"Trumpet F/O" 1, 2, 3

The spacecraft are probably the replacement for the Trumpet ELINT satellites operating in a Molniya orbit. As no name is known, these are referred here as "Trumpet Follow On". Unlike the SDS-3 series of relay satellites, these are placed directly into the Molniya orbit, whereas the SDS-3 were placed at first in a lower interim transfer orbit.

These satellite most likely use a large, unfurlable dish antenna to collect the signals. Advances in both antenna and electronics technologies have polly allowed for a large reduction in size compared the Trumpet predecessors.

Secondary Payloads

Trumpet F/O 1 (or NROL 22) carried the first SBIRS-HEO-1 early warning package. It is also the host satellite for NASA's TWINS A (Two Wide-angle Imaging Neutral-atom Spectrometers) payload. The TWINS mission provides a new capability for stereoscopically imaging the magnetosphere. By imaging the charge exchange neutral atoms over a broad energy range (~1-100 keV) using two identical instruments on two widely spaced high-altitude, high-inclination spacecraft, TWINS will enable the 3-dimensional visualization and the resolution of large scale structures and dynamics within the magnetosphere. The TWINS instrument is based on the MENA instrument of the IMAGE satellite.

Trumpet F/O 2 (or NROL 28) is the host for the SBIRS-HEO-2 early warning package and the TWINS B scientific package.

Trumpet F/O 3 is likely the host for the SBIRS-HEO-3 early warning sensor.