Cosmic Vision 2015-2025: ESA's Long Term Programme in Space Sciences

Mem. S.A.It. Vol. 81, 467 c SAIt 2010 Memorie della

Cosmic Vision 2015-2025: ESA's long term programme in space sciences

J. Clavel

ESTEC/SRE-SA Postbus 299, 2200 AG - Noordwijk, The Netherlands e-mail: [email protected]

Abstract. ESA’s space science programme is brieﬂy reviewed, with a particular emphasis on its long term plan, “Cosmic Vision 2015-2025”. The mission selection process is presented together with the current status of the diﬀerent projects selected and currently under assessment. The strategy for implementing the plan is outlined, as well as the programmatic and international context.

Key words. Space vehicles: instruments – Telescopes

1. Introduction European member states globally spend on av- erage 250 to 300 MEuros/year on space sci- The Science Programme is a mandatory pro- ence (in addition to their mandatory contri- gramme of the European Space Agency to bution to ESA). The content of the science which all 18 member states must contribute programme is defined by the European scien- in proportion to their Gross National Product tific community through open calls for mission (GNP). Every three years, the Council of concepts followed by peer review and the even- Ministers decides by unanimity the Level of tual selection of future missions to be devel- Resources (LoR) for the next 5 years. The oped and launched 10 to 15 years later. The council of ministers met in November 2008 cycle is repeated every 10 years or so. Two pre- and allocated a total budget of 2.327 billion vious cycles established the Horizon 2000 and Euros for the 5-year period 2009-2013. This Horizon 2000+ science programmes, in 1984 corresponds to a LoR of 465 MEuros/year at and 1994-1995, respectively. The current cy- 2008 Economic Conditions. Since payloads cle, Cosmic Vision 2015-2025 (CV in short) are generally built and funded nationally, to was initiated in 2004. be exhaustive one should add to this figure ESA is currently operating 12 scientific the space science expenditures of ESA mem- satellites which were selected and developed as ber states. Because of different accountabil- part of the Horizon 2000+ programme. ity systems, the latter is not straightforward to establish. Furthermore, it varies substan- – The X-Ray observatory XMM-Newton, tially from year to year. Nevertheless, a re- launched in December 1999 continues to cent study commissioned by the European collect 0.1-10 keV images and spectra of Science Foundation shows that in recent years all kind of celestial sources, from planets Send offprint requests to: J. Clavel to the most distant quasars. 468 Clavel: Cosmic Vision

– The Integral observatory has been gath- satellite to map the Cosmic Microwave ering hard X-ray and gamma-ray im- Background (CMB) radiation tempera- ages and spectra from celestial sources ture and polarisation with µK sensitivity. since its launch in October 2002. Both Compared to WMAP, Planck features a XMM-Newton and Integral are observato- much better angular resolution (up to 5 ries opened to the world-wide astronomical arcmin), a greater sensitivity and 9 fre- community via calls for proposals and the quency channels which will vastly im- usual peer review selection process. prove the control of systematics and re- – In exchange for ESA’s contribution moval of foreground parasitic emission. to NASA’S Hubble Space Telescope, Planck will pin down cosmological param- European astronomers have access to at eters to a 1 percent accuracy and stands least 15% of HST observing time. a good chance of detecting inflation di- – Since its launch in December 1995, the rectly through the imprint left by gravita- ESA-NASA SOHO observatory has been tional waves on the CMB polarisation sig- collecting a wealth of data on the Sun, from nal. Through the Sunyaev-Zeldovich effect, its deep core interior to the outer corona, it will discover thousands of distant galaxy the solar wind and its interaction with the clusters and thereby tighten the constraints interplanetary medium. on the dark energy equation of state. – The 4 Cluster spacecrafts have been pro- – Finally, the Rosetta spacecraft, launched viding vital 3D in-situ measurements of in March 2004, is on its way to comet the earth magnetosphere and its interaction 67P. It will rendezvous the comet in May with the solar wind since their launches in 2014 and land a probe on its surface in July and August 2000. November 2014 for in situ measurements. – Launched in June 2003, Mars Express is On September 5, 2008, Rosetta collected in orbit around the red planet and provides spectacular images and a wealth of mea- a wealth of scientific data, including high surements while it flew-by asteroid 2867 resolution stereo images. Steins from a distance of 800 km. In July – Venus-Express was launched in November 2010, Rosetta will encounter a second as- 2005. The probe collects data on the teroid, 21 Lutetia Venusian surface and atmosphere from the vantage point of its polar orbit around the All above Horizon 2000+ missions are in planet. good health and their operations are funded – With its 3.5 m diameter telescope feed- through 31 December 2012. For complete- ing 3 cryogenically cooled instruments, ness, ESA is also partner on 4 nationally-led Herschel is the most sensitive far-IR to sub- projects currently in operation: millimeter (100 − 800µm) observatory in – CoRoT, a CNES mission to detect exo- operations to date. It will revolutionize our planets via the transit method and perform understanding of the interstellar medium astro-seismologic measurements of several and in particular of the early stages of the tens of thousands of stars. CoRoT was process by which stars and planetary sys- launched in December 2006. tems form. Its vastly improved sensitiv- – Chandrayan, a lunar Orbiter developed ity will permit deep cosmological surveys by the Indian space agency, ISRO and and shed light on the formation process to which Europe through ESA con- of galaxies and large scale structures of tributes several instruments. Chandrayan the Universe. Launched on May 14, 2009, was launched in October 2008. Herschel is currently en route toward its fi- – Double Star, a collaborative project nal Lissajous orbit around the second Sun- with the Chinese National Space Earth Lagrange point L2. Administration, consists of 2 satellites – Launched together with Herschel in a sin- in earth orbit that study the earth mag- gle Ariane-V rocket, Planck is also on its way to L2. Planck is a third generation netosphere. Launched in December 2003 Clavel: Cosmic Vision 469

