THEMIS ARTEMIS THEMIS mission update Status and Plans

THEMIS ARTEMIS THEMIS mission update: Status and Plans Vassilis Angelopoulos UCLA THEMIS Mission Update 1 2017 -06 -20 GEM

THEMIS ARTEMIS Summary • THEMIS and ARTEMIS hardware in mint condition: as good as new – No radiation effects, battery in excellent state of charge – Fuel more than sufficient to accomplish ambitious plans in next several years – Maneuvers coordinating with Heliophysics/Geospace System Observatory continue • Unique orbits (in equatorial magnetosphere) allows collaborations with: – MMS, Van Allen Probes, Arase, Cluster, Geotail and ground-based assets • New discoveries in context of HSO are mounting – More than 130 refereed pubs/year on average, over the last 4 years • Next few years will be the most exciting ever; THEMIS @ center of H/GSO – 2018 -2020 explore global connections – 2021/2022 MMS-THEMIS will align! GRL Cover THEMIS Mission Update AGU Monogr. on Magnetotails, Magnetospheres and Low Frequency Waves 2 2017 -06 -20 GEM

THEMIS ARTEMIS Recent Accomplishments • Simultaneous ARTEMIS-Geotail-THEMIS data show DTi~15% EA, Lobe implicating RX. Artemyev+ 2017 • MMS-THEMIS see e- injections at both dawn & dusk, showing their wide extent. • THEMIS at dayside discovered foreshock bubbles’ own shocks, accelerating i+, e-. • First direct observations of growth rate of upstream ULF waves (possible by ARTEMIS) • THEMIS has made the first observations of switch-off shocks (at magnetopause). • … and the first detection of the X-point displacement from the flow stagnation, as previously predicted by simulations. THEMIS Mission Update 3 2017 -06 -20 GEM

THEMIS ARTEMIS Plans for FY 18 -20 • Recent observations have shown that most of the energy conversion occurs at substorm recovery, at the tail-dipole interface as it expands tailward. • Also that dayside transients and pressure pulses at dayside affect inner magnetosphere as well as global energy conversion rate. Feb. 12, 2018 Aug. 29, 2018 • THEMIS will be increasing the P 3 orbit apogee to 15 RE to better capture these newly appreciated phenomena, and their global interactions. • It will also continue to be a centerpiece of the HSO using its fuel to coordinate observations with MMS, Arase, Van Allen Probes, GBOs and other missions. • These plus new instrument modes will explore entirely new phenomena THEMIS Mission Update 4 2017 -06 -20 GEM

THEMIS ARTEMIS Plans for FY 21/22 • By that time THEMIS and MMS/Cluster will be aligned. Conjunctions to explore near-Earth RX- tail/dipole relationships, lobe-plasma sheet interface and the 3 D nature of substorms. • All THEMIS probes brought to 13. 2 RE apogee, use remaining fuel to retain close apsidal separations thereafter. • An ideal configuration to launch Small-Sats or M. O. to augment this unique armada of satellites. THEMIS Mission Update 5 2017 -06 -20 GEM

THEMIS ARTEMIS Conclusions • THEMIS unscathed by space radiation, and with an experienced ops and science instrument teams is opening up new research directions for Heliophysics. • Utilizing its fuel and coordinating abilities with other missions it is the centerpiece of NASA’s Heliophysics / Geospace System Observatory, in line with the recommendations of the Decadal Survey. • Thanks to its unique location, comprehensive instruments and compelling new research directions THEMIS is looking forward to serving the science needs of the community in the next 5 years. THEMIS Mission Update 6 2017 -06 -20 GEM