AIAA Panel on Small, Distributed, Fractionated Spacecraft 1 Long Beach, CA Sept. 18, 2007 Introduction THEMIS Overview Lessons Learned Importance of a Micro-Sat Program THEMIS: An Example of a Cost-Effective Mission of Small, Distributed, Fractionated Spacecraft, a Pathfinder for a Micro-Sat Program Vassilis Angelopoulos, UCLA With contributions from: Peter R. Harvey, Ellen R. Taylor, Greg Delory, SSL/UCB Michael J. Cully, Warren Chen, Kevin Brenneman, ATK Space And an incredible THEMIS team!

AIAA Panel on Small, Distributed, Fractionated Spacecraft 2 Long Beach, CA Sept. 18, 2007 Maximizing Substorm Science on THEMIS: Probe Alignments Vassilis Angelopoulos, UCLA ESS April 13, 2006 Simulation: J. Raeder, UNH Visualization: Tom Bridgman, GSFC/SVS

AIAA Panel on Small, Distributed, Fractionated Spacecraft 3 Long Beach, CA Sept. 18, 2007 Mission overview Instrument I&T UCB Mission I&T UCB-JPL Encapsulation & launch BGS Operations UCB Probe instruments: ESA: Thermal plasma SST: Super-thermal plasma FGM: Low frequency magnetic field SCM: High frequency magnetic field EFI: Electric field Ground SST ESA EFIa EFIs FGM SCM T spin =3s Release CCAS Bus I&T ATK

AIAA Panel on Small, Distributed, Fractionated Spacecraft 4 Long Beach, CA Sept. 18, 2007 Modular Science-craft Design Power positive in all attitudes Passive thermal design Passively spin stable under all deployment conditions S-Band COM system always in view of earth every orbit at nominal attitude. In view for greatest part of orbit in any attitude Mono-propellant blow-down RCS (propulsion) system is self balancing on orbit Modular tanks, instruments, panels Highly integrated bus and instruments: thermally, mechanically, electrically and electronically

AIAA Panel on Small, Distributed, Fractionated Spacecraft 5 Long Beach, CA Sept. 18, 2007 Standard Delta 10 ft. Fairing Static Envelope 3712 PAF Probe Carrier Assembly (PCA = 5 Probes + Probe Carrier) on L/V Probe Carrier Assembly (PCA = 5 Probes + Probe Carrier) on L/V THEMIS Launch Configuration Probe Carrier Assembly (PCA) on Delta 3 rd Stage Launch Configuration Dedicated launch accommodated within standard Delta vehicle configuration and services 10’ Composite Fairing required to accommodate five Probes on the Probe Carrier in the “Wedding Cake” configuration PC stays attached to Delta 3 rd stage after probe dispense Each probe dispense from the PCA is coordinated with but independent of the other probes No single probe anomaly precludes dispense of remaining probes Star 48 3 rd Stage

AIAA Panel on Small, Distributed, Fractionated Spacecraft 6 Long Beach, CA Sept. 18, 2007 Production Line Approaches: Development and Instrument I&T EFI Instrument production Bus production Instrument Integration: assembly line

AIAA Panel on Small, Distributed, Fractionated Spacecraft 7 Long Beach, CA Sept. 18, 2007 First round: F2 VibXY JPL: April-May, 2006 Second Round: PCA VibXY June 25 – Aug 16, 2006 Production Line Approaches: Environmental testing at JPL in 2 rounds First Round: F2 Thermal Balance/T-Vac Second Round: Two-at-a-time mini TB/TV

AIAA Panel on Small, Distributed, Fractionated Spacecraft 8 Long Beach, CA Sept. 18, 2007 Launch Processing: Round-robin w/ one primary EGSE Spin Balance Dry Weigh & Pressurize Final checks PCA Integration Transportation to Pad 17B: Feb 3 3 rd stage mating

AIAA Panel on Small, Distributed, Fractionated Spacecraft 9 Long Beach, CA Sept. 18, 2007 Successful mission attributes: It’s a small team of happy people!

AIAA Panel on Small, Distributed, Fractionated Spacecraft 10 Long Beach, CA Sept. 18, 2007 The Feat: Outstanding Science at Reasonable Cost THEMIS is now poised to resolve the mystery of substorms in its prime mission in January-April 2008, as proposed. THEMIS came at a cost of $0.1B compared to $1-2B for similar space physics missions in the past (Cluster) and future (MMS). How? THC THE THD THB THA the 1 st Substorm …was captured by THEMIS On March 23, 2007

AIAA Panel on Small, Distributed, Fractionated Spacecraft 11 Long Beach, CA Sept. 18, 2007 Successful multi-probe mission attributes: Small satellites with modular design Small satellites: Enforce small team mentality(too many cooks spoil the broth) “Projectized”, lean team, operating efficiently Consists of multi-talented, multi-tasking individuals Modular satellite design: Ensures clear interfaces and clear team organization Facilitates parallel development, and I&T process Small and modular both facilitate production line approach: First probe needn’t be completely error-free for line to benefit Most important benefit is schedule, comes from staggering Other benefits: Reduces errors (same person does same thing) Increases productivity and quality (twice the time to do 5) Corrections forwards and backwards are more robust

AIAA Panel on Small, Distributed, Fractionated Spacecraft 12 Long Beach, CA Sept. 18, 2007 The importance of a Micro-satellite program Scientific problems requiring constellations of small satellites abound. We are only now beginning to explore the wavenumber domain of space plasma interactions. There are very few missions like THEMIS to learn from. A line of micro-sat launches can provide a much needed test-bed for Small Distributed Fractionated Spacecraft. Why micro? Launch is easier, task/schedule smaller Why a program? Continuity ensures heritage in core teams Can be modeled after NASA’s rocket program Benefits: Rapid Science Discoveries Continuous Instrument Development for New Capabilities Education / Workforce Development Feeds Into Larger Missions / Indirect Science Discovery