JuanCastillo29/space-mission-intelligence-data huggingface dataset:
Spacecraft/payload accelerations are estimates from ongoing SLS analysis. Dynamic excitations, occurring predominantly during liftoff and transonic periods of SLS flights, are superimposed on steady-state accelerations from specific mission trajectory analyses to produce combined accelerations that should be used in payload structural design. The combined payload accelerations are a function of launch vehicle characteristics as well as payload dynamic characteristics and mass properties.
In general, payload maximum lateral load factors tend to be lower for high max. axial load factors and vice versa. Representative design load factors for SLS Block 1 payloads are shown in Table 5-1. Representative design load factors that envelope the rollout, prelaunch, liftoff, and boost and core stage ascent loads for Block 1B payloads are shown in Table 5-2; values in this table are sensed load factors, not kinematic accelerations.  Table 5-3 provides the low frequency load factors which need to be combined with the random vibration load factors. Payload cantilevered fundamental mode frequencies are recommended to be a minimum of 8 Hz lateral and 15 Hz axial to ensure applicability of the design load factors.
Payloads wanting to utilize their own heritage separation systems will be evaluated on a case by case basis. For initial sizing, if the payload and its provided separation system meet the frequency recommendations, the provided load factors may be used. Otherwise mission-unique vehicle dynamic coupled load analyses would be performed to determine the applicable design load factors for payloads that bring their own separation systems.
The electronic version is the official approved document.

[Table: Table 5-1. Block 1 SPL Component Load Factors Due to Low Frequency Loads]

|  | Flight Phases |  |  | Vehicle Axial |  |  | Vehicle Lateral and Radial |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Liftoff through Ascent/Boost |  |  | +0.6, -3.5g |  |  | ±3.0g |  |  |
| Ascent/Core through In-Space |  |  | -4.1g |  |  | ±0.5g |  |  |

[Table: Table 5-2. Block 1B PPL/CPL Combined Load Factors]

|  | Case |  |  | Vehicle Axial (G) |  |  | Vehicle Lateral(G) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Liftoff |  |  | +1.0 |  |  | ±1.5 |  |  |
| Liftoff/Transonic |  |  | -2.0 |  |  | ±2.0 |  |  |
| Max Q |  |  | -2.3 |  |  | ±2.0 |  |  |
| Core Stage Flight |  |  | -3.5 |  |  | ±0.5 |  |  |
| MECO |  |  | -4.1 |  |  | ±0.5 |  |  |

[Table: Table 5-3. Block 1B PPL/CPL Accelerations Due to Low Frequency Loads]

|  | Flight Phases |  |  | Vehicle Axial |  |  | Vehicle Lateral and Radial |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Liftoff through Ascent/Boost |  |  | +0.6, -3.5g |  |  | ±3.0g |  |  |
| Ascent/Core through In-Space |  |  | -4.1g |  |  | ±0.5g |  |  |
The spacecraft/payload thermal environment is controlled during pre-launch activity, maintained during ground transport, and controlled after mate to the launch vehicle.
Drag-on clean air from within the payload encapsulation facility will be circulated throughout the Integrated Spacecraft/Payload Element (ISPE) following payload encapsulation, until preparation for transport to the Vehicle Assembly Building (VAB). The ISPE will have a dry air blanket purge provided by Mini Portable Purge Units (MPPUs) during transportation to the VAB transfer aisle. Transit from the processing facility to VAB is identical for the PLF aft purge. A dry air purge will be provided to the ISPE while in the VAB prior to stacking on the SLS vehicle. During this VAB blanket purge prior to lifting, the USA purge, PLF aft and forward purge, and Block 1 cargo PLF have identical gas properties as their respective environments for transportation from the processing facility to the VAB. No active purge will be provided during the maximum eight-hour lifting and stacking operations. This encompasses the time between disconnecting the MPPU blanket purge and reconnecting the Mobile Launcher (ML) purge system. Once mating operations are complete, a continuous purge is established through T-0 quick disconnect fitting. A dry air and gaseous nitrogen (GN2) purge (during tanking) will be provided to the USA or PLF through the purge
The electronic version is the official approved document.

