Any satellite sent to space must be able to deal with the battle with Earth’s gravitational pull, withstanding the harsh conditions of launch before reaching the zero-gravity environment it was designed for. But what if we could send raw materials into orbit and build the satellite there instead? DARPA (the Defence Advanced Research Projects Agency) has formed partnerships with a number of universities to develop 3D printing technology and in-orbit assembly of satellite components. It’s recently put out a new request for proposals to explore biological growth mechanisms in space – the exciting prospect of living organisms that can increase in size, develop structures, and repair themselves.

Satellite launches from Earth began on October 4, 1957, when the Soviet Union successfully launched Sputnik 1, the world’s first artificial satellite. It marked the beginning of the space age and was followed by the U.S. launch of Explorer 1 in 1958. Over the decades that followed, advancements in rocketry culminated in the development of Saturn V capable of delivering humans to the Moon. The 1960s and 1970s saw the rise of communication, weather, and reconnaissance satellites and with the advent of reusable spacecraft like the Space Shuttle in the 1980s space became more economical. 

One of the biggest challenges facing agencies launching space satellites is the challenge of size and weight. The bigger and heavier it is, the more expensive it is to launch. DARPA’s 2022 NOM4D program aims to solve this by sending lightweight materials to space for on-site construction, rather than build them before launch. This innovative approach enables building much larger, more mass-efficient structures into orbit that would perhaps otherwise be impossible to launch fully assembled. The idea opens new possibilities for optimised designs that aren’t limited by launch vehicle dimensions and lifting capability. 

The partnerships established by DAPRA include Caltech (the California Institute of Technology) and the University of Illinois Urbana-Champaign have already demonstrated wonderful advances in the first two phases. They are now continuing phase 3 with launch companies to undergo in-space testing of the assembly process. In many ways though, the concept is not new, the ISS for example has been built in orbit over many decades, it’s the first time however that the approach is being used for smaller satellites. 

The Caltech experiment will operate independently in orbit without human interaction once deployed. It’s going to be fascinating to watch this momentous test. On-board cameras will provide live monitoring of the construction process as an autonomous robot assembles lightweight composite fibre tubes into a circular truss 1.4 meters in diameter, representing an antenna structure. It’s a little bit like popular children’s toys like K’Nex but of course, a little more advanced. 

If successful, the technology could be scaled up to eventually construct space-based antennas exceeding 100 meters in diameter, transforming space exploration with enhanced communicating and monitoring capabilities. It goes much further than this though. DARPA is now exploring the possibility of “growing” large biological structures in space too. 

Recent advances in metabolic engineering, knowledge of extremophile organisms and developments in tunable materials like hydrogels are making space grown organic structures a tantalising possibility. It aims to DAPRA have put out a request for proposals to explore the concept. These biologically manufactured structures could enable projects that are impractical with traditional methods with dreams of space elevator tethers, orbital debris capture nets and expandable commercial space station modules perhaps not so far from being a reality. By harnessing biological growth in the unique conditions of space, entirely new construction possibilities may become feasible. Just imagine!

Source : DARPA demos will test novel tech for building future large structures in space and Large Bio-Mechanical Space Structures