S A A R R O B I I MISSION TO TITAN
PROJECT ASSUMPTIONS SA SAROBI mission to to Tita tan Exploring the mysteries of the moon’s possible life and icy crust MISSION CHECKLIST: • analysing geological content ✔ • verification of the artificial life hypothesis ✔ • drilling into the surface of titan ✔
BIOCHEMISTRY OF TITAN • Surface area: 8.3 × 107 km 2 • Gravity: 1.352 m/s 2 (0.14g) • Temperature : 93.7 K ( − 179.5 °C) • Surface pressure: 146.7 kPa (1.45 atm) • Atmosphere composition : • Stratosphere: 98.4% nitrogen (N 2 ), 1.4% methane (CH 4 ), 0.2% hydrogen (H 2 ); • Lower troposphere: 95.0% N 2 , 4.9% CH 4
BIOCHEMISTRY OF TITAN • dissociation of the atmospheric N 2 and CH 4 creates an array of organic molecules in Titan’s atmosphere • these produce a solid organic haze in the upper atmosphere that obscures to the lower atmosphere and surface • ethane accumulates on the surface and mixes with liquid methane Are they the key to understanding life on Titan?
ALTERNATIVE LIFE • an article published in Science Advances in February 2015, conducted by scientists from Cornell University, has suggested the possibility of an alternative, nitrogen-based biochemistry • it would be possible for a structure of liquid methane membranes to exist and rely on the polarity of nitrogen-containing groups, identically as liposomes rely on the non-polarity of alkyl groups cryogenic AZOTOSOMES might have the flexibility of a lipid bilayer
AZOTOSOMES acrylonitrile
AZOTOSOMES • azotosome begins the simulation as a grid of molecules • self-assembles into its preferred structure • good thermodynamic stability, • high energy barrier to decomposition, • area expansion modulus similar to that of phospholipid cell membranes in oxygen-rich solutions • 10ppm concentration
high gain antenna low gain RTGs providing probe antenna power lander containing drill and rover + reaction wheels and monopropellant thrusters for attitude control radar altimeter and imaging cameras to map surface
parachute will detach at low altitude to prevent canopy falling on the lander airbags to cushion landing probe will scan surface of Titan in order to find suitable landing spot
tetrahedral Landing platform means it will unfold to the La Land nding ing correct orientation no matter which side it lands on platform
antenna for communication with orbiting probe ice-melting drilling device
heated side panels to • drilling device will use thermal heat from RTG or MMRTG reduce friction to heat both the drill head and side drilling device also equipped • drill head will melt ice below the device while side with low frequency radar panels ensure good lubrication reducing friction similar to that used to and the possibility of getting stuck penetrate the ice in Greenland by NASA • electrical energy will also be produced and used to operate the rotary motion of the drill head allowing removal of debris and heated rotary drill head cutting action • low frequency will be used to communicate with the lander above ground and also to scan its Drilling dev Dr evice surroundings features
ARMADILLO ROVER Spherical configuration , beyond the typical wheeled rover design • increased manoeuvrability and protection • can move in any direction it wants allowing it to turn sharply with no turning radius • able to reach places that a typical rover would not be able to traverse • any impacts experienced by the rover will be dissipated more evenly over the outer shell of the rover thus protecting its internal components from severe damage total mass = 320kg • smooth profile reduces the chances of the rover getting stuck diameter = 1m
ARMADILLO ROVER Titan’s surface at the Huygens landing site, 10.2 o S, 192.4 o W. There are at least eight rocks visible in the image – numbered in red with size indicated for two of them. Distance from the lander is shown in blue. Rocks are thought to be H 2 O ice mostly coated by organic solid material. Image from ESA
outer shell which rotates freely and outer cage will be made an inner cage housing all internal of see-through mesh, to components enable camera vision from the interior small spikes anchored on the outer cage will provide the rover with additional friction and impact protection Ar Armadillo illo rover ver internal cage will rotate through all features three axes through the use of 3 sets of wheels
