An artist’s rendering of HawkEye 360’s Cluster-3 satellites. These are expected to reach an initial operational capability by late August.

HawkEye 360 plans to have its third cluster of RF sensing satellites operational by August.

Sharing its name with the lovable Captain Benjamin ‘Hawkeye’ Pierce from the cult television series MASH, the third cluster of the eponymous satellites reached space on 30th June. They were carried aloft by SpaceX’s Falcon-9 rocket launched from Cape Canaveral Space Force Station, Florida.

HawkEye 360 has its original HawkEye-A/B/C satellites in orbit, collectively known as Cluster-1. These were launched on 3rd December 2019. Cluster-2 added a further three satellites to the constellation as has Cluster-3.

All HawkEye satellites are designed to detect and locate Radio Frequency (RF) transmissions across a waveband of 144 megahertz/MHz to 15 gigahertz. This encompasses transmissions from Very/Ultra High Frequency (V/UHF 30 megahertz/MHz to three gigahertz/GHz) radios. Also covered are transmissions from marine Automatic Identification System transponders (AIS: 161.975MHz to 162.025MHz), marine X-band (eight gigahertz to ten gigahertz) navigation radar and mobile satellite communications.

Rob Rainhart, the company’s chief operating officer, says the Cluster-3 satellites “will be able to detect and geolocate many types of RF signals. We can tune the satellites to focus on important regions from 144MHz to 15GHz.” He says that common signals of interest include “VHF marine radios, a variety of UHF push-to-talk radios, maritime and land-based radar systems, L-band satellite devices (1.3GHz to 1.7GHz) and emergency beacons.”

Improvements

Mr. Rainhart adds that, compared to earlier generations of HawkEye satellites, the Cluster-3 spacecraft “have filled in 1.5GHz of potential coverage range, while improving detection of GNSS (Global Navigation Satellite Signal) interference.” Other improvements include the satellites’ ability to “digest more data at a faster rate thanks to increased on-board processing.” Meanwhile the satellites are equipped with “improved software-defined radios that can simultaneously collect across a wide range of frequencies.” In sum, “the overall system is designed to produce faster, more accurate geolocations.”

Now in orbit the satellites will undergo “a series of functional tests to verify that every system is working as expected.” The satellites will then be moved into formation. “The entire commissioning process takes about two to three months. We expect to achieve initial operating capability as soon as late August.”

Magnificent Seven

More satellites are on the horizon: “HawkEye 360 has seven additional next-generation clusters fully funded and scheduled for launch in 2021 and 2022. These will complete our baseline constellation.” Each cluster incorporates “advancements … such as extending the potential frequency range we can detect and the amount of data we can collect.” The full baseline constellation promises revisit rates of 20 minutes depending on location, says Mr. Rainhart. This “will give our customers impressive depth for situational awareness of rapidly changing circumstances.”

by Dr. Thomas Withington