Reducing launch communication blackouts with HaloNet

Launch operations are reliant on line-of-sight connectivity throughout launch ascent to monitor rocket trajectory, status, and performance. Today’s launch operators are accustomed to communication blackout periods when their launch vehicle moves beyond line-of-sight from land masses covered by Earth-based antenna stations. These blackouts can pose risk to missions and often must be mitigated through non-optimal fixes - such as fuel-inefficient tailoring of launch trajectories to reduce communication blackouts during critical mission phases (e.g. engine burns, satellite separation).

It is critical that launch telemetry connectivity solutions evolve to significantly reduce or even eliminate communications blackouts, ensuring consistent connections with launch vehicles for real-time monitoring to confirm safe launch operation and enable optimized vehicle performance. These real-time connectivity solutions need to be scalable, flexible, and readily available to meet the industry’s accelerating launch cadence in the United States and the rest of the world.

Viasat is directly addressing this challenge with HaloNet, the near-Earth communications solutions portfolio that unifies space and terrestrial connectivity into a cohesive service offering. Within this portfolio, Viasat’s launch telemetry data relay service is built on satellite network technology that’s been trusted and in use for more than 30 years. It delivers a transparent data relay capability that provides continuous telemetry communications during launch ascent. Developed by Viasat’s Defense and Advanced Technologies (DAT) segment, the capability is specifically designed to support launch operators and enable real-time, continuous telemetry connectivity and eliminate communication blackouts during launch ascent.

Viasat’s HaloNet launch telemetry data relay service leverages Viasat’s global L-band geostationary (GEO) satellite network and associated ground infrastructure to provide continuous communications with launch vehicles offering network redundancy and resilience with geographic diversity. This means that launch operators can rest assured that the connection with the launch vehicle will remain, even in the event of a site failure.

Viasat and Blue Origin team members on console in mission control center during Blue Origin’s New Glenn launch. Image credit: Blue Origin

Operators can plan their launches with optimal launch trajectory design and operational flexibility with the knowledge that Viasat’s launch telemetry data relay service eases many of the traditional challenges associated with launches, including:

• Connectivity Blackouts – Global satellite coverage can fill any gaps left by ground stations. The combined coverage of Viasat’s L-band satellite network provides continuous line-of-sight connectivity for launch trajectories in all inclinations up to Low-Earth Orbit (LEO) altitudes (~500 km) and above. As a result, operators can design and select launch trajectories that are optimized for target orbit and fuel consumption. This also enables increased mass-to-orbit and/or accelerated time-to-delivery for customer spacecraft. Additionally, if a vehicle failure occurs, the launch operator will have access to the critical telemetry data needed to help identify the root cause of a failure – potentially saving investigation and redesign efforts before a vehicle can be recertified for flight.
• Flexibility and Scalability in Operations – Current launch operations require blocking of a physical asset (e.g., mechanically-steered antennas) for a specific user and, as a result, cannot support more than one launch at a time. Availability and access for scheduling these ground assets are also in direct competition with existing orbiting satellites needing direct-to-earth communications during scheduled overhead passes. Viasat’s launch telemetry data relay service is built on a network beam-hopping solution that does not require the exclusive devotion of a whole satellite antenna, enabling continuous, uninterrupted service and simultaneous support of multiple launch vehicles. Satellite resources can follow the launch vehicle using a pre-defined beam-hop track that can be augmented with dynamic adjustment through the ingestion of live vehicle position data. This service capability is delivered with high availability, operating reliably in parallel with Viasat’s support of thousands of other mobile communication users, ensuring flexibility and effortless scalability
• Access to Licensed Spectrum – Ground stations typically use frequencies within the Unified S-Band (USB) commercial band, which requires licensing and approval through national regulatory authorities and can be necessary on a per-mission basis. The combination of obtaining licenses for multiple down-range ground stations, potentially across multiple geographic regions, can be a strenuous and scheduling-impacting process for launch operations. Viasat’s service alleviates this by using the company’s existing L-band frequencies over the already licensed and operational satellite assets, so there is minimal-to-no coordination required. In instances where use of Viasat’s service is subject to authorization from the launching country’s national regulatory body, a repeatable, standardized approach will be managed on a country-by-country basis.

HaloNet’s launch telemetry data relay service is filling an upcoming gap as NASA’s Tracking and Data Relay Satellite Service (TDRSS) system moves towards retirement. Viasat has partnered with Blue Origin to successfully demonstrate the capability as part of its work under NASA’s Communications Services Project (CSP).

To learn more about this revolutionary approach to meet the growing industry demand for continuous and resilient connectivity services, visit https://www.viasat.com/government/connectivity/space/near-earth-communications/.