The MMS mission was launched on March 13, 2015 aboard an Atlas V rocket from Space Launch Complex 40, Cape Canaveral, Florida Each of the four observatories were successfully released at five minute intervals spinning at 3 rpm approximately 1.5 hours after launch

Schiff, Conrad

NASA Technical Reports Server

Oct. 19-23, 2015 ISSFD 2015 – MMS Session MMS - 1
Magnetospheric MultiScale Mission 
(MMS) Overview
Conrad Schiff
https://ntrs.nasa.gov/search.jsp?R=20150020826 2019-08-31T05:41:06+00:00Z
Oct. 19-23, 2015 ISSFD 2015 – MMS Session MMS - 2
MMS Launch
• The MMS mission was launched on March 13, 2015 aboard an Atlas V 
rocket from Space Launch Complex 40, Cape Canaveral, Florida
• Each of the four observatories were successfully released at five minute 
intervals spinning at 3 rpm approximately 1.5 hours after launch
Oct. 19-23, 2015 ISSFD 2015 – MMS Session MMS - 3
Science Goals
• Study magnetic reconnection in the Earth's magnetosphere
• Magnetic reconnection converts magnetic energy into kinetic energy 
– Oppositely directed parallel field lines are pinched
– They join and snap apart like a breaking rubber band
• Benefit: understanding of how the Earth lives with the Sun (e.g. Class X 
Flash 0156 GMT Tuesday, Feb. 15, 2011)
– Power grid problems
– Communications disruption
– Aurora formation 
Credit: European Space Agency 
Oct. 19-23, 2015 ISSFD 2015 – MMS Session MMS - 4
Flight Dynamics Concept
Use the formation as a 
‘science instrument’ to 
study the magnetosphere
Formation scale matches 
science scale
Night-side science 
(neutral sheet) bound by 
power (limits shadow 
duration)
Need to prevent close 
approaches
Maneuvers used to 
maintain formation 
against relative drift (DV) 
and to maintain attitude 
pointing (DH)
10-160 km
30-400 km
Sun
Oct. 19-23, 2015 ISSFD 2015 – MMS Session MMS - 5
MMS Flight Summary
(March 12, 2014 10:34 pm EST)
GSE Time
Multiple opportunities for joint observations with THEMIS and Van Allen Probes
Oct. 19-23, 2015 ISSFD 2015 – MMS Session MMS - 6
MMS Instrument Suite Components
(view looking from the bottom of the IS Deck)
DISDES
* On S/C Deck
DES
DES
DES
DIS
DIS
ADP (2x)
FEEPS*
ASPOC
FEEPS
ASPOC
SDP
SDP
SDP
SDP
SCM Pre-Amp*
EDI-GDU
EDI-GDU
HPCA
CEB
CIDP
Purge Man
AEB
TP/HPDB
Safe/Arm
Panel
ADP - Axial Double Probe
AFG - Analog Flux Gate 
Magnetometer (mounted on 
boom)
ASPOC - Active Spacecraft 
Potential Control
CEB - Central Electronics Box 
(Fields)
CIDP - Central Instrument Data 
Processor
DES - Dual Electron Spectrometer
DFG - Digital Flux Gate 
Magnetometer (mounted on 
boom)
DIS - Dual Ion Spectrometer
EDI/GDU - Electron Drift 
Instrument/ Gun Detector 
Unit
EIS - Energetic Ion Spectrometer
FEEPS - Fly’s Eye Energetic 
Particle Sensors
HPCA - Hot Plasma Composition 
Analyzer
IDPU - Instrument Data 
Processing Unit (FPI)
SCM - Search-Coil Magnetometer 
(mounted on boom)
SDP - Spin-Plane Double Probe
TP/HPDB – Test Panel Heater 
Power Distribution Box
EIS
DIS
Oct. 19-23, 2015 ISSFD 2015 – MMS Session MMS - 7
• Boom Lengths
– Mag boom: 5 m
– Axial boom: ≈ 12.5 m
– Wire boom 60 m
• Spacecraft Dimensions
– Diameter: ≈ 3.4 m
– Height: ≈ 1.2 m 
Spin axis – within 2.5 
deg of ecliptic north
Spin rate – 3 +/- 0.2 rpm
Onboard controller tasked with 
performing all spin-attitude and 
delta-V maneuvers Not to scale
Spacecraft Fully Deployed
Oct. 19-23, 2015 ISSFD 2015 – MMS Session MMS - 8
Spacecraft GN&C Block Diagram
Sensors
ACS Flight SW Resides in C&DH
Actuator
C&DH 
Processor
Card
Star
Sensors
AMS
Quaternion
Body rate
Delta-V
Acceleration
Star Sensors
Data process
AMS data 
process
•Delta-Vi
•10 s averaged 
acceleration
Command 
Generation
(Create 
arm table)
EVD All needed 
Thrusters
Thruster 
CMD
CMD
verified
Navigator
(GEONS)
10 s averaged acceleration; 
thruster firing status
DSS
Sun Pulse
Sun elevation 
angle
DSS
Data process
Table, pps
pps
USO
20 MHz frequency 
signal
Sun Acq
Delta-H
FD Ground Support System 
(FDGSS):
• GEONS monitoring
• Orbit maneuver planning, 
monitoring and calibration
• Orbit product generation
Nav. Data 
via C&DH
Attitude Ground System 
(AGS): 
• AMS parameter estimation
• Attitude maneuver 
planning
Science
Checkout
Delta-V  (w 
or w/o 
attitude/ 
rate 
control)


Magnetospheric MultiScale Mission (MMS) Overview

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server