ODAR

0113-EX-ST-2015 Text Documents

Near Space Launch Inc.

2015-03-10ELS_159887

March 10, 2015 Orbital Debris Assessment for GEARRSII on the AFSC5 Atlas 5 Mission Sensitive But Unclassified (NPL)

REFERENCES: A. NASA Procedural Requirements for Limiting Orbital Debris Generation, NPR 8715.6A, 5 February 2008 B. Process for Limiting Orbital Debris, NASA-STD-8719.14A, 25 May 2012 C. P-POD Status SpX-3 Agreement History (Orbital Information) , ISS_CM_019 Rev 01/2011 D. McKissock, Barbara, Patricia Loyselle, and Elisa Vogel. Guidelines on Lithium-ion Battery Use in Space Applications. Tech. no. RP- 08-75. NASA Glenn Research Center Cleveland, Ohio E. UL Standard for Safety for Lithium Batteries, UL 1642. UL Standard. 4th ed. Northbrook, IL, Underwriters Laboratories, 2007 F. Kwas, Robert. Thermal Analysis of ELaNa-4 CubeSat Batteries, ELVL-2012-0043254; Nov 2012 G. Range Safety User Requirements Manual Volume 3- Launch Vehicles, Payloads, and Ground Support Systems Requirements, AFSCM 91-710 V3. H. UL Standard for Safety for Household and Commercial Batteries, UL 2054. UL Standard. 2nd ed. Northbrook, IL, Underwriters Laboratories, 2005 I. Opiela, John. “RE: DAS 2.0 Orbital Lifetime Inquiry” April 5, 2013. E-mail. The intent of this report is to satisfy the orbital debris requirements listed in ref. (a) for the GEARRSII mission. It serves as the final submittal in support of the spacecraft Safety and Mission Success Review (SMSR). Sections 1 through 8 of ref. (b) are addressed in this document; sections 9 through 14 fall under the requirements levied on the launch vehicle compliance assessment and are not presented here. Sensitive But Unclassified (NSL) 2

The following table summarizes the compliance status of the Nano Racks GEARRSII auxiliary payload mission flown on Orbital 2. The CubeSat manifested, comprising the GEARRsII mission are fully compliant with all applicable requirements. Table 1: Orbital Debris Requirement Compliance Matrix Requirement Compliance Assessment Comments 4.3-1a Compliant Lifetime of debris is days 4.3-1b Compliant Lifetime of debris is days 4.3-2 Not applicable No planned debris release 4.4-1 Compliant On board energy source (batteries) incapable of debris-producing failure 4.4-2 Compliant On board energy source (batteries) incapable of debris-producing failure 4.4-3 Not applicable No planned breakups 4.4-4 Not applicable No planned breakups 4.5-1 Compliant 4.5-2 Not applicable 4.6-1(a) Compliant Worst case lifetime 0.2yrs 4.6-1(b) Not applicable 4.6-1(c) Not applicable 4.6-2 Not applicable 4.6-3 Not applicable 4.6-4 Not applicable Passive disposal 4.6-5 Compliant 4.7-1 Compliant Non-credible risk of human casualty 4.8-1 Compliant No tether release Sensitive But Unclassified (NSL) 3

Section 1: Program Management and Mission Overview The GEARRSII mission is sponsored by the AFRL at Kirkland Air Force Base. Program/project manager and senior scientific and management personnel are as follows: GEARR: Jeff Dailey, Project Manager Program Milestone Schedule Task Date GEARRSII kick off meeting 1/2015 CubeSat Build, Test, and Integration 1/2015 Enviromental Testing 1/2015 CubeSat Delivery/integration to CalPoly 1/29/2015 Launch 4/16/2014 Figure 1: Program Milestone Schedule The GEARRSII mission will deploy from Atlas 5. GEARRSII CubeSat size 10cm x 10cm x 30 cm, with mass of 2.8 kg total. The GEARRSII is designed and built by Near Space Launch Inc. The GEARRSII will launch on the AFSC5 Atlas 5 rocket. The current launch date is April 16th 2015 in an orbit approximately 700 X 300 km at inclination of 60.0 deg (ref. (c)). Sensitive But Unclassified (NSL) 4

