JuanCastillo29/space-mission-intelligence-data huggingface dataset:
High launch costs have affected all aspects of space planning. High launch costs have been the greatest factor limiting the number and reducing the scope of space missions. Reduced launch cost will directly allow more, bigger, better missions. (Wertz and Larson, 1996, p. 117) High launch costs lead to high spacecraft costs through “intense pressure to make every kilogram of the spacecraft pack as much performance and capability as possible.” (Wertz and Larson, 1996, p. 154) Space hardware must be very light and so it tends to be fragile, creating a problem during launch. Weight removal is difficult and requires extensive analysis and testing to ensure surviving launch. Reliable, tested and proven, standard, inexpensive off-the-shelf systems can not be used because of their weight. Using more mass allows increased design margins, use of redundancy, and operational robustness. (Wertz and Larson, 1996, p. 154) Reduced launch cost will directly allow heavier, more robust and reliable, and better performing spacecraft to be developed at lower cost.
Low cost commercial launch “will change our lives. The development of a robust space economy promises growth, astounding new products and services, amazing high-tech jobs and a quantum leap in our national security capabilities.” “Launch cost has always been the primary constraint in the space business. If access to space weren’t so expensive we’d have an astounding amount of entrepreneurial activity in Low Earth Orbit (LEO) and beyond. Space tourism, materials development, pharmaceutical research, power generation, communications, earth imaging and national security all have “killer apps” just waiting for reliable and affordable access to space.” (Autry, 2017)
Until the 2000’s, communications satellites were the principal commercial launch market. The total number of commercial launches was roughly 25 to 35 per year until the Falcon 9 expanded the market and became the largest supplier, passing the Ariane 5. Communications satellites use a limited number of internationally allocated International Conference on Environmental Systems geosynchronous slots.

The commercial satellite launch market is far from an open and competitive market, since most suppliers and customers have been government regulated and subsidized. Prices can be affected by political reasons.
In a restricted market, lower costs might not have much impact. None the less, “Satellite design and manufacturing is beginning to take advantage of these lower-cost options for space launch services.” And, “(T)he satellite manufacturing industry may ‘experience a shock similar to what the launcher industry is experiencing’” (Wikipedia, Space launch market competition) Ultimately, a commercial market tends to reduce costs and improve performance.
The space shuttle had some capabilities that the Falcon 9 lacks. The Falcon 9 payload to ISS is much lower than shuttle due to the need for the Dragon capsule, even though the payloads to LEO are similar. The Falcon Heavy payload to LEO is more than twice the space shuttle’s. (Spacex.com, 2018) The Falcon 9 and Dragon are expected to carry crew to the ISS, but the shuttle also could sustain a crew in orbit for weeks and had a large workspace in the payload bay. Both the space shuttle and Falcon 9 can return cargo to Earth.
The Falcon 9’s cost to NASA is lower than shuttle’s because Falcon 9 launch is a contracted service rather than supported by an in-house capability. Most Falcon 9 launches are commercial, so the cost of development and operations is spread over many launches per year. NASA shuttle management was well aware of this cost spreading effect and initially planned to have all US launches, commercial, military, and NASA science, use the shuttle. After Challenger, most space shuttle flights were restricted to building the ISS or where humans were needed, as in Hubble repair. The low flight rate of the space shuttle was a major factor in its high cost. (Rutledge, 93-4063)
The cost of space launch has been substantially reduced. This provides greatly expanded opportunities to exploit space for commercial users, the military, and NASA. The commercial competitive launch approach sponsored by NASA provided an unconstrained environment that allowed a focused management to cut costs using good engineering. Competition drives innovation and forces efficiency, cuts costs and creates new opportunities.
The commercial low launch cost opportunity, competing foreign space efforts, and a possible new military push into space suggest that NASA should plan for lower launch costs and try to increase the number and size of missions. The previous assumptions and design decisions made for the space station should be reconsidered, especially the use of recycling rather than resupply for life support. Further commercialization may be advantageous.
Table A1 shows the first launch date and the launch cost to Low Earth Orbit (LEO) in current dollars for many historical rocket systems. Most of the data was obtained from past compilations, but the Saturn V, Space shuttle, Falcon 9, and Falcon Heavy launch costs are calculated below.
International Conference on Environmental Systems | System | First launch date | $k/kg | Reference |

