The InSight HP3 Penetrator (Mole) on Mars: Soil Properties Derived from the Penetration Attempts and Related Activities

The NASA InSight Lander on Mars includes the Heat Flow and Physical Properties Package HP³ to measure the surface heat flow of the planet. The package uses temperature sensors that would have been brought to the target depth of 3-5 m by a small penetrator, nicknamed the mole. The mole requiring friction on its hull to balance remaining recoil from its hammer mechanism did not penetrate to the targeted depth. Instead, by precessing about a point midway along its hull, it carved a 7 cm deep and 5-6 cm wide pit and reached a depth of initially 31 cm. The root cause of the failure - as was determined through an extensive, almost two years long campaign - was a lack of friction in an unexpectedly thick cohesive duricrust. During the campaign - described in detail in this paper - the mole penetrated further aided by friction applied using the scoop at the end of the robotic Instrument Deployment Arm and by direct support by the latter. The mole tip finally reached a depth of about 37 cm, bringing the mole back-end 1-2 cm below the surface. It reversed its downward motion twice during attempts to provide friction through pressure on the regolith instead of directly with the scoop to the mole hull. The penetration record of the mole was used to infer mechanical soil parameters such as the penetration resistance of the duricrust of 0.3-0.7 MPa and a penetration resistance of a deeper layer ( > 30 cm depth) of 4.9 ± 0.4 MPa . Using the mole's thermal sensors, thermal conductivity and diffusivity were measured. Applying cone penetration theory, the resistance of the duricrust was used to estimate a cohesion of the latter of 2-15 kPa depending on the internal friction angle of the duricrust. Pushing the scoop with its blade into the surface and chopping off a piece of duricrust provided another estimate of the cohesion of 5.8 kPa. The hammerings of the mole were recorded by the seismometer SEIS and the signals were used to derive P-wave and S-wave velocities representative of the topmost tens of cm of the regolith. Together with the density provided by a thermal conductivity and diffusivity measurement using the mole's thermal sensors, the elastic moduli were calculated from the seismic velocities. Using empirical correlations from terrestrial soil studies between the shear modulus and cohesion, the previous cohesion estimates were found to be consistent with the elastic moduli. The combined data were used to derive a model of the regolith that has an about 20 cm thick duricrust underneath a 1 cm thick unconsolidated layer of sand mixed with dust and above another 10 cm of unconsolidated sand. Underneath the latter, a layer more resistant to penetration and possibly containing debris from a small impact crater is inferred. The thermal conductivity increases from 14 mW/m K to 34 mW/m K through the 1 cm sand/dust layer, keeps the latter value in the duricrust and the sand layer underneath and then increases to 64 mW/m K in the sand/gravel layer below.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11214-022-00941-z.

[A Systematic Review of Personality Disorders and Addiction: Epidemiology, Course and Treatment]

AIM

This paper provides a systematic overview of the comorbidity of personality and addictive disorders including behavioural addictions.

METHOD

Systematic review.

RESULTS

Personality disorders and substance-related addictions show high comorbidity rates. This is equally true of behavioural addictions. Most empirical research is on comorbidity with borderline personality disorder. For treatment of individuals with dual diagnoses, three psychotherapies have been demonstrated to be effective. Pharmacotherapeutic approaches have hardly been investigated.

CONCLUSION

METHODologically integrative treatment represents therapy of choice for patients with dual diagnoses. Comorbidity of personality disorders and behavioural addictions needs further investigation.

[Psychiatry with open doors. Part 1: Rational for an open door for acute psychiatry]

Despite the reform efforts of the last decades modern acute psychiatry still stands between conflicting priorities in everyday practice. The protection of patient autonomy might conflict with a regulatory mandate of psychiatry in societal contexts and the necessity of coercive measures and involuntary treatment might become problematic with respect to presumed but contentious interests of the patient. The conflicts particularly concern questions of involuntary commitment, door closing, coercive and isolation measures. Research on the topic of therapeutic effectiveness of these practices is rare. Accordingly, the practice depends on the federal state, hospital and ward and is very heterogeneous. Epidemiological prognosis predicts an increase of psychiatric disorders; however, simultaneously in terms of medical ethics the warranty of patient autonomy, shared decision-making and informed consent in psychiatry become increasingly more important. This challenges structural and practical changes in psychiatry, particularly in situations of self and third party endangerment which are outlined and a rationale for an opening of the doors in acute psychiatric wards is provided.

[Ego identity and self-concept problems in children of psychotic parents. Results of a qualitative cross-sectional study]

OBJECTIVE

In contrast to previous high-risk studies of children of parents suffering from psychosis a new approach to the difficulties of affected children will be tested, using the linguistic and narrative tools of biography studies.

METHODS

The transcribed texts of biographical interviews of affected children will be analysed linguistically and hermeneutically through "close reading".

RESULTS

The linguistic and interpretative study of these texts will demonstrate the children's specific problem of identity-formation and their construction of reality and biography through the order of language (as shown by their uses of metonymy and metaphor).

CONCLUSIONS

By using the method of biographical research a) the creative potential of patients and their children is exposed, b) a qualified view of mental illnesses can be reached in the field of symbolic practice.