Section 2: Spacecraft Description GEARRSII is a CubeSat Mission. CubeSat CubeSat CubeSat size CubeSat Names Quantity Masses (kg) 1 3U (10 cm X 10 cm X 30 cm) GEARR 2.8 The following subsection contain descriptions of GEARRSII CubeSat. Sensitive But Unclassified (NSL) 5

Figure 2: GEARRSII CubeSat Description The primary mission of GEARRSII is to demonstrate a global Communications link to the GlobalStar network of satellites in orbit above us. Once ejected from the atlas 5 power management comes online after 5 minutes. 30 minutes after ejection the GlobalStar communications link is powered on and system status data is transmitted. Once communications is verified and Instrument module power up and begins operation mode. Sensitive But Unclassified (NSL) 6

GEARRSII structure is made of 6061-T6 aluminum. Internal and external materials used are, standard electrical components, Printed circuit boards, Stainless steel hardware and solar cells. The GlobalStar radio uses a 25mm x 25mm ceramic patch antenna. There are no hazardous materials used on GEARRSII. The power system consists of Four Li-Poly batteries at 8.1V / 5500mA with a total power of 22Ah available to the system. A built in protection module on each pack for over/under charge and short circuit. The Li-Poly batteries carry the UL-listing number BBCV2.MH29381 and the protection circuit model 32005. Sensitive But Unclassified (NSL) 7

Figure 3: 3U CubeSat Specification Sensitive But Unclassified (NSL) 8

Section 3: Assessment of Spacecraft Debris Released during Normal Operations Section 3 provides rationale/necessity for release of each object, time of release of each object relative to launch vehicle separation, release velocity of each object with respect to CubeSat, expected orbital parameters (apogee, perigee, and inclination) of each object after release, calculated orbital lifetime of each object, including time spent in Low Earth Orbit (LEO), and an assessment of spacecraft compliance with Requirements 4.3-1 and 4.3-2. No releases are planned on the GEARRSII mission therefore this section is not applicable. Section 4: Assessment of Spacecraft Intentional Breakups and Potential for Explosions. Note: This entire section applies to GEARRSII mission. Malfunction of lithium ion or lithium polymer batteries and/or associated control circuitry has been identified as a potential cause for spacecraft breakup during deployment and mission operations. While no passivation of batteries will be attempted, natural degradation of the solar cell and battery properties will occur over the post mission period, which may be as long as 0.9 years. These conditions pose a possible increased chance of undesired battery energy release. The battery capacity for storage will degrade over time, possibly leading to changes in the acceptable charge rate for the cells. Individual cells may also change properties at different rates due to time degradation and temperature changes. The control circuit may also malfunction as a result of exposure to the space environment over long periods of time. The cell pressure relief vents could be blocked by small contaminants. Any of these individual or combined effects may theoretically cause an electro-chemical reaction that result in rapid energy release in the form of combustion. There are NO plans for designed spacecraft breakups, explosions, or intentional collisions on the GEARRSII mission. Section 4 asks for a list of components, which shall be passivated at End of Mission (EOM), as well as the method of passivation and description of the components, which cannot be passivated. No passivation of components is planned at the End of Mission. Sensitive But Unclassified (NSL) 9

