine.
The paper is titled “Development of SunVoyager Interstellar Precursor Probe Driven by Inertial Confinement Fusion Propulsion”, published in the Journal of Spacecraft & Rockets, May 2024.
https://arc.aiaa.org/doi/10.2514/1.A36045
