ai-aerospace/ams_data_full_2000-2020 huggingface dataset:
321   Figure 11.  Capping System  The cap feeding assembly is a passive mechanism driven by constant force springs. All the sample cell  caps are placed in the runnel and driven into the capping station by a cap guide made of Teflon. A cable is attached to the cap guide and routed along the runnel with rollers, and feeds into a redundant constant force spring box. The feeding of the caps into the capping station is managed by the capping arm. The cap feeding assembly was designed to only provide caps into the capping station when a new sample cell requires it. The arm was designed to block the caps from feeding into the capping station when the capping arm is driving a cap downward to seal a sample cell. When a new cap is required, the capping arm is driven upward to allow a cap to slide underneath. To insure that the cap does not get jammed, a cap capturing slide pops from the opposite side to capture the new cap. As the new cap is pushed into position, the capturing slide is pushed back to its stowed position. At this point the cap is still supported by the caps on one side and the capturing slide on the other. When the command is given, the capping arm begins to push the cap downward and blocks other caps from feeding into the capping station. The cap and capping arm engage through matching chamfers to center the cap onto the sample cell. As discussed in the sample cell section, the chamfer on the cell ensures the cap has enough run for the cap to self-align and seal in place.  The capping arm is driven by an ACME screw supported with bearings and Belleville washers to prevent jamming when bottoming out the assembly. The ACME screw is driven by a worm drive gearbox that is connected to the same type of stepper motor as for the carousel. Similar to the carousel, the worm drive is used to stop and lock motion. The worm drive gearing is designed to lock out the capping arm at any position. Because of the high mechanical gearing, special attention was given to the bracket design to ensure the mechanism would not self-destruct if the capping arm was driven past its operational limits.
322 The components were designed so that the capping arm can hard stop at either end without breaking  anything. During normal operation, position is managed by the linear encoder; however, in case of losing control of the capping arm, mechanical switches are positioned at either end of travel. 

Figure 12.  Capping Mechanism  The secondary function of the capping assembly is to engage the sample cell to the fluid transfer station. This subassembly consists of the injector housing, injector needle, and a spring loaded injector guide.  

Figure 13.  Capping Mechanism - Actuation – Section View  As the sample cell is driven into the fluid transfer station bore, the injector guide reacts against the bottom of the sample cell and aligns the injector with the bottom cell valve, while supporting the injector from
323 getting bent; the capping arm continues driving the sample cell until the valve is fully open and the injector  fully sealed in the sample cell.    3.4 The Fluidic Management Subsystem  The fluidic subsystem consists of three fluid reservoirs, a multi-port valve, a pump, and a fluid transfer station.  

Figure 14.  Fluid Transfer Station  The fluid transfer station consists of an injector needle with a spring loaded guide to support the needle when engaging the sample cell. The spring guide acts as a backup system in case the sample cell spring in the carousel fails, in which case, as the capping arm backs out, the spring guide will push out the sample cell from the fluid transfer station and allow the mechanism to continue functioning. If this failure would occur, the failed sample cell would simply drag along the bottom of the WASP housing.  

Figure 15.  Fluid Management System  The finalized WASP fluidics subsystem incorporates a COTS VICI 4-position valve and a COTS VICI Cheminert M6 pump to select and deliver fluids from three custom Teflon reservoirs. The custom fluid reservoirs reside internal to the carousel and the design assumes water, methanol and oxalic acid as the three fluids of choice. The M6 bi-directional pump is capable of delivering fluids with an accuracy and
324 precision of ±0.5% and -/0.1%, respectively, at flow rates of 10 mL/min when exposed to a maximum  backpressure of 100 psi (0.69 MPa). Plumbing consists of COTS 1/16” (1.6-mm) OD, 300-nm ID PEEK tubing and COTS zero-dead-volume PEEK compression-style fittings. A relative layout of the solvent delivery subsystem is shown in Figure 16, depicting the pump, valve, and sample cell injection interface. A block diagram depicting basic fluid delivery pathways is illustrated in Figure 19. After each extraction cycle, fluid lines are flushed with a desired clean solvent back into a used sample cell in order to mitigate sample cross contamination.  

