Extra-Vehicular Activity (EVA) spacesuits are both enabling and limiting. Because pressurization results in stiffening of the pressure garment, an astronaut’s motions and mobility are significantly restricted during EVAs. Dexterity, in particular, is severely reduced. Astronauts are commonly on record identifying spacesuit gloves as a top-priority item in their EVA apparel needing significant improvement. Apollo 17 astronaut-geologist Harrison “Jack” Schmitt has singled out hand fatigue and dexterity as the top two problems to address in EVA spacesuit design for future Moon and Mars exploration. The NASA-STD-3000 standards document indeed states: “Space suit gloves degrade tactile proficiency compared to bare hand operations... Attention should be given to the design of manual interfaces to preclude or minimize hand fatigue or physical discomfort.”
While the difficulty of using pressurized suits and gloves can be well mitigated in EVA operations outside orbiting space-craft (e.g., on the ISS), because optimally adapted tools can be created for predictable and specialized tasks, future EVA operations on Mars, and also on the Moon or on small bodies such as the two moons of Mars — Phobos and Deimos — will require interacting with a wide range of terrain, materials, and hardware under often unpredictable conditions. This makes having optimally adapted interfaces for all circumstances impossible to achieve in practice.
Beyond the challenges of dexterity and discomfort, astronauts are also at significant risk of injury. Hand and upper-extremity overuse and repetitive injuries have been, and continue to be, a common problem in EVAs. The constraints and pressures of spacesuits and gloves have been shown to negatively impact upper-extremity function in ways that can rapidly result in overuse/repetitive injuries, which then negatively impact mission productivity. In addition to fingers, an astronaut’s hands, wrists, arms, and shoulders may also experience significant fatigue when used in repetitive motions and/or when held in fixed positions for extended periods of time against a pressurized spacesuit’s neutral posture.
Mars Drone Operations as a Worst-Case Scenario
Meanwhile, the future human exploration of Mars, characterized by long-duration surface missions, is anticipated to have intense EVA requirements, with the expectation that astronauts will need to operate a wide variety of science and exploration instruments, tools, machines, and other surface systems, including human-supervised or operated robotic assistants. Examples of the latter may include robotic arms, cranes, drills, trenchers, dirt-movers, mobile communications assets, vehicles, and a wide range of other mobile systems.
One of the most demanding anticipated needs for dexterous and sustained subtle control inputs during EVA could be the operation of unmanned aircraft systems (UAS), or drones, as robotic assistants. The recent success of NASA’s Mars helicopter Ingenuity has demonstrated that UAS likely have a bright future on Mars. In the context of human Mars exploration, drones could have a wide range of important usages, including scouting, searching (including in search and rescue ops), surveying, sampling (including aseptic sampling for astrobiology while conforming to planetary protection guidelines), examining otherwise inaccessible targets, monitoring, inspecting, fetching, filming, and more. While many of these tasks may be performed in Intra-Vehicular Activity (IVA) mode from the confines and comfort of a habitat, including a pressurized rover, all would need to be available options during EVAs as well.
Drones present an epitomic challenge, as they are normally operated via relatively complex human-machine interfaces (HMI) requiring good situational awareness, sustained hand-eye coordination, use of both hands, including of several fingers on each, and thus high dexterity. How might an astronaut in EVA operate a remote-controlled flyer in real-time if the EVA spacesuit glove were to remain as restrictive as it is now? Solving for the real-time operation of drones viewed as a worst-case scenario in robotic system control complexity during EVAs means that the control of other robotic assets will de facto also be solved.
The Astronaut Smart Glove
The NASA-STD-3000 document lists as a key design goal for EVA spacesuits that gloved hand dexterity should approach that of bare-hand operations. To meet this aspirational goal in practice, spacesuit gloves have to either be significantly improved in dexterity (Approach A), and/or be rendered usable more or less as they are, but in ways that minimize workload to still achieve effectively the needed performance of dexterity (Approach B). The Astronaut Smart Glove (ASG) is an Approach B solution.