and July 2004, the two spacecrafts nicely – Bepi-Colombo is a collaborative ven- complement the Cluster flotilla. ture with the Japanese Space Agency – Cassini-Huygens, is a collaborative mis- JAXA whereby ESA provides the Mercury sion with NASA and the Italian space Planetary Orbiter (MPO) and JAXA devel- agency ASI to study the Saturnian system ops the Mercury Magnetospheric Orbiter and in particular its Titan moon. Launched (MMO). Thanks to its sophisticated pay- in October 1997, the mission consisted of load and relatively low orbit, Bepi- a Saturn orbiter developed and operated Colombo will provide high resolution im- by NASA plus the ESA probe Huygens, ages of Mercury and in situ measurements which successfully landed on Titan surface that will vastly improve our knowledge on January 14, 2005. After obtaining the of the mysterious planet. The two Bepi- first in-situ measurements and images of Colombo probes will be launched together Titan, Huygens ceased functioning. Cassini by a single Ariane-V rocket in August 2014 continues to orbit Saturn and collect data and arrive at Mercury in 2020. on the planet and its many satellites. – ESA is also collaborating with the French space agency CNES to develop Several other H2000+ missions are still under Microscope, a mission that will provide a development: stringent test of the Equivalence Principle, – LISA Pathfinder is a technology demon- one of the founding pillars of General strator for the ambitious LISA mission. Relativity. Specifically, ESA is developing When launched in mid-2011, it will the Field Emission Electric Propulsion demonstrate the feasibility of putting two (FEEP) technology, a low thrust low-noise free-floating test masses in purely geodesic propulsion system that has 0.1 micro- motion, free from electromagnetic, solar Newton accuracy. Microscope is currently wind or any other perturbations. LISA slated for launch in 2012. Pathfinder will also validate the technology required to measure the relative positions Two projects that were initially envisaged in of the two test masses to picometer accu- the framework of the H2000+ programme but racy. never formally approved have been put back – Gaia is the successor of the success- into competition with the new Cosmic Vision ful Hipparcos Astrometric mission. When missions. These are: launched in December 2011, it will mea- – LISA, a very ambitious collaborative mis- sure the parallax and proper motions of a sion with NASA the purpose of which is billion stars down to micro-arcsec accu- to detect and measure gravitational waves racy as well as their radial velocity and en- in the astrophysically interesting 0.1−10−4 ergy distributions over the 320-1000 nm Hz frequency range, inaccessible from the range. This will allow the reconstruction ground. LISA features a constellation of 3 of the formation and accretion history of identical spacecrafts in a 1 AU orbit around the milky-way. Among other things, Gaia the sun. Separated by 5 million kilome- will also detect tens of thousand of Jupiter- tres, the 3 S/C form an equilateral trian- size exo-planets as well as comets, aster- gle that is inclined by 60 degrees with re- oids and trans-neptunian objects in our own spect to the ecliptic plane and trails the solar system. earth by 50 millions kilometres. The pas- – Through ESA, Europe is also collabo- sage of gravitational waves through the so- rating with NASA on the James Web lar system distorts space-time and there- Space Telescope (JWST). Europe is cur- fore the 3 sides of the triangle by a minute rently developing the near IR spectrograph amount which depends on the strength of NIRSpec as well as half of the Mid-IR the GW source, its distance and its direc- Instrument MIRI. On behalf of NASA, ESA will also launch the JWST spacecraft tion. This is precisely this minuscule de- on an Ariane V rocket in 2014. formation which LISA will measure via 470 Clavel: Cosmic Vision

