Technological line of launch vehicles
Ñonfigurations: Monoblock À1 The logic of the technological line
|
Launch vehicle |
À1 |
À3 |
À4 |
À7 |
À7-ÊÂÁ |
|
Starting mass, t |
167 |
478 |
618-628 |
1031-1080 |
1031 |
|
Payload mass, t |
3,7 |
14 |
23-24 |
37-40 |
46-47 |
|
Exchange of components |
- |
- |
+ |
+ |
+ |
|
Retractable nozzle on core block |
- |
- |
+ |
+ |
+ |
Òåõíîëîãè÷åñêàÿ îñíîâàTechnological basis:
• rocket modules, unified by LRE and fuel tank diameter;
• fuel components-liquid oxygen + kerosene;
• the engine circuit is closed, with afterburning of the oxidizing gas;
• number of main engines on each block - 1;
• number of combustion chambers in the engine - 1;
• configurations - from monoblock to seven-block;
• the type of engine - RD-191, selected by the developers of the "Angara" launch vehicles.
Name: À1.
Composition:
- unified two-tank rocket block forming the first stage;
- non-unified rocket block of the second stage, coupled to the first according to the "tandem" scheme.
Purpose: launching light payloads into low and medium orbits.
Note: the carrier is offered by Khrunichev company and is being developed within the framework of the "Angara" program.
Name: À3.
Composition:
- 2 unified two-tank boosters of the first stage;
- unified central two-tank rocket
block (second stage), connected to the boosters according to the "package" scheme;
- non-unified third-stage rocket block.
Note: the carrier is offered by the Khrunichev company and is being developed within the framework of the "Angara" program.
Four-block configuration
Name: À4.
Composition:
- 3 unified single-tank equal-volume boosters of the first stage;
- unified central two-tank rocket
block (second stage), connected to the boosters according to the "package" scheme;
- non-unified third-stage rocket block.
Appointment:
- multi-purpose, should replace the Proton and Angara 5I.
Ñâîéñòâà:
• number of launches per year-up to 15;
• layout - four-block;
• exchange of components between blocks - yes;
• number of detachable hydraulic connectors – 6;
• starting the engines in flight - yes;
• launch scheme – three-stage;
• reusable – in the future, it is planned to save the side
modules.
Main parameter:
- reliability.
Possible modifications:
1. No external nozzle on the central module.
2. The layout without the upper stage, the fuel tanks of the central module have an increased capacity. When using an effective external nozzle on the central module, the maximum capacity of such a carrier exceeds 18 t of payload on the LEO.
Seven-block configuration
Name: À7.
Composition:
- 2 unified single-tank equal-volume boosters of the first stage;
- 4 unified single-tank equal-volume boosters of the second stage;
- unified central two-tank rocket block (third stage), connected to the boosters according to the "package" scheme.
Appointment:
- launching payloads to low orbits;
- reservation of spacecraft launches on GSO and other high-energy trajectories.
Features:
• the number of launches per year - from 1.5 at a moderate to 6
at an intensive rate of operation;
• configuration - seven-block;
• exchange of components between blocks - yes;
• number of detachable hydraulic connectors – 8;
• starting the engines in flight - no;
• launch scheme is three-stage;
• reusable blocks-initially not provided, in the future, if
necessary, it is introduced by equipping individual blocks with a rescue system.
Main
parameter:
- load capacity.
Main technological parameter:
- specific load capacity (mass of the payload, attributed to the amount of thrust of one main engine).
Possible modifications:
1. Central unit with larger diameter tanks.
2. The central block containing the non-unified propulsion system:
- significantly less power;
- containing two engines or an engine with two rotary combustion chambers.
3. Similar in volume central and side modules + an additional
oxygen-hydrogen rocket block as the upper stage.
The logic of the technological line
When developing a technological range, first of all, we are interested in its
technological maximum-the layout that has the greatest capabilities, in
which the organicity of the properties is not violated (i.e., in it, the main result
is achieved by unified technical means, without system complication
of the design). Therefore, options that use the upper stage
of significant dimensions, the volume of tanks of which is comparable to the volume of tanks of the modules
of the first stage, as well as schemes of indirect connection of blocks, immediately disappear. In other words,
the basis of the layout should be the central rocket block and
the side boosters directly attached to it. In the layout, the blocks of which have
the same diameter of the fuel tanks, the maximum number of such accelerators is
six.
