Alén Space collaborates with the Spanish National Institute of Aerospace Technology (INTA) in its mission ANSER (Advanced Nanosatellites Systems for Earth Observation Research). This project, which will be made up of a cluster of four nanosatellites, is one of the initiatives that INTA has launched within its Small Satellite Constellation Programme. Alén Space oversees the mission’s Inter-satellite Link (ISL) system.

The main goal of the ANSER project is to monitor the quality of the water in reservoirs and swamps in Spain, using technological advances to distinguish the different levels of contamination in its shallow layers. This set of nanosatellites will also allow the study of global warming caused by the increase of greenhouse gases in the atmosphere (especially the accumulation of carbon dioxide) and the effect that solar radiation has on our planet.

The four nanosatellites of the ANSER mission will fly in close formation (about 10 kilometres apart) and they are ready to work together, as a single satellite, with fragmented payloads on the different CubeSats. They will be managed by a distributed attitude control to avoid disorientation and the loss of any of them.

Alén Space’s Inter-satellite Link (ISL) system enables in orbit communications among satellites. This way, the ‘lead’ nanosatellite is the one in charge to connect with the ground station and to receive information from the other ‘follower’ nanosatellites, which allows the cluster to act as a single satellite. The ISL, which will operate in a 401-402 MHz radio frequency, can be optimised if its power and bitrate is modulated, thus allowing a greater transmission range among satellites, which in this mission could reach 100 kilometres.

The ISL system developed for ANSER by Alén Space is designed to meet these three main requirements:

  • Continuous communication. The ISL operates as another satellite bus to keep the CubeSats connected.
  • Low consumption. To preserve the satellite power, a solution with an extremely low consumption has been sought.
  • Compatibility. The operation of ISL is compatible with TTC (Telemetry, Tracking and Command) since it will use the same antenna and it will have the same electrical and mechanical interfaces.

Alén Space’s COO, Diego Nodar, explained the work carried out in this project and how this Inter-satellite Link (ISL) system works at the 3rd Space Engineering Congress.

Diego Nodar also detailed future functionalities that may be included in the ISL system. Firstly, the ranging: how using the same radio interface, satellites can know their relative position. Then, to cover the ISL and TTC functionalities, a long-distance transmission chain will be incorporated to include communications with ground stations. And lastly, the architecture used would allow the implementation of On-board Computer (OBC) functions, so low consumption OBC, TTC and ISL systems can be used.

The ANSER project plans to put its four nanosatellites in orbit in 2021 to collect information in the following years. This mission can be an important step for the development of more successful projects in the nanosatellites field in Spain.