interface while on the ML, prior to pad rollout and through launch countdown. No active purge is provided during the transition from the ML system to the MPPUs prior to rollout, nor from the MPPUs to the pad system after rollout. The maximum outage duration during these two events is 2 to 4 hours each.
The purpose of this thermal design environments section is to present the physical interface environments and the shared compartment environments for PPL, CPL, and SPL. These environments are used to develop design criteria for payloads, systems, and major assemblies, and shall be used as boundary temperatures and analytical constraints. The environments will consist of descriptions of thermal environment characteristics throughout the mission phases of the vehicle including rollout, prelaunch (unfueled and fueled), launch, ascent and in-orbit.
Aerodynamic heating on the outside of SLS payload enclosures (OSA, USA or PLF) result in an internal time-dependent radiant heating environment around the spacecraft/payload before Orion separation, USA jettison or PLF jettison. Fairings use different coatings on external surfaces to minimize fairing skin temperatures. Spacecraft/payload thermal environments are further attenuated by acoustic suppression systems within the payload volume.
SLS Block 1 Crew Configuration Thermal Environments

The SLS Block 1 environmental temperature for SPL installed in a dispenser located within the OSA is shown in Table 5-4 for pre-launch, Table 5-5 for ascent, and Table 5-6 for on-orbit.

[Table: Table 5-4. Block 1 SPL Pre-Launch Environment Temperatures]

|  | Mission Phase |  |  | Integrated Payload (°F) |  |
| --- | --- | --- | --- | --- | --- |
| Rollout, NO purge, MAX |  |  | 130 |  |  |
| Rollout, NO purge, MIN |  |  | 26 |  |  |
| On-Pad, Purge ON, MAX |  |  | 101 |  |  |
| On-Pad, Purge ON, MIN |  |  | 29 |  |  |
| On-Pad, Tanked, Purge ON, MAX |  |  | 95 |  |  |
| On-Pad, Tanked, Purge ON, MIN |  |  | 17 |  |  |
| On-Pad, Tanked, Purge ON, MAX Time = 0.0 seconds |  |  | 88 |  |  |
| On-Pad, Tanked, Purge, ON, MIN Time = 0.0 seconds |  |  | 24 |  |  |
The electronic version is the official approved document.

[Table: Table 5-5. Block 1 SPL Ascent Environment Temperatures]

| Mission Phase | Dispenser Temperature Ascent (°F) |  | Dispenser |  | Dispenser Temperature Shutdown (°F) |
| --- | --- | --- | --- | --- | --- |
|  |  |  | Temperature |  |  |
|  |  |  | On-Orbit (°F) to |  |  |
|  |  |  | TLI |  |  |
| Ascent, MAX | 88 | 90 |  |  | 87 |
| Ascent, MIN | 24 | 18 |  |  | 4 |

[Table: Table 5-6. Block 1 SPL On-Orbit Environment Temperatures]

| Mission Phase |  | Dispenser Temperature |  |  | Dispenser Temperature |  |
| --- | --- | --- | --- | --- | --- | --- |
|  |  | TLI to TLI + 24 hours |  |  | TLI + 24 hours thru Lunar Flyby |  |
|  |  | (°F) |  |  | (°F) |  |
| On-orbit, MAX | 116 |  |  | 130 |  |  |
| On-orbit, MIN | 6 |  |  | 53 |  |  |
The electronic version is the official approved document.

[Table: Table 5-7. Block 1B CPL-to-PLA Interface Temperatures]

|  | Mission Phase |  |  | Min (Deg. F) |  |  | Max (Deg. F) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Rollout |  |  | 30 |  |  | 106 |  |  |
| On-Pad Unfueled |  |  | 53 |  |  | 103 |  |  |
| On-Pad Fueled |  |  | 34 |  |  | 101 |  |  |
| Launch to Core Stage Separation |  |  | 28 |  |  | 89 |  |  |
| Core Stage Separation to SECO1 |  |  | 19 |  |  | 90 |  |  |
| SECO1 to ORION Separation |  |  | -92 |  |  | 92 |  |  |
| ORION Separation to USA Jettison |  |  | -106 |  |  | 86 |  |  |
Compartment Bulk Gas Temperatures

Compartment bulk gas temperatures for both the Orion-to-PLA Shared Compartment and the PLA-to-EUS compartment are documented in this section. Table 5-8 documents the compartment bulk gas temperatures for the Orion-to-PLA Shared Compartment. Table 5-9 documents the compartment bulk gas temperatures for the PLA-to-EUS Shared Compartment. This compartment gas temperature and the CPL exchange heat through convection between the gas and the areas of the CPL that have a view through the top of the PLA to the EUS below.

