The concept of an inflatable space habitat isn’t exactly what you might have had in mind when envisioning our space future. Although the world of science fiction is littered with inflatable bases – from Arthur C Clarke’s A Fall of Moondust – which, in 1961, before humans had travelled to the Moon, proposed inflatable igloos − to the recent blockbuster, The Martian, which saw inflatables’ latest big screen outing as a habitat on Mars.
As is often the case with technology, even things which seem improbable eventually come true and in April will see the first inflatable space habitat, when an inflatable module known as the Bigelow Expandable Activity Module (BEAM) is launched to the International Space Station (ISS). If successful, the potential from the technology could offer a cheaper, more efficient and safer habitat for future space explorers, with the possibility to go beyond low Earth orbit and perhaps even onwards to the planet Mars. “Inflatable habitats, which are also known as expandables, are lightweight and require minimal payload volume on a rocket but expand after being deployed in space to provide a comfortable area for astronauts to live and work,” explains Stephanie Schierholz, a lead spokesperson for Human Exploration at NASA, which is working with private space company Bigelow Aerospace to test the technology. “From an engineering point of view, they greatly decrease the amount of transport volume needed to get them into space.” Today, inflatable habitats are seen as an important investment for future space exploration.
“Up until now there has been a great deal of attention and focus on transport systems but not nearly as much as where we are going and what we are going to do when we get there,” says Mike Gold from Bigelow Aerospace, which is developing inflatable space habitats, including BEAM. “Our job is to bring the future to today”. Bigelow is already looking ahead to the longer term potential for inflatable habitats, including as a separate space station which could cater for space tourists and scientists alike and habitats for deep space exploration.
The delivery of the first ever inflatable module to the ISS will not only be the first in space technology demonstration of this type of habitat but also the first commercial habitat in space – a game changer in terms of where the space industry is heading, with more and more private companies seeing space as serious business. It will also be delivered to the ISS by a commercial space company – SpaceX, on a flight which had been rescheduled from September 2015 following the SpaceX mishap earlier that year. The delivery by SpaceX is in itself is testament to just how far we have come in space.
The BEAM inflatable will form part of the space station for the next two years, where a series of tests will be conducted to validate the overall performance and capability of expandable habitats. Even the way the BEAM habitat will be attached to the space station feels like something from a science fiction promise of the future. Taking place around five days after the SpaceX Dragon supply capsule arrives at the space station, there will be no spacewalking astronauts to attach BEAM to the ISS’s Tranquility Node. Instead the Space Station’s robotic Canadarm2 will be used. Operated remotely by controllers at NASA’s Mission Control in Houston and the Canadian Space Agency in Montreal, it will transfer BEAM from the trunk of Dragon to its new home, in a process which will take just eight hours.
It will be another four months after BEAM’s arrival, before NASA crew living on the space station will activate a pressurisation system to expand the structure to its full size, using air stored within the packed module. “This will primarily be a technology demonstrator, to analyse how BEAM reacts in the orbital environment,” explains Gold. “Although it can last much longer than the two years it will be in orbit.”
Prior to inflation, BEAM will measure just eight feet (2.4 metres) in diameter but, once attached to the space station and expanded, it will offer astronauts 565ft^3 of room and will weigh 3,000lb which is roughly 1,360kg. The habitat is windowless with two metal bulkheads, an aluminium structure and multiple levels of soft fabric with spacing between layers, protecting an internal restraint and bladder system. The exact fabric used is confidential but Gold describes it as “a flexible fabric weave, which provides protection from radiation and physical debris.” BEAM will also be fitted with various sensors and radiation monitors, to take measurements and monitor its performance.
Once inflated the astronauts on board the ISS will be able to go inside BEAM. “It will be a historic moment when the first astronaut steps – or floats – into it,” explains Gold. For the first time astronauts will be inside a private structure in space. However, astronauts on the space station won’t be able to live in BEAM but they will spend time in the module, three to four times a year, for a few hours at a time, conducting inspections and gathering information about its performance. “BEAM has no internal power, so crew members will have to carry battery-operated lights while conducting tests inside” explains Schierholz. “Instead, the primary purpose of the crew is to collect deployment dynamics sensor (DDS) data, perform surface sampling, conduct periodic changeout of the radiation area monitors (RAM) and inspect the general housekeeping condition of the module”.
Apart from its inflatable structure, in many other ways BEAM will be just like any other module on the ISS, with ventilation in BEAM using air pushed from the ISS through an inter-modular duct. The aim of the test is to help scientists and engineers understand the potential for this type of habitat for future space explorers. “Learning how an expandable habitat performs in the thermal environment of space and how it reacts to radiation, micrometeoroids, and orbital debris will provide information to address key concerns about living in the harsh environment of space,” adds Schierholz.
Two years in space
After two years attached to the space station, BEAM will be jettisoned with the help of the robotic Canadarm2. The robotic arm, once again remotely operated, will remove BEAM and release it on a trajectory so that it burns up on re-entry to the Earth’s atmosphere within less than a year. Even this will be historic, as it will be the first time the Space Station has jettisoned an object as large as BEAM, rather than returning it to Earth in a cargo vehicle, such as the Space Shuttle.
