The ultraquiet and highly efficient electric ducted fans that Whisper Aero has developed for aircraft propulsion could someday end up inside NASA spacecraft—not in their propulsion systems, but as a key component of the ventilation systems.
NASA awarded the Tennessee-based tech start-up a small business innovation research (SBIR) contract to design a quiet and efficient cabin ventilation system for crewed spacecraft, and that work could potentially extend to larger space habitats such as the International Space Station (ISS), Whisper announced on August 27.
According to NASA, one of the biggest sources of noise that spacecraft occupants must endure is the environmental control and life support (ECLS) system, which includes ventilation fans and other loud subsystems such as thermal cooling pumps. Noise from the ECLS isn’t just an annoyance for astronauts; it can interfere with voice communications, render alarms inaudible, and deprive astronauts of much-needed restful sleep.
That noise has remained problematic throughout the entire history of NASA’s human spaceflight program. Back in the Apollo days, astronauts in the command module would turn off the noisy cabin fans and use their spacesuits’ built-in ventilation systems instead.
Since then, NASA made some improvements to its ventilation technology and incorporated mufflers and silencers to dampen the noise inside its now-retired space shuttles and the International Space Station. However, those improvements added significant volume and weight to the spacecraft, and they did not reduce enough noise to truly resolve the problem.
Now that NASA is preparing to launch its crewed Orion capsule to the moon, where the agency aims to establish another orbital outpost like the ISS, the agency is once again mulling over noise abatement methods. According to Whisper, current cabin ventilation fans produce around 80 decibels of sound—about as much as a typical washing machine or vacuum cleaner—and will require additional duct mufflers to make the vehicles habitable.
“Unless a new fan is designed, lunar and Mars spaceflight vehicles, spacesuits, and surface habitats will continue to struggle with acoustical annoyances that hinder mission success,” Whisper officials wrote in a company statement.
Whisper’s proprietary electric ducted fan technology, originally designed for aircraft propulsion systems, could be a game-changer for NASA’s noisy ventilation systems. The company’s ducted fan design not only reduces noise but also maximizes efficiency while minimizing weight. It has also incorporated the technology into quiet electric leaf blowers.
Whisper says it is targeting a sound pressure level of 61 decibels from 2 feet away, which “would enable future astronauts to work together more comfortably in an environment more typical for normal conversations (30-60 dB) as opposed to an ambient similar to the persistent presence of a noisy washing machine or vacuum cleaner (70-80 dB).”
“We’re well suited and excited to meet the stressing acoustic and reliability requirements for NASA,” said Whisper chief engineer Devon Jedamski. “Our investment in a mixed-fidelity and multi-disciplinary design framework, anchored in significant test data from similar developments, has prepared us to quickly produce a bespoke solution for the needs of current and future NASA habitats.”
If NASA awards Whisper a follow-on Phase II SBIR contract, the company will build and test a prototype of its ventilation fan in 2025 and compare aerodynamic and acoustic test results with baseline measurements of NASA’s own spacecraft cabin ventilation fan.
So far Whisper has flight-tested its electric ducted fans in drones it developed with backing from the U.S. Air Force. The company has yet to announce any partnerships with airframers interested in using the technology for commercial electric aircraft, but it has revealed conceptual designs for an electric regional aircraft called the Whisper Jet and a 100-passenger Whisper Jetliner. It has been working with the Department of Energy's Oak Ridge National Laboratory in Tennessee to model its technology using the world's fastest supercomputer.
“Whisper is now designing the quietest, most efficient fans on Earth and in space,” said Whisper chief operating officer Ian Villa. “This program will further cement Whisper as the definitive next-generation propulsion provider of choice and accelerate Whisper’s commercialization flywheel.”