Sub-Neptune targets of the SPACE program. HD 86226c is shown with a green square marker, and the other SPACE targets are shown in purple. Top: temperature-radius plane. Gray circles show the known population of planets with radii between 1.8 R_⊕ and 4 R_⊕ based on the entries of the NASA Exoplanet Archive³ in May 2024. Black crosses mark JWST Cycle 1–4 targets, except for the SPACE targets TOI-431 d and HD 86226 c, which will be observed in Cycle 4. Bottom: mass-radius plane. Color curves show models from Zeng et al. (2019) for various planetary compositions and temperatures.