JuanCastillo29/space-mission-intelligence-data huggingface dataset:
Copernicus-2 Option: Addition of an In-Line Tank to Achieve 130-day Transit
Times

To reduce transit times by 20 days—from 150 to 130 days, the Copernicus-2 configuration positions an “in-line” LH2 tank between the NTPS and integrated saddle truss/drop tank assembly (shown in Figs. 8 and 10). This configuration has an IMLEO of ~443.8 t consisting of the “wet” NTPS (~136.4 t), in-line tank (~118.5 t), saddle truss/drop tank assembly (~119 t) and the crew PL section (~69.9 t). The overall vehicle length is ~117.6 m including the Orion MPCV at ~8.9 m. The LH2 tank length in the NTPS is ~19.7 m and it carries ~86.1 t of propellant (close to its maximum capacity of ~87.2 t). The in-line and drop tank lengths are the same at ~20.5 m and each tank carries ~91.5 t of LH2 propellant.

With these equal tank lengths, the masses of in-line tank element and the saddle truss/drop tank assembly are balanced at ~118.8 t. For this 130-day transit mission, there are four primary burns (with three restarts) and ~253.8 t of LH2 propellant is used. A fourth engine is added to the NTPS to reduce the total engine operating time and minimize g-losses (~326 m/s) during the TMI maneuver but this increases NTPS inert mass at the expense of LH2 and RCS propellant loading. With ~100.4 klbf of total thrust and a Isp of 906 s, the total
engine burn time for this mission is ~84.2 min. The first TMI perigee burn is the longest single burn at ~35 min. After this burn, the drop tank is drained and then jettisoned to reduce vehicle mass and propellant consumption during the second perigee burn (~21.8 min). The in-line tank and NTPS supply the propellant for the remaining MOC (~17.5 min) and TEI burns (~9.9 min). Copernicus-2 also requires one additional HLV launch as well as the development of the in-line tank element with its own ZBO cryocooler system. For the longer in-line tank, the cryocooler system requires ~9.13 kWe of electrical power supplied by PVAs on the NTPS and in-line tank. Even with a fourth engine added, the total burn time requirement on the engines is increased by 13 percent (from 74.6 to 84.2 min). An alternative to adding a fourth NTR engine would be to add oxygen “afterburner” nozzles to Copernicus’ three NTR engines. In the “LOX-Augmented” NTR (LANTR) option (Refs. 20 and 21), oxygen is injected into the divergent section of the nozzle downstream of the sonic throat. Here it mixes with reactor-heated H2 and undergoes supersonic combustion adding both mass and chemical energy to the engine’s exhaust. By operating the LANTR engines with a LOX-to-LH2 mixture ratio (MR) = 1 during the first TMI perigee burn, the engine’s thrust level can be increased by over 62 percent—from 25 to ~40.6 klbf. The addition of oxygen lowers the Isp to ~725 s but this is still ~270 s higher than that achieved by LOX/LH2 engines.
Copernicus-3 Option: Addition of Twin Drop Tanks to Achieve 120-day Transit
Times

In the Copernicus-3 configuration (shown in Figs. 8 and 11), the saddle truss/drop tank assembly is replaced by a 4-sided “star truss” with twin LH2 drop tanks that supplement the propellant carried by the NTPS and in-line tank. Copernicus-3 has an IMLEO of ~551.3 t including the NTPS (~139.9 t), the inline tank (~133.8 t), the “star truss” with drop tanks (~210.3 t) and the crew PL section (~67.3 t). Two drop tanks (~190 t) carrying ~159.4 t of LH2 (~79.7 t per tank) are delivered to LEO on two HLV launches, then attached to the ~25.4 m long star truss (~20.3 t) during the LEO assembly phase. Each drop tank is ~18.2 m long. The overall vehicle length is ~118.2 m including the 8.9 m Orion MPCV. The LH2 loading in the off-loaded NTPS, in-line and twin drop tanks is ~83.1, ~98.6, and ~159.4 t, respectively. The lengths of NTPS and in-line LH2 tanks are ~19.7 and ~21.9 m. During the four primary mission burns ~321 t of LH2 propellant is used. With 100.4 klbf of total thrust and Isp ~906 s, the total
engine burn time for this mission is ~106.4 min, close to the ~2 hr demonstrated on the NRX-XE engine. After completing a long first perigee burn (~52 min), both drop tanks are jettisoned. The remaining burn durations are as follows: second perigee burn (~20.7 min), MOC (~22.2 min) and TEI (~11.5 min). Four HLV launches are required to deliver the major transportation systems elements (the NTPS, in-line tank and two drop tanks) to LEO. An upgraded SLS is used to deliver the crewed payload element and the large but lightweight star truss.
Falcon Heavy

[Figure: Figure 1. Launch cost per kilogram to LEO versus first launch date.

