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Home , 2005 in spaceflight, Ariane (rocket family)

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ATV

John Ellwood Project Manager, ATV, Directorate of Human , Microgravity & Exploration, Les Mureaux,

Jean-François Clervoy ATV Senior Advisor , Directorate of Human Spaceflight, Microgravity & Exploration, Les Mureaux, France

Frederic Castel ATV Support, Les Mureaux, France

ules Verne, the first of five Automated Transfer Vehicles (ATVs), stands on the J brink of flight. Its inaugural mission, set for the second half of 2007, will conclude an extensive 3-year test campaign. During the coming crucial months, the programme faces three key objectives: prepare for flight, fine- tune the interfaces with the International Space Station and the ISS partners, and ready -5 for launching its largest to date.

Introduction The ATV marks a new step for Euro- pean space transportation and lays a cornerstone for human spaceflight. It is the most ve r s atile spacecraft eve r developed, uniquely to self-navigate in and control its own rendezvous. It is a critical resupply tool for the ISS and for the Station partners, especially Final Preparations for after Shuttle flights end in 2010 and the ISS must rely on ATV for reboost and disposal at the end of its life. the First Flight of With ATV technology, ESA has the c apa ci ty for au tom ati c re n d e z vo u s between spacecraft – crucial for robotic ’s Space Ferry s a m p l e - re t ur n mi s s io ns, a s s e m bl i n g

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Human Spaceflight

ATV’s flight sequence, from launch (bottom left) to its fiery end in the atmosphere (bottom right). At top centre is the main control room in Toulouse. (ESA/D. Ducros)

ATV’s complexity is comparable to that of the Apollo craft that took mankind to the Moon. (ESA/D. Ducros)

complex spacecraft, and future human planetary exploration. Several European countries made the political commitment in 1988 to participate in the Station by signing the Inter Governmental Agreement with the USA and other participants. In 1992, ESA began a joint study with NASA to define ATV missions to what was then Space Station Freedom. The following year, ESA and the Russian space agency agreed to study possible ATV missions t o M ir- 2 an d, lat e r, to t h e Ru s s i a n segment of the ISS. After numerous political changes in the former USSR and following a US decision in 1993 to include in building the Station, it was finally decided in 1994 to build AT V. In February of that year, the 111th ESA Council Meeting in Paris agreed to the M ann ed Spa ce Tra n s p o r t at io n P rog- ra m m e, including AT V.At the Ministerial meeting in Toulouse in October 1995, AT V ’s full development won fo rm a l approval. For more than a decade, ATV has i nvo l ved dozens of companies and thousands of engineers from 10 Euro- pean countries under the prime The Mission contractorship of EADS-Astrium Space Europe. Since summer 2004, it has been A typical ATV mission begins with Tra n s p o r t ation (F). T he comp ani es a s s e m bled and tested at ESTEC, at launch into a circular orbit atop a new include Alcatel Alenia Spazio, Contra- times requiring new technical solutions, version of Ariane-5 from the French ves Space, Dutch Space, Snecma, minor changes and a lot of fine-tuning. Guiana equatorial site. It is injected into Alcatel Espacio, Crisa and MAN. Eight The technical complexity of t h e the Station’s orbital plane, inclined at Russian companies are also involved, programme has led to a 3-year delay in 51.6º to the Equat o r. Under the with the main contractor, RSC , the inaugural launch. Now, after responsibility of the ATV Contro l in charge of building 10% of ATV. meeting nu m e rous challenges, Ju l e s Centre (ATV-CC) in Toulouse (F), it The 19.4 t Jules Verne is the most Verne is in the home strait, aiming for separates from Ariane after 70 minutes complex space vehicle ever developed in launch in the second half of 2007. and a ct ivat e s it s n av i g at ion s ys te ms,

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which fire thrusters to begin its move The approach and docking are fully towards the ISS. automatic. If there are any problems, tanks connect to the Station plumbing After several days of raising its orbit, either the ATV computers or the Station and discharge their contents. The 100 kg ATV comes within sight of the ISS and c rew can tri gg er on e of t h re e of air for breathing is manually injected begins navigating relative to its target, programmed anti-collision manoeuvres. by the crew into the ISS atmosphere. For f rom about 30 km behind and 5 k m With ATV secure ly docked, the up to 6 months, ATV remains attached below. The computers begin final app- Station crew enters the cargo section mostly dormant, with the hatch open roach manoeuvres over the next two and re m oves the payload: supplies, into the Station. The crew gradually fill , closing in at a relative speed of a science hardware and lightweight bags t he c a rgo s e c t io n wi t h u nw a n t e d few cm per second while both craft are with fresh food, mail and tapes from equipment and rubbish. Every 10–45 flying around the Earth at 28 000 km/h. their families. Meanwhile, ATV’s supply days, ATV fires its thrusters to boost the