Since the batteries used do not present a debris generation hazard even in the event of rapid energy release (see assessment directly below), passivation of the batteries is not necessary in order to meet the requirement 4.4-2 (56450) for passivation of energy sources “to a level which cannot cause an explosion or deflagration large enough to release orbital debris or break up the spacecraft.” Because passivation is not necessary, and in the interest of not increasing the complexity of the CubeSats, there was no need to add this capability to their electrical power generation and storage systems. Assessment of spacecraft compliance with Requirements 4.4-1 through 4.4-2 shows that the GEARRSII is compliant. Requirements 4.4-3 and 4.4-4, addressing intentional break-ups are not applicable. The following addresses requirement 4.4-2. The CubeSate not been designed to disconnect their onboard storage energy devices (lithium polymer batteries). However, the CubeSats batteries still meet Req. 56450 by virtue of the fact that they cannot “cause an explosion or deflagration large enough to release orbital debris or break up the spacecraft”. Table 2: GEARRSII CubeSat Cells CubeSat Technology Manufactor Model UL Listing Number GEARRSII Lithium Polymer YOKU Energy Polypower 5500mAh MH29381 The batteries are all consumer-oriented devices. All battery cells have been recognized as Underwriters Laboratories (UL) tested and approved. Furthermore, safety devices incorporated in these batteries include pressure release valves, over current charge protection and over current discharge protection. The fact that these batteries are UL recognized indicates that they have passed the UL standard testing procedures that characterize their explosive potential. Of particular concern to NASA Req. 56450 is UL Standard 1642, which specifically deals with the testing of lithium batteries. Section 20 Projectile Test of UL 1642 (ref. (e)) subjects the test battery to heat by flame while within an aluminum and steel wire mesh octagonal box, “[where the test battery] shall remain on the screen until it explodes or the cell or battery has ignited and burned out” (UL 1642 20.5). To pass the test, “no part of an exploding cell or battery shall penetrate the wire screen such that some or all of the cell or battery protrudes through the screen” (UL 1642 20.1). Sensitive But Unclassified (NSL) 10

Steel Screen Top (20 openings/in) Steel Screen Bottom (20 openings/in) Test Subject Aluminum Screen (16-18 wires/in) Flame Figure 4: Underwriters Laboratory Explosion Test Apparatus The batteries being launched via CubeSat will experience conditions on orbit that are generally much less severe that those seen during the UL test. While the source of failure would not be external heat on orbit, analysis of the expected mission thermal environment performed by NASA LSP Flight Analysis Division shows that given the very low (<=41.44 W-hr, maximum for PhoneSat) power dissipation for CubeSats, the batteries will be exposed to a maximum temperature that is well below their 212oF safe operation limit (ref. (f)). It is unlikely but possible that the continual charging with 2 to 6 W of average power from the solar panels over an orbital life span greater than 2 years may expose the two to four batteries (per CubeSat) to overcharging which could cause similar heat to be generated internally. Through the UL testing, it has been shown that these batteries do not cause an explosion that would cause a fragmentation of the spacecraft. A NASA Glenn Research Center guideline entitled Guidelines on Lithium-ion Battery Use in Space Applications (ref. (d)) explains that the hazards of Li-Ion cells in an overcharge situation result in the breakdown of the electrolyte found in Li-ion cells causing an increase in internal pressure, formation of flammable organic solvents, and the release of oxygen from the metal oxide structure. From a structural point of view a battery in an overcharge situation can expect breakage of cases, seals, mounting provisions, and internal components. The end result could be Sensitive But Unclassified (NSL) 11

“unconstrained movement of the battery” (ref. (d), pg 13). This document clearly indicates that only battery deformation and the escape of combustible gasses will be seen in an overcharging situation, providing further support to the conclusion that CubeSat fragmentation due to explosion is not a credible scenario for this application. It is important to note that the NASA guide to Li-ion batteries makes no mention of these batteries causing explosions of any magnitude whatsoever. Section 5: Assessment of Spacecraft Potential for On-Orbit Collisions Calculation of spacecraft probability of collision with space objects larger than 10 cm in diameter during the orbital lifetime of the spacecraft takes into account both the mean cross sectional area and orbital lifetime. Figure 5: GEARR configuration ∑ [ ( ) ( )] Equation 1: Mean Cross Sectional Area for Convex Objects ( ) Equation 2: Mean Cross Sectional Area for Complex Objects All CubeSats evaluated for this ODAR are stowed in a convex configuration, indicating there are no elements of the CubeSats obscuring another element of the same CubeSats from view. Thus, mean CSA for all stowed CubeSats was calculated using Equation 1. This configuration renders the longest orbital life times for all CubeSats. Sensitive But Unclassified (NSL) 12