The choice in favor of a seven-block carrier allows you to use
the smallest technological equipment in its production and provide it with
maximum load. It is especially relevant in the context of declining demand for SV.
The logic here is obvious: lower cost of products and better reliability
is achieved by increasing the serial production. An example of this is the R7 rocket,
it has 5 main units, unified by engines and, in part, by
fuel tanks, on which there are 20 unified main combustion chambers.
To date, more than 1.5 thousand launches of various modifications of the P7
have been carried out (the main modifications concerned the upper stages), for which
more than 7.5 thousand rocket blocks and more than 30 thousand main combustion chambers were produced. It is not
surprising that the production technology of the R7 was developed quickly enough,
and the rocket has long demonstrated high reliability.
The proposed A7 is based on the same logic that led to the creation of P7, although the carrier schemes are different. But we must remember that the P7 was created as a combat missile and in a hurry. The state of the technological base then was
as follows:
- There was no closed circuit LRE;
- the exchange of components required time to create and develop the technology;
- the seven-block layout without the overflow of components
is weakly efficient and significantly complicates the control system, which was then
based on lamp devices;
- the combustion chamber was the most difficult
element of the LRE, the creation of the chambers used in the RD-107/108 was a major success
and there was no time to develop a larger chamber.
The idea of the technological series was based on the following prerequisites:
1. For liquid launch vehicles, the maximum load capacity can be provided by a seven-block layout (without loss of organic properties).
2. A seven-block layout is not able to be effective without losing overall
unification if there is no overflow of components between the blocks.
3. Russia inherited from the USSR the technology of production of closed-circuit oxygen-kerosene liquid propellants, for which the optimal volume ratio of components
is 2:1.
Hence the constructive solutions follow:
- use a two-tank central rocket block;
- use component overflow between modules;
- apply single-pack side modules;
- strive to ensure that the number of side rocket modules is a multiple of three.
The A7 component exchange system will allow you to implement a three-stage layout scheme, which makes it effective without an upper stage. Various variants of the component exchange scheme are possible, in which two, three, and four modules are discarded in the first division. It also makes sense to use three single-tank and three autonomous side modules in the layout. The main option was chosen, in which the side modules are grouped in three so that the module containing fuel is located at the extreme. The first division involves two the oxidizer modules, the extreme ones in the groups, in the second – the four remaining modules. This overflow scheme is chosen for the following reasons:
- the scheme requires a minimum number of detachable hydraulic connectors – 8;
- when switching in the overflow system, the fuel lines should not
reverse the flow of components;
- the side modules should be placed organically on the central block of a larger
diameter.
The resulting A7 vehicle has unique technological characteristics:
- the axial symmetry of the layout is preserved;
- low-cost, easy-to-use, and affordable components are used;
- there is no engine start in flight;
- high unification of engines and fuel tanks;
- there are only 8 fuel tanks per 7 modules;
- no more than 4 standard sizes of fuel tanks;
- low altitude relative to the starting mass;
- high specific characteristics: payload coefficient, payload mass related to engine power, diameter and volume of fuel tanks.
To meet all the projected needs, it would be enough to use a rocket engine with a thrust of ~150 tp. Such an engine in Russia is in the number of several dozen copies – this is the NK-33, but its production needs to be restored.
The final appearance of the proposed technological range was influenced by the fact that the lead developer, Khrunichev company, had already been chosen to create the heavy – class carrier "Angara" , which relied on the development of the RD-191 oxygen-kerosene engines with a thrust of about 200 tp (196 tp at the ground and 213 tp in the vacuum). The universal diameter of the blocks was also determined – 2.9 m, which made it possible to transport the blocks entirely by rail. Such parameters superimposed on the proposed tecnological line showed that:
- the payload capacity of the A4 is only slightly inferior to the developed launch vehicle "Angara 5I";
- the A7 carrier has a payload capacity of about 40 t and remains unclaimed for the foreseeable future;
- at the Khrunichev company also mastered the production of fuel tanks of other diameters, for example, 4.1 m, which makes it possible to reduce the length of the central block A7 to a convenient size.
For comparison, the values of the A4 and A7 load capacities for the NK-33 and RD-191 engines are given below.
Load capacity on LEO (H=200 km, i=63°), t
LRE NK-33 RD-191
À7 24-27 37-40
À4 14-15 23-24