| --- | --- | --- | --- |
| Ariane 44 | 1988 | 17.9 | Wertz and Larson, 1996 |
| Ariane 5G | 1996 | 13.1 | Futron, 2002 |
| Athena 1 | 1995 | 31.7 | Wertz and Larson, 1996 |
| Athena 2 | 1995 | 16.6 | Futron, 2002 |
| Atlas IIA | 1991 | 19.8 | Wertz and Larson, 1996 |
| Atlas-Centaur | 1964 | 28.0 | Koelle, 1991 |
| Cosmos | 1967 | 12.4 | Futron, 2002 |
| Delta 3910 | 1975 | 28.0 | Koelle, 1991 |
| Delta E | 1960 | 167.8 | Koelle, 1991 |
| Delta II | 1989 | 15.3 | Futron, 2002 |
| Delta III | 1998 | 11.7 | Koelle, 1991 |
| Dnepr | 1999 | 4.9 | Futron, 2002 |
| Falcon 9 | 2010 | 2.7 | SpaceX.com, 2018 |
| Falcon Heavy | 2018 | 1.4 | SpaceX.com, 2018 |
| H-2 | 1994 | 26.4 | Wertz and Larson, 1996 |
| Kosmos | 1967 | 8.0 | Wikipedia, Comparison, 2018 |
| Long March 2C | 1974 | 10 | Futron, 2002 |
| Long March 2E | 1971 | 7.7 | Wertz and Larson, 1996 |
| Long March 3B | 1984 | 6.3 | Futron, 2002 |
| Pegasus XL | 1990 | 43.5 | Futron, 2002 |
| Proton SL-13 | 1965 | 4.1 | Wertz and Larson, 1996 |
| Rockot | 1994 | 10.4 | Futron, 2002 |
| Saturn V | 1968 | 5.2 | Williams, 2016 |
| Saturn IB | 1966 | 17.3 | Koelle, 1991 |
| Scout | 1961 | 111.8 | Koelle, 1991 |
| Space shuttle | 1981 | 61.7 | Pielke and Byerly, 2011 |
| Soyuz | 1966 | 7.6 | Futron, 2002 |
| Start | 1993 | 16.7 | Futron, 2002 |
| Taurus | 1989 | 20.4 | Wertz and Larson, 1996 |
| Titan II | 1962 | 31.0 | Wertz and Larson, 1996 |
| Titan IV | 1989 | 24.7 | Wertz and Larson, 1996 |
| Titan-Centaur | 1974 | 11.2 | Koelle, 1991 |
| Vanguard | 1957 | 894.7 | Koelle, 1991 |
| Vega | 2012 | 10.0 | Wikipedia, Comparison, 2018 |
| Zenit 2 | 1985 | 4.4 | Futron, 2002 |
| Zenit 3SL | 1999 | 7.6 | Futron, 2002 |

Table A2 shows the computation of the launch cost per kilogram to LEO in current dollars for the Saturn V, space shuttle, Falcon 9, and Falcon Heavy.
2 | Koelle, 1991 |
| Vanguard | 1957 | 894.7 | Koelle, 1991 |
| Vega | 2012 | 10.0 | Wikipedia, Comparison, 2018 |
| Zenit 2 | 1985 | 4.4 | Futron, 2002 |
| Zenit 3SL | 1999 | 7.6 | Futron, 2002 |

Table A2 shows the computation of the launch cost per kilogram to LEO in current dollars for the Saturn V, space shuttle, Falcon 9, and Falcon Heavy.

| System | Saturn V | Shuttle | Falcon 9 | Falcon Heavy |
| --- | --- | --- | --- | --- |
| kg to LEO | 140,000 | 27,500 | 22,800 | 63,800 |
| Cost per launch, 2018 $M | 728 | 1,697 | 62 | 90 |
| 2018 $k/kg | 5.20 | 61.72 | 2.72 | 1.41 |
| Reference | Williams, 2016 | Pielke and Byerly, 2011 | SpaceX.com, 2018 | SpaceX.com, 2018 |

