An exoskeleton that uses inflatable artificial muscles to reduce physical exertion and improve mobility for astronauts on missions to the Moon and Mars.
Researchers at the University of Bristol are developing flexible robotic pants, similar to an exoskeleton, to be worn under a space suit. The objective is to reduce the physical effort and fatigue of astronauts on future missions to the Moon and Mars, improving leg mobility in reduced gravity environments.
On missions to the surface of the Moon or Mars, astronauts work in bulky pressurized suits that restrict the natural movement of their legs. The knee and ankle joints are particularly affected, which increases the effort required to walk, climb or carry equipment over uneven terrain.
“What we are trying to solve is to reduce the energy that astronauts need while wearing the space suit and help them regain mobility”, explained the researcherto Reuters.
The device helps with knee extension and ankle mobility, which are the joints most affected by a large and heavy suit.
“It’s like having an extra layer of muscles”
The system is made of fabric and uses inflatable artificial “muscles” to aid movement. These muscles combine an outer layer of nylon with an inner layer of thermoplastic, allowing airtight inflation. High-strength anchoring components like the waistband and knee straps are made with Kevlar.
“It’s a very strange feeling. It’s like having an extra layer of muscles. So your own muscles don’t have to work as hard. It’s almost as if someone is giving you a little push so you can move more easily,” Pulvirenti described during a demonstration of the equipment.
The team is developing two models: a supportive version, intended to increase lower limb mobility in pressure suits, and a resistive version, designed as a countermeasure to add load throughout the day and help maintain muscle mass. The ultimate goal is to integrate both functions into a single piece of clothing.
Tests in a simulated lunar environment
In October 2025, the system was tested at the facility from the University of Adelaide, Australia, an environment that simulates lunar terrain. The device was integrated into a spacesuit and evaluated in tasks such as walking, climbing and carrying loads on uneven terrain.
“We tested it on a simulated analogue space mission in Australia and the feedback was very positive. Both in the perception of comfort and assistance and in the scientific data we collected, namely muscle activation and joint movement, everything indicates that the device works”, afirmou Pulvirenti.
Combat loss of muscle mass
On prolonged missions, reduced gravity causes rapid muscle weakening. To counter this effect, astronauts follow intensive daily exercise regimes, which can last around two hours.
“There is something missing from the astronauts’ exercise routine on Earth. . It’s probably the dynamic load throughout the day. Two hours of intense exercise may not be enough to maintain muscle mass for prolonged periods. A device like this can provide that additional load throughout the day and complement the exercise regime,” explicau Pulvirenti.
The team believes that the technology could also have applications on Earth, namely in physical rehabilitation and mobility support systems, whether to facilitate movement or to add resistance and help preserve muscle mass.
The next step is to obtain funding to present the technology to the European Space Agency.