laser interferometry with picometer accu- – What are the conditions for planet forma- racy. Through phase and amplitude modu- tion and the emergence of life? lation, LISA will provide an angular reso- – How does the Solar System work? lution of up to 1 arcmin for the strongest – What are the fundamental physical laws of sources and an estimate of the mass and the Universe? (luminosity-) distances accurate to better – How did the Universe originate and what is than 1 %. In 2011, the LISA Pathfinder will it made of? hopefully demonstrate most - but not all - the technologies required for LISA. The plan also identifies specific aspects of each – Solar Orbiter is the next generation Solar general theme that are judged to be ripe for Observatory to be put into a 0.3 AU orbit investigation with new space missions in the around the Sun and up to 27 degree above period 2015-2025. It proposes a strategy for the ecliptic. implementing these missions and identifies the new technologies that must be developed to enable such projects. 2. The Cosmic Vision process 2.1. Selection of scientific themes 2.2. Cosmic Vision implementation In April 2004, ESA issued a Call for Cosmic strategy Vision science themes, i.e. for important sci- Based on the Cosmic Vision (CV) plan, ESA entific questions that are likely to remain un- elaborated a strategy for its implementation resolved at the horizon 2015-2025 and con- that is compatible with the financial concepts of space missions to answer them. The straints imposed by the LoR and missions cur- European (and beyond) community responded rently under development or in operations. The massively and submitted 151 novel ideas, more plan was eventually endorsed by the Science than twice as many as for H2000. Programme Committee (SPC), the most senior The Space Science Advisory Committee body that governs ESA Science programme (SSAC) of ESA, assisted by its three thematic and where each member states is represented working groups, the Astronomy Working by one national delegate. Groups (AWG), the Solar System Working The CV2015 implementation strategy fore- Group (SSWG) and the Fundamental Physics sees: Advisory Group (FPAG), analysed the re- sponses from the community and pre-selected – 3 Call for mission proposals, with roughly a few themes. These themes were presented one call being issued every ∼ 3.5 years over and discussed at a workshop in Paris in the period 2007 to 2015. September 2004 which more than 400 scien- – Each Call has a financial envelope of 950 tists attended. The SSAC and the three WGs MEuros, to be spent into one Large (L) and are teams of scientists chosen for their scien- one Medium (M) size mission. tific standing and who are expected to repre- – The cost to ESA of an L mission is capped sent the views of the European scientific com- to 650 MEuros at 2006 economic condi- munity as a whole rather than any particular tions (EC). national interest. The SSAC prepared a first – The cost to ESA of an M mission is capped version of the Cosmic Vision plan which was to 300 MEuros (2006 EC) presented to the scientific community during – As a rule, M missions must have their tech- a workshop in Noordwijk, Holland in May nology ready at the time of their selection, 2005. The plan was further elaborated during whereas some technology development is the summer and eventually issued in October acceptable for the more complex and am- 2005 as ESA-BR 2471. The plan identifies four bitions L missions. Specifically, M mis- main scientific themes as follows: sions must achieve Technology Readiness Level (TRL) 5 before development, which 1 http://www.esa.int/esapub/br/br247/br247.pdf Clavel: Cosmic Vision 471

