About NASA ’ s Magnetospheric Multiscale Mission (MMS)

1. About NASA’s Magnetospheric Multiscale Mission (MMS) MAGNETIC RECONNECTION is a little-understood physical process at the heart of space weather. It can spark solar flares, cause coronal mass ejections and other phenomena that can imperil Earth-orbiting spacecraft and disrupt power grids on Earth.

2. Much of what we know about the physics of Magnetic Reconnection comes from theoretical studies and computer models. MMS will study this process in situ, measuring magnetic fields crossing, reconnecting, and releasing magnetic energy in the form of heat and charged-particle kinetic energy.

3. The MMS-FIELDS instruments will measure the electric and magnetic fields with unprecedented high (millisecond) time resolution and accuracy.

4. Development of the MMS-FIELDS instrument suite is centered in Durham at the University of New Hampshire’s Space Science Center

5. Illustration: One of four MMS spacecraft with the FIELDS instruments identified

6. SDP Spin-Plane Double Probe Electric Field Measurements

7. One of four SDP deployers that will be on each of the four MMS spacecraft Title

8. The Spin-plane Double Probe (SDP) consists of four 60-meter wire booms with spherical sensors at the end. Specially coated Titanium hemispheres form each SDPs E-Field probe. These are provided to UNH by our colleagues in Sweden (KTH and IRFU) and Finland (University of Oulu)

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11. SDP Preamplifier The SDP doors and preamplifiers are provided to UNH by our colleagues at the University of Colorado (LASP)

12. The electronics to operate the SDP and process its E-field measurement are provided to UNH by our colleagues in Sweden (KTH)

13. The mechanical design, fabrication, assembly and test of the SDP deployers is the responsibility of engineers at UNH

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17. ADP Axial Double Probe Electric Field Measurement The ADP consists of two 12-meter antennas deployed axially near the spacecraft spin axis.

18. The Axial Double Probe (ADP) consists of two 12-meter antennas deployed axially near the spacecraft spin axis.

19. The photo shows one of two 12-meter extensible booms on each spacecraft deployed from its stowed configuration in a small canister Title The design, fabrication, assembly and test of the ADP is the responsibility of our colleagues at the University of Colorado (LASP)

20. ADP deployment test

21. ADP Launch Latches

22. ADP Preamplifiers

23. ADP Receiving Elements These 2-meter antennas launch in this folded configuration. Each will deploy on-orbit atop a 12-meter extensible boom.

24. Thermal Vacuum test preparation for ADP Receiving Elements

25. Title Vibration test preparation for a pair of ADP Receiving Elements

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27. ADP Receiving Element Hinges

28. The electronics to process the ADP E-field measurement are provided by our colleagues in Sweden (KTH) and calibrated with the booms by our colleagues at the University of Colorado (LASP)

29. ADP Receiving Element testing in the clean room at the University of Colorado Title

30. EDI Electron Drift Instrument Electric and Magnetic Field Measurements

31. EDI Measurement Principle The EDI determines the electric and magnetic fields by measuring the drift of ~1 keV electrons emitted from a pair of Gun Detector Units (GDU). Each GDU sends and receives a coded beam to and from the other EDI-GDU. The University of New Hampshire, in collaboration with the Space Research Institute of the Austrian Academy of Sciences (IWF) and the University of Iowa, provides the The EDI GDU and electronics.

32. Setup for testing of the EDI Gun Detector Unit (GDU) in the UNH vacuum chamber

33. Electron Gun Electronics (IWF, Austria)

34. Calibration of the EDI Gun and electronics in the vacuum chamber at IWF (Austria)

35. Title EDI GDU Assembly in the Clean Room at UNH

36. EDI Sensor Stack (UNH)

38. SCM Search Coil Magnetometer AC Magnetic Field Measurement

39. The SCM will measure the 3-axis AC magnetic field and will be used with the ADP and SDP to determine the contribution of plasma waves to the turbulent dissipation occurring in the diffusion region. Title

40. SCM Development is at LPP, the Laboratory for Plasma Physics (France)

41. This magnetically-quiet facility was built by LPP at Chambon la Forêt (France) for calibration of the Search Coil Magnetometers. The only metal in this building are the copper coils on these rings for controlling the magnetic field environment of the sensor in calibration at the center. Title

42. AFG & DFG Analog & Digital Fluxgate Magnetometers DC Magnetic Field Measurement

43. UCLA and the Space Research Institute of the Austrian Academy of Sciences (IWF) provide the AFG and DFG sensors and electronics with calibration support from the Technical University of Braunschweig (TU-BS, Germany).

44. Two magnetometers provide redundant measurements of the DC magnetic field and structure in the diffusion region.

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46. Magnetometer sensors (AFG, DFG, SCM) for one MMS spacecraft in a test setup at UNH

47. The 3-layer magnetic shield can is needed to isolate the magnetometers from the Earth’s magnetic field for testing in the laboratory

48. CEB Central Electronics Box The CEB provides power, control and data processing for the suite of FIELDS sensors. The Royal Institute of Technology (KTH, Sweden) provides the power supply. The University of New Hampshire provides the CEB and the software with contributions from the sensor team institutions: KTH, LASP, UCLA and IWF.

49. CEB Thermal Vacuum test at UNH Title

50. Low Voltage Power Supply. 1of 8 custom-made electronics boards in each CEB Title