The major impression given by Figure 1 is of two large initial and recent cost drops with a long intermediate period of more constant cost. Three early systems had launch costs to LEO above $100 k/kg, even approaching $1,000 k/kg. Vanguard was the first and by far most expensive launch system. Costs dropped rapidly to the Saturn V used for Apollo, which still has the lowest historical cost except for three Soviet systems and the two recent Falcons. Vanguard’s launch cost was about 170 times that of the Saturn V.]

The average launch cost did not change much from 1970 to 2000, especially since many systems with initial flight before 2000 continue to be used. From 1970 to 2000 the average launch cost was $18.5 k/kg, with a typical range of $10 to $32 k/kg. Of the 22 systems initially launched from 1970 to 2000, only 7 have costs below $10 k/kg,
International Conference on Environmental Systems and they are all Soviet or Chinese and their cost may be subsidized.

Only 2 systems have costs above $32 k/kg, the shuttle at $61.7 k/kg and the small and costly Pegasus.
A major drop in cost occurred in 2010 with the Falcon 9 at $2.7 k/kg. The Falcon Heavy reduces the cost to $1.4 k/kg. Shuttle’s launch cost was about 20 times that of the Falcon 9 and about 40 times that of the Falcon Heavy. The average 1970 to 2000 launch cost of $18.5 k/kg is reduced by a factor of 7 for the Falcon 9 and and 13 for the Falcon Heavy. (Costs from Appendix A are in 2018 dollars. Some differ from unadjusted costs in the abstract.)
Copernicus-3a Option: Addition of Second Set of Drop Tanks to Achieve 100-day
Transit Times

In transitioning from 120 to 100-day transit times the total mission V increases by ~42 percent— from ~8.83 to ~12.5 km/s. To satisfy the high-energy requirements of this mission, Copernicus-3a (shown in Figs. 8 and 12) adds a second set of drop tanks to the star truss. Adjustments are made to the PL as well. The crew size is reduced to four and the mass of the TransHab and consumables needed for the mission are reduced accordingly.

Composite LH2 tanks are also used instead of Al/Li. Lastly, the operating temperature of the engines’ (UC-ZrC) graphite composite fuel is increased to achieve a specific impulse of ~940 s (see Table 1). The resulting vehicle has an IMLEO of ~720.7 t, which includes the NTPS (~137.6 t), the in-line tank (~123.7 t), the star truss with four common LH2 drop tanks (~397.5 t) and the crew PL section (~61.9 t). The PL element includes the Orion MPCV (~15.1 t) which carries additional propellant (~5.1 t) for the final Earth slowdown burn (V ~1.266 km/s) before re-entry while the MTV flies past Earth and is disposed of in heliocentric space.

[Figure: Figure 11.—Copernicus-3 Option: Supports 120-day transit times for the 2033 mission.]

[Figure: Figure 12.—Copernicus-3a Option: Supports 100-day transit times for the 2033 mission.]

The LH2 tank lengths in the NTPS and in-line element are ~19.7 and ~21.9 m, and they carry ~87.2 and ~95.5 t of propellant, respectively. Copernicus-3a’s four drop tanks carry ~327.8 t of propellant (~82 t per tank), and each tank is ~18.6 m long. The drop tanks are jettisoned in pairs after the first and second perigee burns to reduce vehicle mass and propellant consumption during the TMI maneuver. The overall vehicle length is ~117.6 m. The total usable propellant for the mission is ~480.7 t. With 100.4 klbf of thrust and Isp ~940 s, the
total engine burn time is ~165.4 min. This value exceeds the ~2 hr demonstrated on the NRX-XE engine by ~45 min. The first perigee burn is the longest single burn at ~78.3 min and also exceeds the single burn duration record of ~62 min set by the NRX-A6 engine. The duration of the remaining burns are as follows: second perigee burn (~37.3 min), MOC (~33.3 min), and TEI (~16.5 min). Seven HLV launches are required to deliver the major transportation systems elements (the NTPS, in-line tank, four drop tanks, and PL element) to LEO. A single SLS with sufficient PL volume will be used to launch the large but lightweight star truss.
element to reduce vehicle mass and propellant consumption. The ERV then performs the TEI burn on July 1, 2035 and begins the 90-day transfer back to Earth. On the final approach to Earth, the ERV does a final slowdown burn (V ~2.257 km/s) after which the crew separates and re-enters using the Orion MPCV capsule. The ERV flies past Earth at a sufficiently high altitude and is disposed of into heliocentric space.

