However, if we are to travel further we will need to better understand and overcome the biological challenges of long term space travel.
The BAMMsat project aims to enable biological research that will uncover these threats and better understand the effects spaceflights can have on astronauts as they travel beyond the International Space Station to deep space destinations such as the moon and Mars.
The next major milestone is a manned mission to Mars, which NASA estimates will be achievable in the 2030s. Space exploration pushes the boundaries of science and technology, as well as the limits of the human body, so before we are able to send astronauts further into space, we need to expand our knowledge of the resulting long term effects of microgravity and high radiation on the human body – how will the body react to long duration space flight and what physical programmes and standards need to be put in place?
According to Nasa the risks associated with extended periods of space travel can be group using the acronym – RIDGE – short for Space Radiation; Isolation and Confinement; Distance from Earth; Gravity fields and Hostile/Closed Environments.
So the number one priority, when it comes to deep space, is keeping astronauts alive and healthy. Data will be critical to this, however, current space medicine and biology is profoundly limited and testing is prohibitively expensive.
The objective of the BAMMsat-on-BEXUS project is to improve technology for biological research in space, with an ultimate aim of supporting human spaceflight. The technology is being developed by a team of academics and students from Cranfield University and the University of Exeter.
Science in small spaces
The project team is developing a miniaturised lab system that is compatible with 3U CubeSats, a sub-type of miniaturised satellites designed for space research, consisting of three units stacked together.
The compact system holds many advantages over other techniques used to research the influence of space conditions on living systems.
“Researching the effects of microgravity and radiation in on-ground facilities has technical constraints that can add complexity to data interpretation,” explained Aqeel Shamsul, a PhD student at Cranfield University and head of the project. “However, in-flight experiments come with their own challenges, often entailing expensive launch missions.
“These factors are limiting research into the effects of environmental space factors on biological systems, therefore impeding progress in deep space travel. We’re combatting this by designing a cheaper way to conduct biological research in space, with a system that can facilitate experiments within remarkably small dimensions.”
CubeSat’s are built to a standard dimension and that standardisation means that a lot of the technologies and interfaces for a CubeSat can also be standardised.
The lab system that’s been developed includes a disk with multiple chambers along its edge that contain isolated biological samples. A motorised system turns the disk to position different chambers opposite microfluidic inlet and outlet openings, which can channel small amounts of fluids without human intervention.
The device can then supply food or extract waste from the samples using a fluidic pump.
The disk can also be turned to orientate a chamber in front of a microscope, which can send an image of the sample back to researchers on Earth. In addition, the rotating disk allows the samples to be aligned with a visible spectrometer. This technology can measure the amount of light absorbed, reflected or transmitted from the sample to reveal certain biochemical characteristics, such as protein quantification.
Compared to other equivalent systems that have one block containing one sample, the multi-chambered disk system allows numerous experiments with different samples to occur simultaneously. Biological samples can include microorganisms such as Escherichia coli (E. coli) and Caenorhabditis elegans (C. elegans).
C. elegans in particular is a valuable study organism for researching the effect long term space travel will have on the human body. This is because both humans and C. elegans are eukaryotic organisms, and share many genes and molecular pathways.
These factors, along with the fact that the genome of C. elegans has been completely sequenced, allow them to be used as a model organism in experiments that research human disease progression. At only a millimetre long, and with minimal survival requirements, they can be relatively easily transported into space with minimal human intervention.
“As well as using a small organism, light weighting other components of the system was important to ensure the satellite could be viably and economically launched into space,” added Shamsul. “One area where this had to be considered in detail was the motor system used to turn the disk containing sample chambers.”
To deliver the high torque required to turn the disk, the project needed a motor system capable of delivering the necessary power but also one that remained compact. To achieve this EMS, a UK supplier of Faulhaber motors was brought into the project.
According to Shamsul, “We originally considered a stepper motor for the BAMMsat system, but EMS showed us that a brushed DC motor would better fit our torque and space requirements.”
EMS conducted thorough calculations to find a system that would deliver maximum performance in the given space envelope. After careful consideration, a 22mm diameter brushed motor from the Faulhaber SR series was selected. The motor was paired with an encoder to deliver fine speed control, as well as a planetary gearhead to maximise torque and being small and light weight, the motor system ensured minimal weight and bulk was added to the CubeSat.
To infinity and beyond
The BAMMsat system is planned to be launched into the stratosphere in October 2021. With the help of the Swedish National Space Agency, German Aerospace Centre (DLR), European Space Agency and their partners, the prototype will be flown using a high-altitude balloon.
This will allow the BAMMsat team to test aspects of the system, such as the control system and payload hardware, in a spaceflight-representative environment.
The ultimate aim of the stratosphere mission is to increase the system’s Technology Readiness Level (TRL). Developed by NASA, the TRL scale measures the maturity of a particular technology on a scale of one to nine, with one meaning it’s at basic research level, and nine indicating it’s been flight proven through successful mission operations.
Once the BAMMsat system has been validated for future missions, it could go on to conduct biological research in low Earth orbit (LOE) and deep space, including trips to the International Space Station (ISS).
“The BAMMsat project is a result of impressive collaboration between a number of engineering sectors, incorporating aerospace, biological and mechanical expertise,” said Dave Walsha, sales manager at EMS. “University projects are at the forefront of this type of technology, and the potential of this system to enable safe long term space travel is sensational.”
The project is intended to look at microgravity and radiation from high-energy particles and their impact on Earth’s biology whether that’s human biology, food or bacteria and for many it’s biology that is the biggest challenge when it comes to deep space travel and the prospect of settlements on planets like Mars.
But while the BAMMsat project will help fill the knowledge gap when it comes to long term human duration in space, it will also be able to benefit those of us who are left back on earth. A better understanding of how a virus or bacteria behaves in space could lead to better vaccines, while a better understanding of the ageing process could benefit all of us.
