Manned expedition to the Moon


Variants 1-2 Other

Variants 3-4 Cargo delivery

Variants 5-6 What are we searching for on the Moon?

Variant 7

Variant 8


Launch vehicles for a manned expedition to the Moon


   To carry out a lunar expedition, you must:
1. Deliver a lunar module (LM) with two astronauts to the Moon, while its ability to leave the Moon should be no less than that of the take-off stage of the Apollo spacecraft (mass 4548 kg).
2. Deliver the main unit (MU) to a low lunar orbit a ship capable of returning three astronauts to Earth. The mass of the engine must be at least 12 tons, of which 5.5 tons of fuel. In addition to the LM and MU, the lunar complex (LC) includes a brake block (BB). If the BB lands on the moon, then it is a landing stage (as it was in the Apollo program). Otherwise, a unified lunar module (ULM) is used, performing both landing and launch (as was assumed in the Soviet lunar program).
   To launch the lunar complex to the Moon , it is planned to use the last stage of the launch vehicle, fueled by the orbital station (OS). In addition, you will need to refuel the brake block. Fuel components can be delivered to the OS in a ready-made form, or produced from water. For the delivery of components or water to the OS, it is planned to create a special device adapted to solve such a task, which will reduce the cost of its production and development. The main purpose of such a device will be to ensure the minimum cost of delivering a kilogram of payload to the OS.
   If the delivered cargo is water, then an electrolysis-cryogenic complex is required for the OS. With an electric power of 100 kW of solar panels, it is able to process fuel into liquid components within a year, taking into account the inevitable technological interruptions 85 t of water.
   The proposed method will allow the use of heavy, medium and light launch vehicles for the lunar expedition.
   Below, 6 of the 8 variants that we have studied are offered for consideration.
   Variants 3, 4 involve the use of a single carrier - "Proton-M" or "Angara 5", having as the last stage a universal oxygen-hydrogen block (UOHB). These variants are strained in the mass reserves, especially variant 3, where it may be necessary to reload the LC to 1.5 tons, while the cargo will have to be delivered separately. Their disadvantage is the increased waiting time for the crew to refuel and prepare the LC and UOHB.
   Variants 5.6 are easier and more accessible to implement. They assume the withdrawal of the MU of a separate launch vehicle. For this purpose, the ready-made carrier "Zenit 2" (it is necessary to complete the restoration of the ground launch at Baikonur), and in the future - the developed "Soyuz-3". When removing the lunar module and BB, the capabilities of the "Proton-M" carrier are not fully used, which makes it possible to place additional cargo on it. Such a load can be additional fuel or solid-fuel accelerators intended for the initial acceleration of the LC. A separate launch will allow the LC crew to arrive at the OS by the time UOHB-BB-ULM is ready, and stay on it only for the rest period. Then the main part of the expedition in time will not overlap with the acute period of adaptation to weightlessness, it will be possible to avoid wasting extra strength and weakening the skills of the crew.
   Variants 7, 8 are promising, for their implementation you will need to create two new launch vehicles, as well as have another component on the OS - liquid methane. The MU carrier can also be created on the basis of the Soyuz launch vehicle with a reduced or underutilized central block. Variant 7 is stressful in terms of mass characteristics, and will probably be in demand for a flight to an already delivered cargo module or for changing the crew of the lunar base.
   In variant 7, BB is used as a landing stage, and the mass of the LM is equal to the mass of the take-off stage of the Apollo lunar module. In other variants, ULM is used. Variant 3 is equal to variant 3 in terms of capabilities 7, in other cases, it is possible to deliver an additional non-returnable cargo to the Moon.
   Table 1 shows the data on the variants presented: the total mass of the refueled fuel, the initial mass of the lunar module, the mass of the lunar module starting from the Moon, and the mass of the additional cargo delivered to the Moon.



Variants

Tipe of launch vehicle

Refueling,
t

LM mass with cargo,
t

Initially LM mass,
t

Increase of payload mass on the Moon,
t

1

7 (1025 )

65

-

-

-

2

7 (1025 )

95

-

-

-

3

-̻/ 5

54,8

7,8

5,88

-

4

5

58,1

8,9

5,92

0,70

5

-̻ + -2

60,2

10,8

6,3

0,47

6

-̻ + -2

56,4

9,9

5,97

1,38

7

1̻ + launch vehicle 295 t

58,8

4,55

4,55

-

8

-2̻ +

launch vehicle 282 t

66,9

8,8

5,71

1,32


Tabl. 1


   In the proposed variants, the mass of the upper stage and LC is less than in the Apollo project. This is due to the achievements in the field of rocket science and navigation devices made over the past time. First of all, this is the realized high specific impulse of the engines UOHB (KVD-1 - 4550 Ns/kg) and the DM block (3538 Ns/kg). The energy-mass perfection of the MU is assumed to be moderate, and the lunar module-at the level of the Apollo program. The calculations used low parameters of the ULM propulsion system, the reliability of which is critical for the safety of the crew (specific impulse-3000 N*s/kg, except for variant 7). The American lunar module had landing and take-off stages, each of which contained a considerable supply of fuel for maneuvers. A single module that performs both landing and launch allows you to fully use the fuel of the DM block and reduce your own onboard supply, since it does not leave fuel on the Moon. This will also be facilitated by a more detailed exploration of the landing site by modern means, which will reduce the time for maneuvering. In addition, with equal opportunities, the ULM has less weight of the landing gear.
   The following are brief descriptions of the variants presented for lunar expeditions.