[Figure: Figure 13.—Copernicus-2 MTV and components configured for a very fast split crewed mission.]

For the outbound mission leg, the Copernicus-2 spacecraft (Fig. 14) has an IMLEO of ~402 t consisting of the NTPS (~134.5 t), the in-line tank (~92.4 t), the integrated saddle truss/LH2 drop tank assembly (~122.8 t), and the crewed PL element (~52.3 t). The NTPS, in-line and drop tank elements (again using composite tanks) carry ~87.2, ~71.3, and ~95 t respectively, for a total LH2 propellant loading of ~253.5 t. By using two separate vehicles for the crewed mission, three engines are again sufficient for each. With ~75.3 klbf of total thrust, an Isp of 940 s, and ~239 t of usable propellant, the total
engine burn time for this mission is ~109.6 min. The first TMI perigee burn is the longest at ~52.6 min. After this burn, the drop tank is drained and jettisoned to reduce vehicle mass and propellant consumption during the second perigee burn (~28.8 min). The NTPS supplies all the propellant needed for MOC (~28.2 min). The “round trip” ERV has an IMLEO of ~360.3 t consisting of the NTPS (~131.3 t), the in-line tank (~101.4 t) and the integrated saddle truss/LH2 drop tank assembly (~122.9 t). The composite tanks used in the ERV’s NTPS, in-line and drop tank elements carry ~87.2, ~77, and ~95 t respectively, for a total propellant loading of ~259.2 t. The ERV’s NTPS performs five primary burns (and four restarts) and its three engines provide ~75.3 klbf of total thrust. With ~244.3 t of usable propellant and a Isp of ~940 s, the
total engine burn time for this mission is ~112.1 min. The first TMI perigee burn is the longest at ~41.3 min. After this burn, the drop tank is drained and jettisoned. The durations of the remaining burns are as follows: second perigee burn (~13.7 min), MOC (~13 min), TEI (~28.6 min), and final slowdown burn (~15.5 min). The long TEI burn is attributed to the addition of Copernicus-2’s ~40.2 t crewed PL mass plus the high TEI V requirement (~3.075 km/s) for the 90-day transit back to Earth. The total and longest single engine burn times required for the ERV mission while substantial, are still below the capabilities demonstrated by the NRX-XE (~2 hr) and NRX-A6 engines (~62 min).

[Figure: Figure 14.—“Split Crewed Mission” Option: Supports 100 to 90-day transit times.]

