Engineering topics

Lyons, F.

Publications and source records attributed to Lyons, F..

5 records

NASA NTRS2017

Failure Mechanisms of Ni-H2 and Li-Ion Batteries Under Hypervelocity Impacts

Lithium-Ion (Li-Ion) batteries have yielded significant performance advantages for many industries, including the aerospace industry, and have been selected to replace nickel hydrogen (Ni-H2) batteries for the International Space Station (ISS) program to meet the energy storage demands. As the ISS uses its vast solar arrays to generate its power, the solar ar-rays meet their sunlit power demands and supply excess power to battery packs for power de-livery on the sun obscured phase of the approximate 90 minute low Earth orbit. These large battery packs are located on the exterior of the ISS, and as such, the battery packs are ex-posed to external environment threats like naturally occurring meteoroids and artificial orbital debris (MMOD). While the risks from these solid particle environments has been known and addressed to an acceptable risk of failure through shield design, it is not possible to completely eliminate the risk of loss of these assets on orbit due to MMOD, and as such, failure consequences to the ISS have been considered.

Miller, J. E.↗

NASA NTRS2017

Failure Mechanisms of Ni-H2 and Li-Ion Batteries Under Hypervelocity Impacts

Lithium-Ion (Li-Ion) batteries have yielded significant performance advantages for many industries, including the aerospace industry, and have been selected to replace nickel hydrogen (Ni-H2) batteries for the International Space Station (ISS) program to meet the energy storage demands. As the ISS uses its vast solar arrays to generate its power, the solar arrays meet their sunlit power demands and supply excess power to battery packs for power delivery on the sun obscured phase of the approximate 90 minute low Earth orbit. These large battery packs are located on the exterior of the ISS, and as such, the battery packs are exposed to external environment threats like naturally occurring meteoroids and artificial orbital debris (MMOD). While the risks from these solid particle environments has been known and addressed to an acceptable risk of failure through shield design, it is not possible to completely eliminate the risk of loss of these assets on orbit due to MMOD, and as such, failure consequences to the ISS have been considered.

Miller, J. E.↗

NASA NTRS2008

STS-118 Radiator Impact Damage

During the August 2007 STS-118 mission to the International Space Station, a micro-meteoroid or orbital debris (MMOD) particle impacted and completely penetrated one of shuttle Endeavour s radiator panels and the underlying thermal control system (TCS) blanket, leaving deposits on (but no damage to) the payload bay door. While it is not unusual for shuttle orbiters to be impacted by small MMOD particles, the damage from this impact is larger than any previously seen on the shuttle radiator panels. A close-up photograph of the radiator impact entry hole is shown in Figure 1, and the location of the impact on Endeavour s left-side aft-most radiator panel is shown in Figure 2. The aft radiator panel is 0.5-inches thick and consists of 0.011 inch thick aluminum facesheets on the front and back of an aluminum honeycomb core. The front facesheet is additionally covered by a 0.005 inch thick layer of silver-Teflon thermal tape. The entry hole in the silver-Teflon tape measured 8.1 mm by 6.4 mm (0.32 inches by 0.25 inches). The entry hole in the outer facesheet measured 7.4 mm by 5.3 mm (0.29 inches by 0.21 inches) (0.23 inches). The impactor also perforated an existing 0.012 inch doubler that had been bonded over the facesheet to repair previous impact damage (an example that lightning can strike the same place twice, even for MMOD impact). The peeled-back edge around the entry hole, or lip , is a characteristic of many hypervelocity impacts. High velocity impact with the front facesheet fragmented the impacting particle and caused it to spread out into a debris cloud. The debris cloud caused considerable damage to the internal honeycomb core with 23 honeycomb cells over a region of 28 mm by 26 mm (1.1 inches by 1.0 inches) having either been completely destroyed or partially damaged. Figure 3 is a view of the exit hole in the rear facesheet, and partially shows the extent of the honeycomb core damage and clearly shows the jagged petaled exit hole through the backside facesheet. The rear facesheet exit hole damage including cracks in the facesheet measures 14 mm by 14 mm (0.55 inches by 0.55 inches). The remnants of the impacting particle and radiator panel material blown through the rear facesheet hole also created two penetrations in the TCS blanket 115 mm (4.5 inches) behind the rear facesheet. Figure 4 shows these two impacts, which are located 75 mm (3 inches) apart. Some deposits of material were found on the payload bay door beneath the TCS blanket, but no additional damage occurred to the door. Figure 5 illustrates the relationship of the facesheet entry hole to the TCS blanket damage, which may indicate the direction of the impacting particle. The image on the left side of Figure 5 shows an overhead view of the damaged radiator after the facesheet holes were cored out of the panel. The entry hole location and the two underlying TCS blanket damage sites are annotated on the image. Section A-A, running through the entry hole and TCS blanket damage locations, describes a 25 angle from the longitudinal axis of the shuttle. The 2nd impact angle can be seen in section A-A on the right side of Figure 5. An average 17 angle of impact to the surface normal was derived by measuring the angles of the two damage sites in TCS blanket to the entry hole.

