Many remain unconvinced.
Despite having a setup that has been pretty much operating for years, how many data points are in the paper? Eighteen. Now, if this were a really time-consuming experiment, I wouldn't let that bother me. Hell, some synchrotron experiments have only a single data point. But this is clearly not a time-limited experiment.
The microwave was pulsed for about 40 seconds, and an entire data run seems to take about 200 seconds. Allowing five minutes between measurements, it should have been possible to record 12 data points for the same settings every hour. Indeed, although the researchers have numerous variables at their hands to change between experiments, they only play with one. In previous papers, they played with two, but still this limited exploration and limited data is really disheartening.
Then there's the error analysis: the authors estimate many measurement uncertainties so that each thrust measurement has an uncertainty of about ten percent. That sounds brilliant, right? Except the authors ignore the main uncertainties. In one experiment at 60 Watts of microwave power, the authors measure thrust of 128 microNewtons, while all three data points for 80 Watts of microwave power have thrusts of less than 120 microNewtons. Indeed, the thrust at 60 Watts for all data overlaps pretty much perfectly for all data taken at 80 Watts. They can only claim a slope by turning the power down to 40 Watts, where they do consistently measure less thrust.
The Cannae drive is also propellentless like the EMdrive but is a different design. They will test their system orbit in a cubesat in 2017
Cannae is not using an EmDrive thruster in their upcoming launch. Cannae is using it’s own proprietary thruster technology which requires no on-board propellant to generate thrust. In addition, this project is being done as a private venture. Cannae is only working with our private commercial partners on the upcoming mission.
Theseus Space is going to be launching a demo cubesat (probably in 2017) which will use Cannae thruster technology to maintain an orbit below a 150 mile altitude. This cubesat will maintain its extreme LEO altitude for a minimum duration of 6 months. The primary mission objective is to demonstrate our thruster technology on orbit. Secondary objectives for this mission include orbital altitude and inclination changes performed by the Cannae-thruster technology.
Cannae’s thruster technology is capable of generating thrust from a few uN up through several newton thrust levels and higher levels. The Cannae thruster technology is particularly useful for small satellite missions due to low power, mass and volume requirements. Our thruster configuration for the cubesat mission with Theseus is anticipated to require less than 1.5 U volume and will use less than 10 watts of power to perform station keeping thrusting.
Once demonstrated on orbit, Theseus will offer their thruster platforms to the satellite marketplace
Cannae is commercializing proprietary propulsion technology requiring no on-board propellant to generate thrust.
The core of their technology uses the Lorentz Force imbalances created by their thrusters to create propulsion. Cannae has demonstrated 2 separate prototypes of a superconducting thruster which requires no dielectric material to generate thrust.
Inventor, Guido Fetta, delivered a paper on superconducting prototype demonstration at the 2014 AIAA Joint Propulsion Conference. Cannae has since improved upon the initial design and has demonstrated improved thrust and performance of their superconducting prototype at their Pennsylvania test facility.
Cannae is also commercializing a thruster that does not require superconducting operation in order to generate thrust. This thruster also requires no on-board propellant to generate a Lorentz Force imbalance. Cannae has demonstrated prototypes of this new thruster technology at our Pennsylvania test facility.
Cannae has various deep space probes and space freighter designs if their in orbit tests work out
The deep space probe concept vehicle outlined in this section is used to propel a scientific instrument and communication payload with a mass of 2000 kgs to a 0.1 light year (LY) distance in a 15 year time frame. This vehicle uses existing superconductor and vehicle subsystem technology performance levels. No improvements to technological performance levels are required to build the vehicle described in this section.
There are 10 Cannae Drives included in the deep space probe design.
5 x 50 MHz Thruster cavities (continuously powered)
3 x 1 GHz Steering cavities (powered as needed)
2 x 1.5 GHz Roll-control cavities (powered as needed)
The 5 Cannae Drive thruster cavities provide continuous acceleration of 8.66 x 10^-3 m/s2 to the probe. This is equivalent to accelerating at 1/1132 G. The small acceleration is constantly applied in one direction throughout the life time of the probe, continually increasing the velocity of the probe with respect to the Earth reference frame. The total thrust developed by the 5 thruster cavities is 85.5 newtons.
The three medium sized Cannae Drive cavities provide steering for the probe. These cavities are intermittently powered to provide course corrections or for flight maneuvers.
The two small Cannae Drive cavities are used to modulate the roll rate of the space probe. These cavities are also used intermittently.
All of the Cannae Drives are fixed in position on the vehicle. This eliminates moving parts from the propulsion system, allowing for longevity of operation.
Deep space probe cavity design
The Cannae Drive cavities are manufactured of aluminum. Aluminum (or another appropriate alloy) is used to minimize the thruster system mass. A substrate layer is then coated on the inside of the cavity. A top coat of 400 nm YBCO layer is then deposited over the substrate layer.
The thrusting cavities are designed with asymmetric features in areas of high electric field and in areas of high magnetic field. The average effective differential in axially-directed radiation pressure is 15% over the entire cross section of each thruster cavity. The unbalanced force developed in the thruster cavity is directed through the axial center of the 5 thruster cavities.
The design maximum H-field on the top plate of the thruster cavity is 4000 A/m with nominal maximum operating H-field on the top plate of 3270 A/m. This relatively low field is used to prevent field emission in the areas of high E-field and to keep the ohmic losses in the regions of high H-field to a minimum.