[Table: Table 5-8. Block 1B Orion-to-PLA Shared Compartment Gas Temperatures]

|  | Mission Phase |  |  | Min (Deg. F) |  |  | Max (Deg. F) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Rollout |  |  | 30 |  |  | 99 |  |  |
| On-Pad Unfueled |  |  | 53 |  |  | 98 |  |  |
| On-Pad Fueled |  |  | 48 |  |  | 97 |  |  |

[Table: Table 5-9. Block 1B PLA-to-EUS Compartment Gas Temperatures]

|  | Mission Phase |  |  | Min (Deg. F) |  |  | Max (Deg. F) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Rollout |  |  | 30 |  |  | 104 |  |  |
| On-Pad Unfueled |  |  | 52 |  |  | 101 |  |  |
| On-Pad Fueled |  |  | 34 |  |  | 94 |  |  |
The electronic version is the official approved document.

[Table: Table 5-10. Block 1B USA Cone Radiation Sink Temperature]

|  | Mission Phase |  |  | Min (Deg. F) |  |  | Max (Deg. F) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Rollout |  |  | 30 |  |  | 105 |  |  |
| On-Pad Unfueled |  |  | 50 |  |  | 104 |  |  |
| On-Pad Fueled |  |  | 44 |  |  | 103 |  |  |
| Launch to Core Stage Separation |  |  | 42 |  |  | 131 |  |  |
| Core Stage Separation to SECO1 |  |  | 52 |  |  | 131 |  |  |
| SECO1 to ORION Separation |  |  | -64 |  |  | 127 |  |  |
| ORION Separation to USA Jettison |  |  | -110 |  |  | 79 |  |  |

[Table: Table 5-11. Block 1B USA Barrel Radiation Sink Temperature]

|  | Mission Phase |  |  | Min (Deg. F) |  |  | Max (Deg. F) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Rollout |  |  | 30 |  |  | 104 |  |  |
| On-Pad Unfueled |  |  | 50 |  |  | 103 |  |  |
| On-Pad Fueled |  |  | 44 |  |  | 102 |  |  |
| Launch to Core Stage Separation |  |  | 43 |  |  | 111 |  |  |
| Core Stage Separation to SECO1 |  |  | 47 |  |  | 111 |  |  |
| SECO1 to ORION Separation |  |  | -72 |  |  | 105 |  |  |
| ORION Separation to USA Jettison |  |  | -112 |  |  | 71 |  |  |
The electronic version is the official approved document.

[Table: Table 5-12. PPL-to-PLA Interface Temperatures]

|  | Mission Phase |  |  | Min (Deg. F) |  |  | Max (Deg. F) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Rollout |  |  | 30 |  |  | 100 |  |  |
| On-Pad Unfueled |  |  | 54 |  |  | 98 |  |  |
| On-Pad Fueled |  |  | 45 |  |  | 97 |  |  |
| Launch to PLF Separation |  |  | 40 |  |  | 91 |  |  |
| PLF Separation to Beginning of TLI Burn |  |  | -121 |  |  | 150 |  |  |
PLF Compartment Bulk Gas Temperatures

[Table: Table 5-13 documents the compartment bulk gas temperatures for the PLF Compartment. Table 5-14 documents the compartment bulk gas temperatures for the PLF Compartment. This compartment gas temperature and the PPL exchange heat through convection between the gas and the areas of the PPL that have a view through the top of the PLA to the EUS below.]

[Table: Table 5-13. PLF Compartment Gas Temperatures]

|  | Mission Phase |  |  | Min (Deg. F) |  |  | Max (Deg. F) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Rollout |  |  | 30 |  |  | 100 |  |  |
| On-Pad Unfueled |  |  | 54 |  |  | 99 |  |  |
| On-Pad Fueled |  |  | 49 |  |  | 98 |  |  |

[Table: Table 5-14. PLA-to-EUS Compartment Gas Temperatures]

|  | Mission Phase |  |  | Min (Deg. F) |  |  | Max (Deg. F) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Rollout |  |  | 30 |  |  | 102 |  |  |
| On-Pad Unfueled |  |  | 56 |  |  | 97 |  |  |
| On-Pad Fueled |  |  | 36 |  |  | 93 |  |  |
The electronic version is the official approved document.

