The interstellar heliopause probe technology reference study Original Research Article

The interstellar heliopause probe (IHP) is one of ESA’s technology reference studies (TRS). The TRS aim to focus the development of strategically important technologies of relevance to future science missions by studying technologically demanding and scientifically interesting missions that are currently not part of the science mission programme. Equipped with a highly integrated payload suite (HIPS), the IHP will perform in situ exploration of the heliopause and the heliospheric interface. The HIPS, which is a standard element in all TRSs, miniaturize payloads through resource reduction by using miniaturized components and sensors, and by sharing common structures and payload functionality. To achieve the scientific requirements of the mission, the spacecraft is to leave the heliosphere as close to the heliosphere nose as possible and reach a distance of 200 AU from the Sun within 25 years. This is possible by using a trajectory with two solar flybys and a solar sail with characteristic acceleration of 1.1 mm/s2, which corresponds to a 245 × 245 m2 solar sail and a sail thickness of 1–2 μm. The trajectory facilitates a modest sail design that could potentially be developed in a reasonable timeframe. In this paper, an update to the results of studies being performed on this mission will be given and the current mission baseline and spacecraft design will be described. Furthermore, alternative solar sail systems and enabling technologies will be discussed.