to the begining 


Variants 1-2


   Variants 1 and 2 demonstrate the capabilities of the proposed launch vehicle system and rely on the use of an A7 carrier with an oxygen-hydrogen upper stage. The carrying capacity of the A7 carriers of both variants will be 51 t on LEO, and fuel mass in OHB - 64 t and 98 t accordingly. They are capable of delivering a fully assembled LC mass to the space station 47 t. Option 1's OHB, fueled on the OS, is capable of putting the LC on a trajectory to the Moon. This makes it possible to "copy" the Apollo expedition, avoid refueling the LC and use only high-boiling components in it. The OHB of variant 2 provides not only the departure of the LC to the Moon, but also its insertion into a low lunar orbit (i.e., it is delivered to it 47 t of payload). To visualize the possibilities of the 2nd variant in the program parameters "Apollo", note that in a rough approximation, its LC may contain a second, additional LM. During the flight to the Moon, special measures will be required, including a special orientation mode that protects the remaining OHB fuel from overheating. A7 certification for manned launches is not expected, astronauts land in the LC during its service on the OS.
   Table 2 below shows the main parameters of variants 1 and 2.


 

Variant 1

Variant 2

Launch vehicle launch mass, t

1025

1025

Characteristics velocity OHB, m/s

3200

4050

Payload mass, t (LEO)

50.8

51.1

Payload mass, t (OS)

47.1

47.0

Refueling mass fuel, t

64.3

97.7

Construction mass OHB,

12.7

19.5

Cost equivalent of the output mass, 

79.3

95.9

Payload mass in lunar orbit, t

33.0

47.0

Relative specific gravity the cost of payload in lunar orbit

1.00

0.85


Tabl. 2


   From the point of view of the present time, the implementation of these variants looks unlikely due to the redundancy of their capabilities and the high cost of creating an A7. In terms of cost indicators, they are significantly inferior to the variants that provide for refueling on the OS of LC units.


to the begining 


Variants 3-4


   The lunar complex (LC) consists of the main unit (MU) - the return vehicle, the brake unit (BB) and a unified lunar module(ULM).
   The MU includes an orbital compartment and a descent vehicle from the Soyuz spacecraft, modified for a flight to the Moon, as well as a newly developed aggregate compartment with a fuel reserve of at least 5,5 t. Total mass of MU in LC structure 12 t, crew 3 people. BB is a standard DM unit, modified for refueling with liquid oxygen on the OS, which is put into orbit with an empty oxidizer tank and a full fuel tank. The ULM is designed for a soft landing on The moon, launch from it, and ensure a rendezvous with MU in lunar orbit. It has a detachable landing platform, including landing supports and a bottom screen. Research equipment is also attached to it. The main systems of the ULM propulsion system are duplicated. In the event of a failure of one of its systems, the ULM propulsion system must ensure that the crew returns from any stage of the module's independent flight.
   The lunar complex is put into orbit by a carrier of the type "Proton-M" or "Angara 5", using as the last stage Universal oxygen-hydrogen block (UOHB). In variant 3, the unit holds 44 tons of fuel, which is provided for by its design, in variant 4, it is slightly more - 47.3 tons. When removing the LC elements, the following is installed on the UOHB BB, on it - ULM, on top - MU.
   After launching into the base orbit, the UOHB-LC bundle makes a flight to the OS using the correction propulsion system (CPS) located on the UOHB. The CPS provides the approach of the UOHB + payload bundle to the OS with the minimum speed that allows it to be captured by the OS. The question of the feasibility of placing the crew in the MU during the withdrawal remains open. Before the start of refueling (possibly before mooring to the OS), the MU is separated from the bundle and docked with the orbital station.
   After refueling the UOHB and BB, the crew moves to the MU, where they leave the orbital station and dock with the ULM, or the MU is connected by the aggregate compartment to the rest of the layout using the OS manipulator. The lunar complex with a fueled UOHB is diverted to a safe distance from the orbital station, and fuel is deposited on the remnants of the CPS components, The UOHB launches and puts the LC on a trajectory to the Moon, after which it separates. During the withdrawal, the crew will experience an increasing overload of up to 0,72
g. If the MU is docked to the ULM, the overload will be negative. If the MU is connected to the rest of the layout by an aggregate compartment, then after removal it is separated, withdrawn, unfolded and docked with the ULM. In variant 3, a small pre-release pulse will be required, which will provide BB.
   During the flight to the Moon , trajectory corrections with a total impulse of up to 20 m/s will be required, for which the propulsion system MU is supposed to be used. Braking to enter a low circular lunar orbit with a height of about 100 km is carried out by the braking unit, while the negative overload for the crew will not exceed 0,3
g.
   Next, a series of propulsion system MU inclusions transforms the orbit into an elliptical one with a periselation of about 10 km, after which the MU with one astronaut is separated and transferred to the waiting orbit. In the area of periseleniya, the propulsion system BB turns on and fully generates fuel, providing the ULM with a minimum speed relative to the lunar surface. The BB then separates, is carried away by venting the remaining boost gases and components, and falls to the Moon. The estimated horizontal speed of the ULM during separation is 100 m/s in the variant 3 and 125 / in the variant 4, altitude 10 km. ULM performs further braking with its own engines. The final stage of the landing is performed manually by the astronauts.
   After completing the research program, the ULM with the crew launches and enters orbit, leaving the landing platform on the Moon. Next, the ULM performs a series of orbital maneuvers required for rendezvous with the MU. The rendezvous ends with a docking, in which the MU plays an active role. The astronauts transfer the research results to the MU, separate the empty ULM, and put the MU on a return trajectory to Earth.
   Before entering the atmosphere, the MU is divided into compartments, two of them - the orbital and aggregate-are destroyed, and the lander performs a controlled descent and makes a soft landing.
   The main characteristics of variants 3 and 4 are given in the table 3.