means that a breadboard has been devel- ter along the line-of-sight is inferred through oped, tested and qualified in representative the Weak gravitational Lensing (WL) distor- conditions. tion of galaxy shapes and orientations it in- – As a baseline, payloads continue to be de- duces. Because it is a statistical method, WL veloped and financed by national mem- requires a very large sample of galaxy shapes ber states outside of the ESA science pro- to be measured over the entire extra-galactic gramme LoR. sky. The overall distortion is small and re- – As explained above, LISA will compete quires sub-arcsec angular resolution to be mea- with new CV projects for selection as an sured to the required level of accuracy. The L class mission and Solar Orbiter as an M second proposal, SPACE, aims at constrain- class mission. ing the DE equation of state through its effect on the growth of cosmic structures as a function of time. More specifically, it mea- 2.3. Selection of mission concepts sures Baryonic Acoustic Oscillations (BAO) as Based on the Cosmic Vision Plan elaborated a function of look-back time. BAO are small by the SSAC and WG and on the strategy pro- amplitude modulations (5-10%) in the distri- posed by ESA executive and approved by the bution of matter imprinted at early stages of SPC, ESA issued the first of the 3 Cosmic the universe when radiation and matter decou- Vision Calls for mission proposals in March pled shortly after the big-bang (z ∼ 1000). This 2007. The Call foresees the selection of one M initial imprint seeded the subsequent growth mission for launch in 2017 and one L mission of structures in the Universe. The later evolu- for a launch in 2018. tion of BAO depends on the competing effects Again, the scientific community responded of gravity, which accelerates the formation of massively to the Call, submitting a total of 50 galaxies and clusters of galaxies and DE which proposals by the 29 June 2007 deadline, more tends to rip them apart. This is precisely the than twice as many as for H2000+. Over the effect which SPACE aims at measuring by cor- summer, the SSAC and the WGs evaluated the relating the redshifts of half a billion galaxies proposals and eventually selected 4 M and 3 up to z ∼ 2. On the advice of a specially ap- L mission concepts for assessment, plus one pointed ad-hoc scientific committee and of the “mission of opportunity”, i.e. a mission whose AWG, the DUNE and SPACE proposals were cost to ESA is ≤ 100 MEuros. The selection merged into one single mission concept bap- was announced in October 2007. tised EUCLID. EUCLID aims at constraining the DE equation of state to 1% accuracy, suffi- cient to distinguish between competing mod- 2.4. Cosmic Vision M-class missions els of its origin. Since the systematic errors currently under assessment which limit the power of the WL and BAO methods are “orthogonal”, EUCLID is more The M-class missions selected for assess- powerful that the sum of DUNE & SPACE. ment studies are EUCLID, PLATO, MARCO- Furthermore, it is theoretically possible that POLO, and CROSS-SCALE, plus the SPICA BAO and WL yield conflicting results. This mission of opportunity. would be a strong indication of a break-down EUCLID aims at constraining the equation of General Relativity, a result which cannot be of state of Dark Energy (DE) and its evolu- achieved through DUNE or SPACE alone. In tion as a function of cosmic time. It is a survey its current design, EUCLID features a 1.2 m mission which combines two proposals from diameter telescope feeding an optical imaging the community, DUNE & SPACE. The DUNE channel (∼ 0.2” resolution), a NIR (Y, J, H) concept proposed an imaging and photomet- photometric channel and a 0.8-1.7 µm spectro- ric survey in the visible to near IR in order metric channel with a resolution λ/∆Λ= 400. to map the total amount of matter (luminous During 4 years, EUCLID will survey 20,000 and dark) and therefore the growth of structure as a function of redshift. The amount of mat- square-degrees down to 24.5 magnitudes in the 472 Clavel: Cosmic Vision visible and measure the photometric redshift ates particles? How does reconnection convert of half a billion galaxies as well as the spec- magnetic energy? How does turbulence control troscopic redshift of a subsample of 108 galax- transport in plasmas? The mission will com- ies brighter than AB = 22. Preliminary discus- prise up to 7 identical spin-stabilised space- sions with NASA for an eventual merging of crafts, separated by distances varying between EUCLID with its US equivalent JDEM into a 1.4 and 25 earth-radii so as to investigate single joint dark energy mission have been put plasma phenomena on a range of spatial and on hold because of schedule incompatibilities temporal scales. CROSS-SCALE will work between Cosmic Vision and the US decadal in partnership with its JAXA sister mission ASTRO2010 survey. SCOPE, thereby adding 2 spacecrafts to the The goal of PLATO is to discover a large constellation. Each spacecraft will include a number of close-by earth-size exoplanets and different but complementary suite of instru- characterise their mass and radius with 1% ac- ments for in situ plasma measurements. The curacy. PLATO features between 12 and 54 constellation will be put into orbit by a single small telescopes, providing a total collecting Soyuz-Fregat launch. area of 0.3 m2 and a > 600 deg2 FOV. Two SPICA is a very ambitious JAXA mission fields will be observed for 2.5 years each in for medium to far IR (5-210 µm) astronomy to order to collect the light-curves of 20,000 F, which ESA would contribute a 3.5 m diameter G & K