Figure 16.  Fluid Management System  3.5 Additional Considerations:  Inlet Funnel  The sample introduction was not part of the scope for this project. However, because an inlet is required, some development was done to address the means by which the sample is introduced into the test cells. How the sample is introduced to the test cells is critical in minimizing cross contamination of samples. Because the sample will be manually introduced, we used a funnel to guide the sample into the test cell. The funnel can be lowered into the sample cell, so that the neck of the funnel recesses inside the cell when delivering the soil sample. The funnel assembly is supported and guided by pins with springs under it to prevent the funnel from falling in and jamming the mechanism, and passively return it to its stowed position after use. An ultrasonic motor was attached to the funnel to excite the sample particles downward.    For flight, antistatic adhesion coatings will be applied to the funnel to minimize dust clinging onto the funnel surface due to electrostatic effects; Ball Aerospace has developed a coating that minimizes these effects in dry and dusty environments. The funnel’s plunging step into the sample cell and the funnel’s ultra-sonic motor actuation would be automated to ensure proper sample delivery.
325 4.0 CONTROL SOFTWARE AND ELECTRONICS 

A great deal of consideration was placed upon developing a software command and telemetry interface that is highly intuitive and user-friendly, while also maintaining an elevated degree of versatility and customization. Given that the system is nominally intended to operate with an opaque aluminum cover—with all core mechanisms being visually inaccessible—Figure 17 illustrates that there is a wide array of LED indicators made available via the software interface, which provides an easily-decipherable display of general system status and positioning. This interface approach ensures that the user will never lose track of any system parameter during normal operation.  In addition to an assortment of intuitive LED indicators, the system is largely controlled via an interactive message center that provides the user with instructions, buttons, numeric inputs, indicators and/or plots that appear, disappear and automatically update depending upon user-initiated commands. For the advanced user, a quick-setup option is available that will allow the user to input predetermined sample processing parameters if desired.  A collection of versatile subroutines have been developed to perform the following tasks:   Initialize the WASP carousel to its home encoder index.   Initialize the WASP carousel to sample cell index #1. This move is relative to the home encoder  index.   Move the carousel to a user-specified cell index. This move requires the carousel to be initialized  to cell index #1.   Initialize the capping mechanism to its home encoder index.   Move the capping mechanism to apply a cap and/or engage with the solvent delivery needle.   This move is relative to the home encoder index.   Move the capping mechanism to an intermediate position to allow the carousel to spin, but not  allow another cap to feed. This move is relative to the home position.   Turn the WASP heater on or off.   Acquire an analog temperature measurement from the infrared thermocouple.   Drive the VICI pump to dispense or aspirate a user specified volume of solvent at the user  specified flow rate.   Position the VICI valve at a user specified position.  These subroutines are used in multiplicity throughout the main WASP LabVIEW user interface state machine. The front panel of the main WASP user interface is depicted in Figure 18.
327   Figure 19.  Updated WASP Software Algorithm Flow Diagram  4.1 ASPS Electronics Overview  COTS National Instruments (NI) hardware controls all aspects of the WASP system and was integrated in  conjunction with the software interface as outlined in above. An NI 2-axis stepper motor controller controls the motors responsible for positioning the carousel and capping plunger; and a PCI-7332 board with four DIO ports that are used for heater modulation, as well as four analog inputs that capture the infrared temperature sensor telemetry. A NI Universal Motion Interface Connector Block serves as the central hub, to which all motion devices, heaters and thermocouples/thermistors are connected. The pump, valve, motor, and infrared temperature sensor also utilize COTS driver and amplifier modules in order to operate. 

Figure 20.  WASP electronics box CAD model
330 Design of a Separation System  Marman Clamp systems usually share the design objectives below. All three design objectives should be  kept in mind and balanced against each other (along with weight and cost):  1. Create a stiff connection to the payload under worst case load conditions; retain until deployment 2. Release the payload upon command, with proper separation dynamics, minimal imparted shock,  and no “re-contact” between separated payload and band or any other part of sep system (including debris from pyrotechnic release)  3. Create robust processes for installation, preloading, and testing of flight system, compatible with  proper safety measures   Figure 2 shows the components of a typical system. The band is tensioned to the required preload, compressing the shoes (V-wedges) radially, generating axial preload, clamping the rings together. The clamped rings behave like a preloaded fastener head, creating predictable joint stiffness as long as gapping between the rings does not occur. Most systems have no trouble being stiff in axial compression, as the joint acts as a solid cylinder. Stiffness under axial tension is more difficult to achieve as the load path goes from flanges to the clamped toes of the joint to the mating flange. 

