1. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 1 The LNF Space Climatic Facility (SCF) Purpose and status of the SCF Science and technology projects at the SCF S. Dell’Agnello, INFN-LNF for the LARES Collaboration, (PI I. Ciufolini, Univ./INFN-Lecce) the LNF Support Services

2. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 2 Purpose of the SCF Thermo-optical characterization of LAGEOS/LARES prototypes Thermal thrusts (TT) due to asymmetric absorption and re-emission of (IR) radiation by CCRs generate the largest NGP on Lense-Thirring (LT) measurement in GR –  LT (due to TT) ~ 2-3%, while LARES goal is  LT ≤ 1% –Governed by slow CCR thermal relaxation time,  CCR, never measured in space climate –Computed  CCR = (2000 - 7700) sec: ~ 250 % range ! –T ECLIPSE ~  CCR ! T ORBIT = 13300 sec Rubincam effect (from our NASA/Goddard LARES collaborator

3. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 3 FE model and thermal simulation SUN=on, IR=off  CCR = 2400 ± 40 sec (2% stat. fit error) Error on T = 0.5 K 1) Metal (Al T6016) ~ at “room T” (± 2K) 2) CCRs (fused silica) “cold” (260-285 K), with slow relaxation time Sun = off, IR = off at t = 0 T CCR (K) t(sec) T = 2800 sec

4. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 4 SCF layout (purchased equipment) Cryostat (old linac RF cavity) –Vac: < 10-5 mbar –Tshield = 77 K(LN2) Solar simulator (TS-Space) –in front of  = 40 cm, 4 cm thick Quartz window –Absolute calib. 1 Sun (AM0) –Uniformity: ± 5% –UV-Vis-IR: 250nm - 3.5  m –  = 35 cm Earth IR simulator (in-house) –  = 30 cm black disk –T = 250 K Thermography –RTD/PT100/PT1000 –IR camera, Ge window

5. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 5 Our software capabilities SW for satellite thermo-optical simulation (“Thermal Desktop”) FE/FD modelers IR/VIS optical properties. Also f( ) Orbital and radiation simulator LARES-LNF performed the first ever thermal simulation of f. silica CCRs –Before, CCR treated as isothermal Volumetric radiation (next release): state- of-art Retro-reflection CCR assembly components Al retainer KEL-F CCR 3 Al screws

6. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 6 LNF RD and AD support services The two technical stalwarts supporting the SCF are –Cryogenics Service, Accelerator Division. DA  NE cryo plant (He and N); large Experiment solenoids (KLOE, FINUDA), GW antenna … –Mechanics, design, metrology Service, Research Division. “I&I” activities at LNF and external Labs We acknowledge great support by C. Sanelli (AD) and M. Curatolo (RD) for mission-critical acquisitions (and more) –Thermal Desktop and IR camera Non-invasive thermography 3-17  m, 320 x 240 pixels T accuracy < 0.1 K Great for diagnostics of large physics installation G. Delle Monache certified thermography operator

7. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 7 Status of the SCF Design complete. All equipment purchased. Delivery next 2 mo. Same LN 2 tank as Nautilus. Dedicated TL, vacuum system Cryostat tested to 10 -5 mbar. Leaks fixed RTDs, PT100 T probes. LabView Parts inside (shield, fixtures, shrouds, …) painted w/Aeroglaze Vac bake, outgassing to be performed with 2nd identical cryostat Will start with Earth IR simulator made in-house DONE NEXT LARES: d ~ 30 cm Earth IR Simulator d = 30 cm LAGEOS CCR matrix: ~ 15 cm IR camera 60 o Matrix cooler Heater ~ 1 m ~ 2 m

8. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 8 Fund. Physics (FP) & Technology Applications (TA) LAGEOS-LP LAser GEOdynamics Satellite-Legacy Project ----> FP and TA LARES: LAser RElativity Satellite ----> FP and TA GOLEM GNSS Observation via Laser Earth-based Measurement ---->TA –GNSS = Global Navigation Satellite System –GNSS constellations (≤ 30 sats each): GPS-1-2-3, GLONASS, GALILEO (EGNOS) Fundamental physics in Deep Space ? (or a better measurement of thermo-optical systematics …) NOTE: LAGEOS-LP and GOLEM TA submitted to “InnovAction”, Udine, 9/Feb/06

9. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 9 LAGEOS-LP (Legacy Project) 1976 NASA/Bendix corp. design. Al sphere, brass core. Quartz CCRs in closed cavities 2005, LNF: “Matrix reloaded”

10. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 10 Simulation results Various climate conditions: –Sun or Sun ± 5% –Earth IR –Sun then IR or IR then Sun –45 deg exposure to Sun or IR –Single CCR or matrix –T (Al) = 280, 300, 320 K Fit  (  CCR ): 2% (Sun) - 6% (Earth) But  CCR varies with T range, up to 12% In fact, the constant of the process is  CCR  T 3 0  CCR = m c/(4  A T 3 0 ) T 0 = (T f -T i )/2 =  T/2 A. Bosco, G. Delle Monache, C. Cantone If  (T) ≤ 0.5 K   (  CCR )/  CCR ≈  (  CCR  T 3 0 )/(  CCR  T 3 0 ) ≈ 3%. BUT: need experiment in the SCF and, conservatively,  EXP (T) ≈ 0.1 K

11. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 11 LAGEOS main technological application(s) ILRS (Int. Laser Ranging Service) tracks LAGEOS and 30+ satellites. Towards mm level ranging accuracy IERS (Int. Earth Reference Service) issues two int. standards for civil and science applications –ITRF (Int. Terrestrial Reference Frame - cartesian) –ICRF (Int. Celestial Reference Frame - equatorial) The impact of the availability, accuracy and reliability of the ITRF is enormous Contributions to IERS: SLR, VLBI, GPS, LLR, DORIS

12. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 12 LAGEOS and the ITRF SLR, and mostly the LAGEOS, measure –Tectonic plate motion (via the stations) –Absolute vertical positions and motions –absolute calibration of satellite radar altimeters (meteorology) The geo-center (Earth center of mass) is made 100% with the LAGEOS. The scale (of length) is also dominated by the LAGEOS The axis orientation is made 50% by the LAGEOS and 50% by VLBI The LAGEOS orbits are mankind’s “fixed stars” The gold-plated feature of SLR, ie the LAGEOS, is LONG TERM STABILITY With a measurement of  CCR and with a TT-free LARES we can provide an important contribution. ITRF2004 is coming. With a better control on systematics could it come sooner ?

13. Option 2: Helmert parameter TY w.r.t. ITRF2000 of weekly ILRS solutions and its monthly running average (combination ILRSA; Jan 2004 - Dec 2004) From E.C. Pavlis talk on ILRS contribution to IERS (ILRS Oct. 2005 workshop, Eastbourne, UK) Y-translation [mm]

14. From E.C. Pavlis talk on ILRS contribution to IERS (ILRS Oct. 2005 workshop, Eastbourne, UK) Conclusions Representative absolute accuracy of SLR observation 1-8 mm Satellite orbits fit to about 10 mm WRMS ILRS weekly geocenter assessments accurate to 3.3, 2.5 and 5.3 mm for Tx, Ty and Tz (2.8, 2.6, 4.9 for Option 2) ILRS weekly global scale assessments accurate to 0.4 ppb (0.3 for Option 2) Additionally, ILRS products useful contribution to IERS products Scale [ppb]

15. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 15 FP: LARES While waiting for direct detection of Grav. Waves, the LT is the only measured dynamical effect in GR  if Earth wouldn’t spin  d  /dt = 0  (  CCR ) ≤ 5% will make –TTs negligible for LT (node,  ) –Perigee (  also usable for FP ! much more sensitive to TTs than  very sensitive to new physics ! It’s similar to a  in particle physics Change LAGEOS design to build the next- generation test mass to probe gravity in NEO (Near Earth Orbits)

16. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 16 Our new “concept” of test mass Weak points of LAGEOS –CCRs: 2/3 TTs –Al rings: 1/3 TTs –Max TT: F ~ 40 nN a ~ 10 -10 m/sec 2 Proposed solution –Shell-over-the-core (better T uniformity according to ANSYS) –CCR back-mounting (no more Al rings outside) G. Delle Monache

17. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 17 New (KATIA) model from the ground up M. A. Franceschi T. Napolitano Grooved W alloy core for ultimate eddy current suppression

18. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 18 Specs Outer diameter: 320 mm Mass: ~ 123 kg * S/M: ~ 2.6 x 10 -3 m 2 /kg *(Lageos ~ 2.8 x 10 -3 m 2 /kg) Jz/Jx: ~1.03 * Jz: ~ 0.886 kg · m 2 * CCR mounting: from inside CCR heat transfer: “shell over the core” Outer shell material: Al alloy (Cu alloy) Inner core material: W alloy Ring Material: KEL-F Structural screws: Stainless Steel (Ergal) * adjustable parameters Density (kg/m 3 ) Al alloy 2700 Cu alloy 8900 W alloy 16900÷18500 Thermal Conductance (W/mK) Al alloy 200 Cu alloy 391 W alloy 137

19. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 19 Prototype to study feasibility New design needs accurate test before we can convince the LARES collaboration KATIA-to-CAM Tested machining of  =10cm half-shell Surveyed proto with CMM All OK ! Purchased final mills and Al for full size prototype (  =30cm) NEXT: –Full “LARES-mini” –Full size proto

20. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 20 Full LARES FEM and thermo-optical analysis Major constraint for analysis –FEM: < 20000 nodes –Matrix proto in SCF feasible on average WinPC –Full proto and/or orbit simulation very demanding CCR: automatic meshing gives way too many nodes, ~ 450 ! –Mesh “by hand” and use all tips, tricks and symmetries: got down to 110 nodes/CCR –102 CCRs: total 11220 nodes C. Cantone 110 nodes 1st step: FEM (meshing) with ANSYS

21. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 21 The half-shell ANSYS brick elements: 3513 nodes ANSYS shell elements: 1344 nodes 2nd step: embed CCRs in the Shell in THERMAL DESKTOP

22. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 22 TA: GOLEM (GNSS Obs. via Laser Earth Meas.) Only 2 GPS-2 and 4 GLONASS satellites have traditional fused silica CCRs. Very difficult SLR, due to distance (> 20000 Km, vs 6000 Km of LAGEOS): only at night, with the best meteo and best “core” stations. Too resource consuming. Glonass not very collaborative GNSS: enormous impact in all many fields. IGS (Int. GPS/GNSS Service). But GPS/GLONASS is proprietary/military at heart GALILEO changes the picture: ONLY civil use …. AND: –100 CCRs on each and every one of the 30 satellites !!! –5,000 US$/CCR  15 USM$ worth of CCRs Future: cannot afford the weight of traditional CCRs. Innovative, metal, hollow CCRs are mandatory GPS-3 will have HOLLOW METAL CCRs. GALILEO ?

23. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 23 Collaboration on GPS-3 Proposed to us in Sep-Dec 05 by NASA/ILRS-GSFC (Goddard Space Flight Center, Greenbelt; ~ Washington) after we presented the SCF project in June 05 at GSFC Collaborate in testing the functionality of Be OR Al hollow CCR for GPS-3. Our contribution will be –Test of mech. and thermo-optical properties in the SCF –Simulation of the above for independent verification GOAL: selection of the flight model, and ….. Hollow CCRs work: LNF has used them on a few m range. BUT no long term experience in space. Few test CCRs flown at few hundred Km Made in 3 pieces, glued (Be; LNF) or bolted (Al; GSFC) Most severe problem is CCR warping in space climate, which could prevent light return. 300-400 K CCR T variation ? G. Delle Monache is starting to work on this

24. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 24 GOLEM The project is taking shape –Will not cost us money, and will put the SCF to excellent use –They are helping us to setup a LASER-TEST system for LARES –We asked a fellowship (”assegno di ricerca” to LNF) The next generation GNSS (Galileo, GPS-3) –MW-ranged with ?? m accuracy. Well, single orbits don’t close to better than 20-30 cm (V.J. Slabinski, our LARES collaborator, at GPS Conference, November 05, London ) –LASER-ranged with mm to cm level accuracy GPS and SLR fully complementary. With GALILEO and GPS-3 we will have the best combination. SLR will provide GNSS the needed long term absolute calibration and stability

25. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 25 Laser-test system for LARES/GOLEM Purchased: 1) Nd-Yag laser (ILRS Recommended) 2) He-Ne laser 3) Firewire system, DAQ and analysis Software and 2 CCD camera to study the Far Field Diffraction Profile (FFDP). Cannot launch LARES without Performing FFDP characterization.

26. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 26 Laser ranging in the solar system LLR (Lunar Laser Ranging) –De Sitter effect with historic Apollo 11, 14, 15 (US) and Lunakhods (USSR) –Apache Point Lunar Laser-ranging Observatory (APOLLO) –“The accelerated universe and the moon”, G. Dvali 2004 Mercury and Mars –Successful ranging to Marcury satellite and to Mars Global Surveyor (the farthest SLR ever ! J. Mc Garry et al). –Martian rovers for accurate altimetry LATOR (Laser Astrometric Test Of Relativity) LISA-PathFinder …. Technology application: SPQR (Eneide mission) on ISS

27. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 27 Probing gravity in the outer solar system (Disclaimer: unavoidable,1-slide, simple introduction - then I’ll tell you right away one specific item where the SCF can give a specific contribution) NEO: LAGEOS (and we hope also LARES !) Terrestrial planets: ~50 yrs of space research In the outer SS (Jupiter and beyond) the only probe with adequate navigation capabilities are the PIONEERS: accurate and robust navigation system, spanned the whole SS –VOYAGERS: Deep Space, but factor 50 worse navigation –GALILEO (not the GNSS): inaccurate, up to Jupiter only –CASSINI: being studied, but still, only up to Saturn

28. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 28 The Pioneer Anomaly Doppler data (1987-1998, 40-70.5 AU) provide clear anomalous deceleration. Pioneer Explorer Collaboration. a P = (8.74  1.33)  10 -10 m/s 2 –~9 times the largest LAGEOS TT due to Solar-Yarkovsky Most likely systematic effect is asymmetric TT due to forward-backward asymmetric (HGA ?) thermo-optical parameters (existing and/or induced by the on-board RTG activity) –Propulsion system ? Novelty: full engineering telemetry data (1972-2002) retrieved from old VAX hw and available by JPL, AS OF NOW

29. Anomaly kicks off at Saturn, 10 AU, reached in 3.5 yrs

30. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 30 How can we contribute ? I contacted the PI, Slava G. Turyshev of JPL. Potential items of interest –Re-analysis of full set of Pioneer data IN CONJUNCTION with telemetry data What a good topic for thesis or fellowship –Thermal modeling of the Pioneers New mission design

31. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 31 New mission: Deep Space Gravity Probe The option the PI from JPL (S. Turyshev) pushes for that and we like

32. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 32 Conclusions The SCF is a 1m x 2m climatic thermo-vacuum test facility designed to test the functionality of small payloads and for the characterization of test masses Projects: –Our INFN-GR2 commitment: LAGEOS-LP and LARES –GOLEM (proposed to LNF by NASA/Goddard) and DSGP (on- going contact with NASA/JPL) This is the integrated activity that we submitted to the LNF management in Sep-Dec 05 Expect first measurements by beginning of March 06

33. INFN-LNF, 13-JAN-06, Fundamental Physics WGSimone.DellAgnello@lnf.infn.it 33 Fused silica (suprasil T19) CCR thermo-optical properties