STEREO (Solar Terrestrial RElations Observatory) p
as a Mars Space Weather Resource
Janet Luhmann, SSL
May 2013
The twin spacecraft STEREO mission was instrumented for these science objectives:
1.
2.
3.
4.
To Understand the causes and mechanisms of CME initiation To Characterize the propagation of CMEs through the heliosphere
To Discover the mechanisms and sites of energetic particle acceleration in the low corona and the interplanetary medium To Develop a 3D time‐dependent model of the magnetic topology, temperature, density, and velocity structure of the ambient solar wind Each STEREO spacecraft contains a full suite of both imaging
and in-situ data capability
p
y ((though
g no magnetographs)
g
g p )
UCLA Russell Group processes and serves MAG data and science
While STEREO SECCHI images the Sun, IMPACT and PLASTIC measure all the in‐situ signatures of space weather‐ including the ICMEs and SEP events
Mars Atmosphere and Volatile
E l i N (MAVEN) Mi
EvolutioN
Mission
i
MAVEN is the last Mars Scout Mission
(PI Bruce Jakosky,
Jakosky LASP)
Scheduled for launch in Nov 2013
MAVEN Science Questions
MAVEN Science Questions
MAVEN will determine the role that loss of volatiles to space has played through time, providing definitive answers about Mars climate history:
•
What is the current state of the
upper atmosphere and what
processes control it?
•
What is the escape rate at the
present epoch and how does it
relate to the controlling
p
processes?
•
What has the total loss to space
been through time?
The MAVEN spacecraft also contains a full particles and fields
package,
p
g ,p
plus a UV spectrometer
p
and solar EUV flux monitor
• 3-axis attitude control (wheel based)
• Mono-propellant propulsion system
• Single-fault tolerant during all critical events
• Launch (Wet) Mass: 2550 kg max
• Spacecraft Dry Mass: 903 kg max
• Power: 1135 W at Mars Aphelion
LPW (2)
SWEA
Electra (behind)
SWIA
SEP
“Gull-Wing” Solar Arrays
Fixed HGA
MAG (2)
SEP
Articulated Payload Platform
(IUVS/STATIC/NGIMS)
The PF Package
Solar Wind Ion Analyzer
(SWIA) – SSL
EUV
Solar Wind Electron
Analyzer (SWEA) –
IRAP(CESR) / SSL
SWEA
LPW
2 PLCS
SWIA
Langmuir
g
Probe and Waves
(LPW) – LASP / SSL
LPW/Extreme Ultra-Violet
(LPW-EUV) – LASP
Solar Energetic Particle
Detector (SEP) – SSL
SEP
2 PLCS
STATIC
MAG
2 PLCS
Magnetometer (MAG) –
GSFC
Supra-Thermal and Thermal
Ion Composition (STATIC) SSL
MAVEN Will Measure the Energetic Drivers, Reservoirs, and Escape Rates
• MAVEN will determine the present
state of the upper atmosphere and
today’s rates of loss to space.
• Measurements will allow determination
of the net integrated loss to space through
time.
MAVEN Mission Architecture
Launch on Atlas V-401
Ten-Month Ballistic Cruise to Mars
20-Day Launch Period:
November 18 –
December 7, 2013
Orbit Insertion:
22 Sept 2014
One Year of Science Operations
MAVEN Orbit and Primary Science Mission
Science Mission
• Elliptical orbit to provide coverage of all altitudes
• The orbit precesses in both latitude and local solar time
• One-Earth-year mission allows thorough coverage of near-Mars space
The STEREO orbits at ~1 AU provide changing perspectives
on the Sun and multipoint
p
in-situ sampling
p g
STEREO +ACE real‐time multipoint measurements at 1 AU give the latest state of space weather (NOAA RT data plots, images from SOHO, SDO)
NOAA SWPC plots
SOHO/LASCO, SDO/AIA images
http://stereo.ssl.berkeley.edu/multistatus.php
l i
li i S
Real‐time multipoint SEP
events in early April 2013
-and here are some Multipoint ‘reconstructions’
of coronal mass ejection
j
magnetic
g
flux ropes
p in
Interplanetary space in August 2010
Moestl et al., ApJ 2012-from magnetometer data
Sometime in 2015 the STEREO Spacecraft will ‘flip over’ and continue
their mission. They have enough fuel to operate for ~100 years.
STEREO location on November 15, 2014, just after MAVEN arrives
STEREO goes behind the Sun (Earth perspective) and is occulted (=no data):
STEREO-A dates: Mar 17-Jul 14, 2015
STEREO-B dates: Jan 20-Mar 28 and Aug 25-Oct 19, 2015
Bottom Line:
STEREO provides an incredibly lucky
opportunity to enhance the capability
of the MAVEN mission toward understanding solar activity effects at Mars.