The latest work on EmDrive propulsion for spacecraft is described.
YBCO superconducting cavities are incorporated into the thrusters.
Three engine types using multiple cavities are detailed.
A Single-Stage-To-Orbit spaceplane is described and mission parameters given.
An Interstellar Probe is described and mission parameters given.
In an IAC13 paper the dynamic operation of a second generation superconducting EmDrive thruster was described. A mathematical model was developed and, in this paper, that model is used to extend the performance envelope of the technology. Three engine designs are evaluated. One is used as a lift engine for a launch vehicle, another as an orbital engine for the launcher and a third as the main engine for an interstellar probe.
The engines are based on YBCO superconducting cavities, and performance is predicted on the basis of the test data obtained in earlier experimental programmes. The Q values range from 8×107 to 2×108 and provide high values of specific force over a range of accelerations from 0.4 m/s/s to 6 m/s/s.
The launch vehicle is an “all-electric” single stage to orbit (SSTO) spaceplane, using a 900 MHz, eight cavities, fully gimballed lift engine. A 1.5 GHz fixed orbital engine provides the horizontal velocity component. Both engines use total loss liquid hydrogen cooling. Electrical power is provided by fuel cells, fed with gaseous hydrogen from the cooling system and liquid oxygen. A 2 ton payload, externally mounted, can be flown to Low Earth Orbit in a time of 27 min. The total launch mass is 10 ton, with an airframe styled on the X37B, which allows aerobraking and a glide approach and landing.
The full potential of EmDrive propulsion for deep space missions is illustrated by the performance of the interstellar probe. A multi-cavity, fixed 500 MHz engine is cooled by a closed cycle liquid nitrogen system. The refrigeration is carried out in a two stage reverse Brayton Cycle. Electrical power is provided by a 200 kWe nuclear generator. The 9 ton spacecraft, which includes a 1 ton science payload, will achieve a terminal velocity of 0.67c, (where c is the speed of light), and cover a distance of 4 light years, over the 10 year propulsion period.
The work reported in this paper has resulted in design studies for two Demonstrator spacecrafts. The launcher will demonstrate the long-sought-for, low cost access to space, and also meet the mission requirements of the proposed DARPA XS-1 Spaceplane. The probe will enable the dream of an interstellar mission to be achieved within the next 20 years.
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