Figure 1: Generic Marman Clamp System 

Table 1 shows a comparison of the traditional Marman system design approach to the alternative approach taken in our systems. These differences will be discussed in more detail to illustrate why our approach is an improvement.
331   Figure 2: Generic Marman Clamp System Section  Table 1: Design Comparison: Traditional versus Improved Separation Systems  Feature Traditional Marman Systems Improved Separation System  Release Element Pyrotechnic or frangible bolt separation High-reliability, shock dissipating release  device  Number of  release points 2 release points minimum, 3 or more for larger rings Single point release, redundant initiators  Band  Thin, flexible “strap” of steel (un-controlled shape)  Thicker, less flexible machined Alum band of controlled shape with free-state larger than installed state for release energy  Band Dynamics Less predictable release dynamics; Dependent on band strain energy for release, Springs and/or tethers (extractors) to assist release and move band away from rings into catchers; Straps to contain ends of band after release Predictable release dynamics due to controlled shape; Band “spring” energy sufficient for release, catchers “park” band away from rings after release; tethers and straps not necessary  Band End fittings Trunnions w/ spherical ends connected to strap, or riveted “bathtub” fittings “one-piece” band with integral machined ends (bathtub fittings); release bolts at each end have spherical washers  Band preload Lower preload, lighter system Higher preload, stiffer/stronger system  Interface Rings Lighter weight on “flyaway” ring, shear lip, controlled gap, longer lips, angle >20 deg to reduce tension requirement Matched stiffness, short lips for direct load path, minor inner “gapping” acceptable, smaller angle (15 deg)  Clamps/Shoes/V-Wedges/Retainers Aluminum, Titanium, or steel Aluminum w/ Titanium for highly loaded end  shoes  Install and preload process Set preload w/ bolt torque or strain gauges, tap band to equalize; pyrotechnic safety practices Instrumented bolt indicates load, no tapping - single segment band w/ proper lubrication; reduced safety requirements  Preload Indication Bolt torque, strain gauge on band or bolt(s) Calibrated, Instrumented bolt
333 Spacecraft and payloads. Use of a high-reliability release device allows for one release point. This not  only addresses the above shortcomings of pyros, but drives the design of the entire system in a very favorable direction.  The CBOD (see Figure 3) consists of two bolts with opposite hand, high lead threads which engage the  same central flywheel nut. The flywheel is fixed, and released, with a retractable pin. When the CBOD is stowed, it functions as a single long bolt, which engages the ends of the clamp band with a simple nut at each end. The band preload creates tension in the CBOD bolts, which exert a back-drive torque on the flywheel. Upon release of the pin, the flywheel is free to spin, releasing both bolts (and the band ends). CBOD slows the release event, dissipating band strain energy into rotational kinetic energy of the CBOD flywheel. This allows for higher band preloads without excessive release shock. Excess release shock can create unpredictable band behavior, potential rebound of the band, and possible damage to the vehicle or spacecraft.   Redundancy in CBOD is achieved with the use of a pin pulling device with dual NASA standard initiators  (NSIs). This is the smallest and lightest part of the release device, and a very efficient means of meeting redundancy requirements. The CBOD is fully-resettable for multiple uses, with replacement of the NSIs only. The CBOD has controlled thread-form, rolled threads, and each is proof-tested. Margins on CBOD are verified by proof-load testing, and release performance of every flight unit is tested at component level and after integration. A Small CBOD version has  5/16-in (8-mm) bolts and 3500-lb (15.6-kN) rating; the  larger version has ½-inch (13-mm) bolts and a 13,500-lbf (60-kN) rating. The CBOD has been used successfully in over 450 Flight band releases.   Several pyrotechnic system failures have been associated with failure of the explosive bolt  5. Higher  design margins are possible with the CBOD compared to explosive bolts since the latter must balance  margins of retention and release against each other. Mounting configuration of the CBOD includes spherical seats for the end of the bolts and ensures CBOD is loaded purely in tension. High design margins, and an 18,500-lb (82.3-kN) component proof load test (~1.4x nominal load) on the CBOD cover potential overload encountered during or after preloading.   A single release point band equipped with the CBOD allows for a new design approach in which the band  release is not dependent on stored strain energy in the band, or on external springs & tethers. Instead, the band is fabricated to a free-state which is larger in diameter than the rings. This creates stored elastic energy in the stowed condition and positive motion of the band away from the rings upon release. This will be discussed in more detail, to illustrate how the device has driven the improved design.  

Figure 3: 13,500-lb (60-kN) Clamp-Band Opening Device (CBOD)
339   Figure 6: Hydraulic Loading Tool in-place, rings mated to fixture plates 

Preliminary Sizing, Analysis, and Test  Marman systems are prone to stack-up of design margins resulting in over-designed (and overweight) systems. Analysis uncertainty, probabilistic load cases, margin-on-margin can drive design loads excessively high. Choose realistic load cases with reasonable margins to size band, shoes and rings as these have a big impact on system weight. A reasonable choice is to design and test to 1.25x worst case load predictions. Maintaining high margins on the release element (>2.00) has been recommended, and allows for any increase in loads, with a relatively low impact on system weight 15.  With design loads defined, a band tension can be determined such that complete axial gapping of the clamped joint will not occur at the maximum load case (an exception is small localized gapping due to elastic deformations). Initial band load is determined using a standard set of equations used for Marman systems, derived from a force balance about the clamped section 16:   Axial Line Load:              W axial = F axial / πD  Moment Line Load:        W moment  = 4M / πD2  Total Line load:               W total =  W axial + W moment   Band Preload estimate:  P band = W total D (tanβ-μ)/(1+ μtanβ) ~ W total D tanβ (neglecting friction)  A margin on gapping of 1.25 is normally applied to this result. The above loads allow for initial sizing and modeling of band, shoes rings, and other components. Finite Element Modeling is then used to analyze for stiffness and model system gapping behavior under load.   Not surprisingly, all agree on the need for extensive development testing to validate any separation  system design. Testing is performed to confirm analysis results for system stiffness and gapping loads, and to validate or refine the flight band tension callout. Tests verify uniform loading of the band and proper stowing using the stow and load procedure steps. High-speed video is used to verify proper release performance of the band and system. These development tests are all performed prior to a comprehensive qualification test program.     D = ring diameter  β = ring ramp half-angle  μ = coefficient of friction
340 Examples of Early Low-Shock Separation System Designs 

