Capabilities of Gossamer-1 derived small spacecraft solar sails carrying Mascot-derived nanolanders for in-situ surveying of NEAs

Abstract

Any effort which intends to physically interact with specific asteroids requires understanding at least of the composition and multi-scale structure of the surface layers, sometimes also of the interior. Therefore, it is necessary first to characterize each target object sufficiently by a precursor mission to design the mission which then interacts with the object. In small solar system body (SSSB) science missions, this trend towards landing and sample-return missions is most apparent. It also has led to much interest in MASCOT-like landing modules and instrument carriers. They integrate at the instrument level to their mothership and by their size are compatible even with small interplanetary missions.The DLR-ESTEC GOSSAMER Roadmap NEA Science Working Groups' studies identified Multiple NEA Rendezvous (MNR) as one of the space science missions only feasible with solar sail propulsion. Parallel studies of Solar Polar Orbiter (SPO) and Displaced L1 (DL1) space weather early warning missions studies outlined very lightweight sailcraft and the use of separable payload modules for operations close to Earth as well as the ability to access any inclination and a wide range of heliocentric distances. These and many other studies outline the unique capability of solar sails to provide access to all SSSB, at least within the orbit of Jupiter. Since the original MNR study, significant progress has been made to explore the performance envelope of nearterm solar sails for multiple NEA rendezvous.However, although it is comparatively easy for solar sails to reach and rendezvous with objects in any inclination and in the complete range of semi-major axis and eccentricity relevant to NEOs and PHOs, it remains notoriously difficult for sailcraft to interact physically with a SSSB target object as e.g. the HAYABUSA missions do.The German Aerospace Center, DLR, recently brought the GOSSAMER solar sail deployment technology to qualification status in the GOSSAMER-1 project. Development of closely related technologies is continued for very large deployable membrane-based photovoltaic arrays in the GOSOLAR project.We expand the philosophy of the GOSSAMER solar sail concept of efficient multiple sub-spacecraft integration to also include landers for one-way in-situ investigations and sample-return missions. These are equally useful for planetary defence scenarios, SSSB science and NEO utilization. We outline the technological concept used to complete such missions and the synergetic integration and operation of sail and lander. We similarly extend the philosophy of MASCOT and use its characteristic features as well as the concept of Constraints-Driven Engineering for a wider range of operations.

A radar package for asteroid subsurface investigations: Implications of implementing and integration into the MASCOT nanoscale landing platform from science requirements to baseline design

“…the bus mass would increase by about 10% with the addition of one relatively large instrument. If the carrier mission provides still more mass allowance, a set of multiple MASCOT type landers based on a common infrastructure but carrying different instruments and individually optimized for these can also be considered [49].…”

Solar Sails for Planetary Defense & High-Energy Missions

“…At the 2017 Planetary Defence Conference, a diversion from an ongoing MNR mission towards a fictitious newly discovered impactor, "2017 PDC", was studied (see [174] for details). Pre-impact rendezvous was not achieved from the reference scenario [10] but 2 potentially useful trajectories were found.…”

“…Total mission duration is ~12 years; arrival at 2011 AG 5 on May 25 th , 2037, about 3 years before impact. [174] It would be possible to combine MNR solar sail technologies, tuned and optimized for deflection trajectories [97][98][99] with parallel advances in kinetic impactor guidance technology [227][228][229][230] using small spacecraft concepts [123].…”

“…When all unnecessary standard equipment units are removed, payloads of 500 kg, 250 kg, and 50 kg, can respectively be injected on escape trajectories of c 3 ≈56 km²/s², 60 km²/s², and 64 km²/s². Still higher velocities can be achieved by adding upper stages similar to the launch configurations of NEW HORIZONS [174] or LISA Pathfinder. [231]…”

Membrane Deployment Technology Development at DLR for Solar Sails and Large-Scale Photovoltaics

“…We report on some of the options to design MNR missions and nano-landers carried by solar sails in [46][47] [48].…”