Lear, Dana M.↗

NASA NTRS2007

Investigation of MMOD Impact on STS-115 Shuttle Payload Bay Door Radiator

The Orbiter radiator system consists of eight individual 4.6 m x 3.2 m panels located with four on each payload bay door. Forward panels #1 and #2 are 2.3 cm thick while the aft panels #3 and #4 have a smaller overall thickness of 1.3 cm. The honeycomb radiator panels consist of 0.028 cm thick Aluminum 2024-T81 facesheets and Al5056-H39 cores. The face-sheets are topped with 0.005 in. (0.127 mm) silver-Teflon tape. The radiators are located on the inside of the shuttle payload bay doors, which are closed during ascent and reentry, limiting damage to the on-orbit portion of the mission. Post-flight inspections at the Kennedy Space Center (KSC) following the STS-115 mission revealed a large micrometeoroid/orbital debris (MMOD) impact near the hinge line on the #4 starboard payload bay door radiator panel. The features of this impact make it the largest ever recorded on an orbiter payload bay door radiator. The general location of the damage site and the adjacent radiator panels can be seen in Figure 2. Initial measurements of the defect indicated that the hole in the facesheet was 0.108 in. (2.74 mm) in diameter. Figure 3 shows an image of the front side damage. Subsequent observations revealed exit damage on the rear facesheet. Impact damage features on the rear facesheet included a 0.03 in. diameter hole (0.76 mm), a approx.0.05 in. tall bulge (approx.1.3 mm), and a larger approx.0.2 in. tall bulge (approx.5.1 mm) that exhibited a crack over 0.27 in. (6.8 mm) long. A large approx.1 in. (25 mm) diameter region of the honeycomb core was also damaged. Refer to Figure 4 for an image of the backside damage to the panel. No damage was found on thermal blankets or payload bay door structure under the radiator panel. Figure 5 shows the front facesheet with the thermal tape removed. Ultrasound examination indicated a maximum facesheet debond extent of approximately 1 in. (25 mm) from the entry hole. X-ray examinations revealed damage to an estimated 31 honeycomb cells with an extent of 0.85 in. x 1.1 in. (21.6 x 27.9 mm). Pieces of the radiator at and surrounding the impact site were recovered during the repair procedures at KSC. They included the thermal tape, front facesheet, honeycomb core, and rear facesheet. These articles were examined at JSC using a scanning electron microscope (SEM) with an energy dispersive x-ray spectrometer (EDS). Figure 6 shows SEM images of the entry hole in the facesheet. The asymmetric height of the lip may be attributed to projectile shape and impact angle. Numerous instances of a glass-fiber organic matrix composite were observed in the facesheet tape sample. The fibers were approximately 10 micrometers in diameter and variable lengths. EDS analysis indicated a composition of Mg, Ca, Al, Si, and O. Figures 7 and 8 present images of the fiber bundles, which were believed to be circuit board material based on similarity in fiber diameter, orientation, consistency, and composition. A test program was initiated in an attempt to simulate the observed damage to the radiator facesheet and honeycomb. Twelve test shots were performed using projectiles cut from a 1.6 mm thick fiberglass circuit board substrate panel. Results from test HITF07017, shown in figures 9 and 10, correlates with the observed impact features reasonably well. The test was performed at 4.14 km/sec with an impact angle of 45 degrees using a cylindrical projectile with a diameter and length of 1.25 mm. The fiberglass circuit board material had a density of 1.65 g/cu cm, giving a projectile mass of 2.53 mg. An analysis was performed using the Bumper code to estimate the probability of impact to the shuttle from a 1.25 mm diameter particle. Table 1 shows a 1.6% chance (impact odds = 1 in 62) of a 1.25 mm or larger MMOD impact on the radiators of the vehicle during a typical ISS mission. There is a 0.4% chance (impact odds = 1 in 260) that a 1.25 mm or larger MMOD particle would impact the RCC wing leading edge and nose cap during a typical miion. Figure 11 illustrates the vulnerable areas of the wing leading edge reinforced carbon-carbon (RCC), an area of the vehicle that is very sensitive to impact damage. The highlighted red, orange, yellow, and light green areas would be expected to experience critical damage if impacted by an OD particle such as the one that hit the RH4 radiator panel on STS-115.

Hyde, J.↗

NASA NTRS2007

Investigation of MMOD Impact on Shuttle Payload Bay Door Radiator

Post flight inspections on the Space Shuttle Atlantis conducted after the STS-115 mission revealed a 0.11 inch (2.8 mm) hole in the outer facesheet of the starboard payload bay door radiator panel #4. This hole is the possible result of micrometeoroid/orbiting debris (MMOD) impact. The payload bay door radiators in this region are 0.5 inch (12.7 mm) thick aluminum honeycomb with 0.011 in (0.279 mm) thick aluminum facesheets topped with 0.005 in (0.127 mm) silver-Teflon tape. Inner facesheet damage included a 0.267 in (6.78 mm) long through crack with measurable deformation in the area of 0.2 in (5.1 mm). There was also a 0.031 in (0.787 mm) diameter hole in the rear facesheet. A large approximately 1 in (25 mm) diameter region of honeycomb was also destroyed. Since the radiators are located on the inside of the shuttle payload bay doors which are closed during ascent and reentry, the damage could only have occurred during the on-orbit portion of the mission. This paper will document the data collected from the impact site and will include results of the SEM/EDX analysis. Evidence will be presented that suggests a source of the impact as well as an analysis of the impact site features that indicate projectile directionality. Results of hypervelocity impact testing on representative samples in an attempt to simulate the impact event will be presented and discussed. Finally, the results of a study showing the regions of the orbiter vehicle that would be vulnerable to an equivalent projectile will be given.

Hyde, J. L.↗