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Human Spaceflight

requirement: even with any combination of two possible onboard failures, the craft must still be safe for the crew and for the Station itself. It must also tolerate one failure and still complete its mission. This high level of autonomy, courtesy of several layers of safety and f a i l u re management, allows ATV to fulfil the entire mission on its own, from navigation in orbit to rendezvous man- oeuvres and finally docking with the Station. The whole software package, the most complex ever developed in Europe, has a million lines of code. Electromagnetic testing at ESTEC in 2005 ATV’s main computer and its thre e i n d e p e n d e n t sub-computers act as the pilot, controlling the mission. In the S t at i o n’s altitude, which is nat u ra l ly event of a major failure during the degraded by the faint but continuous critical approach phase to the ISS, or if atmospheric drag. any manoeuvre endangers the Station, a Preparing for acoustic tests at ESTEC Once its resupply mission is accom- dedicated backup computer will inter- plished, and it is filled with discarded vene using highly reliable and robust items, ATV is closed off by the crew and software. t e s t s, had concluded successfully. In automatically separates. Its thrusters use This backup computer isolates ATV’s parallel, functional and operations tests their remaining propellants to drop out normal system and commands a special were performed at both the ATV-CC in of orbit – not at a flat angle used for the ‘retrieve’ manoeuvre to take the vehicle Toulouse and the Functional Simulation smooth reentry of manned vehicles, but into a safe trajectory. This independent Facility (FSF) at EADS-Astrium in Les as steeply as possible for a controlled mode relies on separate computers, Mureaux, 50 km west of Paris. and safe destructive reentry high above s e p a rat e so ft w a re, s e pa rat e bat t e r i e s, the Pacific Ocean. separate trajectory-monitoring sensors, Acoustic and thermal testing From its first operational fl i g h t , and separate thrusters; only the The Large European Acoustic Facility E u ro p e ’s most challenging spacecra f t p ropellants are shared. This backup at ESTEC simulated the stress that ATV will play a vital role in Station servicing. system is so segregated from the main will encounter during the first 3 minutes It is also a way for Europe to pay its ATV systems that it is like a copilot of flight atop Ariane-5. The entire ATV share in ISS running costs by spending responsible for safety hidden inside the structure – the size of a double-decker money within European industry rather automated spacecraft. London bus – must withstand frequen- than by cash transfers to its ISS cies up to 8 kHz at 143 dB, a level lethal partners. Preparations and Tests to the human body. 2005 saw small technical problems and In the second half of 2006, Jules Verne The Challenges failures late in the processing of Jules completed a series of critical thermal ATV is the most versatile spacecraft ever Verne, including a small fatigue failure vacuum tests that replicated the harsh built – it first acts as the upper stage of in a propulsion va l ve Ariane-5, then it is a fully independent and an anomaly in the spacecraft, and, after docking with the drive mechanism of t h e Station, it is a supply, life-support and c r u c i a l s ol a r a r ray s. reboost module. Finally, it prov i d e s Tog e t h e r, th ey snow- waste-disposal. balled into a launch Its unique level of a u t o n o my and delay of more than a safety makes it the first fully automated year. resupply spacecraft of its kind. Even By the end of 2006, with a malfunction, ATV does not rely the comp lex env i ro n- on human intervention to ensure mental test campaign, mission success and Station safety. including the main The ATV’s design respects a tough acoustic and therm a l

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ATV

The Functional Simulation Facility in Les Mureaux is replicating the flight of Jules Verne

