Apollo's Electric Propulsion R&D lab is designed for speed

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.

Chamber Length Application Advantage
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
Hey-Zeus 4 meters Acceptance testing High volume

minimal chamber effects

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.

Advanced propellant research

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.

Nine generations of ACE

The ACE development process has been guided by customer requirements at every step. Through nine 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.

Performance characterized at a wide range of input power levels

ACE is designed to operate at a single voltage set point, and we've tested at points between 200W and 1000W. Our customer pipeline indicates 400W as a popular operating power choice.

Tested by The Aerospace Corporation

The Aerospace Corporation, a federally funded research and development center tested our thruster at the power levels between 260 W and 500 W with Xenon. In this power range the thrust varied from 15 to 29 mN, system Isp varied from 952 to 1407 seconds and efficiency from 28% to 41%.

Tested to survive the shock and vibration loads of all customer launch vehicles

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.

Designed for manufacturing; designed for testing


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.

Subsystem level

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.

System level

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.

Design to test

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.

Designed to meet range safety and transportation requirements

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 US and international launch sites to ensure a smooth shipping process leading to your launch.

Lifetime testing underway

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 2,800 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 have tested 12,000 cycles of the thruster as part of our qualification test sequence.

What can ACE do for your constellation?

Reach out to us at info@apollofusion.com and let's talk.