WASHINGTON — Airbus and the French Space Agency CNES have agreed to cofinance a constellation of four Earth observation satellites while leaving the door open for Airbus to finance additional satellites with other partners.

The four satellites, referred to as the CO3D system, are expected to launch in 2022 aboard a Vega C rocket, with each satellite capable of imaging the Earth at a resolution of 50 centimeters.

In an interview, Philippe Pham, Airbus Space Systems’ head of Earth observation, navigation and science, said CNES is investing just under 100 million euros ($112 million) into the four satellites. Airbus is supplying “a bit more than the equivalent,” he said.

Pham said Airbus views the contract as a steppingstone to a larger constellation of “20-plus” satellites.

“We designed it as a constellation with capacity building to a ‘mini-constellation’ using the same design,” he said.

The CO3D satellites will each have a mass of 300 kilograms, and will use all-electric propulsion. The constellation is dual purpose: providing imagery to the French government, including scientific and military users, and imaging capacity for Airbus to commercialize.

Pham said Airbus’ desire to quickly expand on the initial four-satellite constellation stems from demand for faster revisit rates to image areas of customer interest. More CO3D satellites can put Airbus on the same footing as Maxar Technologies’ DigitalGlobe division and its future WorldView Legion constellation.

Maxar Technologies is targeting a revisit rate of 40 times a day for select parts of the world with WorldView Legion, a constellation of small imaging satellites whose first launch is in late 2020 or early 2021. Maxar Technologies hasn’t said how many satellites will comprise WorldView Legion, though a December FCC filing suggests it could be as many as 12.

Pham said Airbus can be “in the very same range as Maxar” with its current satellites: the 1.5-meter resolution Spot-6 and Spot-7, the 50-centimter resolution Pleiades-1A and -1B , the four 30-centimeter resolution Pleiades Neo satellites it is building now, plus a number of CO3D satellites. He did not quantify that number.

Airbus is looking for customers and partners to jointly invest in future CO3D satellites, he said. What form those investments take can vary.

“It is a mix of Airbus investment plus customers wanting to buy in. It could be a satellite, launch system, etcetera, but also access to services,” he said. “It’s a more case-by-case discussion with customers, with partners, to have some specific partnership or contracting conditions to further extend the constellation and the capacities in orbit, and to deliver data.”

The timing of the constellation expansion is linked to future co-investors, he said.

Pham said it is too early to determine if the July 10 failure of a Vega rocket will delay the first CO3D launch, which uses the next-generation Vega C. As of May, Vega C’s maiden flight was scheduled for March 2019 with a science satellite for the Italian Space Agency called Lares-2.

Italian rocket builder Avio manufacturers the Vega and Vega C launchers, which share the same Zefiro-9 third stage booster. Initial indications suggest the July 10 failure was related to Vega’s Zefiro-23 second stage booster, which will be replaced on Vega C with the more powerful Zefiro-40. Avio, Arianespace, and the French and European space agencies have not yet determined the cause of the launch failure.

Airbus’s four Pleiades Neo satellites are or were scheduled to launch in pairs, one in July 2020 and the second in early 2022 on Vega C missions, Pham said.

Pham said the Pleiades Neo and CO3D satellites are designed to be compatible with multiple Arianespace launchers, and that Airbus has included the ability to switch vehicles if necessary into those launch contracts.

“We have a backup policy with the launch authorities, so we will do all our efforts to remain on time and to get it done as planned,” he said.

Four CO3D satellites will take up half the space in a Vega C payload fairing, Pham said. He added that Airbus is closely following the development of small launch vehicles that could carry future CO3D satellites on dedicated missions.

Pham said Airbus is working with ground station operators Swedish Space Corporation and KSAT on strengthening their antenna networks to provide more links, particularly at medium latitudes. Airbus plans to rely on those networks to downlink imagery from the CO3D satellites.

Airbus and CNES plan to use data from the CO3D satellites to create a 3D map of the Earth’s landmass. CNES President Jean-Yves Le Gall hailed the program as one that “embodies French ambition and ingenuity.”

“It will allow a higher refresh rate, improved performance and better resilience,” he said. “This partnership between CNES and Airbus perfectly illustrates French excellence in Earth observation from space.”