for shipping in summer 2007. The respecting the tough safety requirements transportation of ATV and its 400 t of of human spaceflight. support equipment from The Nether- At the same Moscow plant, a 2-month lands to will take campaign began in April to test ATV’s t e m p e rat u re e nv i ronm e n t o f s p a c e. 2 weeks by sea aboard the ship Toucan. physical interfaces – the docking system, These were the most critical environ- the complex associated electronics and mental tests for ensuring that all the Testing the links with the ISS the refueling system with real fluids and systems are robust enough to withstand For the past seve ral months, the pressurised tanks. Jules Verne has the the 6-month orbital mission. challenge has been to run parallel test unique capability to refuel the Station Since early 2006, a primary goal of campaigns in diff e rent countries and with 860 kg of propellants and remove the Jules Verne campaign at ESTEC has sites. The primary goal of this complex 840 kg of liquid waste. been to test the full interaction between and time-consuming strategy is to In summer 2006, thanks to the the extensive flight software and the real ensure that ATV hardware and software Europe’s largest ship hull test facility at flight hardware of the spacecraft as a can handle all the possible nominal and Val de Reuil, west of Pa r i s, it wa s wh o l e. Using the Electrical Gro u n d off-nominal scenarios that Jules Verne p o s s i ble to re p l i c ate the re n d e z vo u s Support Equipment of h u n d reds of might face during its demonstrat i o n s u c c e s s f u l ly. Fo r the first ti me, the cables and dozens of computers, the flight. system worked under complete closed- flight was replicated. For instance, at the RSC Energ i a loop conditions where all aspects of the Similar testing also began early last plant outside Moscow, home of t h e spacecraft were either represented for year at the FSF. This facility housed ATV docking mechanism, the refuelling real – software, sensors, trajectories – or actual mechanisms from Jule s Ve r n e a n d system and the complex associat e d simulated, such as thruster firings. replicas of its electronic ‘bra i n’ a n d electronics, major computer simulations ‘ n e r vous system’ plus ground equipment we re underway from December to to simu l ate all the external interfaces, March. The objective was to test the In 2006, ATV’s computer and sensors mounted on a mobile including up to 60 electronics ra c k s. To be final version of the software that will platform (left) proved they could approach and dock with the ISS s u re th at t he Faci lity ex a c t ly re p l i c at e s lin k ATV and the Russia n Zve z d a (right) from 250 m out Ju le s Ve r n e, howeve r, the results from the module during rendezvous and docking. t wo ca mp aign s wi ll be c lo se ly c ompare d . Tests included actual communications To make the tests even more realistic, the hardware and GPS simulators. During c o n t rol c e ntr e in Tou lous e wa s adde d in to AT V ’s stay at the Station, Zve z d a ’s th e lo op in e arly 2 007. T he pre p a rat i o n s computers will order the ferry to fire its and the successful closed-loop simu l a- thrusters to boost the Station’s altitude. tions with Jule s Ve r n e took more than At this ‘Ground Debugging Complex ’ , 3 months of intense wo rk. a powerful simulator could introduce Now that all the numerous tests and s eve ral failure scenarios and cre at e campaign challenges are nearing d e g raded situations that the AT V completion, Jules Verne should be ready a rc h i t e c t u re had to cope with wh i l e

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Human Spaceflight

This re n d e z vous test campaign Astronaut Jean-Francois brought the different systems together Clervoy demonstrates the p e r f e c t ly by using real ATV f l i g h t loading of late cargo into ATV sen sors un d er l if e-si ze re n d e z vo u s conditions and feeding measurements into the flight control computer. At the Further information on same time, a simulator calculated the ATV can be found at www.esa.int/SPECIALS/ movements of the vehicle in space. A ATV/ third system physically translated these c o m p u t at ion s in to a re l at i ve mot ion Facing page: ESA’s ATV team b e t ween the sensors, carried by an in Les Mureaux, November industrial robot, and their targets on a 2006. Holding the ATV huge mobile platform representing the display photo are Daniel ISS. The integration of all these systems Sacotte (left, Director, HME), Jean-Jacques Dordain into a closed-loop test wo rked as (centre, Director General) planned from some 250 m out all the and John Ellwood (right, ATV way to docking. Project Manager)