International Conference on Environmental Systems The space shuttle carried 27,500 kg to LEO but only 16,050 kg to ISS.
(Wikipedia, Space Shuttle) The cost per kilogram for shuttle launch to ISS was $1,697 M/16,050 kg = $105.8 k/kg in current dollars using the shuttle cost from Table A2.
In 2008 NASA awarded a $1.6 billion to SpaceX for 12 cargo delivery flights to ISS. (Wikipedia, SpaceX Dragon) The cost per launch in current dollars is $1,792 million/12 = $149 M/launch. This cost is higher than the $62 M for a Falcon 9 launch because of the added requirement for the cargo-containing Dragon capsule. NASA awarded five more cargo-supply missions to SpaceX in late 2015, with an undisclosed cost estimated at $140 or 150 million per launch, $144 to 154 million in current dollars. (de Selding, 2016) The costs were corrected from the reported basis years to current dollars using the Consumer Price Index (CPI). (CPI Inflation Calculator, 2018) The average current cost estimate is about 150 million.
Each 2008 contract launch was required to carry 5,000 lbs (2,273 kg) to ISS, but the potential payload to ISS is much larger than the contract minimum, 6,000 kg. (Spacex.com, 2018) (Wikipedia, SpaceX Dragon) The cost for Falcon 9 and Dragon cargo to ISS is $150 M/6,000 kg = $25 k/kg, 24% of the shuttle cost to ISS and a reduction by a factor of 4.2. The cost reduction factor for cargo to ISS is much less than the reduction factor for LEO, but it is still a significant cost reduction.
APPENDIX A ACRONYMS AND ABBREVIATIONS ...........................................................122 APPENDIX B ADMIT SURVEY ...............................................................................................127
TABLE

[Table: TABLE 4-1. USEFUL PSM TO EARTH ESCAPE ......................................................................36
TABLE 5-1. BLOCK 1 SPL LOAD FACTORS DUE TO LOW FREQUENCY LOADS ..........38
TABLE 5-2. BLOCK 1B PPL/CPL COMBINED LOAD FACTORS .........................................38
TABLE 5-3. BLOCK 1B PPL/CPL ACCELERATIONS .............................................................38
TABLE 5-4. BLOCK 1 SPL PRE-LAUNCH ENVIRONMENT TEMPERATURES .................39
TABLE 5-5. BLOCK 1 SPL ASCENT ENVIRONMENT TEMPERATURES ...........................40
TABLE 5-6. BLOCK 1 SPL ON-ORBIT ENVIRONMENT TEMPERATURES .......................40
TABLE 5-7. BLOCK 1B CPL-TO-PLA INTERFACE TEMPERATURES ................................41
TABLE 5-8. BLOCK 1B ORION-TO-PLA COMPARTMENT GAS TEMPERATURES .........41
TABLE 5-9. BLOCK 1B PLA-TO-EUS COMPARTMENT GAS TEMPERATURES ..............41
TABLE 5-10. BLOCK 1B USA CONE RADIATION SINK TEMPERATURE.........................42
TABLE 5-11. BLOCK 1B USA BARREL RADIATION SINK TEMPERATURE ....................42
TABLE 5-12. PPL-TO-PLA INTERFACE TEMPERATURES...................................................43
TABLE 5-13. PLF COMPARTMENT GAS TEMPERATURES ................................................43
TABLE 5-14. PLA-TO-EUS COMPARTMENT GAS TEMPERATURES ................................43
TABLE 5-15. PLF RADIATION SINK TEMPERATURE ..........................................................44
TABLE 5-16. BLOCK 1 SPL INTERNAL ACOUSTIC ENVIRONMENTS .............................47
TABLE 5-17. BLOCK 1B USA/PLF INTERNAL ACOUSTICS ENVIRONMENT..................49
TABLE 5-18. CPL VEHICLE DYNAMICS CRITERIA .............................................................50
TABLE 5-19. PPL VEHICLE DYNAMICS CRITERIA..............................................................51]
The electronic version is the official approved document.