   Both variants are similar with one significant difference. If in variant 4, the UOHB puts the lunar complex on a trajectory to the Moon, then in variant 3, the UOHB capabilities are not enough for this and additional acceleration is required using the DM block. As a result, the engine of the DM block is started three times against two in variant 4. Taking into account the fact that the mass of the LC variant 4 is slightly larger, it is obvious that it is preferable. The reason why both variants are considered here is that the output mass of LC is at the limit of the capabilities of the carriers, despite the fact that there are restrictions on the ratio of steps imposed by the location of the areas of their fall.



 

Variant 3

Variant 4

Launch vehicle

"-"

"-5"

UOHB mass, t

52,736

56,378

UOHB fuel, t

44,000

47,300

UOHB construction, t

7,350

7,680

Character. output on LEO velocity, m/s

3697

3781

Character. velocity at launch to the Moon, m/s

3105

3200

CPS mass, t

1,386

1,398

including fuel for the flight to OS

0,924

0,932

Refueled hydrogen, t

6,286

6,757

Refueled oxygen (for UOHB and BB), t

48,485

51,314

Lunar complex, t

37,140

38,200

Mass of MU+BB+ULM on OS before refueling

26,369

27,429

Main unit, t

12,000

12,000

Fuel MU, t

5,500

5,500

Brake block (11D58M), t

17,345

17,345

BB construction, t

2,300

2,300

BB fuel for additional acceleration, t

0,979

0,000

BB fuel for the first braking, t

7,723

8,158

BB fuel for the second braking, t

6,343

6,887

All fuel, t

15,045

15,045

Total oxidizer, t

10,771

10,771

Specific impulse of the propulsion system, N*s/kg

3538

3538

Component ratio

2,52

2,52

Character. additional acceleration speed, m/s

95

0

Character. speed in 1st braking, m/s

850

850

Character. speed in 2nd braking, m/s

1725

1701

Unified lunar module, t

7,795

8,855

ULM dry mass, t

3,903

4,777

ULM fuel, t

3,892

4,078


Tabl. 3

to the begining


Variants 5-6


   The lunar complex (LC) consists of the main unit (MU) - the return vehicle, the brake unit (BB) and a unified lunar module (ULM).
   The MU includes an orbital compartment and a descent vehicle from the Soyuz spacecraft, modified for a flight to the Moon, as well as a newly developed aggregate compartment with a fuel reserve of at least 5,5 t. Total mass of MU in LC structure 12 t, crew 3 people. BB is a DM unit with enlarged fuel tanks, modified for refueling with liquid oxygen on the OS. It is put into orbit with an empty tank of oxidizer and a full tank of fuel. ULM is designed for a soft landing on the lunar surface, providing crew activities on the Moon and delivering it and research materials to lunar orbit. It has a detachable landing platform, including landing supports and a bottom screen. Research equipment is also attached to it. The main systems of the motor system ULM installations are duplicated. In the event of a failure of one of its systems, the ULM propulsion system must ensure that the crew returns from any stage of the module's independent flight.
   The lunar module and the DM block are put into orbit by the Proton-M carrier, which uses the Universal oxygen-hydrogen Block (UOHB) as the last stage, containing 44 t of fuel, which is provided for by its project. When outputting, the ULM is set to the DM block. In variant 5 , the carrier can simultaneously capture several tons of cargo. In variant 6, the UOHB is equipped with an accelerator that makes a significant contribution to acceleration when launching to the Moon. In Table 4, the case is considered when the accelerator is a powerful CPS, discarded after fuel generation.
   After launching into the base orbit, the UOHB-BB-ULM After launching into the base orbit, the UOHB-LC bundle makes a flight to the OS using the correction propulsion system (CPS) located on the UOHB. The CPS provides the approach of the UOHB + payload bundle to the OS with the minimum speed that allows it to be captured by the OS.
   The MU is put into orbit by the Zenit-2 carrier or another one that provides the required payload capacity, makes an independent flight and docks with the orbital station.
   After refueling the UOHB and BB, the crew moves to the MU, where they leave the orbital station and dock with the ULM, or the MU is connected by the aggregate compartment to the rest of the layout using the OS manipulator. The lunar complex with the fueled UOHB is withdrawn to a safe distance from the orbital station, at the right moment the accelerator (CPS) is launched, and then the UOHB itself, which accelerates the LC, fully generating fuel, and then immediately separates. In variant 6, the emptied CPS is discarded during withdrawal. The additional flight path to the moon is carried out by the DM unit. During the withdrawal, the crew will experience an increasing overload of up to 0,6 - 0,65
g. If the MU is docked to the ULM, the overload will be negative. If the MU is connected to the rest of the layout by an aggregate compartment, then after removal it is separated, unfolded and docked with the ULM.
   During the flight to the Moon , trajectory corrections with a total impulse of up to 20 m/s will be required, for which the propulsion system MU is supposed to be used. Braking to enter a low circular lunar orbit with a height of about 100 km is carried out by the braking unit, while the negative overload for the crew can reach 0,25
g.
   Next, a series of propulsion system MU inclusions transforms the orbit into an elliptical one with a periselation of about 10 km, after which the MU with one astronaut separates and moves to the waiting orbit. In the area of overpopulation, the propulsion system BB turns on and fully generates fuel, after which the BB is separated and removed by venting the remaining boost gases and components. ULM performs further braking with its own engines. In option 5, the lunar module will need to extinguish a fairly significant remainder of the orbital velocity at ~425 m/s more than in variant 6. The final landing stage is performed manually by the astronauts.
   After completing the research program, the ULM with the crew launches and enters orbit, leaving the landing platform on the Moon. Next, the ULM performs a series of orbital maneuvers required for rendezvous with the MU. The rendezvous ends with a docking, in which the MU plays an active role. The astronauts transfer the research results to the MU, separate the empty ULM, and put the MU on a return trajectory to Earth.
   Before entering the atmosphere, the MU is divided into compartments, two of them - the orbital and aggregate-are destroyed, and the lander performs a controlled descent and makes a soft landing.
   In variant 5, the ULM consumes more fuel during landing and delivers a smaller payload to the Moon than the ULM of variant 6, despite having a higher initial mass. With the same cargo and crew return capabilities, the ULM of variant 5 delivers 0.47 tons more cargo to the Moon, and the ULM of variant 6 delivers 1.38 tons more cargo than the ULM of variant 3.
   Additional features of a separate launch allow you to increase the time spent on the Moon to almost a full lunar day (the maximum time people spent on the Moon was 75 hours in the Apollo 17 expedition), or up to 2-3 months if an additional cargo module was delivered to the Moon. At the same time, it is possible to deliver the entire crew to the Moon, as well as use the MU modification with an increased fuel reserve instead of the orbital compartment. In this case, before launching to Earth, the aggregate compartment of the lunar module is separated, and the cabin remains docked to the MU and acts as an orbital compartment.
   The main characteristics of variants 5 and 6 are given in the table 4.