Getting Ready for Operations Under a contract signed with ESA in p rovides mission execution and be loaded horizontally through the large 2003, CNES has developed the ATV management, performed by CNES. In opening at the aft end of the pressurised C o n t ro l Cen tre, re s p o n s i ble fo r the second room are the flight dynamics module. At this stage, the ATV service monitoring and controlling the vessel e n g i n e e r s. An E ng i ne e r i n g S up p or t module, housing the avionics and the during its mission. Since early 2006, Team occupies the third, with experts p ropulsion systems, will not yet be dozens of simulations to monitor the from ESA and EADS-Astrium ready to mated to the cargo section. For flexi- Jules Verne approach to the Station have help in case of a problem. bility, a small fraction of the dry cargo required a high degree of technical skill There is no CapCom (Capsule Com- can be loaded through the docking n ever seen befo rein European operat i o n s. municator) in the ATV-CC but, in case hatch up to 8 days before launch, when While attached for up to 6-months, of emergency, the flight director can the craft is undergoing final prepara- ATV will not only resupply, refuel and contact the crew in orbit. The official tions on top of the Ariane-5. boost the ISS, it will also be used to language during all ATV operations is The first ATV flight is a demonstrat i o n desaturate the Station’s control gyros English, including the communications mission, so it will carry a heavier propel- an d , i f n e c e s s a r y, ma no e u vr e t h e with Moscow and Houston. lant load than subsequent missions. The complex to avoid . extra load will allow several scenarios S eve ral m issi o n scen a rio s re q u i re The Extensive Launch Campaign and manoeuvres to be tested, such as c o m p l ex interactions and share d Since ATV is the heaviest and most re t re ating into a parking orbit and responsibilities between ATV-CC and challenging spacecraft ever developed in delaying rendezvous until the following the Mission Control Centres in Moscow Europe, together with the demanding day. The rest of Jules Verne’s payload and Houston. For the first time, three re q u i rements of manned spacecra f t will be 860 kg of refuelling propellants space centres around the globe must safety, the launch campaign at for the Station’s own propulsion system, work together. Special high-level ‘Multi- will take 3.5 months. 2 8 0 k g o f dri nking wat e r, 2 0 kg of ox yg e n El ement Pro c e d u re s ’ h ave been First, in the EPCU S5 (Ensemble de and t he 20 10 k g of reboo st pro p e l l a n t s. developed, allocating the tasks to be Préparation de Charges Utiles) building, The ex t ra propellants not consumed fo r performed sequentially to the centres where are prepared for launch, u n expected scenarios during fre e - fl i g h t involved. A dozen simulations involving a major leak test will check ATV’s 48 m3 will be used for additional Stat i o n the three centres are under way to fine- p ressurised section and all other reboosting. All the fluids and gas will be tune the range of possible scenarios, pressurised components such as water loaded fo l l owing strict safety rules. from perfect to degraded missions. and gas tanks and the propulsion and In parallel, the special version of the During the fl i g h t ’s highly critical the refuelling systems. Ariane-5 will undergo its own launch p h a s e s, from launch to docking and Then comes the loading of the dry preparations. from departure to reentry, the entire 60- c a rg o, in white standard bags of person team in the ATV-CC will work in different sizes, stored in the racks of the Ariane’s Largest Payload three adjacent control rooms separated pressurised section. Most of the 1610 kg Jul e s Ve r n e will be launched by a by large glass walls. The main room of dry cargo carried by Jules Verne will modified version of Ariane-5 known as

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ATV

t he ‘A r i a n e - 5 E vol ut i o n St o r abl e ’ The second major change is the around the world. Passing over south- (A5 ES-ATV). It comes equipped with modified path taken by the 775 t east Au s t ralia, reignites fo r the powerful -2 main engine and Ariane-5 during ascent and insertion, 40 seconds to circularise the orbit at features the storable-propellant upper a l l owing for the more seve re aero- 2 6 0 km. Four minutes lat e r, AT V stage (Etage à Propergols Stockables, dynamic and thermal demands and the separates over the southwest Pacific and EPS) and its re i g n i t able Aestus engine. different centre of gravity. becomes an independent spacecraft. On On subsequent flights, the launcher will About 3.5 minutes after lift-off, the its own, the EPS reignites an orbit later inject the 20 750 kg ATV into the ISS fairing protecting the ATV is ejected. to deorbit and burn up safely during a orbital plane at around 300 km altitude. F ive and a half m i nutes lat e r, the precise reentry. For Jul es Ve r n e, wi th a mas s of 1 9 4 0 0 k g , cryogenic main stage (Etage à Propergol the circular orbit is at 260 km. C r yog é n i q u e, EPC) separat e s, leav i n g The Launch Date This first ATV is more than double ATV with its the upper stage. This ATV From April to mid-summer, an extensive the heaviest single payload ever lifted by will reach its initial circular orbit using review is being conducted with NASA Ariane-5. To handle such a heavyweight, t wo burns separated by a 45 m i nu t e and the Russians to be sure that Jules the Vehicle Equipment Bay, supporting coast. The first EPS burn lasts about Verne, the facilities and the trilateral the ATV atop the launcher, has been 9 m i nu t e s, ove r t h e At la n t ic Oc e an , p ro c e d u res are re a dy to support the significantly strengthened. followed by a ballistic coast half way inaugural mission. Whatever happens, the mission will not depart earlier than the second half of 2007. Once Jules Verne is ready to go, the launch window depends on several factors such as the angle of the at the time of docking, spacecraft traffic and availability of the ISS aft docking port, Station requirements for cargo and reboost and, finally, Ariane-5 constra i n t s f rom its own busy commerc i a l manifest. Finally, all the international partners must agree upon the best date among the possible windows to resupply the Station with up to 6 t of cargo. e

The ISS Expedition-16 crew, Yuri Malenchenko (right) and Peggy Whitson (left) began ATV training at the end of February 2007 at the European Astronaut Centre

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