stars to a relative photometric accu- actively cooled (to < 5K) telescope, a ground- racy of 10−6/month, and 500,000 stars to some- station and the nationally funded SAFARI far- what less precision. The light-curves will be IR instrument. The other two JAXA-provided searched for the small dimming produced by instruments are a Mid-IR coronagraph and a a planet as it transits in front of its parent star. Mid-IR Camera & Spectrometer. Conceived The light-curves will also be subjected to as- as a general purpose observatory, SPICA rep- troseismologic analysis in order to precisely resents the next logical step beyond Spitzer determine the age, mass and size of the stars. and Herschel, improving upon their sensitivi- PLATO will improve upon the NASA Kepler ties and resolutions thanks to its larger and ac- mission by detecting a larger number of earth- tively cooled mirror. Among other things, its size planets and characterising their mass and coronagraph will collect the first uncontami- radius. PLATO will be put into a large ampli- nated mid-IR spectra of young massive plan- tude orbit around the Sun-Earth L2 point by a ets. SPICA will be injected toward an L2 orbit Soyuz-Fregat launcher. by a JAXA H2A launcher. In July 2008, JAXA MARCO-POLO is a mission to perform in- officially approved the selection of SPICA for situ analysis of a primitive Near-Earth Object a 2-years pre-project phase, akin to a phase-A (NEO) - Comet or Asteroid - and return a sam- study. ple to earth for laboratory analysis. This will During the first half of 2008, all 5 M mis- shed light on the initial conditions and evolu- sion concepts went through a 3-months ESA tion of the solar nebula, the properties of the internal study aimed at propagating the scien- building blocks of terrestrial planets and the tific requirements into a baseline design and formation history of planetesimals. The space- identifying the technologies which must be de- craft consists of an orbiter with 7 instruments veloped to enable the missions. No show stop- on-board and a lander featuring 5 instruments pers were indentified but these quick studies for a 3 months in-situ analysis of surface and already showed that, with the exception of sub-surface NEO materials. MARCO-POLO SPICA, none of the M mission fits into its is a collaborative mission with the Japanese 300 MEuros financial envelope. The results of space agency JAXA. these studies served to prepare the Invitation- CROSS-SCALE aims at quantifying the to-Tender (ITT) to industry for a follow-on in- coupling between different scales in the plasma depth technical assessment of the mission con- that surrounds the earth. It will seek an answer cepts. The ITT were issued during the summer to questions such as: how do shocks acceler- 2008 to which European space industries re- Clavel: Cosmic Vision 473 sponded with technical and financial proposals ies of XEUS and its American equivalent for a detailed study and design of the missions. Constellation-X. The combined ESA-NASA- For each of the 5 missions, two industries were JAXA mission was re-baptised International eventually selected to perform two competi- X-ray Observatory (IXO). Instead of 2 space- tive assessment studies in parallel. The indus- crafts in formation flying, the baseline mis- trial studies lasted from September 2008 to sion now consists of one single satellite with August 2009. Following a Call for Declaration a ≥ 20 m deployable optical bench to pro- of Interest issued in June 2008, instrument con- vide the required focal length and high energy sortia have been selected who are responsible sensitivity. The diameter of the mirror is 3.3 for the nationally funded assessment studies m. The model payload consists of several fo- of the mission payloads. These payload stud- cal plane instruments, including a Wide-Field ies will run in member states in parallel to Imager, a Narrow-Field Imager and a high- ESA funded system studies in order to define resolution grating spectrometer. IXO will be the baseline instrumentation of each mission. put into a halo orbit around L2 by an Ariane-V The results of the system and payload studies or an Atlas V launcher. The IXO concept went will be combined and presented to the scien- through internal assessments both at ESA and tific community and the ESA advisory struc- at NASA, with JAXA participation. A base- ture in December 2009. Two important outputs line design was selected jointly by the three of the assessment studies are a cost estimate agencies in early 2009. This forms the basis and an evaluation of the technological maturity of the two competitive industrial studies which of each mission. Where necessary, technology will be initiated July 2009 and last 18 months. development plans have been prepared and are Though no “show stoppers” have been identi- being implemented. fied so far, it is nevertheless clear that IXO will require several years of technological development, in particular in the area of light-weight 2.5. Cosmic Vision L-class missions X-ray mirrors and advanced Transition Edge currently under assessment Sensors micro-calorimeters. The two L-class missions selected by the The SSAC retained one mission to the SSAC for an assessment phase are IXO (for- outer solar system for assessment studies, to be merly XEUS) and LAPLACE/EJSM. selected from the two original LAPLACE and IXO represents the next-generation general TANDEM proposals submitted by the commu- purpose X-ray observatory. With ≥ 3 m2 effec- nity. In February 2009, ESA and NASA jointly tive area at 1 keV and advanced focal plane down-selected LAPLACE for further assess- detectors, its