 

Variant 5

Variant 6

Launch vehicle BB+ULM

"-"

"-"

Launch vehicle MU

"-2"

"-2"

UOHB mass, t

52,736

60,714

UOHB fuel, t

44,000

44,000

UOHB construction, t

7,350

7,350

Character. output on LEO velocity, m/s

3697

3768

Character. velocity at launch to the Moon, m/s

2603

3117

CPS mass, t

1,386

9,364

including fuel for the flight to OS

0,924

1,190

Refueled hydrogen, t

6,286

6,286

Refueled oxygen (for UOHB and BB), t

53,871

50,101

Lunar complex, t

48,716

41,808

BB+ULM mass on OS before refueling

20,560

17,422

Main unit, t

12,000

12,000

Fuel MU, t

5,500

5,500

Brake block (DM modification), t

25,868

19,902

BB construction, t

3,300

2,600

BB fuel for additional acceleration, t

7,796

0,969

BB fuel for the first braking, t

8,739

8,722

BB fuel for the second braking, t

6,032

7,611

All fuel, t

22,568

17,302

Total oxidizer, t

16,156

12,386

Specific impulse of the propulsion system, N*s/kg

3538

3538

Component ratio

2,52

2,52

Character. additional acceleration speed, m/s

617

83

Character. speed in 1st braking, m/s

850

850

Character. speed in 2nd braking, m/s

1256

1682

Unified lunar module, t

10,848

9,906

ULM dry mass, t

5,022

5,637

ULM fuel, t

5,827

4,270


Tabl. 4


to the begining 


Variant 7


   The lunar complex (LC) consists of the main unit (MU) - the return vehicle, the lunar module (LM) and the landing stage (LS).
   The MU includes an orbital compartment and a descent vehicle from the Soyuz spacecraft, modified for a flight to the Moon, as well as a newly developed aggregate compartment with a fuel reserve of at least 6,1 t. Total mass of MU in LC structure 13,1 t, crew 3 people. The MU is launched into orbit by a carrier using a Universal oxygen-hydrogen block (UOHB) as the last stage, containing44 t of fuel. After entering orbit, the MU separates, turns around, docks with the UOHB, and transports it to the OS. The UOHB is equipped with an SFRE for the fuel precipitation used during the launch to the Moon.
   During the period of operation of the UOHB, a significant characteristic speed is achieved-more than 5 km/s, which is why a new launch vehicle will need to be created to launch the MU. If you create the first stage on oxygen-kerosene fuel and implement modern design achievements (the pressure in the engine chamber is 25 MPa, the specific impulse in the vacuum is 3300 N*s/kg, the mass of the structure is 1/12 of the mass of the stage), you will get a carrier with a starting mass 295 .
   The LS is designed to put the LC into lunar orbit and deliver the lunar module to the surface of the Moon. It has landing supports and rigging to accommodate research equipment. LM is designed to support the activities of the crew on the Moon and deliver it and research materials to the lunar orbit.
   The lunar module is put into orbit by the carrier "Angara-1M". The last stage of this carrier runs on oxygen-methane fuel and is later used as a landing stage. After launching into the base orbit, the LS-LM bundle makes a flight to the OS using the correction propulsion system (CPS) located on the LS. CPS provides the approach of the LS-LM bundle to the OS with the minimum speed that allows it to be captured by the OS.
   The LC is assembled at the space station in the following order: UOHB-LS-LM. During assembly and refueling, the main unit is docked to the orbital station. After refueling the UOHB and LS, the crew moves to the MU, where they leave the orbital station and dock with the LM, or the MU is connected by the aggregate compartment to the rest of the layout using the OS manipulator. The LC-UOHB bundle is diverted to a safe distance from the orbital station, the solid fuel rocket engine is used to deposit fuel, the UOHB is launched and puts the LC on a flight path to the Moon, after which it separates. When you output the crew will experience an increasing overload of about 0,75
g. If the MU is docked to the LM, the overload will be negative. If the MU is connected to the rest of the layout by an aggregate compartment, then after removal it is separated, unfolded and docked with the LM.
   During the flight to the Moon , trajectory corrections with a total impulse of up to 20 m/s will be required, for which it is planned to use the propulsion system MU. Braking to enter a low circular lunar orbit with a height of about 100 km is carried out by the landing stage.
   Next, a series of propulsion system MU inclusions transforms the orbit into an elliptical one with a periselation of about 10 km, after which the MU with one astronaut separates and moves to the waiting orbit. In the area of periseleniya LS performs braking and landing, the final stage of which is carried out in manual mode.
   After completing the research program, the LM with the crew launches, using the landing stage as a launch platform, and enters orbit. Next, the LM performs a series of orbital maneuvers required for rendezvous with the MU. The rendezvous ends with a docking, in which the MU plays an active role. Astronauts transfer the results of research to MU, separate the empty space LM and put MU on a return trajectory to Earth.
   Before entering the atmosphere, the MU is divided into compartments, two of them - the orbital and aggregate-are destroyed, and the lander performs a controlled descent and makes a soft landing.
   The main characteristics of option 7 are shown in the table 5.