Once a CubeSat has been ejected from the P-POD and deployables have been extended Equation 2 is utilized to determine the mean CSA. Amax is identified as the view that yields the maximum cross-sectional area. A1 and A2 are the two cross-sectional areas orthogonal to Amax. Refer to Appendix A for dimensions used in these calculations The GEARRSII orbit at deployment is 700 km apogee altitude by 300 km perigee altitude, with an inclination of 60.0 degrees. With an area to mass (3.97 kg) ratio of 0.0346 m2/kg, DAS yields 0.1 years for orbit lifetime for its stowed state, which in turn is used to obtain the collision probability. Orbital lifetime GEARR will see an average of 10-9.2 probability of collision. Table 4 below provides complete results. Table 3: CubeSat Orbital Lifetime & Collision Probability CubeSat GEARRSII Mass 2.8 Mean C/S Area (m^2) 0.0214 Area-to Mass (m^2/kg) 0.0076 Stowed Orbital Lifetime (yrs) 0.2 Probability of collision (10^X) -9.7 Mean C/S Area (m^2) 0.0277 Area-to Mass (m^2/kg) 0.0099 Deployed Orbital Lifetime (yrs) 0.1 Probability of collision (10^X) -9.4 Sensitive But Unclassified (NSL) 13

There will be no post-mission disposal operation. As such the identification of all systems and components required to accomplish post-mission disposal operation, including passivation and maneuvering, is not applicable. The probability of GEARRSII spacecraft collision with debris and meteoroids greater than 10 cm in diameter and capable of preventing post-mission disposal is less than 10-8.4, for any configuration. This satisfies the 0.001 (10-6) maximum probability requirement 4.5-1. Since the CubeSats have no capability or plan for end-of-mission disposal, requirement 4.5-2 is not applicable. Assessment of spacecraft compliance with Requirements 4.5-1 shows GEARRSII to be compliant. Requirement 4.5-2 is not applicable to this mission. Section 6: Assessment of Spacecraft Postmission Disposal Plans and Procedures GEARRSII spacecraft will naturally decay from orbit within 25 years after end of the mission, satisfying requirement 4.6-1a detailing the spacecraft disposal option. Planning for spacecraft maneuvers to accomplish postmission disposal is not applicable. Disposal is achieved via passive atmospheric reentry. Calculating the area-to-mass ratio for the worst-case (smallest Area-to-Mass) post- mission disposal among GEARRSII in its configuration as the worst case. The area-to- mass is calculated for is as follows: ⁄ ( ) ( ) ( ) Equation 3: Area to Mass DAS 2.0.2 Orbital Lifetime Calculations: DAS inputs are: 700 km maximum perigee X 300 km maximum apogee altitudes with an inclination of 60.0 degrees at deployment in the year 2014. An area to mass ratio of 0.0076 m2/kg for the GEARRSII CubeSat was imputed. DAS 2.0.2 yields a 0.2 year orbit lifetime for GEARRSII. Sensitive But Unclassified (NPL)

This meets requirement 4.6-1. For the complete list of CubeSat orbital lifetimes. Assessment results show compliance. Section 7: Assessment of Spacecraft Reentry Hazards A detailed assessment of the components to be flown on GEARRSII was performed. The assessment used DAS 2.0, a conservative tool used by the NASA Orbital Debris Office to verify Requirement 4.7-1. The analysis is intended to provide a bounding analysis for characterizing the survivability of a CubeSat’s component during re-entry. For example, when DAS shows a component surviving reentry it is not taking into account the material ablating away or charring due to oxidative heating. Both physical effects are experienced upon reentry and will decrease the mass and size of the real-life components as the reenter the atmosphere, reducing the risk they pose still further. The following steps are used to identify and evaluate a components potential reentry risk relative to the 4.7-1 requirement of having less than 15 J of kinetic energy and a 1:10,000 probability of a human casualty in the event the survive reentry. 1. Low melting temperature (less than 1000 C) components are identified as materials that would never survive reentry and pose no risk to human casualty. This is confirmed through DAS analysis that showed materials with melting temperatures equal to or below that of copper (1080 C) will always demise upon reentry for any size component up to the dimensions of a 1U CubeSat. The remaining high temperature materials are shown to meet the human casualty requirement through a bounding DAS analysis of the highest temperature components, generally stainless steel (1500 C). A component of similar dimensions and possessing a melting temperature between 1000 C and 1500 C, can be expected to posses as negligible risk similar to stainless steel components. Probability of human casualty was calculated if a component exceeded 15J of energy upon reentry. See 2. Table 4. GEARRSII CubeSat comply with Requirement 4.7-1, to have less than 1:10,000 risk of human casualty. As documented in, Table 4: GEARRSII Survivability DAS Analysis, and Appendix A-E, mission are conservatively shown to be in compliance with Requirement 4.7-1 of NASA-STD- Sensitive But Unclassified (NSL) 15

