The concept is being developed as a potential large strategic science mission for NASA by a team led by the Applied Physics Laboratory at Johns Hopkins University.

An orbiter to Neptune was considered as part of the aborted Mariner Mark II program in the 1990s, and several mission concepts for an orbiter were developed in the 2000s, including a concept by the California Institute of Technology[4] and a version by the University of Idaho and Boeing,[5] though none were selected for further development.

The 2011-2022 Planetary Science Decadal Survey recommended a Flagship-class orbiter mission to an ice giant with priority behind what would become the Mars 2020 rover and the Europa Clipper.

NASA's Trident was a finalist for selection as a Discovery mission in 2020, with a proposed launch in 2025 and an intent to focus on Triton.

[14] In June 2021, it was announced that Trident was not selected for development and launch,[15] while Interstellar Express is yet to be approved by CNSA.

Both a static lander similar to the Huygens probe to Titan and an impactor that would release surface material for direct study by the orbiter were considered.