Apollo team members are domain experts in propulsion lab design and construction, with a total of 8 labs – a majority of the electric propulsion labs in the US – either built or rebuilt by individuals on our team. By combining deep expertise with large capital investments and pragmatic engineering choices, Apollo created an R&D lab with capabilities unlike any other.
|Mr. Fusion||0.3 meter||PPU, component testing||Small size|
|Ms. Fusion||1 meter||Propellant R&D||Testing speed|
|T3||1 meter||Thruster R&D||Testing speed|
|Ursula||3 meters||Qualification and lifetime testing||
+/- 60° C
minimal chamber effects
|Five *||4 meters||Acceptance testing||
minimal chamber effects
* Under construction. Commissioning in Q3 2018.
What sets our lab apart is speed. Research labs and competitor labs typically take days or weeks to perform an experiment. In contrast, Apollo's R&D lab has the capacity for hundreds of tests per week and rapid design iteration between tests. This is why ACE has evolved so quickly. We've been able to test a new generation of hardware with significant improvements every few weeks.
Performance, reliability, safety, plume impingement, and deposition characteristics are mission critical success criteria for all candidate propellants. In the search for the ideal propellant, Apollo's engineers have tested 15 different options, from standards like Krypton and Xenon to a range of more exotic options. Years of experience and our comprehensive propellant test program give us great confidence in the suitability of our recommended propellant for customer missions.
The ACE development process has been guided by customer requirements at every step. Through seven major versions and many small updates, we've iterated the design in response to radiation requirements, shock and vibration test results, and other qualification test findings. We've optimized the design for faster assembly, shorter component lead times, and easier manufacturing. And we've made design choices to satisfy system integrator, export, range safety, ODAR, and DoT requirements. Each iteration is a significant improvement commercially and operationally.
ACE is designed to operate at a single voltage set point, and our customer pipeline indicates 300W and 500W as popular operating power choices. We've tested a wide range of input levels and are happy with the performance we've seen between 200W and 1000W of system input power per thruster.
Apollo tested ACE in an independent lab at The Aerospace Corporation where thrust, Isp, and efficiency measurements closely matched (within 0.5%!) Apollo’s own lab tests. These results confirmed that ACE has 3x better impulse per kg and 3x better impulse per liter than competing thrusters. The full Aerospace Corporation report is available at customer request.
Vibration tests were based on the loads experienced on 10 different launch vehicles. This involves vibration testing above qualification levels to ensure launch conditions are well within the defined operating limit of each component.
During development, Apollo performed a review of critical components. Components that posed an increased risk of failure, were difficult to manufacture or source, or were integral to thruster operation were identified and targeted for additional attention.
The development process included manual assembly of many Engineering Model and Engineering Qualification Model units. Based on this process, several subsystems were redesigned for performance, manufacturing, and ease of assembly, many with six or more generations of improvements in response to test data.
A full schedule of Manufacturing Readiness Activities is underway with Apollo's contract manufacturing partner to identify opportunities to improve ACE for manufacturing and assembly.
AFI has made a number of design decisions that improve the ability to troubleshoot, diagnose, and correct problems which may occur in orbit. Our design includes comprehensive diagnostics and a remote operations mode for full manual control.
The Apollo team has consulted with domain experts and worked with the US Department of Transportation, other federal agencies, and with multiple range safety teams from many international launch sites to ensure a smooth shipping process leading to your launch.
Apollo is performing a number of thruster qualification test sequences developed in line with international best practices and customer requirements. Preliminary modeling indicates that 200,000 Ns is the lifetime of an ACE thruster. This is approximately 4,000 hours of firing time depending on the fired thrust of the system. So far we have tested over 1,200 hours with one propellant (around 75,000 Ns). We are testing at least 10,000 cycles of the thruster as part of our qualification test sequence, with over 400 cycles completed to date.