[Table: TABLE 5-20. BLOCK 1B PPL/CPL SHOCK ENVIRONMENT ................................................51
TABLE 6-1. SECONDARY PAYLOAD (SPL) MAXIMUM DIMENSIONS ............................79
TABLE 6-2. SPL CENTER OF GRAVITY (CG) ENVELOPE ...................................................80
TABLE 7-1. SSPF CAPABILITY OVERVIEW ..........................................................................85
TABLE 7-2. SSPF RESOURCE OVERVIEW .............................................................................86
TABLE 7-3. MPPF CAPABILITY OVERVIEW .........................................................................90
TABLE 7-4. MPPF RESOURCE OVERVIEW ............................................................................91
TABLE 7-5. PHSF CAPABILITY OVERVIEW ..........................................................................93
TABLE 7-6. PHSF RESOUCE OVERVIEW ...............................................................................94
TABLE 7-7. VAB RESOURCE OVERVIEW ..............................................................................97
TABLE 7-8. ML RESOURCE OVERVIEW ..............................................................................100
TABLE 7-9. CT RESOURCE OVERVIEW ...............................................................................101
TABLE 7-10. PAD B RESOURCE OVERVIEW ......................................................................103
TABLE 8-1. SLS PAYLOAD INTEGRATION AND MANAGEMENT PROCESS* (1 OF 3)113
TABLE 8-1. SLS PAYLOAD INTEGRATION AND MANAGEMENT PROCESS* (2 OF 3)114
TABLE 8-1. SLS PAYLOAD INTEGRATION AND MANAGEMENT PROCESS* (3 OF 3)115]
[Figure: FIGURE 3-1. SLS PERFORMANCE AND MISSION CAPTURE BENEFITS .........................12 FIGURE 3-2. SLS BLOCK CONFIGURATIONS .......................................................................13 FIGURE 3-3. SLS VEHICLE COORDINATE SYSTEM ............................................................14 FIGURE 3-4. SLS BLOCK 1 CREW CONFIGURATION ..........................................................15 FIGURE 3-5. SLS BLOCK 1 CARGO CONFIGURATION (REFERENCE ONLY) .................16 FIGURE 3-6. SLS BLOCK 1 ISPE CREW CONFIGURATION .................................................17 FIGURE 3-7. SLS BLOCK 1B CREW CONFIGURATION .......................................................18 FIGURE 3-8. SLS BLOCK 1B CARGO CONFIGURATION .....................................................18]
The electronic version is the official approved document.

[Figure: FIGURE 3-9. SLS EXPLORATION UPPER STAGE..................................................................19 FIGURE 3-10. REPRESENTATIVE SLS BLOCK 2 CARGO CONFIGURATION ..................20 FIGURE 3-11. SLS BLOCK 1 PROGRESS IN SUPPORT OF FIRST FLIGHT (EM-1) ...........21 FIGURE 4-1. NASA’S EXPLORATION CAMPAIGN OVERVIEW .........................................22 FIGURE 4-2. NOMINAL SLS FLIGHT DESTINATIONS .........................................................23 FIGURE 4-3. NOMINAL SLS BLOCK 1B ASCENT PROFILE (CARGO) ..............................24 FIGURE 4-4. SLS BLOCK 1 DISTANT RETROGRADE ORBIT (DRO) (EM-1) ....................26 FIGURE 4-5. REPRESENTATIVE SECONDARY PAYLOAD JETTISON “BUS STOPS” ....26 FIGURE 4-6. SLS BLOCK 1 HYBRID FREE RETURN (EM-2) ...............................................27 FIGURE 4-7. SLS BLOCK 1B NEAR RECTILINEAR HALO ORBIT (NRHO) (EM-3) .........28 FIGURE 4-8. MASS DELIVERY DEFINITION FOR CARGO CONFIGURATIONS .............29 FIGURE 4-9. SLS BLOCK 1B/2 USEFUL PSM TO CIRCULAR ORBITS (ENGLISH) ..........31 FIGURE 4-10. SLS BLOCK 1B/2 USEFUL PSM TO CIRCULAR ORBITS (SI) .....................32 FIGURE 4-11. SLS BLOCK 1/1B/2 USEFUL PSM TO ELLIPTICAL ORBITS (ENGLISH) ..33 FIGURE 4-12. SLS BLOCK 1/1B/2 USEFUL PSM TO ELLIPTICAL ORBITS (SI) ................34 FIGURE 4-13. USEFUL SLS PSM TO EARTH ESCAPE ..........................................................35 FIGURE 5-1. PRESSURE ENVELOPE BLOCK 1B CREW PAYLOADS ................................45 FIGURE 5-2. PRESSURE ENVELOPE BLOCK 1B CARGO PAYLOADS ..............................46 FIGURE 5-3. BLOCK 1B USA/PLF INTERNAL ACOUSTIC ENVIRONMENT ....................48 FIGURE 5-4. LAUNCH RF EME (PEAK ENVIRONMENT) ....................................................53 FIGURE 5-5. ON-ORBIT RF EME (PEAK ENVIRONMENT – 57° INCLINATION) .............55 FIGURE 5-6. LC 39B LIGHTNING PROTECTION SYSTEM REPRESENTATION ..............56 FIGURE 6-1. RANGE OF SLS SPACECRAFT/PAYLOAD ACCOMMODATIONS ...............58 FIGURE 6-2. RANGE OF SLS FAIRINGS AND STAGE ADAPTER CONCEPTS .................59 FIGURE 6-3. SLS BLOCK 1 ISPE ...............................................................................................60 FIGURE 6-4. SLS BLOCK 1B/2 ISPE .........................................................................................61]
The electronic version is the official approved document.