[Table: Table 5-15. PLF Radiation Sink Temperature]

|  | Mission Phase |  |  | Min (Deg. F) |  |  | Max (Deg. F) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Rollout |  |  | 30 |  |  | 101 |  |  |
| On-Pad Unfueled |  |  | 53 |  |  | 100 |  |  |
| On-Pad Fueled |  |  | 50 |  |  | 98 |  |  |
| Launch to PLF Separation |  |  | 50 |  |  | 120 |  |  |
At approximately T-0, the ground purge is disconnected and venting becomes a function of the changing vehicle altitude and speed. During ascent, SLS Block 1B crew configuration payloads will be exposed to a compartment pressure within the envelope shown in Figure 5-1, and a peak depressurization rate of -0.30 psi/sec near 60 seconds. During ascent, SLS Block 1B cargo configuration payloads will be exposed to a compartment pressure within the PLF envelope shown in Figure 5-2, and a peak depressurization rate of -0.42 psi/sec near 60 seconds.
20 115.4 25 120.7 31.5 125.5 40 130.1 50 131.5 63 132.8 80 133.5 100 133.8 125 134.2 160 134.0 200 134.0 250 132.2 315 130.1 400 127.4 500 124.8 630 122.4 800 119.1 1000 116.3 1250 112.9 1600 109.1 2000 106.4 2500 103.6 3150 101.0 4000 98.0 5000 95.1 6300 92.2 8000 89.4 10000 86.9
SLS Block 1B Internal Acoustics

The payload internal acoustic environment is considered equivalent for both the SLS Block 1B crew (USA) and cargo (PLF) configurations. Therefore, acoustic environments for PPL, CPL and SPL are defined in Figure 5-3 and Table 5-17. Potential for additional

[Figure: Figure 5-3. Block 1B USA/PLF Internal Acoustic Environment, 95/50, 60% Fill Effect]
The electronic version is the official approved document.

[Table: Table 5-17. Block 1B USA/PLF Internal Acoustics Environment, 95/50, 60% Fill Effect]

|  | 1/3-Octave Band Center |  |  | Sound Pressure Level |  |
| --- | --- | --- | --- | --- | --- |
|  | Frequency (Hz) |  |  | (dB re: 20 μPa) |  |
| 20 |  |  | 118.7 |  |  |
| 25 |  |  | 122.6 |  |  |
| 31.5 |  |  | 128.2 |  |  |
| 40 |  |  | 134.8 |  |  |
| 50 |  |  | 135.4 |  |  |
| 63 |  |  | 135.2 |  |  |
| 80 |  |  | 134.8 |  |  |
| 100 |  |  | 134.6 |  |  |
| 125 |  |  | 132.5 |  |  |
| 160 |  |  | 132.9 |  |  |
| 200 |  |  | 132.5 |  |  |
| 250 |  |  | 132.5 |  |  |
| 315 |  |  | 132.5 |  |  |
| 400 |  |  | 130.5 |  |  |
| 500 |  |  | 128.5 |  |  |
| 630 |  |  | 126.0 |  |  |
| 800 |  |  | 124.0 |  |  |
| 1000 |  |  | 122.0 |  |  |
| 1250 |  |  | 120.2 |  |  |
| 1600 |  |  | 117.8 |  |  |
| 2000 |  |  | 116.0 |  |  |
| 2500 |  |  | 114.5 |  |  |
| 3150 |  |  | 112.5 |  |  |
| 4000 |  |  | 111.0 |  |  |
| 5000 |  |  | 109.0 |  |  |
| 6300 |  |  | 107.0 |  |  |
| 8000 |  |  | 105.5 |  |  |
| 10000 |  |  | 103.5 |  |  |
| Overall Sound Pressure Level |  |  | 144.7 |  |  |
SLS Block 1B Crew Configuration Random Vibration

No random vibration environment is defined for the CPL interface. At the CPL interface, for frequency less than 100 Hz, the random vibration environment is covered by the sine environment defined in Section 5.5.2. The USA internal acoustic environment, in Section 5.4.2, covers excitation produced by random vibration at the CPL interface, for frequency greater than 100 Hz. No random vibration load factor is defined for the CPL.  The USA internal acoustic levels, in Section 5.4.2 are a more appropriate source environment for CPL secondary structures and components.
SLS Block 1B Crew Configuration Sinusoidal Vibration

The sinusoidal vibration levels should be used in conjunction with the low frequency loads to aid in the design of CPL secondary structure.  The CPL sinusoidal vibration MPE level at the PLA interface is shown in Table 5-18.