What matters most about the test with BEAM on the ISS is that it is laying the ground work for future space explorers. “In visions of the space future from both NASA and ESA you often see expandable habitats,” says Mike. It is creating the foundations for future space missions where habitats need to be lighter than they have traditionally been and cheaper to be protected from budget cuts. “This is an important investment for advanced technologies that NASA will need for missions into deep space and eventually on the journey to Mars,” adds Schierholz. “Expandable modules, which are lower-mass and lower-volume systems than metal habitats, can increase the efficiency of cargo shipments, possibly reducing the number of launches needed and overall mission costs.”
By using expandables, you are essentially able to get larger habitats to space, with less mass required, therefore reducing the size of the rocket needed.
Another benefit is protection against radiation. Radiation exposure in space remains a major threat to humans travelling to Mars, not only during the journey to the Red Planet, but for future astronauts living and working on Mars, where there is increased radiation exposure because of Mars’ thinner atmosphere and weak magnetic field. Even astronauts living and working on-board the ISS are exposed to higher levels of radiation than on Earth and there are career limits for ISS crew exposure to radiation. There is also the additional risk from solar flares. However, inflatables could have the answer to reducing the amount of radiation astronauts are exposed to. “Inflatables can offer advanced protection against radiation in space” says Gold. “With metallic habitats you get interaction and scattering but expandables reduce the effect because of the materials they are made from.” One of the most important aspects of the testing of BEAM will be to measure and quantify the potential level of protection this type of habitat can offer.
“The soft goods used in the BEAM structural shell are expected to provide radiation protection,” adds Schierholz. “We will be able to directly compare measurements taken through other ISS modules to assess how effectively the BEAM module shields against the radiation field seen in low-Earth orbit.”
Not a new idea
Although all of the potential from BEAM and future inflatable habitats, may seem like new and novel ideas, the concept holds its origins in the dawn of the space race. “This is something that goes back to the beginning of NASA” explains Gold. “Look at the very first communications satellites Echo 1 and Echo 2. NASA engineers back then faced the same problems; limited space on rockets, but wanting to put a large payload into orbit. So they utilised a balloon-like concept.” Such was the success of this, that NASA tried to migrate it to human spaceflight. The Space Agency even went as far as to commission tyre maker Goodyear to make prototypes of an inflatable space station. However, like with many ideas at the dawn of the Space Race, the concept was later shelved.
In the 1990s, the idea of an inflatable habitat was revived, thanks in part to the development of materials such as Kevlar. According to Gold: “During the Bush Administration, people were once again looking at beyond Earth orbit, back to the Moon and then Mars. By then science had matured so they looked again at the concept of inflatables.” However, the idea of Mars again fell by the wayside but the concept of inflatables were transitioned from Mars missions to crew quarters. NASA then developed the TransHab inflatable module as an idea for a crew module on the ISS, although the name, derived from ‘Transit Habitat’ reflected the original intention to be an interplanetary vehicle to transfer humans to Mars.
TransHab was cancelled due to a mix of financial and political reasons, and the technology was later purchased by Bigelow Aerospace, with the company being founded in 1999. “Bigelow is leveraging NASA technology which has been licensed to the company” explains Schierholz. Bigelow was later awarded a $17.8m contract from NASA for the BEAM module. This collaboration with the commercial industry is part of the NASA NextSTEP initiative for human spaceflight with the aim of developing capabilities for deep space exploration such as around the Moon, known as cis-lunar space and to the planet Mars. According to Schierholz: “NASA’s journey to deep space will include key partnerships with commercial industry for the development of advanced exploration systems.”
The shape of space habitats to come
Longer-term, inflatable habitats are once more seen as having the potential for missions beyond Earth orbit, as well as for future habitats in low Earth orbit. For NASA, a successful BEAM demonstration on the ISS will certainly be a giant stepping stone to understanding the role that expandable structures could have for future space habitats. Gold says, Bigelow Aerospace are already developing what comes after BEAM. Known as B330, the new generation expandable habitat will be capable of housing up to six astronauts, in a volume of 12,000ft^3 and have a lifespan of 20 years. Bigelow believe the larger habitat has potential as a scientific module, as well as potential ‘hotel’ for tourists in orbit around the Earth, or as a larger space station with multiple habitats joined together. “We see the B330 as the backbone of not only low Earth orbit but further into space” says Gold.
Of course there is a lot more to be developed before this can happen – not least the challenges of sustaining human life in space for a much longer time. “Our space explorers will need pure air and water and food that can be grown or nurtured in space,” explains Joe Urso, CEO of Aerus Holdings, a company which works with life support technology developed for the ISS. “Until we can source essentials of air, water and food extra-terrestrially, we will need to protect the sanctity of these resources we send on missions with our space explorers; and guaranteeing purification will be essential.”
The ultimate goal of these types of habitats is to help achieve the goal of a manned mission to Mars. When we reach that point, Gold believes that Bigelow’s technology could make science fact a little less dramatic than science fiction. “Let’s just say, if Matt Damon had had a Bigelow habitat in The Martian, the movie would have been a lot more boring and his life a lot more comfortable”.
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A version of this article first appeared in February 2016 AEROSPACE/RAeS
Sarah Cruddas is Space Journalist, Broadcaster and Author with a background in astrophysics. She is the voice of space on British TV for channels including Sky News, Channel 5 and ITV. Specializing in space exploration she has reported on the industry from across the world.@sarahcruddaswww.sarahcruddas.com