Mission to GanymedeDIFFRACTION CAMERA SEEKINGDIFFRACTION CAMERA SEEKING FOR FOR

THE MICROORGANISMS’ TRACES THE MICROORGANISMS’ TRACES ON GANYMEDEON GANYMEDE

Leonid KsanfomalityLeonid Ksanfomality

Space Research Institute RAS, Profsoyuznaya 84/32, Space Research Institute RAS, Profsoyuznaya 84/32, 117997, Moscow, Russia 117997, Moscow, Russia

ksanf@iki.rssi.ru, ksanf@iki.rssi.ru,

Ganymede Workshop, March 5-7, 2013

An ongoing problem of space experiments is the An ongoing problem of space experiments is the conflict between a large volume of scientific conflict between a large volume of scientific information and limited technical capacity of a radio information and limited technical capacity of a radio link. Despite a search for hypothetical microorganisms link. Despite a search for hypothetical microorganisms by television microscopy method may be a most by television microscopy method may be a most productive way, in the case of lander for the study of productive way, in the case of lander for the study of Jupiter's moons, both the large volume and number of Jupiter's moons, both the large volume and number of microscopic images makes it problematic due to the microscopic images makes it problematic due to the huge information ammount to be returned to the Earth. huge information ammount to be returned to the Earth. It is expected that the concentration of hypothetical It is expected that the concentration of hypothetical microorganisms in soil or ice will be very low; so much microorganisms in soil or ice will be very low; so much a large part of the transmitted information would be a large part of the transmitted information would be useless. To solve these problems is proposed a useless. To solve these problems is proposed a DIFFRACTION CAMERA experiment, which uses a new DIFFRACTION CAMERA experiment, which uses a new physical principle permitting to find wanted micro-physical principle permitting to find wanted micro-objects automatically and to use the radio link channel objects automatically and to use the radio link channel for meaningful information only.for meaningful information only.

The method is based on a little-known optical principle, The method is based on a little-known optical principle, associated with the phenomenon of diffraction. When associated with the phenomenon of diffraction. When coherent light falls on a thin layer of the medium (such as a coherent light falls on a thin layer of the medium (such as a flat micro cuvettes), particles included in it, form diffraction flat micro cuvettes), particles included in it, form diffraction rings on a screen located behind the medium. In the rings on a screen located behind the medium. In the proposed method the screen is a CCD. Diffraction camera proposed method the screen is a CCD. Diffraction camera runs as a detector of objects, which concentration is low, runs as a detector of objects, which concentration is low, and determine their position and size using emerging and determine their position and size using emerging rings. If the laser beam encounters a small obstacle on the rings. If the laser beam encounters a small obstacle on the micro cuvettes, diffraction patterns occur on the CCD. The micro cuvettes, diffraction patterns occur on the CCD. The resulting image of the rings is not subject for radio resulting image of the rings is not subject for radio transmission, but the location of the rings is used to transmission, but the location of the rings is used to calculate the coordinates of each heterogeneity particle in calculate the coordinates of each heterogeneity particle in the medium (e.g., microorganisms). the medium (e.g., microorganisms).

Image of the Image of the cuvettes field for analysiscuvettes field for analysis

The measurement process The measurement process consists of two steps.consists of two steps.

Step 1: to find and check the Step 1: to find and check the emerging diffraction rings. The emerging diffraction rings. The laser beam scans progressively a laser beam scans progressively a target. Rings are registered by the target. Rings are registered by the CCD 1.CCD 1.

Since the angle Since the angle =1.22=1.22// and and RR//L L (since R << L), the (since R << L), the taken distance L = 50 mm provides the first diffraction ring taken distance L = 50 mm provides the first diffraction ring with with the the radius R = 1.9 mm for an object having the size D = 28 mum, radius R = 1.9 mm for an object having the size D = 28 mum, observed at a wavelength λ = 0.9 mum. The range of sizes 0.9-observed at a wavelength λ = 0.9 mum. The range of sizes 0.9-28 mum corresponds approximately to the averaged size of 28 mum corresponds approximately to the averaged size of Earth’ bacteria. The image of the field with detected rings is used Earth’ bacteria. The image of the field with detected rings is used for calculation of coordinates of the wanted objects.for calculation of coordinates of the wanted objects.