Before it became Astronaut Smart Glove, the ASG was just a smart glove, a Human-Machine Interface (HMI). It was originally invented by the Norwegian startup Arveng Technologies (now Ntention) for applications outside the space technologies sector, in particular dance, music, medical applications — to help persons with mobility challenges — and the operation of mass market commercial drones. The motion of fingers of the hand and of the wrist, even very slight ones, are captured through sensors integrated to a thin, form-fitting fabric glove, then translated in real-time into wireless drone commands and control inputs for intuitive, single-handed flight operation.
The smart glove replaces the cumbersome controller box and multiple joysticks interface still in widespread use in the commercial drone industry with a sleek single-hand garment. Via the smart glove, a drone can be made to roll left or right by slightly tilting the gloved hand left or right, to fly forward or backward by slightly tilting the hand forward or backward, to rise up or drop down by opening the hand or closing it slightly, and to yaw left or right by slightly yawing the wrist left or right, respectively. The sensitivity to gesture amplitude needed as control input can be adjusted “on the fly,” meaning that even minimal motions, as one might be limited to while wearing a rigid overglove, can be translated into effective drone control inputs.
Following a public demonstration by Ntention of drone flying ease with the smart glove HMI at the Energy Valley 2019 conference in Oslo, Norway, it was realized that if a smart glove HMI could be integrated into the liner glove of an EVA spacesuit glove, then a robotic system as complex as a drone, and many other simpler ones, could become operable during EVA even in a stiff pressurized suit.
A collaboration was soon established between the Mars Institute, a non-profit Mars science and exploration research organization, Collins Aerospace, Ntention, and NASA Ames Research Center. After a short period of rapid prototyping to create a first iteration of the ASG, the decision was made to conduct a field test, using a Collins Aerospace Moon/Mars engineering concept EVA spacesuit, at the NASA Haughton-Mars Project (HMP) Mars analog field site on Devon Island in the High Arctic.
In addition to the original strictly gesture-based HMI, head-motion sensors were also integrated into the suit allowing the drone camera gimbal to be controlled directly by the astronaut’s head motions. Tilt the head down, and the gimbal motor will aim the camera down, etc. The ASG system also includes vision-based control via an in-suit augmented reality (AR) interface allowing real-time first-person view (FPV) flight operations.
Ready for Mars, and Before That, the Moon
The ASG amplifies the effects of subtle finger, hand, and wrist gestures while wearing existing rigid pressurized spacesuit gloves. It requires no complex integration of rigid mechanical moving parts as in previously proposed solutions such as EVA glove-embedded exoskeletons, or a redesign of the EVA suit glove altogether as in mechanical counter-pressure glove concepts. That is not to say that the latter innovative approaches have no future; merely that the ASG offers a fast-track path to TRL (Technology Readiness Level) maturation, and therefore, the prospect of short-term implementation in human Moon and Mars exploration.
The ASG is indeed a timely development. It is coming together as humanity returns to the Moon and prepares for Mars, as a growing number of complex robotic systems will need to be operated by explorers via simple yet robust and intuitive interfaces, taking full advantage of ubiquitous WiFi and satcom-rich environments, and opportunities offered by mature space exploration technologies such as robotic arms, drones, rovers, and other astronaut-assisting space systems.
Science-fiction author Arthur C. Clarke once said that “Any sufficiently advanced technology is indistinguishable from magic.” Magic was actually the first word that came to mind when we saw the ASG fly a drone for the first time. We anticipate that the Moon and Mars will soon experience that magic too.
This article was written by Pascal Lee, a Planetary Scientist with the Mars Institute, the SETI Institute, and NASA Ames Research Center. Lee is also the Director of the NASA Haughton-Mars Project, an FAA-certificated helicopter commercial pilot and flight instructor, and a FAA-registered UAS operator. For more information, visit here .