John Bucknell presented his updated Turbo Rocket plans at Space Access 2019.
John has previously worked on the SpaceX Raptor engine and has presented a nuclear air-breathing rocket design. The new design is a single-stage to Orbit air-breathing rocket.
It would have a mission-average Isp of more than 1,600sec and payload fractions of 25-50%
John revisited the assumptions around rockets and will use hot hydrogen fuel to enable air-breathing hypersonic rockets to be simplified.
An air-breathing rocket can increase the payload capacity from 1-4% to 25-50%.
The rocket would run at 1000 to 1300 kelvin which does not require new materials.
There has been previous development of hot hydrogen vehicles.
It is a lighter rocket and will use air-braking and then a propulsive thrust landing. Vertical takeoff and vertical landing.
John has a single gas path.
John now has a non-nuclear staged combustion design.
The longer-term plan would be to use this low-cost reusable launch for energy from space-based solar power.
Prometheus Medium would be able to deploy 7,000-8,000 subsats per launch in racks of 100. This array is the first 14,000 elements of an 81,000 element array for 100MW – requiring 10-12 launches. The phased array microwave transmit aperture at 1.5km is big enough to illuminate a 3.5km diameter rectenna from 35,000km apogee and can scale to 1 GW by filling in the sparse array. 5.8GHz frequency is able to beam through atmosphere, weather and darkness with no loss. Baseload with a highly eccentric Molniya orbit requires three satellites in the same orbit, 8 hours apart – costs account for 66% availability.
John has designs for a more efficient and lower cost space-based solar power than previous proposals.
It is a distributed array. There would need to be replacement of the satellite elements in the array.
SOURCES- Live coverage of John Bucknell presentation at Space Access 2019. Interview with John Bucknell.
Written By Brian Wang