[Table: Table 5-18. CPL Vehicle Dynamics Criteria]

| Frequency (Hz) |  | Normal |  |  |  |  | Frequency (Hz) |  | In Plane |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  | Input |  |  | Slope |  |  |  | Input |  |  | Slope |  |
|  |  | (g) |  |  | (dB/Octave) |  |  |  | (g) |  |  | (dB/Octave) |  |
| 5 | 0.22 |  |  |  |  |  | 5 | 0.22 |  |  |  |  |  |
| 20 | 0.22 |  |  |  |  |  | 22 | 0.22 |  |  |  |  |  |
| 27 | 0.26 |  |  | 2.15 |  |  | 31 | 0.31 |  |  |  |  |  |
| 35 | 0.26 |  |  |  |  |  | 60 | 0.31 |  |  | 4.23 |  |  |
| 60 | 0.16 |  |  | -4.92 |  |  |  |  |  |  |  |  |  |
SLS Block 1B Cargo Configuration Random Vibration

No random vibration environment is defined for the PPL. At the PPL interface, for frequency less than 100 Hz, the random vibration environment is covered by the sine environment defined in Section 5.5.4. The PLF internal acoustic environment, in Section 5.4.3, covers excitation produced by random vibration at the CPL interface, for frequency greater than 100 Hz. No random vibration load factor is defined for the PPL.  The PLF internal acoustic levels, in Section 5.4.3 are a more appropriate source environment for PPL secondary structures and components.
The electronic version is the official approved document.

[Table: Table 5-19. PPL Vehicle Dynamics Criteria] [Table: Table 5-20. Block 1B PPL/CPL Shock Environment at the PLA Interface (Q=10)]

| Frequency (Hz) |  | Normal |  |  |  |  | Frequency (Hz) |  | In Plane |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  | Input |  |  | Slope |  |  |  | Input |  |  | Slope |  |
|  |  | (g) |  |  | (dB/Octave) |  |  |  | (g) |  |  | (dB/Octave) |  |
| 5 | 0.22 |  |  |  |  |  | 5 | 0.22 |  |  |  |  |  |
| 20 | 0.22 |  |  |  |  |  | 22 | 0.22 |  |  |  |  |  |
| 27 | 0.26 |  |  | 2.15 |  |  | 31 | 0.31 |  |  |  |  |  |
| 35 | 0.26 |  |  |  |  |  | 60 | 0.31 |  |  | 4.23 |  |  |
| 60 | 0.16 |  |  | -4.92 |  |  |  |  |  |  |  |  |  |
Separation events during an SLS flight that could affect payloads are: the PLF jettison, USA jettison, and the spacecraft/payload separation from the PLA.  The spacecraft/payload separation device located at the top of the PLA is typically closest to the spacecraft/payload and generally produces the highest shock levels. The SLS Program’s goal is to utilize current ELV fairings and spacecraft/payload separation systems, where applicable for SLS Block 1; those shock environments (generally 2,000-4,500 g) for existing launch systems are readily available in ELV payload user’s guides for initial payload definition. Representative payload separation systeminduced shock environment for Block 1B payloads are shown in Table 5-20.  There can be a unique condition where a heritage separation system is supplied by the payload developer. For the heritage separation system supplied by the payload developer, a maximum allowable shock level at the PLA/SLS interface will be provided to the payload developer.
RF Environment. The Launch RF environment is provided in Table 5-20 and Figure 5-4, and the on-orbit external RF environment is provided in Table 5-21 and Figure 5-5.  The environment should be assumed to be the level as indicated on the graph even if tabular data is not available for a specific frequency of interest.  The on-orbit environment is given at an inclination angle of 57° and an altitude of 100 nmi.  If this environment does not envelope mission parameters, please contact the payload office for further data. The environment can be controlled at the request of the payload.

[Table: Table 5-20. Launch RF EME]
Peak (V/m)
Average (V/m)

49 6 5 437–447 7 5 2040 8 8 2106 7 7 2865 17 5 3100–3500 9 5 4440 9 9 4560 9 9 4640 9 9 4740 9 9 5400–5650 113 5 5650.01-5850 189 11 5850.01–5900 113 21 5900.01–5925 21 21 9370–9500 17 5 9500.01–9800 40 7 9800.01–9990 17 5 13750–14000 32 32
The electronic version is the official approved document.