to the begining 


Variant 8


   The lunar complex (LC) consists of the main unit (MU) - the return vehicle, the brake unit (BB) and a unified lunar module(ULM).
   The MU includes an orbital compartment and a descent vehicle from the Soyuz spacecraft, modified for a flight to the Moon, as well as a newly developed aggregate compartment with a fuel reserve of at least 6,0 t. Total mass of MU in LC structure 12,5 t, crew 3 people. MU is launched into orbit by a carrier using a Universal oxygen-hydrogen block (UOHB) as the last stage, containing 44 t of fuel. After entering orbit, the MU separates, turns around, docks with the UOHB, and transports it to the OS. The UOHB is equipped with an SFRE for the fuel precipitation used during the launch to the Moon.
   At the UOHB operation time, a significant characteristic speed is achieved-more than 5 km/s, which is why a new launch vehicle will need to be created to launch the MU. If you create the first stage on oxygen-kerosene fuel and implement modern design achievements (the pressure in the engine chamber is 25 MPa, the specific impulse in the void is 3300 N*s/kg, the mass of the structure is 1/12 of the mass of the stage), you will get a carrier with a starting mass of 282 t.
   The BB is designed to pre-launch the LC on its flight path to the Moon, launch it into lunar orbit, and decelerate the lunar module before landing. ULM is designed for a soft landing on the lunar surface, providing crew activities on the Moon and delivering it and research materials to lunar orbit. It has a detachable landing platform, including landing supports and a bottom screen. Research equipment is also attached to it . The main systems of the ULM propulsion system are duplicated. In the event of a failure of one of its systems, the ULM propulsion system must ensure that the crew returns with any stage of an independent flight of the module.
   The lunar module is put into orbit by the Soyuz-2M carrier. The last stage of this carrier runs on oxygen-methane fuel and is later used as a brake block. After launching into the base orbit, the BB-ULM bundle makes a flight to the OS using the correction propulsion system (CPS) located on the BB. The CPS ensures that the BB-ULM bundle approaches the OS at the minimum speed that allows it to be captured by the OS.
   The LC is assembled at the space station in the following order: UOHB-BB-ULM. During assembly and refueling, the main unit is docked to the orbital station. After refueling the UOHB and BB, the crew moves to the MU, where they leave the orbital station and dock with the ULM, or the MU is connected by the aggregate compartment to the rest of the layout using the OS manipulator. The LC-UOHB bundle is diverted to a safe distance from the orbital station, the fuel is deposited with the help of the solid fuel rocket engine, the UOHB starts and accelerates the LC, fully producing the components, and then immediately separated. Dovyvedenie on the trajectory of the flight to the Moon is carried out by the brake unit. During the withdrawal, the crew will experience an increasing overload up to 0,6
g. If If the MU is docked to the ULM, the overload will be negative. If the MU is connected to the rest of the layout by an aggregate compartment, then after removal it is separated, unfolded and docked with the ULM.
   During the flight to the Moon, trajectory corrections with a total impulse of up to 20 m/s will be required, for which the propulsion system MU is supposed to be used. Braking to enter a low circular lunar orbit with a height of about 100 km is carried out by the braking unit, while the negative overload for the crew can approach 1
g.
    propulsion system MU it is converted to an elliptical one with a periselation of about 10 km, after which the MU with one astronaut separates and moves to the waiting orbit. In the area of periseleniya, the propulsion system BB turns on and fully generates fuel, after which the BB separates, is taken away by venting the remnants of the boost gases and components, and falls on the Moon. ULM performs further braking with its own engines. The final stage of the landing is performed manually by the astronauts.
   After completing the research program, the ULM with the crew launches and enters orbit, leaving the landing platform on the Moon. Next, the ULM performs a series of orbital maneuvers required for rendezvous with the MU. The rendezvous ends with a docking, in which the MU plays an active role. The astronauts transfer the research results to the MU, separate the empty ULM, and put the MU on a return trajectory to Earth.
   Before entering the atmosphere, the MU is divided into compartments, two of them - the orbital and aggregate-are destroyed, and the lander performs a controlled descent and makes a soft landing.
   The main characteristics of option 8 are shown in the table 5.

   Variant 8 has the potential to build capacity. If you increase the UOHB refueling by 14-15 t, and the mass of LC on 2,5 t, that will not require additional acceleration of the LC, and the BB fuel and additional mass will be enough to convert the BB into a landing stage and add two or three hundred kilograms of cargo.


