“ANGARA” LAUNCH VEHICLE FAMILY CONCEPT, DEVELOPMENT STATUS AND OPERATIONAL PLANS

A. Medvedev, A. Kuzin, E. Motorny, Khrunichev Space Center, Russia, B. Katorgin, NPO Energomash, Russia

Abstract “ANGARA” BACKGROUND The design of “Angara” launch vehi- cles family is based on the concept of com- Development of the “Angara” launch mon (so called universal) rocket module of system is one of the most impotent projects the first stage. Full scale development of the undertaken by Khrunichev Space Center. "Angara" space complex has been carried The history of the “Angara” project, out for several years by Khrunichev Space main technological features and innovations Center. The first test flight of this new gen- as well as status of the program and future eration launchers is scheduled to occur in plans were repeatedly presented in mass the last quarter of 2003 from Plesetsk cos- media and in the papers of Khrunichev’s modrome. “Angara 1.1" lightweight launch representatives at various international fo- rums and conferences. For example, the pa- vehicle will be the first to lift into orbit. th Practical realization of modularity concept pers [1,2] were presented at the 37 Session goes through incorporating of the first stage of Scientific and Technical Sub-Comminute Universal Rocket Module (URM-1) in all on the Peaceful Uses of Outer Space Affairs the launchers of the family, either as com- in Vienna in 2000 and at the First Summit plete first stages of lightweight class launch on the Space Transportation Business in vehicles, or as core units and strap-on Paris (1999). boosters of intermediate and heavy launch- As it was described earlier the “An- ers. The second stage has two different vari- gara” family comprises from four main con- ants: “Rockot” LV derived “Breeze-KM” figurations of launch vehicles (Fig. 1). The upper stage for “Angara 1.1" launcher and centerpiece of the Khrunichev’s modular newly developed Universal Rocket Module concept is the URM-1, which is a common (URM-2) second stage for all other configu- unit (with some variations) for all the rations. Descriptions of the URM-1/ URM-2 launchers of the family. Besides the URM-2 propulsion units, which are based on the second stage is used in all the launchers ex- oxygen/kerosene RD-191 and RD-0124A cept “Angara 1.1”. Application of flight- main rocket engines correspondently, are proven upper stages, adapters and payload given in the paper. Programmatic aspects fairings is also one of important principles including development test plans and of “Angara” design concept. schedules of the initial operation phase are In connection with the subject of this discussed as well. Symposium, it is reasonable to look through The "Baikal" first stage reusable specific technological solutions, which were fly-back booster, which is based on the incorporated into the design of above men- URM-1 technology, is aimed to increase the tioned universal rocket modules of the first operational efficiency of the "Angara" and second stages. launchers family. Improvements of the UNIVERSAL MODULES DESIGN RD-191 booster main engine transforming it The URM-1 (Fig. 2) was developed as into reusable design are presented. a first stage of the “Angara 1.1/1.2” light- New design features and concepts, weight class launch vehicles and as a core which have been introduced in "Angara" unit and strap-on boosters of the intermedi- space complex, will increase the Russian ate “Angara A3” and heavy “Angara A5” space launch industry's competitiveness in launch vehicles. Design parameters of the the international commercial launch ser- URM-1 are the result of comprehensive vices market and assured free access to trade-off studies performed by Khrunichev space from national territory.

