Rocket Lab-built Mars smallsats arrive at launch site

Each of the twin spacecraft — called Blue and Gold after the colors of the University of California Berkeley, which will run the mission — weighs 524 kilograms

These days, anything under ~1 tonne or so is considered "small". Spacecraft like the Mars Reconnaissance Orbiter and Psyche were each over 2 tonnes at launch, and some geostationary communications satellites can be upwards of 10 tonnes and the size of a school bus.