A key benefit to the scientific community of a pathfinder to 542 AU is calibration data for an array of instruments on a flagship probe to interstellar space. There are fundamental processes and parameters of the near interstellar medium, whose estimated range of values could be greatly narrowed by in-situ sampling from a fast and small mission. By selecting an angle relative to the sun, plane of the ecliptic and a scientifically interesting target (such as Trappist-1), it is possible to perform initial optical measurements from the Solar Gravitational Lens (SGL) focal region on the same pathfinder. Doing so provides a basic set of data for larger follow-on missions to observe that (and other) solar systems in greater detail. By combining the datasets from 2 solar cycles (22 years) of space weather monitoring satellites, Voyager 1 and other deep space probes, the Practical Interplanetary Propulsion (PIP) Study constructed a radial profile for the solar wind ranging from 1 AU through the foreshock at 83 AU, to a notional heliopause at 123 AU, and the near interstellar medium out to 1,800 AU. The resulting matrix of plasma parameters was applied to a trajectory model “seed code,” to test flight paths for future probes. This paper presents an example pathfinder, consisting of a cubesat bus equipped with a Wind Rider propulsion system and radioisotope power system (RPS). A brief description of those subsystems and how they interact with the solar wind or interstellar medium is included. Trajectory simulation results estimate the trip time from 1 to 542 AU near the plane of the ecliptic takes 6.9 years. Adding a compact imaging instrument enables the probe to sample data from the vantage point of the Trappist-1 SGL, as well as PickUp Ions (PUI) for a 1 year science campaign. Total pathfinder mission time after launch is less than 8 years. A set of policy-making recommendations for enabling such small precursor-type missions is provided in the conclusions, as well as ways to extend the mission to communicate from 1,000 AU to 1,800 AU. Alternatively, a method to gradually decelerate to a near stop at the end of the mission, using the Wind Rider to drag against the interstellar plasma, is also included.