[Figure: FIGURE 6-5.  ORION CREW MISSION INTERFACES TO SLS ..............................................62 FIGURE 6-6. COMPOSITE 8.4 M USA PLF CONCEPT ...........................................................63 FIGURE 6-7. COMPOSITE 8.4M PLF, SHORT CONCEPT ......................................................65 FIGURE 6-8. COMPOSITE 8.4M PLF, LONG CONCEPT ........................................................66 FIGURE 6-9. COMPOSITE 10M PLF, LONG CONCEPT .........................................................68 FIGURE 6-10. COMPOSITE 10M PLF, SHORT CONCEPT .....................................................69 FIGURE 6-11. COMPOSITE UNIVERSAL STAGE ADAPTER (USA) ...................................70 FIGURE 6-12. REPRESENTATIVE USA CONCEPT OF OPERATIONS ................................71 FIGURE 6-13. SLS BLOCK 1B/2 PAYLOAD ADAPTER (PLA) ..............................................72 FIGURE 6-14. REPRESENTATIVE PLA CONFIGURATIONS FOR CPL AND PPL .............73 FIGURE 6-15. 8.4 M PAYLOAD ADAPTERS (PLA) ................................................................74 FIGURE 6-16. CONCEPTUAL PAYLOAD ADAPTER (PLA) FOR BLOCK 1B/2 .................75 FIGURE 6-17. ORION STAGE ADAPTER (OSA) TO SPL INTERFACE ................................77 FIGURE 6-18. SLS BLOCK 1B/2 PLA ACCOMMODATION OF SPLS ..................................78 FIGURE 6-19. SECONDARY PAYLOAD (SPL) ENVELOPE DEPICTION ............................79 FIGURE 6-20. SPL CENTER OF GRAVITY (CG) ENVELOPE WITHIN DISPENSER .........79 FIGURE 6-21. SPDS AVIONICS UNIT SPL INTERFACE (BLOCK 1/EM-1) .........................81 FIGURE 7-1. KENNEDY SPACE CENTER (KSC) FACILITIES ..............................................82 FIGURE 7-2. SPACE STATION PROCESSING FACILITY (SSPF) .........................................83 FIGURE 7-3. SPACE STATION PROCESSING FACILITY (SSPF) FLOOR PLAN ...............84 FIGURE 7-4. MULTI PAYLOAD PROCESSING FACILITY (MPPF) .....................................88 FIGURE 7-5. MPPF FLOOR PLAN .............................................................................................89 FIGURE 7-6. PAYLOAD HAZARDOUS SERVICING FACILITY (PHSF) .............................92 FIGURE 7-7. PHSF AND SURROUNDING FACILITIES .........................................................93 FIGURE 7-8. VEHICLE ASSEMBLY BUILDING (VAB) .........................................................96 FIGURE 7-9. VEHICLE ASSEMBLY BUILDING (VAB) FLOOR PLAN ...............................97]
The electronic version is the official approved document.

