From data relay dilemma to certainty

Satellites are playing an increasingly critical role in missions around the world. From military missions to humanitarian efforts and scientific research, satellites are transmitting vital, time-sensitive information to support these activities. However, historically mission operators have been forced to wait until a satellite passes over a ground station to gain access to data or upload commands to their spacecraft.

Viasat’s HaloNet^TM portfolio delivers a modular set of capabilities that meet the evolving needs of near-earth mission communications. Advanced satellite payload technologies, LEO constellation proliferation, and improved launch affordability are all reshaping the need for diverse space communications, and not every spacecraft and its unique missions can be served by a “one size fits all” communications package. That’s the beauty of HaloNet: access to the disparate transports that operators need in a single unified service that’s interoperable with customers’ current and future space infrastructure.

The HaloNet portfolio offers two data relay services – L-band Tracking, Telemetry, and Command (TT&C) and High-Capacity Data Relay Service – that collectively enable operators to maintain continuous custody of spacecraft, as well as transmit data from the ground to space and back again, without having to wait for ground station passes. These services deliver the synergy, connectivity, flexibility, and reliability that today’s missions require.

The L-band TT&C Data Relay Service leverages Viasat’s global geostationary (GEO) L-band satellite network and associated ground infrastructure. It uses an omnidirectional antenna to provide real-time situational awareness and always-on connectivity between spacecraft and mission operations centers, enabling on-demand command, control, and monitoring.

With this, operators can maintain low data rate connectivity at any point in a spacecraft’s orbit, enabling the spacecraft to report anomalies, issues, or other important information immediately. Additionally, operators can push updated commands to the spacecraft to support high-priority missions or other urgent needs. The L-Band TT&C can also be used as a control pathway for system-level mission operations functions such as reserving resources, activating services onboard the spacecraft, or facilitating pointing, acquisition, and tracking for free space optics.

The High-Capacity Data Relay Service enables on-demand, high-data rate bidirectional data transfer. Ideal for high volume data transmission, the service operates on Viasat’s GEO Ka-band satellites to connect spacecraft to mission operators on the ground for rapid delivery of time-sensitive, high-value data. This could include Earth observation imagery or intelligence to support military operations in hostile or contested environments. 

The Ka-band frequency also supports higher uplink data rates, and the relay is ideal for enabling cutting edge use cases such as space-based data processing, onboard machine learning and artificial intelligence (ML/AI), and software-defined payloads. The high-capacity relay can push bus or payload software and firmware updates, including the largest ML/AI inference models, from ground to space in a matter of minutes, instead of requiring dozens or even hundreds of traditional ground station passes over the course of days to weeks.