Lastly, the total mission IMLEO for the two spacecraft is ~762.4 t. Seven HLV launches are required for the split mission option—four for the Copernicus-2 and three for the ERV—compared to eight total launches required for the “all up” Copernicus-3a configuration. No on-orbit assembly (e.g., attachment of multiple drop tanks) is required just autonomous R&D of several vehicle components.
Harry W. Jones1 NASA Ames Research Center, Moffett Field, CA, 94035-0001
The development of commercial launch systems has substantially reduced the cost of space launch. NASA’s space shuttle had a cost of about $1.5 billion to launch 27,500 kg to Low Earth Orbit (LEO), $54,500/kg. SpaceX’s Falcon 9 now advertises a cost of $62 million to launch 22,800 kg to LEO, $2,720/kg. Commercial launch has reduced the cost to LEO by a factor of 20. This will have a substantial impact on the space industry, military space, and NASA. Existing launch providers are reducing their costs and so are satellite developers. The military foresees an opportunity to rapidly replace compromised space assets that provided communications, weather, surveillance, and positioning. NASA supported the development of commercial space launch and NASA science anticipates lower cost missions, but human space flight planning seems unreactive. Specifically, it has been claimed that commercial spaceflight has not reduced the cost to provide cargo to the International Space Station (ISS). The key factor is that the space shuttle can provide cargo and crew to ISS while the Falcon 9 must also use the Dragon capsule, which adds cost and reduces payload. The cost of a Falcon 9 and Dragon capsule mission to ISS is about $140 million with a payload of 6,000 kg, $23,300/kg. The shuttle payload to ISS is less than to LEO, 16,050 kg, so its cost is also higher at $93,400/kg. The launch cost to ISS has been reduced by a factor of 4. Calculations that show commercial launch provides no cost reduction to ISS assume half the usually cited shuttle cost and allocate it to the actual delivered payload, about half the full capacity. In a split mission, with crew and pressurized cargo launched separately from hardware and materials, the higher Falcon 9 plus Dragon costs would apply only to a fraction of the launch mass. A 4 to 1 cost reduction saves most, 75%, of the total cost. A further reduction to 10 or 20 to 1 saves 90 or 95%, but this is only a small, 15 or 20%, portion of the original cost. The recently reduced space launch cost can be expected to substantially impact human space flight.
HE cost of space launch dropped from very high levels in the first decade of the space age but then remained high for decades and was especially high for the space shuttle. In the most recent decade, commercial rocket development has reduced the typical space launch cost by a factor of 20 while NASA’s launch cost to ISS has declined by a factor of 4.
This paper reviews the history of the reduction in space launch costs, considers the reasons for the decline, and discusses the implications for space users. Very high launch cost was long considered the major impediment to space exploration and exploitation. Many technical approaches were suggested to reduce launch cost but none succeeded until commercially motivated suppliers bypassed the problems long inhibiting government sponsored rocket builders. Surprisingly, launch vehicle reuse - the most anticipated method to cut cost - has not so far actually cut cost and probably contributed to very high shuttle launch cost. The decline in launch costs has removed a major barrier and is expected to increase exploration, exploitation, and human expansion in space. The commercial market, the military, and NASA have responded differently due to their different goals and methods. Rocket builders and
1 Systems Engineer, Bioengineering Branch, Mail Stop N239-8.

users are reacting to market signals by cutting prices, and the military sees an opportunity to increase security using space, but NASA seems slower to adapt.
The military is eager to take advantage of lower launch costs, which provide a forceful and dramatic solution to vital current problems. The United States’ military capabilities greatly depend on space assets, including communications, global positioning, weather, and surveillance satellites. Satellites are vulnerable to attack and difficult to hide or defend, so the ability to rapidly and cheaply replace them is very attractive. “Recent private sector developments in access to space could open the door for a new concept for airpower. If realized these capabilities could fundamentally change the USAF’s power projection paradigm, while building new strategic options for the nation.” (Air University, 2017, p. ii) The Air University white paper explains the problem and proposed solution. “(O)ur current space architecture grows increasingly vulnerable.” “Fast Space envisions sortie-on-demand launch capability, made possible through economically viable business cases, high launch rates, sustainably lower costs, rapid turn-around, and higher reliability.” This provides “The ability to immediately deliver additional effects worldwide such as precision navigation and timing, electronic warfare, cyber effects, directed energy, kinetic attack, and rapid global transport of cargo and personnel.” “In short, competition in space has returned. Space is congested and contested and our advantages in space can no longer be assured. The US military depends on space assets that are increasingly at risk of attack.” (Air University, 2017, pp. 1, 2, 7) Low cost space launch provides the solution to urgent current military problems and could enable a new era of US military dominance through control of space.
The Air University report characterizes NASA’s launch system efforts as directly leading to higher costs than a commercial approach. “A government agency, even a well-run agency, does not have the correct economic incentives to lower costs. NASA was not incentivized to eliminate the operational and labor costs that were part of the Shuttle system. Since NASA depends on political support, which is driven by the number of jobs in congressional districts, the opposite is true. America has proven over its history that private industry, properly incentivized in a pro-competition environment, is much more successful at lowering costs.” “NASA chose the highest technical risk solution from among the three major X-33 bids, as they gave higher points to the bidders with the ‘most new technology’… This is the exact opposite of how almost any commercial firm would have evaluated the process, as ‘technical risk’ is something to be eliminated and mitigated before taking a product or service to market.” “The NAI had to make everybody happy, so it included a significant piece of work for all parties. The ‘political process’ required to achieve buy-in and consensus significantly increased the estimated price.” (Air University, 2017, pp. A-2, 3)
[Table: Table 1 shows the launch cost of the space shuttle and Falcon 9 plus Dragon to the International Space Station (ISS). The numbers are taken from Appendix B:]

