Regular, low-cost Decadal-class science missions to planetary destinations will be enabled by high-ΔV small spacecraft, such as the high-energy Photon, and small launch vehicles, such as Electron, to support expanding opportunities for scientists and to increase the rate of science return. The Rocket Lab mission to Venus is a small direct entry probe planned for baseline launch in May 2023 with accommodation for a single ~1 kg instrument. A backup launch window is available in January 2025. The probe mission will spend about 5 min in the Venus cloud layers at 48–60 km altitude above the surface and collect in situ measurements. We have chosen a low-mass, low-cost autofluorescing nephelometer to search for organic molecules in the cloud particles and constrain the particle composition.

Regular, low-cost Decadal-class science missions to planetary destinations enabled by small high-ΔV spacecraft, like the high-energy Photon, support expanding opportunities for scientists and increase the rate of science return.The high-energy Photon can launch on Electron to precisely target escape asymptotes for planetary small spacecraft missions with payload masses up to ~50 kg without the need for a medium or heavy lift launch vehicle.The high-energy Photon can also launch as a secondary payload with even greater payload masses to deep-space science targets.This paper describes planetary mission concepts connected to science objectives that leverage Rocket Lab's deep space mission approach.The high-energy Photon can access various planetary science targets of interest including the cislunar environment, Small Bodies, Mars, Venus, and the Outer Planets.Additional planetary small spacecraft missions with focused investigations are recommended, including dedicated small spacecraft missions that do not rely on launch as a secondary payload. HIGH-ENERGY PHOTONThe high-energy Photon (Figure 1) is a self-sufficient small spacecraft capable of long-duration interplanetary cruise.Its power system is conventional, using photovoltaic solar arrays and lithium-polymer secondary batteries.The attitude control system includes star trackers, sun sensors, an inertial measurement unit, three reaction wheels, and a cold-gas reaction control system (RCS).S-band or X-band RF ranging transponders support communications with the Deep Space Network or commercial networks and traditional deep space radiometric navigation methods.A Global Position System (GPS) receiver is used for navigation near Earth.ΔV greater than 4 km/sec is provided by a storable, re-startable bi-propellant propulsion system called Hyper Curie using electric pumps to supply pressurized propellant to a thrust vector-controlled engine.The propellant tanks achieve high propellant mass fraction and can be scaled to meet mission-specific needs.