Development of Sub-24” (61 cm) Separation System  For ESPA and ESPA-Grande applications, the secondary payload is cantilevered relative to the launch  axis and space is at a premium along this line (see Figure 9). The required stack height (payload interface to ESPA ring interface) was 2.0” (5 cm), or roughly half that of the NANOSAT system. Stiffness and load requirements were increased compared to our heritage systems. Load requirements for ESPA are based on a 660-pound (300-kg) payload, with c.g. located 20 inches (51 cm) axially from the interface with the Separation System with inertial loads of 8.5G applied in two directions simultaneously 17. This presented a  challenging set of requirements for the sub-24” system (interface bolt circle diameter is just under 24.00” (60.96 cm)). With a desire to retain as many aspects of successful previous designs as possible, the design was revised to meet or exceed the specified requirements for ESPA Grande. The first step to a qualified design was to complete the design and analysis predictions, and fabricate an engineering model for testing.  Figure 8: Orbital Express Separation System  using 2 RUAG Bands and SNC mini-CBOD Figure 7: SNC NANOSAT 43-cm (17-inch) Separation S ystem with Mini-CBOD  Nanosat Separation System      Developed for AFRL, collaborative  effort with RUAG    Four flight units delivered    17” (43-cm) interface diameter   Clamp Band Opening Device (14-kN /  3250-lbf preload Mini-CBOD) imparts  extremely low shock to Spacecraft and  payloads    Protoflight test program included Band  Proof load test, Thermal cycling, Random Vibration, Static structural  testing, and Kick-off/Tip-off verification. Shock response characterized.   Line Load: 42 kN/m (240 lbf/in)   Band Preload: 14.7 kN (3300 lbf)   Band Yield Stress Margin*: 0.42    Launched in 2004, Delta IV Heavy Lift Orbital Express Separation System   Utilized a 37” (94-cm) Soft Separation  System High Performance Clamp Band by RUAG with Clamp Band Opening Device (CBOD) by SNC   Primary structure between NEXTSat  and ASTRO during launch and initial on orbit activities   Separated NEXTSat and ASTRO on  flight and release intermediate structure so that subsequent mates and demates  using the OE docking system can occur   One Flight unit delivered   Line Load: 32 kN/m (184 lbf/in)   Band Preload: 14.7 kN (3300 lbf)   Band Yield Stress Margin*: 1.54   Launched in 2007  * with SFy = 1.1, SFu = 1.4
341   Figure 9: ESPA Separation System  To fit the required envelope, and to maximize stiffness, a major revision was made to the heritage ring  profile (see Figure 10). The stack height of the system was reduced to within the required 2.0” (5 cm). Mounting flange of both rings were moved inboard of the tensioning band to improve load path and increase stiffness. This makes mounting fasteners less accessible, but is easily addressed by either accessing fasteners through holes in the ESPA ring, or installing rings prior to mating the payload to the adaptor ring. Preliminary stiffness analysis showed that the scaled, reduced height ring profile did not meet our stiffness goals, so the section was again revised. We thickened sections and shortened toes on each ring to improve stiffness and load path. These revisions resulted in roughly 3-fold improvement in stiffness, as seen in Figure 11. 

Figure 10: Profile Revision: Heritage design to sub-24" system 

Catchers, switch mounts, and kickoff spring modules were also reduced in height. Fitting of kickoff spring  modules into the smaller envelope was a challenge. The 660-lb (300-kg) payload mass requirement and 1 ft/sec (30 cm/sec) separation velocity (V sep) goal required a larger amount of spring energy in a smaller  volume than our prior designs. Our goal was to keep the kickoff spring module confined to the radial space between the rings, as a baseline. For our engineering system, we designed around a commercially available spring, and added 2 kickoff modules (total of 6) versus the heritage 4. Payloads up to  2/3 the  maximum load will achieve the V sep target. Additional kickoff energy for future programs would be added  by increasing the number of modules, utilizing volume inside the ESPA ring, or both.