| System | Shuttle | Falcon 9 plus Dragon |
| --- | --- | --- |
| Total cost per launch, 2018 $M | 1,697 | 150 |
| kg to ISS | 16,050 | 6,000 |
| Total 2018 $k/kg | 105.8 | 25 |
After an initial decline at the beginning of the space age, Western launch costs have remained very high and relatively constant until recently. High launch costs have been “the greatest limiting factor to expanded space exploitation and exploration.” (Wertz and Larson, 1996, pp. 115-7) The technical causes of high launch cost have been assessed as follows:
1. Goal of maximum performance and minimum weight, originally from ballistic missiles 2. Higher cost of expendables versus reusables 3. High cost of human spaceflight 4. High cost of new technology, hardware, and software 5. Low failure tolerance and consequent intense design effort and detailed oversight 6. High system complexity, parts counts, and number of interfaces (Wertz and Larson, 1996, pp. 126-33) Commercial launchers saved initial development cost by using missile designs, but missiles are designed for high performance, not minimum cost. Comparing rockets to aircraft, it seems that reusability is the obvious path to reducing costs, but the example of the space shuttle does not support this. Reusable rockets have higher development costs and reduced payload due to the need for landing fuel. The Falcon 9 is reusable and has been reused, but the projected cost savings remain in the future. Human spaceflight adds costs for life support, higher reliability, and man rating. Commercial and military payloads are expensive and there is low tolerance for failure. Development and production cost increases with system complexity. (Wertz and Larson, 1996, pp. 126-33) The possible technical approaches to cut launch cost have been assessed as follows:
1. Simplify the vehicle configuration 2. Increase vehicle production and launch rates 3. Use industrial design and production methods (cultural change) 4. Optimize for minimum cost 5. Reduce the parts count 6. Increase simplicity and design margins 7. Reduce instrumentation 8. Design for production and operation (Wertz and Larson, 1996, pp. 147-53) One study suggested that the record low cost of the Saturn V could be reduced by a factor of 5, to a cost similar to the Falcon Heavy. The Pegasus system achieved low development cost using a commercial off-the-shelf International Conference on Environmental Systems approach, but because of its small payload it had the second highest launch cost in recent decades.

Wider design margins can accommodate weight growth without costly last minute weight reducing efforts, help avoid miniaturization, and allow redundancy rather than intensive design to increase reliability. (Wertz and Larson, 1996, pp. 148, 149, 154) “To make significant reductions in launch costs, new ‘clean sheet’ launch systems must be developed. … institutional barriers within government and industry have prevented major inroads is cost reduction.” (Wertz and Larson, 1996, p. 155) The long awaited large reduction in launch cost has now been achieved, but what were the “institutional barriers” that delayed this?
There are many reasons to expect that space launch costs will go lower, even much lower. These include launch vehicle reuse, an expanded market due to lower cost, increased commercial competition, better management and engineering, and technical advances.
The reuse of rockets and entire launch vehicles has been considered important in reducing launch cost, but so far reuse has not led to lower cost. The space shuttle was extremely expensive, largely due to the high cost of refurbishing the shuttle between flights. The Falcon 9 was designed to be reused, at a significant increase in development cost, but so far it has been reused only a few times. Falcon 9 reuse may reduce costs by a factor of two. “SpaceX president Gwynne Shotwell told the Space Symposium conference that the cost of refurbishing the Falcon 9 rocket that originally flew the CRS-8 Space Station resupply mission last year for SES-10 was ‘substantially less than half’ what it would have cost to build a brand new one.” (Morris, 2017) Reuse might provide much more drastic cost reductions. Elon Musk believes that the new Raptor engine can achieve full reusability of all rocket stages and “a two order of magnitude reduction in the cost of spaceflight” to $10 per pound by 2025. (Wang, 2016) General market and competitive effects could lead to further cost reduction. The lower cost of launch should lead to an increased number of space flights, which would lead to cost reduction due to the learning curve, to reliability growth due to failure mode discovery and repair, and would more quickly pay back the initial development cost and so justify more investment in launcher design. Previously the launch market belonged to a limited number of government supported entities possibly more concerned with military capability, launch reliability, national prestige, and creating jobs and economic stimulus than with reducing costs or developing new technology. The commercial rocket business has provided a different engineering-savvy business model that has greatly reduced costs. A growing more competitive market will tend to favor technology advances that cut cost and improve performance.