MUPUS

MUPUS
Name	MUPUS
Mission	Rosetta
Operator	European Space Agency
Manufacturer	Institute for Space Astrophysics and Planetology
Launch	2 March 2004
Launch vehicle	Ariane 5
Mass	30 kg (instrument package)
Type	Surface science package

MUPUS.

MUPUS was a surface science instrument package delivered to the surface of 67P/Churyumov–Gerasimenko by the Philae lander during the Rosetta mission managed by the European Space Agency. Developed by teams at the Institute for Space Astrophysics and Planetology and partner institutions including DLR and Max Planck Institute for Solar System Research, MUPUS was designed to measure thermal, mechanical, and physical properties of the nucleus of 67P/Churyumov–Gerasimenko to complement imaging by instruments such as OSIRIS and compositional data from ROSINA. The package contributed to multinational efforts linking observations from ESA and collaborators including NASA to characterize cometary processes relevant to planetary formation debates involving Nice model and Grand Tack hypothesis scenarios.

Overview

MUPUS was conceived within the context of post-Giotto comet exploration and contemporaneous with missions like Deep Impact and Stardust. It formed part of Philae's science complement alongside instruments such as CIVA, APXS, and CONSERT. The instrument suite aimed to determine surface thermophysical parameters, mechanical strength, and subsurface layering at the landing site near Agilkia and subsequently at Abydos. The project involved collaborations among institutions in Germany, Italy, Poland, and Russia, integrating expertise from laboratories tied to Max Planck Society and universities active in planetary science research.

Design and Instruments

MUPUS combined several sensor types into one compact assembly to meet Philae mass and power constraints. Key components included a hammering probe, a thermal probe, and temperature sensors. The hammering mechanics were engineered to perform impact tests to derive mechanical strength and porosity, analogous to experiments on earlier hardware like Viking landers and pneumatic penetrometers developed for Mars Pathfinder. Thermal instrumentation featured a heat-flow sensor intended to measure thermal conductivity and inertia, building on heritage from instruments such as Huygens probe thermal sensors. Electronics and data handling interfaces were integrated with Philae avionics provided by Astrium contractors and backed by calibration from facilities at DLR and the Italian Space Agency laboratories.

Mission Deployment on Comet 67P

Philae's descent and touchdown sequence in November 2014 placed MUPUS into contact with the nucleus. The planned operations anticipated plunge into Agilkia; after unexpected rebound events caused Philae to relocate to Abydos, the instrument deployment faced altered mechanical conditions. Command sequences were sent via Rosetta relay, with coordination from ESOC and science planning centers including ESA/ESAC and partners at DLR Oberpfaffenhofen. In the initial operational window, MUPUS performed hammering and thermal measurements as part of a coordinated campaign with CONSERT, SESAME, and optical monitoring by OSIRIS and ROSETTA NAVCAM. Limited battery life influenced the cadence and duration of surface experiments.

Scientific Results

MUPUS produced measurements that constrained thermal conductivity, heat capacity, and near-surface layering, informing interpretations about volatile retention and dust mantle properties. Data demonstrated low thermal inertia consistent with a highly porous, insulating layer, supporting models proposed in studies by researchers associated with Max Planck Institute for Solar System Research and University of Bern. Mechanical tests suggested a range of surface strengths indicating crustal heterogeneity, which correlated with morphological units mapped by OSIRIS and terrain analyses by teams linked to CNES and INAF. MUPUS findings fed into interpretations of comet activity observed during perihelion passages tracked by Rosetta and compared against outgassing measurements from ROSINA and dust flux data from GIADA.

Engineering and Operational Challenges

MUPUS operations contended with constraints imposed by Philae's unexpected resting orientation and limited solar power, echoing challenges experienced by earlier landers like Phobos missions. Thermal probe deployment risks included inadequate coupling to the surface and potential contamination from regolith lofted during hammering; mitigation strategies were planned in operations centers at DLR and Italian Space Agency. Data loss and partial telemetry during relay passes to Rosetta required re-sequencing and prioritization of instrument packets overseen by ESA mission control and instrument PIs at institutions such as Max Planck Society affiliates.

Legacy and Impact

MUPUS contributed to a paradigm shift in understanding cometary surface mechanics and thermophysics, influencing instrument designs for subsequent concepts studied by ESA and NASA including future comet sample-return proposals and lander architectures explored by teams at JAXA and Roscosmos. Its dataset has been incorporated into comparative analyses with samples from Stardust and models of solar system small body evolution advanced by researchers at NASA Goddard Space Flight Center and Southwest Research Institute. The collaboration exemplified multinational instrument development practices linking agencies like ASI, DLR, and CNES and fostered proposals for payloads in programs such as Horizon 2061-era studies and decadal survey priorities referenced by NASA.

Category:Spacecraft instruments