Scheme of producing of diffraction rings ("Step 1"), Scheme of producing of diffraction rings ("Step 1"), and scanning of selected areas of the image based on and scanning of selected areas of the image based on the analysis of the position of rings ("Step 2").the analysis of the position of rings ("Step 2").

Then the step 2 starts. Then the step 2 starts.

The LEDs light and diagonal mirror The LEDs light and diagonal mirror are introduced into the are introduced into the measurement channel. Laser and measurement channel. Laser and CCD 1 are disabled. The lens and CCD 1 are disabled. The lens and CCD 2 operate. The LED lights and CCD 2 operate. The LED lights and mirror are attached to the flexible mirror are attached to the flexible plate which avoids mechanical plate which avoids mechanical sliding or rotation.sliding or rotation.

LED light illuminates the cuvettes. The lenses built image of the cuvettes LED light illuminates the cuvettes. The lenses built image of the cuvettes on the CCD 2. Only small selected areas of the image of the micro on the CCD 2. Only small selected areas of the image of the micro cuvettes produced on the CCD 2 are to be scanned. Selected fragments cuvettes produced on the CCD 2 are to be scanned. Selected fragments of the micro image are memorized and transmitted by the radio link. Of of the micro image are memorized and transmitted by the radio link. Of course, the detected objects not necessarily are bacteria. Would the unit course, the detected objects not necessarily are bacteria. Would the unit been equipped by the artificial intellect, the images of inclusions of been equipped by the artificial intellect, the images of inclusions of known inorganic nature will not be transmitted. Shown in the figure known inorganic nature will not be transmitted. Shown in the figure refers to the protection of a particular project study of Jupiter's moons, refers to the protection of a particular project study of Jupiter's moons, located in the radiation belts.located in the radiation belts.

Technical characteristics of the diffraction camera depend on Technical characteristics of the diffraction camera depend on the task. For the mission to the moons of Jupiter, according the task. For the mission to the moons of Jupiter, according to the conceptual design, the power consumption of the to the conceptual design, the power consumption of the camera is 3 W, and the mass of the device about 0.8 kg. For camera is 3 W, and the mass of the device about 0.8 kg. For the example shown above, the file to be only 2 KB (with a the example shown above, the file to be only 2 KB (with a software image compression).software image compression).

LiteratureLiteratureBorn, M. and Wolf, E., Principles of Optics, 6-th edition, Pergamon Press Born, M. and Wolf, E., Principles of Optics, 6-th edition, Pergamon Press Ltd., 1980, pp.370-458Ltd., 1980, pp.370-458..

Ganymede Workshop, March 5-7, 2013

If the microflora on Ganymede exists, it If the microflora on Ganymede exists, it should be present inevitably as traces in solid should be present inevitably as traces in solid ice of the surface, in inactive, or, may be, in a ice of the surface, in inactive, or, may be, in a latent form. Liquid solution in cracks is latent form. Liquid solution in cracks is delivered to the surface and gets solid. It is delivered to the surface and gets solid. It is supposed that a pattern will be studied in a supposed that a pattern will be studied in a liquid form having a low concentration of the liquid form having a low concentration of the microflora traces. An experiment with a usual microflora traces. An experiment with a usual microscope requires a huge amount of the microscope requires a huge amount of the information to be returned, that is impossible information to be returned, that is impossible for technical reasons. for technical reasons. To solve the problem To solve the problem the DIFFRACTION CAMERA experiment is the DIFFRACTION CAMERA experiment is proposed.proposed.