Duration: 12 months
The future space economy will see a significant increase in the number of spacecraft returning to Earth, for returning precious materials, re-usable platforms and people. These spacecraft will be entering increasingly congested airspace and close to civilian populations. However, vehicles travelling at hypersonic speeds suffer from communications blackouts resulting from the plasma sheath forming around the vehicle as it passes through the atmosphere. This leads to a period of minutes where the vehicle position, trajectory and status are unknown and the vehicle itself is unable to receive accurate positional information. This situation is incompatible with the future space economy, due to constraints on vehicle capabilities, such as recovery and/or guidance, and safety implications prohibiting operations. Laser communications have demonstrated the potential to penetrate the plasma sheath and maintain data links with hypersonic vehicles. Accurate time transfer using free-space optical links is in development, making it possible to provide two-way communication with a hypersonic vehicle travelling through the atmosphere, including precise positional and directional information. By combining low to mid-TRL optical and clock payload technologies into a constellation of six or more small satellites, we are able to develop a satellite system able to support missions through the blackout period.