 

Variant 7

Variant 8

Launch vehicle LM

"-1"

"-2"

Starting mass of the carrier MU, t

295

282

UOHB mass, t

51,350

51,350

UOHB fuel, t

44,000

44,000

UOHB construction, t

7,350

7,350

Character. output on LEO velocity, m/s

5221

5313

Character. velocity at launch to the Moon, m/s

3200

2689

Refueled hydrogen, t

6,286

6,286

Refueled oxygen (for UOHB and BB), t

49,185

55,413

Refueled methane (for BB), t

3,374

5,206

Lunar complex, t

35,510

47,000

Mass BB+LM on OS before refueling

8,346

12,095

Main unit, t

13,115

12,521

The main unit in the LC, t

12,320

12,000

Fuel MU, t

6,100

6,000

Brake block, t

18,642

26,201

CPS mass, t

0,333

0,588

including fuel for the flight to OS

0,222

0,392

BB construction, t

3,687

3,100

BB fuel for additional acceleration, t

0,000

6,191

BB fuel for the first braking, t

7,433

8,542

BB fuel for the second braking, t

7,411

8,171

All fuel, t

14,844

22,905

Specific impulse of the propulsion system, N*s/kg

3619

3619

Component ratio

3,40

3,40

Character. output on LEO velocity, m/s

3638

3770

Character. additional acceleration speed, m/s

0

511

Character. speed in 1st braking, m/s, /

850

850

Character. speed in 2nd braking, m/s

2300

1868

Lunar module, t

4,548

8,800

Dry mass LM, t

2,181

5,293

Fuel LM, t

2,367

3,507


Tabl. 5


to the begining 


Emergency situations


1. UOHB engine failure at startup. The lunar complex UOHB bundle is fed to the OS using MU engines, captured, and then the fuel is drained (variants 3, 4, 5, 7, 8). In variant 6, if the situation does not allow for withdrawal on serviceable engines (there are 4 of them in the block), the UOHB is probably lost.
2. BB engine failure during pre-acceleration (variants 3, 6, 7, 8). Pre-acceleration is carried out by MU engines. If the problem can not be fixed or the reserve of the characteristic speed for landing on the Moon is not enough, then the BB is reset, and the MU returns to Earth on a flyby trajectory. An attempt is being made to land the lunar module in unmanned mode.
3. Non-start of the BB engine at the time of launching into lunar orbit. BB is dropped, the lunar module is quickly separated and placed into lunar orbit, MU returns to Earth on a flyby trajectory. An attempt is being made to land the lunar module in unmanned mode.
4. Emergency stop of the BB engine at the time of launching into lunar orbit. The MU lunar module bundle is separated and removed from the BB to a safe distance, after which the parameters of its orbit are determined. It then separates, the MU and its crew return to Earth, and the lunar module heads to the Moon.
5. Failure of one of the lunar module's propulsion system circuits during landing. The LM aborts the landing, drops the landing platform, and enters orbit using the remaining power of the propulsion system.


Notes


   In some variants, it was not possible to fully take into account the weight of the adapters. On the launch vehicle "Saturn-5", the lunar module was covered with an adapter weighing 1816 kg, on which the main unit was installed. This adapter was already discarded on the flight path to the Moon, i.e. its mass was included in the total mass directed to the Moon. When flying to the Moon in the proposed way, it is possible to significantly lighten the adapter (or adapters) during the maintenance of the LC on the OS, or use lighter ones, if they are not loaded when they are put into orbit. The fact is that during the launch of the LC to On the moon, the adapters will experience 4-6 times less static and at least an order of magnitude less dynamic loads compared to the stage of launching into low-Earth orbit.


to the begining 


Supply of the lunar base


   The lunar base (LB) can still be considered only theoretically, but it is impossible to exclude its creation in the future. The existence of the lunar base will be accompanied by an increase in cargo traffic to space and a higher level of development of launch vehicles. Therefore, it is irrational to use existing carriers for its supply . It would be more profitable to create special (adapted) funds for this purpose. The LB should include a landing pad- a flat surface provided with beacons of sufficient size, suitable for landing modules at any point of it.
   For cargo transportation, it makes sense to consider a direct flight that does not require entering lunar orbit and more than one activation of the main propulsion system near the Moon. Direct flight is easier and more reliable, but it generally has more gravitational losses, which depend on the landing site. The area for which the gravitational losses are equal both during direct flight and when using an intermediate orbit is located on the far side of the Moon. On the other hand, for most of the visible side of the Moon, a direct flight gives the advantage is in the accuracy of the guidance and allows you to do with a minimum of corrective pulses. In the event of an engine failure during landing, the cargo cannot be saved, during the remaining time, it is necessary to drain the components from the tanks and deflect the trajectory of the cargo and the rocket block to an angle that is safe for the LB.
   The simplest transportation scheme assumes that one oxygen-hydrogen unit will both launch the cargo to the Moon, and perform braking and landing. The characteristic speed for such a block should be about 6000 m / s, and the gravitational loss-no more than 400 m/s. The main drawbacks will be the large mass of the landing stage structure and the difficulty of providing a thermal regime in a liquid hydrogen tank. Table 6 below shows the estimated parameters of two such SV (carriers including UOHB), but it should be taken into account that the payload mass will be significantly reduced due to the landing equipment, additional thermal insulation and the stock of CPS components required for trajectory corrections and orientation constructions that provide a favorable thermal regime. One of the presented media is A4, which has the following composition:
- three side reusable single-tank accelerators of the "Baikal" type;
- central unit with LRE, equipped with a retractable nozzle (shortened module "Angara");
- OHB.
   The accelerators and the central unit run on oxygen-kerosene fuel and are connected by a component overflow system. A rough estimate shows that the additional snap-in will "eat" up to 5-7 of them 25  payload.
   A more rational and feasible scheme is the delivery of a composite cargo, which is displayed on the NCO by two different carriers. Table 6 shows the media parameters of one of these schemes (light and heavy variants). It is assumed that their first stages are oxygen-kerosene LRE with a modern level of perfection. The carrier of the light version contains a standard UOHB and has a reusable first stage with a total mass of 203 t, from which 40 t is the mass of the structure and components that ensure its return and landing. The payload weight will be 8,1 .
   The launch vehicle of the light version, containing a methane landing unit (LU), has a single-use first stage with a total mass of 115 t, from which 8 t is the mass of the structure and the remnants of the component selection. Weight it will be about 2,5 t. On the OS, the payloads are combined, and a two-stage rocket is formed from the UOHB and LU, while the LU supports are moved apart. UOHB puts the cargo complex on a trajectory to the Moon, and LU provides a soft landing on the landing pad.
    The "methane" carrier of the heavy variant in Table 6 is a large-scale copy of the "light" one, but it can also be built differently: a composite accelerator can be used to accelerate the methane block, including two side reusable autonomous accelerators of the "Baikal" type and a central block based on the URM from "Angara".


