The main improvements of the direct-drive concept beyond the state-of-the-art are related to the gain in power efficiency (close to 100% of the power extracted from the solar panels, no thermal losses due to power conversion, converter mass saving). As a consequence of these significant performance improvements, cheaper and lighter spacecraft can be envisaged, or identical ones with enhanced performances. The socio-economic impacts of EDDA can be appraised in 3 main market applications: GEO telecom satellites, Deep Space Exploration (as interplanetary missions), or the novel On Orbit Servicing.
For the large geostationary (at 36000 km altitude) telecommunication satellites, removal of power converters will result in significant cost and mass reductions, opening the way to less expensive space launches or additional payload onboard (more functionalities / capacity). Direct drive can also provide a reduction of transfer orbit duration.
On-orbit services is an emergent market. Such services include: life extension, end of life deorbiting , debris removal, relocation, transportation… and they can address both GEO and (smaller) LEO satellites. On one hand, a moderate increase of the number of GEO satellites (devoted to telecommunication) is anticipated, and they can require maintenance/repair/upgrading services. On the other hand, the LEO satellite market is currently experiencing deployment of large constellations and mega-constellations. They are meant to provide full Earth coverage of communication networks and Earth observation services in the next years. LEO satellites will therefore increase the already large number of objects orbiting close to the Earth, thereby triggering the needs for services such as debris removal, asset relocation, and deorbiting.
In Deep Space Exploration, development of direct-drive for electric propulsion will be an important enabler for future Deep Space Exploration phases, either on Moon, Mars or Asteroids, where large amount of power to supply electric propulsion is recognized.
The first two markets are related to telecommunications networks which are vital in mankind’s daily life. They can help to protect the planet and the environment (satellites provide data on climate change, measure pollution, monitor natural disasters,…) with downstream impacts on biodiversity, agriculture,…. Besides, Space technologies improve products we use every day, weather forecasts, and communications worldwide.
Advances in Deep Space Exploration, as shown by Artemis Moon missions, holds many promises. On one hand, it enhances safety on Earth (e.g. asteroid aversion such as the DART mission) and it supports defining appropriate risk management strategies. On the other hand, scientific discoveries nurture human curiosity by pushing our boundaries by exploring the unknown and inspiring future generations.