Space Center in 1995…1997. Studies were confidence in reliability and operational aimed to find the way of meeting different functionality of the new engine. sets of requirements stemming from differ- The RD-191 is currently undergoing ences in foreseen operation modes of LVs. hot firing stand tests (Fig. 3). The pneu- Based on the found technical solutions matic/hydraulic diagram of this engine and Khrunichev’s developers came to a conclu- its performances are shown in Fig. 4. The sion that the optimum design should be an RD-191 is an oxygen/kerosene engine, oxygen/ kerosene universal booster module which is designed in the framework of gen- characterized by: erator gas after-burning concept with a ca- • diameter D=2,9 m, pability of combustion chamber’s deflection • length L=25,105 m, in a Cardan suspension. An ignition is pro- • loaded propellant mass ∼120 t vided by a chemical method, by feeding into and equipped with single main rocket en- the combustion chamber special starting gine having a thrust of about 200 tons. fuel, which is self-ignited when in contact These parameters led to the robust solution with liquid oxygen (oxidizer). in wide ranges of operational requirements Besides a mode of throttling down to and forecasted international market changes. 30% of nominal thrust, the engine allows The main engine should have a capability of also a short-time burning in a mode of en- thrust vector control (TVC) as well as a ca- hanced thrust (up to 5% of nominal level) in pability to function during a long time in the emergency situations. mode of lowered thrust (down to 30% of TVC in channels of pitch and jaw is nominal level) for its applications in core provided by deflections of combustion units of intermediate/heavy launchers. The chamber in a Cardan suspension. Besides last requirement appeared due to a pro- this, the engine can feed a generator gas for longed time core booster’s run in flight in running of nozzles providing control on a comparison with strap-on boosters. Addi- roll channel. This feature of the engine is tional engine’s requirements covered high crucial for control of the first stages of light- level of reliability, which should be con- weight launch vehicles and of the core firmed before its installation into the boosters of intermediate/heavy launch vehi- URM-1, and introduction of effective sys- cles. The engine fulfills two additional func- tem for in-flight safety assurance, which tions: should reduce the flight risk coursed by en- • heating of gas (helium) for a pres- gine’s malfunction. surization of propellant tanks and These requirements were met by the • bleeding of fuel after a pump for RD-191 (191M) single-chamber liquid- running of hydraulic actuators providing propellant rocket engine, which was offered deflections of combustion chamber and by the Russian NPO “Energomash”. aerodynamic rudders. RD-191 engine was developed as one of Engine's design includes pipelines, derivatives of the just existing and success- valves and fittings of automatics and con- fully operated RD-171 four-chamber rocket trol, that provide functioning of the engine engine. This engine has not only the highest in various modes. The engine RD-191 is level of thrust in the world, but has a very also equipped with sensors for telemetry high perfection of design. Another deriva- measurements of the burning parameters in tive of the RD-171, the two-chamber RD- flight and with an equipment of monitoring/ 180 engine has just proved itself success- emergency protection system. The last sys- fully on the U.S. “Atlas III” launch vehicle. tem is intended for countering emergency An adoption of such an important compo- situations during the flight. nent as the combustion chamber from the The RD-191 engine was just “fitted” RD-171 and RD-180 engines allowed not to the universal rocket module. In March only to decrease development cost and dura- 1999 its first mock-up/technological sample tion for the RD-191 but also to enhance a was delivered to Khrunichev and was in- stalled on the engineering mock-up of the