Variant

light

heavy

Launch vehicle with OHB, t

263

4(602)

Payload mass, t

8,100

25,150

Mass of the reusable 1st stage, t

203,3

3×107,3

Construction of the 1st stage, t

40,0

3×18,0

Mass of the 2nd stage, t

-

109,6

Construction of the 2nd stage, t

-

9,6

OHB+CPS mass, t

51,974

145,690

OHB fuel, t

44,000

125,140

OHB construction, t

7,350

18,700

CPS mass, t

0,624

1,850

including fuel for the flight to OS

0,416

1,233

Character. output on LEO velocity, m/s

5999

6000

Character. velocity at launch to the Moon, m/s

3203

3200

Carrier with LU, t

142

440

Payload mass, t

2,487

7,722

Mass of the 1st stage, t

114,7

356,2

Construction of the 1st stage, t

8,0

24,9

Mass of LU+CPS on the Earth, t

24,744

76,830

Mass of LU+CPS on OS, t

24,523

76,141

LU fuel, t

20,010

62,129

LU construction, t

4,002

12,426

CPS mass, t

0,733

2,275

including fuel for the flight to OS

0,222

0,689

Specific impulse of the propulsion system, N*s/kg

3619

3619

Component ratio

3,40

3,40

Character. output on LEO velocity, m/s

4803

4803

Character. speed in braking, m/s

3000

3000

Refueled hydrogen, t

6,286

19,517

Refueled oxygen (for OHB and LU), t

53,176

165,109

Refueled methane (for LU), t

4,548

14,120

Cargo complex, t

35,510

110,256

Total payload mass, t

10,987

34,114

Cargo complex mass before refueling, t

15,500

48,126


Tabl. 6


   Cargo transportation differs from the considered manned expeditions by a greater share of fuel and raw materials in the total cargo flow to space, and, as a result, a lower unit cost of cargo delivery.


