Overview
- The arXiv trade study from JPL’s Slava Turyshev rules out chemical rockets for a timely SGL mission and evaluates solar sails, nuclear electric propulsion (NEP), nuclear thermal propulsion (NTP), and hybrids for a 2035–2040 concept.
- Sun‑skimming sails with ~0.05 AU perihelion could enable ~20–30 year transits but demand ultra‑light, heat‑tolerant materials and face mass penalties from required onboard power at hundreds of AU.
- A NEP design carrying about an 800 kg payload on a ~20‑ton spacecraft is estimated to reach ~650 AU in roughly 27–33 years, with radiator size and waste‑heat rejection as dominant engineering constraints.
- A hybrid using NTP for high‑thrust maneuvers such as an Oberth pass and NEP for cruise may allow sub‑20‑year travel times, though both propulsion systems require significant maturation.
- Science operations would proceed along the SGL focal line rather than at a fixed point, giving essentially one imaging opportunity per target and necessitating precise preselection and non‑solar power.