NASA has funded an innovative Interworld Slingshot mission architecture concept designed to map solar system resources from tens of kilometers away using long-distance Raman spectroscopy. Proposed by the SETI Institute, the 300-kilogram spacecraft aims to evaluate lunar ice, asteroid ores, and Martian moon volatiles during high-speed interplanetary flybys.
The Interworld Slingshot Mission Architecture and Spacecraft Design
In-situ resource utilization remains a critical technical hurdle for expanding human presence beyond Earth. Sending dedicated probes to every near-Earth asteroid or lunar site carries a prohibitive cost. To solve this economic and logistical barrier, a new NASA Institute for Advanced Concepts grant explores a different path: deploying a single, relatively small spacecraft to survey multiple resource locations from a distance of tens of kilometers.
The proposal, titled the Interworld Slingshot, outlines an entire mission architecture rather than just a standalone instrument. The concept envisions a 300-kilogram spacecraft roughly the size of a household refrigerator when packed, designed to fit neatly into the Discovery class of missions. Powering the vehicle will be solar panels paired with an efficient solar electric propulsion system.
Utilizing orbital dynamics, the probe will employ gravity assists from celestial bodies to accelerate to speeds unattainable by conventional propulsion alone. This complex series of slingshots sets up a three-part tour across the solar system, targeting the Moon, a near-Earth asteroid, and the Martian system.
Probing Minerals With Long-Distance Raman Spectroscopy
At the technological heart of the proposal is Raman spectroscopy. When a material is struck by a laser, a tiny fraction of the scattered light interacts with its molecular bonds, shifting energy in a recognizable pattern. Scientists read this shifted light to obtain a molecular fingerprint
of the minerals present.
While instruments like SuperCam and SHERLOC have utilized Raman spectroscopy on Mars aboard the Perseverance rover, those devices must operate from a distance of a few meters from rocks. The Interworld Slingshot proposal aims to perform the exact same analysis from a standoff distance of 30 to 50 kilometers while traveling at interplanetary speeds. According to the agency, no existing sensor or mission class currently performs this function.
Achieving this capability requires overcoming staggering engineering hurdles. Operating the technique at a distance of tens of kilometers demands an extreme signal processing setup, physical hardware stabilization, a high-energy pulsed laser, a time-gated photon-counting detector, and a rad-class beam steering system to isolate the Raman signals from planetary surfaces without blurring.
A Three-Part Tour of the Moon, Asteroids, and Martian Moons
The reference mission concept maps out three distinct reconnaissance legs utilizing a single solar electric propulsion spacecraft. The journey begins with a 50-kilometer polar orbit of the Moon, where the spectroscope will map water ice and ilmenite. Ilmenite is a titanium-iron oxide that can be processed into breathable oxygen for astronauts and utilized to manufacture rocket fuel.
Following its lunar survey, the probe will execute a 30-kilometer flyby of a near-Earth asteroid. During this leg, the spacecraft will attempt to identify silicates, metals, and valuable organics like methane that could supply future space miners.
For the final phase, the spacecraft will settle into a 30 to 50-kilometer orbit around either Phobos or Deimos. There, it will detect volatile-rich phases that can inform future Mars mission logistics.
Study Goals, Team Expertise, and Future Implications
The current Phase I study focuses on answering three core technical questions to determine overall feasibility: whether key mineral Raman lines can be detected with adequate signal-to-noise ratios from 50 kilometers, if beam pointing and smear can be stabilized during rapid flybys, and whether a 300-kilogram spacecraft can successfully close its mission architecture across all three destinations.
The study team brings together specialists in Raman instrumentation, spaceborne lidar, and mission design. Pablo Sobron Sanchez led field Raman systems operating at a 120-meter range and contributed to instrument development on Mars rovers. Researchers from NASA Goddard bring direct heritage from ICESat-2 and other orbital laser systems, while experts from NASA Ames guide early mission design, supported by commercial partner OffWorld.
If successful, the concept will establish a cost-effective Discovery-class template. This architecture could eventually scale into a fleet of inner solar system scouts, bringing Landsat-style mineral intelligence to planetary exploration, shaping Artemis siting decisions, and guiding future resource planning.
Worth a look