URM-1 — a first stage of the “Angara 1.1” The first step to enhance the URM-1 launch vehicle (Fig. 5). The engineering reliability is to incorporate into its design mock-up of this launcher was shown at the subsystems, units and aggregates that allow Le-Bourget Airshow in 1999 (Fig. 6). Since repeated running before the beginning of Airshow it passed a variety of on-ground irreversible processes (e.g., take-off of the development/technological tests. launcher from a launch pad). This approach A general design layout of the univer- provides an opportunity to perform the pre- sal rocket module equipped with the RD- launch (on pad) tests including those that 191 engine is shown in Fig. 7. Differences are carried out in order to detect and to between the variants of URM-1 design and eliminate possible failures of on-board sys- operations are caused by the position of tems and units without a replacement of the URM-1 in LV configuration. Additional whole launcher. aerodynamic rudders for roll control equip Delivery procedures of the RD-191 the URMs that are used as first stages of engine envisage comprehensive control/ small launchers. The URMs, which are used technological tests including hot firing ac- as strap-on boosters, have no roll control ceptance test of each fabricated RD-191 en- nozzles. Both upper mentioned URMs func- gine. After test is performed the engine un- tion in flight for 210…240 seconds in al- dergoes a cycle of technological works most nominal level of thrust (except for legs (without reassembling) that includes a ther- of ignition and shut-down). In case URMs mal/vacuum processing of fuel pipelines, a are used as core boosters of intermedi- removal of soot from outside surfaces and a ate/heavy launch vehicles they perform at replacement of ampoules with the starting throttling mode (30% of nominal thrust) fuel. during 130…160 seconds with a total time The Universal Rocket Module of the of burning equals to approximately 320 sec- second stage (URM-2) is intended for use in onds. the “Angara 1.2” small launcher, in the in- An important element of reliabil- termediate “Angara A3” and in the heavy ity/safety assurance of the URM-1 during “Angara A5” launchers. ignition, launch and in-flight operation is A general arrangement of the URM-2 the Emergency Protection System (SAZ by and its main performances are shown in Fig. the Russian acronym), which is installed in 8. the RD-191 engine. It provides the detection It is designed around the RD-0124A of emergency situation on the basis of com- main engine. prehensive analysis of steadily monitored The RD-0124A oxygen/kerosene liq- set of the engine’s health parameters. When uid-propellant rocket engine is being created the parameters are deviating from their by the Chemical Automatics Design Bureau given values, the SAZ forms commands to (CADB) on a basis of the RD-0124 engine- the emergency shut-down of the engine, or prototype (Fig. 9) which was developed by to eliminate the malfunction of the engine, the CADB for the “Sojuz-2” launch vehicle or to change engine mode in such a way that and is currently finishing a complete cycle the mission will be carried out even with the of on-ground testing. detected malfunction. The implementation The RD-0124A engine is a four- of this system enhances significantly reli- chamber rocket engine with a turbine/pump ability and safety of the total launch system system of propellant feed which is designed operations. in the framework of oxidizing generator gas High reliability of the RD-191 and after-burning concept. A distinctive feature propulsion system as a whole is the key of the RD-0124A engine is its ignition in element of the “Angara” concept. Several the conditions of zero gravity. The launch measures were elaborated on the systematic vehicles of “Angara” family use the so- approach and adopted as standard proce- called “cold” separation technique when dures for manufacturing, acceptance tests engines of the upper stage start functioning and operational modes. after the separation of the previous stage is

completed. The starting fuel provides the “Angara A5” launcher will take place in ignition of the RD-0124A engine after oxi- 2005. dizer and fuel from the special “starting ves- Intermediate “Angara A3” launch ve- sels” are pushed out into the chambers. hicle is considered to be a simplified deriva- Combustion chambers of the engine tive of the “Angara A5” launcher with only are deflectable in their supports providing a two strap-on URM-1. flight control by all the channels. The described URM-1 and URM-2 A main mode of the engine’s burning universal rocket modules are intended to is a nominal one without a throttling and operate in the composition of expendable increase of thrust (excluding legs of ignition “Angara” launchers. However, Khrunichev and shut-down). is also working on advanced concepts in- Like the RD-191 engines, every cluding partially reusable launchers. One of RD-0124A engine to be delivered under- the projects uses the URM-1 technology and goes a complete cycle of acceptance tests design to realize the Reusable Fly-back including hot firing tests without a fol- Booster of First Stage concept. The project low-on reassembling. received the “Baikal” appellation. The main Main performances of the RD-1024A goal of this project is to develop, test and engine are given in the table in Fig. 9. put into operation the reusable booster that In case the URM-2 is used in the can be used in launch vehicles of different “Angara 1.2” launcher the total amount of classes. The evolutionary approach foresees loaded propellants should to be decreased the autonomous tests of fly-back booster due to the shorter duration of in-flight stage and first operational launches in configura- running. tion of lightweight class space launcher. The Development and test strategy elabo- development of reusable “Baikal” is sup- rated by Khrunichev team takes into ac- ported by the approach when main require- count all the advantages provided by modu- ments for reusability were included in de- lar concept. This proposition means that all sign documentation of “Angara” launch sys- development tests start from the simplest tem from the initial phase of the program. possible configuration of the test article that This will lead to minimum of redesign and is evolutionary reconfigured to the most so- testing activities. phisticated configuration undergoing tests in A description of the “Baikal’s” design the most severe conditions. and operational features as well as other In the framework of this approach project data on this booster were just pre- flight tests of “Angara” launch system start sented at various international conferences, with the maiden flight of “Angara 1.1” for example [3], while visitors of the Paris lightweight launcher slated for 2003. The Airshow in Le-Bourget and of MAKS-2001 first flight (or flights) will provide the nec- Moscow Airshow in 2001 could see the full- essary level of confidence that URM-1 scale engineering mock-up of this article functions in accordance with design docu- (Fig. 10). Because of this, there is not a ne- mentation. Even in case of failure the losses cessity to dwell on a description of this will be minimal and limited to the cost of booster’s propulsion part, moreover that it is URM-1. Then, after URM-1 is considered identical, in a general, to the liquid- to be the flight-proven article, comes “An- propellant propulsion unit of the URM-1 gara 1.2” with added URM-2 and new flight module. navigation and control system. After However, the requirements for the Khrunichev team will be sure that the first “Baikal’s” reusability put additional func- stage core unit and URM-2 are functioning tionality onto elements of its structure and, flawlessly it will move directly to the “An- in the first turn, onto its main rocket engine. gara 5” heavy launcher. At that time in case In accordance with these requirements, the of necessity we can put into operation small engine should provide not less than 10 mis- launchers of the “Angara” family. Accord- sions without an overhaul at the first phase ing to current plans the first flight of the of the “Baikal’s” operation. After first ex-

