The Department of Defense (DoD) is pioneering a slew of next-generation satellites and sensors to deliver critical data to military command centers from space, and to track and target missile threats and other time-sensitive targets, officials from the Space Development Agency (SDA) and the Missile Defense Agency (MDA) said at the Defense One Tech Summit on June 22.
Digital Communication from Space
The SDA has experimented with optical communications terminals that use lasers to beam data across space. These terminals are essential pieces of the DoD’s future low Earth orbit constellations, which will require satellite-to-satellite optical crosslinks and can immediately send data collected in space. The key objective is to have a mesh network that is entirely laser-connected.
But first, a short primer: Employing optical communications terminals reduces the challenges of data delivered through radio frequency (RF) waves. Optical communications terminals have a very narrow “linewidth,” and to jam that signal, a laser must shine directly down into that telescope – which is not technically feasible over a wide area. But when utilizing RF waves, there is a constant risk of jamming, especially when you put out a lot of power on the ground and ultimately overpower the receiver. Additionally, through optical communications terminals, communications are not easily intercepted. However, when applying RF waves, interference is complicated to prevent. If you’re putting a lot of data out over RF, it’s challenging to hide that, and it’s easy to detect where you could be receiving. There are also interference issues among various channels when you begin to utilize different broadband communication with RF.
The SDA is working on optical links with General Atomics Electromagnetic Systems (GA-EMS). GA-EMS announced in a statement that it signed an agreement with the agency to conduct a series of experiments for optical inter-satellite links using GA-EMS’ laser communication terminals.
“In a few short days, we’ll launch several satellites to do laser connectivity in space, and those satellites will also do laser connectivity down directly to an MQ-9 platform early next year,” said Derek M. Tournear, Ph.D., director at the SDA.
“So the whole goal is to form this high bandwidth, low latency, low probability of jam communication network to go down to any platform, whether on the surface, on a ship, or in the air,” he said. “So we’re excited about this completely new way to move data so that we can start to enable the warfighter.”
New Satellite Tracking Layer for Hypersonic Weapons
The MDA will deorbit two space tracking and surveillance system (STSS) experimental missile warning satellites in the coming years, and will focus on developing next-generation hypersonic ballistic tracking space sensor (HBTSS) satellites to counter hypersonic missile threats.
The two satellites, launched in 2009, have served as risk reduction experiments for MDA’s missile warning enterprise for more than a decade now. They were designed to track ballistic missiles from birth to death with built-in infrared sensors from 1,350 kilometers above the Earth’s surface. The sensing data could then be downlinked to the ballistic missile defense system for missile interception.
“Our adversaries are learning. They understand from a missile defense perspective that we’re heavily relying on terrestrial sensors currently. And so, they’re developing systems that are going to try to defeat that,” said Walter S. Chai, director of Space Sensors and director of Missile Integration and Operations Center at the MDA. “Our adversaries are developing hypersonic glide vehicles that challenge detection due to their speed, maneuverability, and low altitude of flight.”
Therefore, Chai explained, the MDA must be able to sense these targets, acquire low latency to detect targets and engage at a long distance, along with the capability to handle large numbers. “And all of these have to be done in a resilient manner,” he said.
The MDA awarded two contracts for the HBTSS satellite prototype; L3Harris received a $133 million share, and Northrop Grumman received $155 million. The new systems will work in conjunction with SDA’s tracking layer, a proliferated constellation of infrared sensors in low Earth orbit capable of tracking hypersonic and ballistic threats. The tracking layer will pass custody of missiles from satellite to satellite via a planned on-orbit mesh network as the missile fly. Custody of the HBTSS will be given to the HBTSS satellites, which have more advanced sensors to target data to interceptors. HBTSS prototypes are expected to launch in 2023.