�� ARMADILLO ROVER • for purpose of analysis 2D circle of same diameter considered • simplify problem into two point masses • outer shell mass positioned at centre of circle due to uniformity • mass of internal components with an undetermined position 𝐷𝑝𝐻 = ∑ 𝑁𝑝𝑛𝑓𝑜𝑢𝑡 𝑈𝑝𝑏𝑚 ¡𝑁𝑏𝑡𝑡 Fig1. Calculate CoG using center of circle as datum 𝜄 = cos 56 𝑒𝑗𝑡𝑞𝑚𝑏𝑑𝑓𝑛𝑓𝑜𝑢 ¡𝑝𝑔 ¡𝐷𝑝𝐻 CoG 𝑠𝑏𝑒𝑗𝑣𝑡 mass of the outer shell Fig1.5. Calculate maximum gradient mass of the inner shell + components 𝜄
CRITICAL ANALYSIS • assume uniform displacement over a segment of the circle parameterized by its radius r, and angle alpha • equation in figure 3 gives distance of the center of gravity of the segment and therefore the position of the internal component point mass • we will assume radius of segment is 0.45m to fit inside 1m radius with room left for rotation mechanism Fig3. Mass Distribution over Segment 4𝑠 ? si n( 𝛽) Fig4. Position of Centre of Gravity 3(2𝛽 − si n( 2𝛽))
CRYTICAL ANALYSIS • inner mass 50% of total mass • with an alpha value of 62.2 degrees a maximum gradient of 20 degrees can be achieved • if we increase the proportion of the total mass that is inside the rover then we can distribute the mass over a larger segment with the same maximum gradient • eg. at 60% inner mass, 20 degree gradient achieved with alpha of 74 degrees • larger values of alpha will make designing the internal components easier • this will also help with heat dissipation Fig5. Alpha of segment vs Maximum Gradient
ARMADILLO ROVER outer shell wheel actuator three sets of wheels for each axis of rotation allowing internals of rover to rotate freely within • wheels will be able to move in and out to engage and disengage contact with the outer shell • only one set of wheels in contact with outer shell at any one time
outer shell which rotates freely and outer cage will be made an inner cage housing all internal of see-through mesh, to components enable camera vision from the interior small spikes anchored on the outer cage will provide the rover with additional friction and impact protection Ar Armadillo illo rover ver internal cage will rotate through all features three axes through the use of 3 sets of wheels
top of the internal cage will serve as the navigation centre with a camera and topographical mapping tool bottom of the internal cage will be filled with analytical equipment of geological and biochemical nature (represented in red)
EQUIPMENT • ORBITRAP mass analyser and spectrometer • infrared camera in the top hemisphere of the rover • meteorology and physical properties package • robotic arm with a small drill and a heating surface • biochemical analysis chamber with dried nanoparticles
• https://www.atsdr.cdc.gov/toxprofiles/tp125-c6.pdf
BIOCHEMISTRY OF TITAN • search for a ‘polymeric information molecule’ for life in Titan liquids remains an open research topic • polyethers are a possible model for DNA substitute in non-polar hydrocarbon solvents • a two-letter code involving hydrogen bonding with polar molecules containing O and N • the structural substitutes for proteins might include hydrocarbon chains, aromatic ring structures, carbon nanostructures, including graphene
BIOCHEMISTRY OF TITAN • a set of biomolecules compatible with low-temperature methane and ethane liquids could be capable of the same sort of ecological communication and exchange that occurs on Earth • signalling molecules = low-molecular weight hydrocarbons that would be mobile in the Titan liquid • a Titan analogue to viruses could be possible with hydrocarbon shells encasing raw Titan genetic polymers that attach and then insert the genetic polymers into host organisms
POLYIMINE • previous experiments suggested that hydrogen cyanide molecules often link together to form a compound known as polyimine • might support prebiotic chemistry in the ultracold temperatures on Titan • can absorb a wide spectrum of light, including wavelengths that can penetrate Titan's smoggy atmosphere • has a flexible backbone • it can adopt several different structures, from sheets to more coiled shapes
FUTURE • polypyrrol – asymetric artificial muscles • polyamine – conducting polymer useful for electrical components such as transistors • oxygen from ice and methane – heat generation by combustion reaction One day – building a lab on Titan to redesign the way we think of Biology and Chemistry?
S A A R R O B I I MISSION TO TITAN
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