Capella's third-generation synthetic aperture radar satellite, Acadia, is designed to obtain higher-resolution images with an improved signal-to-noise ratio compared with Capella's Whitney satellites. Credit: Capella Space

Earth observation satellites are bulking up.

“Everyone’s moving to these bigger satellites because the cost and volume constraints have changed,” said James Mason, Planet senior vice president of space systems. “All of our customers are demanding different types of data, higher quality and lower latency.”

Precise tailoring

Capella Space’s latest generation of Acadia synthetic aperture radar satellites are 50 percent larger than their predecessors.

Moving from 112-kilogram Whitney to 165- to 187-kilogram Acadia makes no difference in terms of launch costs since Capella is purchasing a dedicated Rocket Lab Electron for each satellite.

“Mass is not as important anymore,” said Christian Lenz, chief technology officer for San Francisco-based Capella. “Things like capacity, performance, [and] lifetime are all more important at this stage.”

Customers for Capella’s SAR imagery and data, including government defense and intelligence agencies, are responsible for the satellite’s redesign.

Acadia satellites are “tailored more precisely towards their needs,” Lenz said.

Customers want high-resolution imagery and a high signal-to-noise ratio. In addition, they prefer Capella’s multi-look images that look less speckled because satellites focus on a location for tens of seconds.

“Latency is another thing that is extremely important to a very important set of customers,” Lenz said. “There are some customers who need their images within 24 hours. There’s also a customer set that needs it within four hours. And an entire new customer set that needs it within 15 minutes.”

To reduce latency, Capella is mounting Mynaric optical communications terminals on Acadia satellites. The terminals, which are compatible with the interoperability standard established by the Pentagon’s Space Development Agency, “provide the promise of having latencies of under 15 minutes sometime in the future,” Lenz said.

Acadia satellites also feature larger solar panels than Whitney and more batteries. Capella bought Electron launches to send Acadia satellites to mid-inclination orbits. Those orbits “give us faster revisit for the areas that people care about,” including the Asia-Pacific region, Lenz said.

Planet is building Pelican satellites to gather imagery with a resolution as high as 30 centimeters per pixel. Customers tasking Pelican satellites will be able to view locations as many as 12 times per day.

Agile aerospace

Planet is well known for gathering daily, moderate-resolution imagery of Earth’s land with a constellation of about 130 Dove and SuperDove cubesats.

The San Francisco-based company also is known for rapidly updating cubesat designs. SuperDoves, which gather imagery in eight spectral bands versus four for Doves, were the 14th iteration of the design. The 17th version is now in the works.

“We’ve spoken a lot over the years about agile aerospace and the transition from a more traditional satellite development model into this more agile, higher paced one,” Mason said.

For Planet, that meant moving from an 11-megapixel camera to 29 megapixels to 47 megapixels as Doves evolved. Each new camera required additional power, better radios, improved hard drives and updates to Planet’s ground infrastructure.

Birds of a feather

Planet’s in-house manufacturing extends from Doves to Pelican and Tanager, 100- to 200-kilogram satellites with a common bus.

The larger bus “removes those hard constraints of trying to pack everything in this tiny box,” Mason said. “It allows us to build more reliable, modular systems because we’ve got a bit more space to work with. We’ve taken the best of what we’ve learned from the SkySats and SuperDoves, and we put that into a new satellite design that is more flexible, more agile, lower cost and higher performance.”

Pelicans, scheduled to begin launching this year, will capture 30-centimeter Earth imagery. Tanager satellites with NASA Jet Propulsion Laboratory hyperspectral sensors are being built for Carbon Mapper, a public-private partnership focused on pinpointing, quantifying and tracking sources of methane and carbon dioxide.

Satellogic launched its first five Mark V satellites last year on a SpaceX Falcon 9 rideshare flight. Mark V includes more room for hosted payloads than Mark IV, plus upgraded radios and computers.

Remapping the world

Satellogic, an agile aerospace proponent that builds satellites in Uruguay, equipped its latest Mark V with a more spacious hosted payload bay and improved downlink capabilities.

Mark V, which began launching in 2022, obtains 80-centimeter multispectral resolution imagery compared with 99-centimeter for its predecessor. Mark V also observes a larger swath: 8 kilometers from a 520-kilometer orbit, compared with five kilometers for Mark IV. And a hyperspectral camera on Mark V provides 18-meter resolution imagery.

“The Mark V is the cornerstone of Satellogic being able to remap the world monthly, weekly and then daily with higher resolution, larger swath and faster download capability,” said Matt Tirman, chief commercial officer for Satellogic North America.

Mark V’s updated electronics did not have a significant impact on satellite size or cost. Each satellite costs satellite about $1 million to build and launch.

“The real leap is going to be our NewSat in 18 to 24 months, which will be in a larger bus with a much higher resolution,” Tirman said.

Blended missions

The 140 satellites in Spire Global’s constellation range in size from three to four, six and 16-unit cubesats. (Cubesats measure 10 centimeters on each side.)

Rendering of Spire Global satellite constellation. Spire manufactures and operates cubesats ranging in size from three to 16 units.

“Generally, our satellites are getting a little bit bigger,” said Joel Spark, Spire co-founder and chief satellite architect.

The adoption of 16U cubesats was prompted by Spire’s Space Services customers whose applications sometimes required more power, data downlink capacity and volume than Spire could offer with 6U cubesats.

Still, Spire does not make a sharp distinction between satellites gathering weather, maritime or aircraft tracking data for Spire products and Space Services satellites. In many cases, hardware and software for multiple customers fly on the same Spire satellites.

When Spire was founded in 2012, the company manufactured its own cubesats because few companies could meet its needs. Now, it’s the rapid iteration cycle that keeps the Vienna, Virginia-based company manufacturing satellites in-house.

“We’re constantly upgrading the technology both from a hardware perspective and a software perspective,” Spark said. “Customers want increasing volumes of data, and they generally want it more quickly.”

To speed up communications, Spire is equipping satellites with both optical and radio-frequency intersatellite links.

“We also preload our satellites with additional processing capability, more than we currently use,” Spark said. “By moving that data processing to the satellite, our customers have been able to do really incredible things.”

For example, Spire’s internal and Space Services customers are improving sensor performance with artificial intelligence. AI also helps satellites work together to monitor objects or areas of interest.

“It’s a brave new world in terms of people being able to use these sensors to do incredible things,” Spark said.

This article originally appeared in the August 2023 issue of SpaceNews magazine.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...