smex

TRACE (Transition Region And Coronal Explorer) was a NASA space telescope designed to investigate the connections between fine-scale magnetic fields and the associated plasma structures on the Sun by providing high resolution images and observation of the solar photosphere and transition region to the corona. A main focus of the TRACE instrument is the fine structure of coronal loops low in the solar atmosphere. TRACE is a SMEX or SMall EXplorer mission, launched in 1998 and obtaining its last science image in 2010

FAST is the second of the Small-Class Explorer (SMEX) missions. It will investigate the plasma physics of the auroral
phenomena which occur around both poles of the earth. This will be accomplished by taking high data rate snapshots with electric
and magnetic fields sensors, and plasma particle instruments, while traversing through the auroral regions.