The Cannae Drive deep-space probe is designed to measure the environment of the interstellar medium. To do this, the vehicle is launched to LEO on a standard launch vehicle. The diameter of the probe in launch configuration is 4.8 meters with a height of 10 meters. These dimensions allow the probe to fit into a standard 5-meter launch vehicle fairing.
Once the vehicle is in LEO, the thruster system is powered and the vehicle accelerates in the direction of its Earth orbit. This causes the probe to slowly spiral away from Earth until it eventually escapes into deep space. The probe continues to accelerate, increasing its velocity and overcoming the gravitational attraction of the Sun. The vehicle will reach escape velocity from the Sun without gravity assists in less than 2 months.
During the LEO-to-solar-escape-velocity phase of the mission, a light-weight radiation shield is deployed to shield the thruster section of the probe from Earth’s thermal radiation and from solar radiation. Once the vehicle flight path is directed away from the Sun, the radiation shield is ejected from the probe. The temporary shielding is not depicted in Figure 1.
The probe is designed to accelerate continuously throughout its operational life time. The mission duration is designed to be 15 years, with mission-life extensions probable. After 15 years of constant 8.65 x 10-3 m/s2 acceleration, the vehicle will reach a distance from Earth of 0.1 LY (approximately 600 billion miles). At 0.1 LY, the vehicle will be travelling at approximately 1.35 % the speed of light (c). At a 0.1 LY distance, it will require over 1 month to send or receive radio signals between the probe and Earth.
For comparison, the Voyager 1 probe is currently travelling at 17.06 km/s. The Cannae-Drive-propelled, deep-space probe increases by the Voyager speed of 17.06 km/s every 23.1 days. Accelerating at design level, the Cannae-Drive-deep-space probe passes the Voyager distance from Earth (120 AU) within 2.0 years of probe launch. The Voyager required almost 35 years to reach this distance. Voyager 1 continues to increase its distance from Earth and will reach a distance of 0.1 LY in a total travel time of 1780 years. The Cannae Drive probe requires 15 years from launch to travel 0.1 LY and the thruster system uses less than 100 watts RF power to do so.
For additional comparison, a propellant-based probe designed to accelerate a 2000 kg payload to a velocity of 1.35% c (the speed of the Cannae Drive probe when it passes 0.1 LY) would require a minimum of 1.8 x 1021 kgs of propellant. This calculation assumes a propellant specific impulse of 10,000 seconds with zero structural, propellant tank and power system mass (final vehicle mass is 2000 kgs). Assuming the propellant has a specific gravity of 1, this amount of propellant could cover the entire surface area of the Earth to a height of over 2 miles. If power and structural mass estimates for the propellant-based probe are included in the propellant-requirement calculation, the situation gets much worse.
The Cannae Drive probe reaches a distance from Earth of 0.1 LY in 15 years. Because of the simplicity of design and lack of moving parts, it is anticipated that the vehicle will continue to accelerate and will continue to transmit data back to Earth. The Voyager and Pioneer deep-space probes have demonstrated that multi-decade missions are achievable. The RTG’s of the Cannae Drive probe are designed to deliver the power required to generate up to 100 watts of RF power to the thruster cavities. As RTG power levels drop below end-of-life design levels, RF power to the cavities will also drop below the 73 watt design level. As long as phase-locked power is sent to the thruster cavities, the probe will continue to accelerate. The acceleration of the probe is directly proportional to the RF power sent into the cavities. Given the proven longevity of RTGs in space applications, the Cannae Drive probe could continue to accelerate and send back data on the interstellar medium for decades.
After 33 years of constant 8.66 x 10-3 m/s2 acceleration, the Cannae Drive probe will have crossed a distance of 0.5 LY from Earth while attaining a speed of approximately 3% of c.
For deep-space applications, a Cannae Drive probe outperforms propellant-driven systems by orders of magnitude. Travel times and vehicle velocities that are impossible for propellant based systems are achievable with a Cannae Drive system. The Cannae Drive technology allows new deep-space missions that have previously existed only in science fiction.
They have space freighter design hat is based on the reactionless thrust of the Cannae Drive. This freighter is a satellite that is launched to LEO on a standard 5 meter fairing launch vehicle. Once in orbit, the freighter is used to raise the orbits of other satellites that are already in a LEO orbit. The value of the freighter is that significant reductions in launch costs are achieved. Satellites that are destined for orbits higher than LEO require only the launch costs associated with the LEO launch. For larger GEO satellites, the launch cost savings can amount to greater than $200 million per satellite.
CANNAE SPACE FREIGHTER SPECS
Mass: 10,000 KGS
Solar power required: 4000 Watts
FREIGHTER DIAMETER: 4.8 Meters
LENGTH: 10 Meters
PHASE LOCKED RF POWER: 40 Watts
CAVITY COOLING POWER REQUIRED: 40 Watts AT 70 K
BRAYTON COOLER POWER: 1600 Watts
COOLING FLUID: Neon gas
CAVITY FREQUENCY (THRUSTER): 50 MHZ
CAVITY FREQUENCY (STEERING): 200 MHZ
CAVITY FREQUENCY (ROLL): 1 GHZ