sensitivity will improve by one ment. LAPLACE is a 3-agencies joint mission to two orders of magnitude upon the highly to the Jovian system consisting of a NASA pro- successful XMM-Newton ESA and Chandra vided Europa Orbiter (EO), a JAXA-provided NASA missions. IXO main scientific objec- Jupiter Magnetospheric Orbiter (JMO) and an tives are to investigate how super-massive ESA-provided Jupiter Planetary Orbiter (JPO). black-holes formed and grew in the early uni- JPO is a three-axis stabilized platform op- verse, how this influenced the formation of timized for remote sensing observations and galaxies, how large scale structures evolved in situ measurements optimized for Jupiter and how they became chemically enriched. System Science complementing EO and JMO. IXO was initially proposed as XEUS, an ESA- Its trajectory around Jupiter includes flybys of JAXA collaborative missions consisting of a the four Galilean moons (Io, Europa, Callisto, mirror spacecraft and a detector spacecraft Ganymede). Among LAPLACE many scien- in formation-flying. An internal study rapidly tific goals, one should underline the study of confirmed that such an ambitious concept was Europa’s capability to sustain life. LAPLACE well beyond the financial envelope of an L- underwent two parallel internal phase-0 assess- class mission. In July 2008, ESA and NASA ments, both at ESA and at NASA. No “show therefore agreed to merge the assessment stud- stoppers” have been identified such that the 474 Clavel: Cosmic Vision two competitive industrial studies will start in Exploration Directorate. The reports will also July 2009. They are expected to last 18 months be presented to the scientific community on and be completed toward the end of 2010. December 1st in Paris. The M Mission candi- LAPLACE will require several years of tech- dates will be evaluated by the AWG and SSWG nological development. Most critical is the pro- during the period mid-November 2009 to mid- tection against the harsh particle radiation en- January 2010. On January 13, 2010, both WG vironment characteristic of the Jovian system. will rank the missions in their respective dis- cipline and issue their recommendations to the SSAC. Based on these recommendations, the 3. The future SSAC will on January 14, select ≥ M Missions LISA must await the in-orbit validation of its for a definition phase. The selection will be technologies by LISA Pathfinder in late 2011. formally approved by the SPC will occur on Both IXO and LAPLACE require technologi- February 18, 2010. cal development that will extend beyond 2011. The Mission Definition Phase will last for It is therefore clear that none of the 3 L mis- 2 years during which the mission candidates sions currently under assessment can be ready will be designed to the level of individual sub- for implementation in 2011. The original plan, systems and components. Each mission will be which was to select 1 L and 1 M mission for subjected to two parallel mission definitions by implementation in 2011, is therefore no longer two independent industries competitively se- feasible. Furthermore, the assessment studies lected via an ITT. The industrial competition have already demonstrated that, with the ex- maximises the chance of later selecting the best ception of SPICA, none of the M mission can- possible and most competitive design for im- didates fits into the 300 MEuro envelope orig- plementation at the end of 2011. The payloads inally envisaged. It was therefore decided to of these missions will be subjected to parallel modify the plan in such a way that 2 M mis- definition studies conducted under the respon- sions will be selected in 2011 for development sibility of nationally funded scientific consor- at a total cost to ESA of 950 MEuro, the budget tia. At the end of this phase, the overall cost of of one Cosmic Vision “slice”. the mission - to both ESA and member states - will be consolidated to a 20%˜ accuracy. During the Definition phase, the relevant technologies 3.1. Timeline for the M-class missions will continue to be developed as required to reach TRL 5 in 2011. To retain a healthy competition up to the end, In late 2011 or early 2012, the advisory at least three M missions will be selected for structure and SSAC will select two of the M a definition phase in early 2010. The 3 mis- mission candidates and recommend their im- sions will be selected among the 5 CV can- plementation to the SPC. For each of the 2 M didates plus Solar-Orbiter. Beyond scientific missions, an ITT will be prepared for compet- excellence, one important selection criterion itive selection of the industrial consortium that is technological maturity. As previously men- will be responsible for the development of the tioned, an M mission must demonstrate that it spacecraft. Similarly, scientific consortia and can reach Technology Readiness Level (TRL) Principal Investigators will be selected via an 5 by the time it starts implementation in 2011. open Call for the construction of the instru- Though the assessment studies are not yet ments. In September 2012, the two M missions completed, it seems that this will be the case will then be ready to enter into implementa- for at least 3 M missions. tion - akin to phase B2/C. Nominally, the de- On 15 November 2009, the M-mission as- velopment of the spacecraft and payload will sessment study reports, traditionally known as last 5 to 6 years such that one M mission can the “Yellow Books”, will be published on the be launched in September 2017 and a second web site of the ESA Scientific & Robotic one in the second half of 2018. Clavel: Cosmic Vision 475