to the begining 


What are we looking for on the Moon


   During the "lunar era" from 1959 to 1973, the Moon it was intensively explored by automatons and six human expeditions. Lunar soil from nine regions was delivered to Earth. Enough time has passed for the research results to be carefully processed and understood. How satisfied are we with the research results? The excitement of the lunar race and the desire to" stake out " a scientific priority did not contribute to the thoughtful preparation of the scientific program. For example, the most important discovery is the availability of stocks the ice in the polar regions of the moon was made much later.
   Comparison of the isotopic composition of terrestrial and lunar rocks showed their significant difference. The age of the Earth and the Moon was the same. There is no definitive answer to one important question about the history of the formation of the lunar seas. And it is possible that this question is a key one for understanding some processes of planet formation in the Solar System.
   The moon is always turned to the Earth with one side, the reverse side was hidden from humanity until the Soviet AMS transmitted its first images. At the same time, it turned out that the reverse side of the Moon is significantly different from the visible one. There are almost no "seas" on it - vast, flat and dark areas of the lunar surface where traces of large impact craters are rare and look relatively fresh. On the contrary, the lunar "land" is simply dotted with them, many have traces of erosion. This suggests that the lunar seas are relatively young formations. How young are they? The results of the study of lunar soil samples were ambiguous. First, they showed that the age of the lunar seas varies significantly. Secondly, different breeds from the same place showed different ages. So, the crystalline rocks from the Sea of Tranquility showed mainly 3,7 10
9 years, individual samples - (2,3-4,4) 109 years, and dust and breccias (4,6-4,7) 109 years. The age of the Ocean of Storms is determined in (1,7-2,7) 109 years, but a long-lived stone was also found there 4,6 109 years.
   Such a different age of the seas is unlikely, it would be much more logical to assume that they were born in the same selenological epoch as a result of the same process. The density of impact craters for all seas does not differ significantly. Can we trust the research results and their interpretation? They seem to need to be rethought for the following reasons.
Dust and breccias contain large amounts of interplanetary matter, in the form of fallen interplanetary dust and meteorite fragments. The speed of the collision with the Moon for some of them did not exceed 3 km/s, so the impact could preserve both their individual fragments and age markers. The time of birth of most of these objects should be attributed to the period of the formation of the Solar System-no less 4,6 10
9 years.
It is also impossible to exclude the injection of ground material from remote areas of the Moon's surface.
   A relatively small amount of foreign (introduced) matter is almost entirely concentrated in the near-surface layer, and makes up a significant proportion of it. It is this layer that has been most thoroughly studied.
   The surface layer of the lunar seas could be formed by a light, unflavored sludge with a thickness of units or tens of meters. Therefore, near-surface rock samples may also be old. To judge the age of the "seas", you need to take samples from a sufficient depth.
   The molten magma that filled the basins of the" seas " could contain relic age markers, such as zircon.
   In the lunar seas, large ring-shaped structures are traced, which gave rise to talk about their impact origin. But the connection between the formation of impact basins and their filling with lava is highly questionable. And the main mystery here is the distribution of the "seas" on the surface of the Moon. If a large celestial body passed by the Earth, collapsed in its gravitational field, and the debris met the Moon on the way, then many shock basins could be formed on its visible side. The case is possible, but unlikely. However, the far side of the moon is also not without large impact basins.
Enlarged photos of the Moon show that the flat surface of the lunar seas is a solidified lava flow. These are not lava flows like volcanic ones, but vast and level lava fields. The lava here emerged from the depths through a network of faults-cracks that covered large areas of our satellite. It is very likely that the cracks are of non-volcanic origin and appeared not as a result of the pressure of magma gases or the melting of solid rocks, but because of the deformation of the solid and thin shell of the Moon.
   The above gives grounds to put forward the hypothesis that the main cluster of lunar seas was formed during the short, by geological standards, epoch of the end of synchronization of the periods of the Moon's rotation around its own axis of the period of its orbital rotation around the Earth. These "seas" are a tidal wave that emerged through the solid surface, flooding low-lying areas of the surface, and the event was catastrophic.
   The "Tidal catastrophe" hypothesis is based on the assumption that the Moon was not always turned to the Earth by one side. Once upon a time, its rotation period was shorter, and the lunar day was shorter than the lunar month. But gradually the rotation slowed down due to the tidal forces caused by the Earth's gravity. Similarly, but more slowly, the Earth slows down its rotation. The deceleration of rotation occurs due to inelastic deformations, internal friction, and the flow of the liquid phase in rocks during their periodic displacements during tides. As long as the rotation of the celestial body is fast enough, it behaves mainly as a solid object, resisting inelastic tidal deformations. Because of this, the shape of the celestial body does not have time to track the cyclical changes in the gravitational field, the tidal wave is far from its maximum values.
   As the rotation slows down under the influence of tidal forces, the height of the tidal wave increases, which, together with heating, leads to an increase in energy dissipation sources, so the deceleration process accelerates. The final period of synchronization of the rotation with the orbital motion proceeds quickly and leads to the release of a significant amount of energy in the subsurface regions.
   The potential of the tidal wave for the Moon today is about 300 m, but in the past it could be 3-5 or more times higher, since the Moon was located closer to the Earth. At the moment of synchronization of rotation, the solid lunar crust could not withstand the stress of deformations and cracked, after which magma emerged to the surface and flooded the low-lying areas. Probably, the cracking did not pass through the elevated areas, but because of their height, the magma only rose along the cracks to a certain level, without reaching the surface. What happened deserves the name "Tidal Disaster.
   After the magma came to the surface, there was such an asymmetry in the shape of the Moon, which made its orientation to the Earth stable.
   The tidal catastrophe explains the absence of" seas " at the poles and their small area on the far side of the Moon. It does not contradict the presence of mascons - tidal forces cause subsurface, but not deep heating, so there may not be a general differentiation of matter by density.
   The tidal catastrophe hypothesis suggests that massive celestial bodies orbiting other massive bodies may have a short-term period in their lifetime, during which their intense internal heating occurs under the influence of tidal forces. This allows us to take a fresh look at some of the anomalies of objects in the Solar system. For example, Saturn's small moon Enceladus (about 500 km in diameter) is in a semi-liquid state, with water breaking out in places, while other, larger satellites do not have signs of internal melt.
   The tidal catastrophe hypothesis suggests that massive celestial bodies orbiting other massive bodies may have a short-term period in their lifetime, during which their intense internal heating occurs under the influence of tidal forces. This allows us to take a fresh look at some of the anomalies of objects in the Solar system. For example, the small moon of Saturn Enceladus (diameter of about 500 km) is in a semi-liquid state, with water in places breaking out, while other, larger satellites do not have signs of internal molten, even more interesting is another celestial body. On December 15, 1970, the lander of the Soviet AMS Venera 7 reached the surface of Venus. The conditions on the planet's surface turned out to be monstrous-a pressure of more than 90 atmospheres and a temperature of about 500 C. Then the term "greenhouse effect" appeared. It consists in the fact that sunlight heats the surface and the lower layers of the atmosphere, and thermal radiation is retained by carbon dioxide, which is more than 96% in the atmosphere. However, studies have shown that the surface of the planet reaches only 3-4% of the sun's rays. The temperature gradient of the atmosphere is interesting-it has an adiabatic profile from the surface to a height of about 50 km (the approximate height of the lower border of the cloud cover), then it halves and remains so until the rarefied layers (about 80 km). That is, despite the huge amount of carbon dioxide by Earth's standards, the upper atmosphere still gives off heat to space, and the greenhouse effect is caused by clouds.
   Based on the data obtained and some calculations (reverse extrapolation of the amount of water in the atmosphere by the ratio of hydrogen isotopes, detection of impact craters), some scientists are inclined to believe that earlier conditions on Venus were milder, and even liquid water could exist, but somehow there was overheating, and a large amount of carbon dioxide passed into the atmosphere.
   It is quite possible that these events occurred quite recently on the geological time scale, and were caused by the same tidal disaster that once befell the Moon. Indeed, Venus rotates very slowly compared to other planets. The rotation period is 243 earth days, which is more than a Venusian year (the rotation is reversed). The inclination of the planet's axis to the plane of the orbit does not differ much from the perpendicular-87.36, and this is a clear sign of a tidal catastrophe that has taken place. And, of course, subsurface heating of the planet's body would be much better for the release of gases from the depths than surface heating.
   If there really was a tidal catastrophe on Venus, then today we are witnessing its final stage. Then the planet should slow down its rotation so quickly that it will be easily measurable with the instruments delivered to its orbit. And if this is confirmed, then humanity will have a new hope. The fact is that the period of catastrophic deceleration will be short-lived, perhaps about a million years, and the human population has a chance to survive by this time. Then it will be possible to make the planet habitable by freezing carbon dioxide from the atmosphere on the shadow side of the planet once. On the illuminated side, there will be an extremely dry climate with a pressure of 2.8-3.5 atmospheres, which will create isolated habitable zones with a pressure equal to atmospheric pressure. The area of comfortable habitation will be no smaller than Africa, and the peculiar conditions will give the Venusian civilization some interesting features.


to the begining