[Figure: FIGURE 7-10. MOBILE LAUNCHER (ML) RESOURCES .......................................................99 FIGURE 7-11. CRAWLER-TRANSPORTER ...........................................................................101 FIGURE 7-12. LAUNCH COMPLEX 39B (LC-39B)................................................................102 FIGURE 7-13. LAUNCH CONTROL CENTER ........................................................................104 FIGURE 7-14. REPRESENTATIVE SLS BLOCK 1 CARGO OPERATIONAL FLOW.........106 FIGURE 7-15. REPRESENTATIVE SLS BLOCK 1B CREW OPERATIONAL FLOW ........107 FIGURE 7-16. REPRESENTATIVE SLS BLOCK 1B CARGO OPERATIONAL FLOW ......107 FIGURE 7-17. PAYLOAD ENCAPSULATION FLOW (USA EXAMPLE) ............................108 FIGURE 8-1. SLS/EGS SPACECRAFT/PAYLOAD INTEGRATION SCHEDULE ...............116]
The purpose of this Space Launch System (SLS) Mission Planner’s Guide (MPG) is to provide future payload developers/users with sufficient insight to support preliminary SLS mission planning. Consequently, this SLS MPG is not intended to be a payload requirements document; rather, it organizes and details SLS interfaces/accommodations in a manner similar to that of current Expendable Launch Vehicle (ELV) user guides to support early feasibility assessments. Like ELV programs, specific payload requirements will be defined in unique documentation once manifested to fly on SLS. SLS users requiring additional mission planning information or more detailed technical interchange concerning specific SLS accommodations should contact the SLS Spacecraft/Payload Integration and Evolution (SPIE) office. SPIE serves as the payload point of contact to SLS and can be reached by email at NASA-slspayloads@mail.nasa.gov.
This document has been developed to respond to queries by the SLS user community concerning SLS accommodations and their general availability. This SLS MPG will be updated as needed to reflect newly baselined capabilities as the SLS payload-specific performance to destination, interfaces, and operational constraints mature.
Capabilities described within the SLS MPG are representative and not necessarily indicative of NASA space exploration intent, planning, funding or requirements. SLS provides the United States with a unique launch capability for which alternative systems do not exist. Therefore, SLS payloads will be compliant with 51 U.S.C. 50131, Requirement to Procure Commercial Space Transportation Services, and the National Space Policy directive to “refrain from conducting United States Government space activities that preclude, discourage, or compete with U.S. commercial space activities, unless required by national security or public safety.”
The NASA Office of Primary Responsibility (OPR) for this document is Exploration Systems Development (ESD) Division. The OPR Designee (OPRD) is the SLS Program, Spacecraft/Payload Integration and Evolution (SPIE) Office. The OPRD is charged with development and management of updates to the document prior to submitting a formal Change Request (CR). Proposed changes to this document will be submitted via a CR to the ESD Control Board (ECB) for disposition.
departure energy. Three major SLS upgrades – Blocks 1, 1B, and 2 - are planned, each available in
a crew and a cargo configuration. The initial Block 1 vehicle will send payload to the Moon via
Trans-Lunar Injection (TLI) starting in early 2020s. The Block 1 crew configuration is currently
planned to be used for an initial uncrewed test flight, Exploration Mission-1 (EM-1), and for the
first crewed lunar flight since 1972, Exploration Mission-2 (EM-2). The Block 1 cargo
configuration is under consideration for Science Mission-1 (SM-1), which will see the vehicle
launch a robotic probe to Jupiter’s moon Europa using a direct trajectory.
JOI (5/23/24)
C3=15 km2/s2 C3=82 km2/s2 2 Earth Flybys
VGA (5/14/22)
JOI (4/4/28)
0 Earth Flybys
EGA-1 (10/24/23)
EGA-2
Launch (11/21/21)
(10/24/5)
Launch
Jupiter s Orbit
(6/5/22)
DSM (7/10/22)

[Figure: Figure 3-1. SLS Performance and Mission Capture Benefits]
The electronic version is the official approved document.

CPL and SPL using the USA. The cargo version can accommodate PPL and SPL using a range of 8.4 m and potentially larger diameter PLFs.
These SLS block configurations support an architecture development approach that minimizes life cycle program costs, enables deep space missions, maintains critical skills and effectively transitions existing infrastructure. The space shuttle-derived design takes advantage of resources established for the shuttle, including the workforce, tooling, manufacturing processes, supply chain, transportation logistics, launch infrastructure, large solid rocket motor production capability and liquid oxygen/liquid hydrogen (LOX/LH2) propellant infrastructure.
Notes: (1) For the purposes of this SLS MPG, “crew” refers to Orion flights on SLS, and “cargo” refers to SLS delivery missions that do not fly the Orion spacecraft; (2) Common names of stages, adapters and fairings will include the diameter in meters (e.g., 8.4m PLF) compliant with international usage; (3) Where a payload accommodation is applicable to more than one SLS Block at a time, it may be referenced as “Block 1/1B/2” or “Block 1B/2”.