[Figure: Figure 5-4. Launch RF EME (Peak Environment)]

[Table: Table 5-21. On Orbit RF EME]

|  | Frequency (MHz) |  |  | Peak (V/m) |  |  | Average (V/m) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 11–12 |  |  | 27 |  |  | 27 |  |  |
| 108.00 |  |  | 17 |  |  | 17 |  |  |
| 404–420.00 |  |  | 11 |  |  | 5 |  |  |
| 420.01–437.00 |  |  | 14 |  |  | 14 |  |  |
| 437.01–447.00 |  |  | 23 |  |  | 14 |  |  |
| 447.01–450.00 |  |  | 14 |  |  | 14 |  |  |
| 1175–1375 |  |  | 30 |  |  | 8 |  |  |
| 1550–1786.99 |  |  | 14 |  |  | 5 |  |  |
| 1787.00 |  |  | 43 |  |  | 43 |  |  |
| 1787.1–2090.99 |  |  | 14 |  |  | 5 |  |  |
| 2091.00 |  |  | 30 |  |  | 30 |  |  |
Peak (V/m)
Average (V/m)

2091.1–2110.00 14 5 2110.01–2120.00 30 30 2120.01–2144.99 14 5 2145.00 93 5 2145.10–2379.99 14 5 2380.00 189 189 2380.1–2839.99 14 7 2840.00 24 6 2840.1–2869.99 14 6 2870.00 24 6 2870.1–2950.99 14 6 2951.00 22 5 2951.1–3999.99 14 6 4000.00 85 85 4000.1–5399.99 15 5 5400.00–5659.99 27 5 5660.00 27 11 5660.1–5850.00 27 5 5850.01–5925.00 27 25 5925.01–6425 9 9 7155–7189 24 24 7209 6 6 8500–8559.99 7 5 8560.00 117 117 8560.10–9354.99 7 5 9355.00 142 5 9355.1–9999.99 7 5 10000.00 48 5 10593.00 10 10 14000–14500 10 10 16700 17 10 23530–23575 24 24 34316 7 7 34500–35200 11 11
The electronic version is the official approved document.

[Figure: Figure 5-5. On-Orbit RF EME (Peak Environment – 57° Inclination)]

Lightning Mitigation. Lightning direct effects are mitigated by a lightning protection catenary wire system at launch pad 39B. However, energy from a nearby lightning strike can couple into launch vehicle and spacecraft/payload cables. Operational controls and shielded umbilical cables will be in place to provide a limited level of protection. Magnetic field levels generated at the vehicle are a function of distance from the lightning event and strength of the lightning event. Given the protections in place, magnetic fields at the vehicle due to a lightning event will likely not exceed 200 A/m and levels this high should be considered rare. Magnetic fields on the order of 20A/m-40A/m will be more common. Weather-related events at the launch complex (LC)-39B pad, such as lightning, are recorded and measured continuously. Sensor data will be available for comparison against payload susceptibility levels. An illustration of the LC 39B pad is given in Figure 5-6. The ML portion of the weather subsystem measures electromagnetic transients associated with lightning events to or near the ML as well as performing a similar function for voltage and current transients measured at the Ground Support Equipment (GSE) power supply feeds to the launch vehicle. The Orion lightning monitoring system provides monitoring during rollout and at the pad. Additional measures beyond these capabilities will be the responsibility of the payload.
Launch vehicle hardware that comes into contact with the spacecraft/payload’s environment is designed and manufactured according to strict contamination control requirements and guidelines. Ground operations at the launch site have been designed to ensure a clean environment for the spacecraft/payload. Details regarding Clean Work Area (CWA) classifications for launch site facilities are outlined in Section 7.0. However, cleanliness requirements for each spacecraft/payload will be evaluated on a case-by-case basis. All SLS payloads will follow specified contamination control procedures to prevent particle release and minimize Foreign Object Debris to ensure mission safety and success. Contamination-critical hardware surfaces will be visually inspected to verify established contamination and nonvolatile residue (NVR) criteria are met. In addition, the surface can also be cleaned using a solvent flush. The solvent is filtered and the particles on the filter are measured and counted. This provides a particle count (within a specific size range) per square foot. Particle fallout filters or wafers may also be placed in an area for a period of time. Afterwards, filters are microscopically examined or scanned electronically to provide a particle count. Additional verification techniques shown below can be provided on a mission-unique basis:
1. Particulate Obscuration — Tape lift sampling 2. NVR — Solvent wipe sampling 3. Particulate Obscuration — Ultraviolet light inspection 4. Particulate and Molecular Fallout — Witness plates After encapsulation, the USA or PLF environment can be continuously purged with air filtered with High-Efficiency Particulate Air (HEPA) filters to ensure the cleanliness of the environment and