[4] Photon first launched in August 2020 on Rocket Lab's I Can't Believe It's Not Optical mission, where it served as a pathfinder.

[11][12] The company announced it was targeting lunar orbit as part of its services, enabled by a bi-propellant propulsion system.

[13][14] The development of Photon included working with potential customers, with significant interest from government agencies.

[11] The first few Photon satellites would be technology demonstrators before transitioning to operational launches for customers, which started with NASA's CAPSTONE cubesat in June 2022.

[11] Rocket Lab planned to launch Photon to Venus in December 2025, delivering a laser-tunable mass spectrometer to the Venusian atmosphere.

A modified version of Photon has bigger propellant tanks and the HyperCurie engine for interplanetary missions.

[16] Pathstone operations were aimed at building flight heritage and focused on testing systems in preparation for launching NASA's CAPSTONE smallsat mission in June 2022.

[23][16] These tests included power and thermal management, attitude control via reaction wheels and communications systems.

After completing all the mission requirements for NASA, Rocket Lab utilised its Photon spacecraft for a low-altitude lunar flyby.

Pioneer first took flight in 2023, supporting a mission for Varda Space Industries where the capsule atop the bus grew crystals of the drug ritonavir.

After growing the crystals and experiencing some regulatory hold-ups, the spacecraft returned to Earth and landed in Utah.

The goal is to send a probe to around 48 km altitude where Venus' atmospheric conditions are closer to those found on Earth.