Presentation on theme: "1 INTERNATIONAL SPACE STATION Sally Robinson 256-961-0338 TIM #1-2 Crew Training Curriculum Development/ PTU Planning Coarsening."— Presentation transcript:
1 INTERNATIONAL SPACE STATION Sally Robinson 256-961-0338 firstname.lastname@example.org TIM #1-2 Crew Training Curriculum Development/ PTU Planning Coarsening of Solid and Liquid Mixtures CSLM January 13, 2000
2 INTERNATIONAL SPACE STATION Understand the payload’s crew training curriculum Understand the requirements for development of training equipment OBJECTIVES
3 INTERNATIONAL SPACE STATION Hardware and Software Description and Operations Overview (PD) Crew Training Curriculum and Hours (PD/SE) Crew Training Equipment (PD) PTC, SSMTF, NBL, and Robotics Capabilities and Interfaces (SE) PTU Classes/Component Fidelities (SE) Generic PSRD, Vol. 1 and Technical Development Specification (SE) AGENDA
4 INTERNATIONAL SPACE STATION Science There have been many theories proposed to explain the coarsening behavior of a two-phase mixture. The best known of these theories is the classical work of Lifshitz and Slyozov and Wagner (LSW). This theory attempts to describe the collective behavior of an ensemble of coarsening spherical particles. The results of the theory are well known. It predicts that the cube of the average particle radius should grow linearly with time and that the distribution of particle radii should assume a unique time- independent form under the scaling of the average particle radius. The LSW coarsening theory and the more recent extensions to nonzero volume fractions of coarsening phase assume that the particles coarsen by a diffusive transport of mass from shrinking to growing particles. In addition, it is assumed that the particles are uniformly distributed in the matrix. This restriction makes it virtually impossible to study the coarsening of liquid-liquid dispersions or dispersions of solid particles in a liquid matrix on the ground since diffusion-controlled conditions cannot be realized because of the influence of sedimentation. In all ground-based coarsening experiments involving small values of solid-volume fraction the particles tend to sink or float because of the density difference from that of the liquid matrix. By going to space, the negative influences of buoyancy on the dispersion can be minimized. CSLM is a microgravity experiment testing the validity of existing coarsening theories by performing space experiments with solid-liquid two-phase mixtures using the Pb-Sn system. The matrix is eutectic liquid and the solid particles are Sn-rich. Sample specimens are prepared by casting off-eutectic alloys of Pb-Sn into a chilled block and then severely cold-working the resulting ingots. After cold work, recrystallization takes place at room temperatures and results in a distribution of fine equiaxed grains. When these "green" samples are placed in an appropriate furnace and heated to a temperature just above the eutectic temperature of Pb-Sn (~183 C), the resulting eutectic liquid penetrates the grains of the structure, producing a dispersion of solid Sn-rich particles floating in a near eutectic- composition liquid. These particles will quickly spheroidize as coarsening proceeds. After a controlled period of time, the samples are rapidly cooled to freeze the structure of the coarsened particles and make accurate metallographic analysis possible. HARDWARE AND SOFTWARE DESCRIPTION AND OPERATIONS OVERVIEW
5 INTERNATIONAL SPACE STATION HARDWARE AND SOFTWARE DESCRIPTION AND OPERATIONS OVERVIEW Hardware The Coarsening in Solid-Liquid Mixtures-2 experiment team at NASA Glenn Research Center has developed a miniature facility to conduct material coarsening study in the ISS Microgravity Science Glovebox (MSG) [or on the Space Transportation System (STS) in the Glovebox (MGBX)]. The system consists of two units, the Sample Processing Unit (SPU) and the Electronics Control Unit (ECU) with both units housed within the MSG facility during operation. The Sample Processing Unit (SPU) heats material samples up to 185 C in less than 9.5 minutes, soaks for various times at 185 +/- 0.2 C, and then quenches the samples to room temperature in less than one minute. The present SPU configuration can house 4 lead/tin samples of 12 mm in diameter by 6 mm high and are heated concurrently. The Electronics Control Unit (ECU) utilizes software to control the SPU and record temperature data. The CSLM-2 ECU is nearly identical to the CSLM-1 ECU. The CSLM-1 ECU was based on an STD buss housing the CPU, A/Ds and a hard drive. The CSLM-1ECU measured approximately 7" x 11.25" x 8.25" and weighed 15 lb. The power for the CSLM-2 ECU system should be about 70 watts and will be obtained through the MSG facility. The ECU and SPU units are stowed onboard then transported by the astronauts to the MSG. The setup is relatively simple with only two cables, one from the ECU to the MSG power connector then one Y-Connector from the ECU to the SPU. A connection to the MSG Vacuum Resource System (VRS) is also required. The system initiation and experiment start are accomplished by simple toggle switches on the front face of the ECU. The astronaut initiates the run then can go on to other work until the run is complete. The astronaut removes the SPU heating chamber and stows it in the MELFI. Another SPU can then be installed and the process begins again. The facility provides a compact simple system for processing material samples in microgravity.
6 INTERNATIONAL SPACE STATION CREW TRAINING CURRICULUM AND HOURS Reference the Training Assessment form.
7 INTERNATIONAL SPACE STATION Training Equipment We plan to use CSLM-1 flight hardware initially for fit check and function training A CSLM-2 prototype unit is planned for additional fit checks and crew training CREW TRAINING EQUIPMENT CSLM-1 Block Diagram showing the ECU with switches and LCD display and the SPU. The SPU has been greatly modified internally, but is identical from the point of view of crew operations, with one exception. After processing, the SPU outer cover is removed and the heating chamber disconnected. This chamber is then stowed in the MELFI. The SPU outer cover can then be replaced and stowed. A new SPU can then be connected and operated.
8 INTERNATIONAL SPACE STATION CREW TRAINING EQUIPMENT CSLM-1 Flight Hardware
9 INTERNATIONAL SPACE STATION CREW TRAINING Procedures –Under construction –See M4UEMSGCSLMN001A.doc and M4UEMSGCSLMN003.doc
10 INTERNATIONAL SPACE STATION PTC- Provides simulators for flight crew training and for integrated training with ground support personnel. SSMTF- Supports development of flight crew procedures and flight hardware, as well as mission training exercises during all phases of ISS. NBL- Robotics- PTC, SSMTF, NBL AND ROBOTICS CABALITIES AND INTERFACES
11 INTERNATIONAL SPACE STATION PTU Classes –Class I: engineering unit or a non-qualified flight item –Class II: software simulation with hardware panels and interfaces –Class III: software simulation with virtual panels and interfaces –Class IV: hardware panel only –Class V: inert object, picture or 3-D mockup PTU CLASSES/COMPONENT FIDELITIES
12 INTERNATIONAL SPACE STATION Component Fidelities –Total Fidelity (T): all functional and physical characteristics representative of the flight design. –Functional Fidelity (F): all functional characteristics representative of the flight design; physical characteristics are not required –Physical Fidelity (P): all physical characteristics representative of flight design; functional characteristics not required –Envelope Fidelity (E): mockup with exterior shape and color representative of flight design –Visual Fidelity (V): no operational/functional capabilities; front panels representative of flight design PTU CLASSES/COMPONENT FIDELITIES
13 INTERNATIONAL SPACE STATION Generic PSRD, Vol. I –Defines physical and functional requirements for a simulator –Identifies the training objectives and training types supported by the simulator, approach used to develop simulator, and parties responsible for providing the simulator components –Documents required interfaces between the simulator and SSTF/PTC GENERIC PSRD, VOL. I AND TECHNICAL DEVELOPMENT SPECIFICATION