perience will be gained the lifetime of the module itself, we can start with the “inter- RD-191 should be enhanced up to 25 mis- mediate” version of the first stage’s univer- sions. Besides this, the engine should allow sal booster with limited level of reusability. an inter-flight maintenance on the bases of The development work on the reus- continuous health-monitoring. able version of the second stage’s booster is Methods that are broadly used in the not yet deployed in a broad scale. aviation practice, but are not actually used CONCLUSION in rocketry, will be of most importance. Specialists of the NPO “Energomash” are Standing at the eve of further intensi- working at the present time by the fication of competition in launch service Khrunichev'’ Statement on Work on a meet- market industrial teams must be aware of ing of these requirements for the RD-191 methods they will use to gain desired mar- engine. ket share. A reusability of the engine and mod- We are convinced that practical reali- ule structure is not the only new feature of zation of the modular concept as well as an the reusable fly-back booster. As it is introduction of reusability for separate known (see [3]), the realization of the con- stages (modules) of space launch vehicles cept on a self-sustained return of the booster are one of the most promising ways for to its launch site was also laid down into the radical enhancement of operational capabili- design of “Baikal”. Numerous systems and ties and reducing costs of current and ad- aggregates, support fly-back mission (an vanced space transportation systems. This air-breathing jet propulsion unit, con- was repeatedly marked and underlined in trol/guidance system, pivoted wing, under- various scientific papers, for example [4]. carriage, etc.) require multi year compre- The works that are being carried out by hensive design and test work. These circum- Khrunichev Center in these directions, give stances give very few opportunities to put sound foundation to hope that “Angara” rapidly this advanced article into operational launch system will not only gain a worthy service. At the same time, with an existence niche in the XXI century launch services of the RD-191M engine’s reusable version market but will have also broad prospects and with an introduction of necessary for further evolution and improvements. changes into the design of the URM-1 basic REFERENCES Potentialities of Multi-functional 1. A. Medvedev. ANGARA LV Fam- Application of “Baikal” First Stage ily: Status Report and Future Devel- Reusable Booster// Paper of 52-d In- th opments // Presentation to the 37 ternational Astronautical Congress, Session of the Scientific and Techni- Toulouse, France, 2001 cal Subcommittee on the Peaceful Uses of Outer Space Affairs, Vienna, 4. A. Medvedev, A. Kiselev, V. Men- Austria, 7-18 February 2000. shikov, Cosmonautics at Boundary of Milleniums: Results and Pros- 2. A. Medvedev, A. Kiselev, E. Mo- pects// “Mashinostrojenie”, Moscow, torny. Proton and Angara Launch 2001. Vehicles Families – Competitive Means of Providing Launch Services in the International Space Market // First Summit on the Space Transpor- tation Business, Paris, 1999.

3. A. Medvedev, Yu. Trufanov, E. Pashkov, E. Motorny, O. Sokolov,