DARPA's NOM4D program seeks to manufacture large structures in space
In anticipation of future space projects involving giant structures in orbit and on the Moon, DARPA has announced the start of its Novel Orbital and Moon Manufacturing, Materials and Mass-efficient Design (NOM4D, pronounced "NOMAD") program. The new initiative seeks to develop new technologies for adaptive, large-scale structure manufacturing in space.
With the race to return to the Moon, put an astronaut on Mars, and the rapid commercialization of Earth orbit, space technology is undergoing revolutionary changes. Not only are commercial companies launching a record number of missions releasing a record number of satellites, there are also new classes of spacecraft on the scene.
On the one hand, there are increasingly sophisticated nanosatellites, but there is also a need for much larger spacecraft and lunar surface structures than have ever been attempted before. The problem is not only how to build rockets big enough to place such installations into orbit, but to ensure the payload survives the launch, which means a lot of volume and mass wasted that will only be needed for a few minutes.
For example, there's the International Space Station (ISS) which weighs about 420 tonnes. It wasn't launched all in one go, but as a series of modules delivered by the Space Shuttle and other boosters. This is one way of building such structures, but each of these modules had to fit inside the size and mass parameters of the launch vehicle and be built with enough strength to withstand the g-forces and vibrations to reach its destination in working order. Once in space, all that strength is no longer needed
NOM4D aims to take a different approach by not just assembling modules built on Earth, but moving manufacturing off Earth to create large, dynamic structures for the US Defense Department that can adapt as their environment or mission changes. The idea is that advanced materials would be sent up from Earth and would then be used to build large structures. In this way, things like antennae and solar arrays can be built that would be larger than those assembled on Earth, but can be much lighter, yet with greater stability, agility, and adaptability.
The assumption behind the program is that by 2030 space will have advanced in terms of logistics and facilities, including fast and frequent orbital launches, regular flights to the Moon, on-orbit refueling of robotic spacecraft, and robots capable of building structures in space, as well as the ability to evaluate and monitor operations in real time.
Participants in the NOM4D program will go through a three-phase process with each phase lasting 18 months and focusing on a specific concept. Phase I will involve meeting the structural efficiency targets for a 1-megawatt solar array, Phase II will concentrate on risk reduction and technical development for a 330-foot-wide (100-m) radio frequency reflector, and Phase III will demonstrate sufficient precision to build an infrared-reflective structure for a segmented long-wave infrared telescope. Each phase will require meeting the technical requirements and the ground-based manufacture of sub-scale demonstrator structures for validation.
"We’re looking for proposers to come up with system designs that are so mass-efficient that they can only be built off-earth, and with features that enable them to withstand maneuvers, eclipses, damage, and thermal cycles typical of space and lunar environments," says Bill Carter, program manager in DARPA’s Defense Sciences Office. "Given the constraints of ground test, launch and deployment, the traditional approach to designing space structures is not likely to result in dramatic improvements in mass efficiency. In order to take the next step, we’ve got to go about materials, manufacturing, and design in a completely new way."
A Proposer's Day webinar for those interested in participating in the program is scheduled for February 26, 2021.