26/09/2017

HABIT Engineering Model delivered


Credits: Atmospheric Science Group

The Engineering Model of HABIT (Habitability, Brines, Irradiation and Temperature) instrument was recently brought to Atmospheric Science Group’s headquarters at Luleå University of Technology, by representatives of the company in charge of its building, Omnisys. The model, which is getting closer and closer to the final design, will be submitted to a long, thorough and intense series of tests from now on, both in the Group’s lab and in field-site campaigns.

Detail of the ultraviolet sensors on ENVPACK unit.
Credits: Linda Alfredsson

The Engineering Model (EM) is the second phase along the development and manufacturing of any space qualified instrument or device, a process which is carefully divided in more or less standard stages to ensure the optimal output of the efforts and money invested in it. After EM, there are two more steps before getting the ultimate Flight Model (FM, which is finally launched to space): the Engineering Qualification Model (EQM), and the Proto Flight Model. EM is also a confirmation of the appropriate coupling between the engineering team responsible for the embodiment of the instrument and the scientific team which conceived it.
At this point, HABIT has acquired a configuration quite similar to that the final instrument will show; their dimensions, shape, and mass are very close to those the FM will have, though some further modifications derived from the integration on the spacecraft requirements can be expected, mostly regarding the mechanical design.
HABIT EM is made of aluminium, and its BOTTLE unit is already coated with gold, since the inner surface of the salt vessels and the electrodes in them have to be in contact with corrosive brines (the goal of this unit is to measure changes in conductivity related to the amount of water absorbed by the salts from the atmosphere). There are some flight-grade components already included in the instrument, though others are commercial ones, as is the case of electronic components for instance. As for the ENVPACK unit, it mounts ultraviolet sensors (UVS), three air temperature sensors (ATS, whose data will eventually be used to characterize the Martian wind regime as well), and a ground temperature sensor (GTS). All of them are similar to those to be installed on the final FM.
Inmediately after the arrival and official unboxing of HABIT EM, which was carried out by the representatives who handed it in, a first set of tests was performed in INSPIRE Lab to check the proper functioning of the device and all its components. Apart from the verification of the correct performance of each of the sensors, this initial trial has served to point at some improvements to be implemented in the further development stages, and also to implement some preliminary calibrations before proceeding with the second test phase, which will consist of a field-site validation. This latter will take place during the NASA’s Spaceward Bound 2017 campaign, which on this occasion has been organised together with the UK Centre for Astrobiology (UKCA), encompassing the 5th Mine Analog Research (MINAR) campaign, which this institute holds at Boulby mine, England.
During this campaign, all HABIT EM’s sensors will be simultaneously and continuously working, in a simulation of the operating conditions on Mars, and the results obtained will be the basis for the next series of more delicate tests dedicated to each sensor separately and then to the whole assembly.


BOTTLE unit (salt vessels),and some of the tests HABIT EM was submitted to in INSPIRE lab.
Crecits: Atmospheric Science Group