HOUSTON — Is it time to go back to Neptune?

Scientists representing NASA’s Jet Propulsion Laboratory proposed a spacecraft and mission on Tuesday at the Lunar and Planetary Science Conference in Texas that would explore Triton, Neptune’s largest moon.

The unusual satellite is believed to be an object — similar in many ways to Pluto — from the solar system’s icy Kuiper belt that was captured billions of years ago by the giant planet’s gravity. And Triton is thought to harbor an ocean, hinting at the possibility that a world quite distant from the sun may contain the ingredients for life.

Unlike multibillion dollar proposals for spacecraft that the agency has usually sent to the outer solar system, this spacecraft, named Trident, aims to be far less expensive, the mission’s scientists and engineers said, or the price of a small mission to the moon.

“The time is now to do this mission,” said Louise Prockter, director of the Lunar and Planetary Institute in Houston and the principal investigator of the proposed mission. “The time is now to do it at a low cost. And we will investigate whether it is a habitable world, which is of huge importance.”