3.2. Timeline for the L-class missions cycle. M missions however, do not carry-over and fresh proposals must be submitted anew. As already mentioned, none of the 3 L mis- In 2012, 3 M and 3 L missions will be selected sions currently under assessment can reach for a 1 year Assessment study. Nominally, 2M TRL 5 by 2011. Furthermore, all 3 missions and 2 L missions will survive selection in require international collaboration with part- 2012 and enter into a 2-years Definition phase. ner agencies and the collaboration schemes are Eventually, one M and one L missions will be not precisely defined yet. The selection of an selected for implementation and launch after L mission will thus be deferred to whenever 2020. more than one mission is technologically and programmatically ready for implementation. Upon completion of the assessment stud- 4. DISCUSSION ies in late 2010, IXO and LAPLACE will compete with LISA for entering Definition phase. WOLFGANG KUNDT: To your list of pos- The selection will be performed by the WG and sible explanations of “Dark Energy”, please SSAC in early 2011. The two surviving L mis- add the one by David Wiltshire whereby DE is sions will then undergo a 2-years detailed def- an artefact introduced by a careless evaluation inition by industry. When completed, the WG of the past light-cones in an inhomogeneous and SSAC will down-select one of the two L Universe (with voids and walls, as observed, missions for implementation. The exact date Shapiro effect). is TBD and depends on the time it takes for the L missions to reach TRL 5. It seems likely JEAN CLAVEL: I am not a DE specialist, but however that this could happen in 2013 or 2014 it seems unlikely to me that such an error could such that the first Cosmic Vision L mission can reproduce the magnitude of the observed ef- be launched in 2020. fect.

WOLFGANG KUNDT: Should massive 3.3. Future calls for & selection of Black-Holes never have formed in the local Cosmic Vision Mission proposals Universe, is there an expected source in the −1 −4 As previously explained, the Cosmic Vision 10 − 10 Hz window such as a very com- implementation strategy foresees 3 Call for pact binary systems? Mission proposals to be issued at a 3.5 years interval. The cycle described above will thus JEAN CLAVEL: As a matter of fact, there is a be repeated in 2011 and again in 2014-2015. dozen of compact X-ray binaries in our galax- For cycle 2, a Call for Mission proposals ies which are “guaranteed sources” of gravita- will be issued in 2011. L missions from pre- tional waves for LISA. Because their physical vious cycles that were not selected will au- parameters are well determined, they will be tomatically be carried-over into the following used to calibrate the LISA GW observatory.