8719.14A. See Appendix for a complete accounting of the survivability of all CubeSat components. Table 4: GEARRSII Survivability DAS Analysis Widt Stainless Steel Length / Height Demise Alt CubeSat Mass (g) h KE (J) Components Diameter (cm) (cm) (km) (cm) GEARRSII Sep Switches 8.0 0.45 1.05 0.00 76.4 0 GEARRSII Spring Plungers 2.0 0.35 1.50 0.00 76.5 0 GEARRSII Motor / Gearhead 25.0 0.80 4.00 0.00 71.4 0 GEARRSII Fasteners / Spacers 45.0 0.00 0.00 0.00 78 0 GlobalStar Patch GEARRSII Antenna 10.0 2.50 2.50 0.20 0 3 Note: Components are modeled as stainless steel unless otherwise noted in component name . Section 8: Assessment for Tether Missions GEARRSII will not be deploying any tethers. GEARRSII satisfy requirement 4.8-1. Section 9-14 ODAR sections 9 through 14 for the launch vehicle are addressed in ref. (g), and are not covered here. Appendix Index: Appendix A. Component List by CubeSat: GEARRSII Sensitive But Unclassified (NSL) 16

Appendix A. Component List for: GEARRSII Melting Temp (C) External/Internal Diameter/ Width (Major/Minor Row Number Components) Length (mm) Height (mm) Low Melting Body Type Comment Material CubeSat Mass (g) Name (mm) Qty GEARR 1 GEARR Yes Demises SII GEARR 2 External Structure External - Major 1 Aluminum 6061 Box 350 100 100 227 Yes Demises SII GEARR GlobalStar Patch Compliant (3J) 3 External - Major 1 Ceramic Square 10 25 25 2 No 1400 SII Antenna GEARR 4 Solar Panels External - Major 4 Fiberglass Panel 352 82 199 2.5 Yes Demises SII GEARR Demises 5 Sep Switches External - Minor 2 Steel / Gold Round 8 4.5 10.5 No 1500 SII GEARR Fiberglass / Copper / 6 Plasma Probe External - Minor 1 Square 7.5 45 45 3 Yes Demises SII Gold GEARR Demises 7 Spring Plungers External - Minor 2 Steel / Stainless Steel Round 2 3.5 15 No 1500 SII GEARR 10 End Plales External - Major 2 Aluminum 6061 Square 150 100 100 2 Yes Demises SII GEARR Aluminum Foil / 11 Batteries Internal - Major 6 Square 750 50 100 13 Yes Demises SII Plastic / Lithium GEARR 13 Comm Board Internal - Minor 1 Fiberglass / Copper Square 45 61 82 1.7 Yes Demises SII GEARR 14 GlobalStar Board Internal - Minor 1 Fiberglass / Copper Square 60 61 82 1.7 Yes Demises SII GEARR Power Management 15 Internal - Minor 1 Fiberglass / Copper Square 125 61 140 1.7 Yes Demises SII Board GEARR Instrument 16 Internal - Minor 1 Fiberglass / Copper Square 45 61 82 1.7 Yes Demises SII Microcontroller Baord GEARR 27 Instrument Baord Internal - Minor 1 Fiberglass / Copper Square 50 61 82 1.7 Yes Demises SII Sensitive But Unclassified (NPL)

GEARR 20 EMI Shield Internal - Major 1 Aluminum 6061 Square 50 90 90 2 Yes Demises SII GEARR 21 Magnotometer Internal - Minor 1 Fiberglass / Copper Square 27 42 52 20 Yes Demises SII GEARR Stainless Steel / Demises 22 Fasteners / Spacers Internal - Minor 45 No 1500 SII Aluminum GEARR 23 Cabling Internal - Minor Copper alloy 50 Yes Demises SII GEARR 24 Damping Iternal - Minor MU-Metal Rod 40 10 75 Yes Demises SII Sensitive But Unclassified (NSL) 18


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Document Modified: 2015-03-10 09:17:53
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