Presentation Title Presented by Andrew Santo APL (443)778-6120 … · 2012. 9. 12. · 6 Rs 5 Rs 4...
Transcript of Presentation Title Presented by Andrew Santo APL (443)778-6120 … · 2012. 9. 12. · 6 Rs 5 Rs 4...
2-3 March 2004 McComas - 1COSPAR – Paris 2004
Solar ProbeStatus Report
Dave McComasSouthwest Research Institute
San Antonio, Texas USAOn Behalf of the Solar Probe STDT
2-3 March 2004 McComas - 2COSPAR – Paris 2004
Science and Technology Definition Team - STDT
U of MichiganThomas Zurbuchen
Florence/JPLMarco Velli
U of New HampshireChuck Smith
GSFCEd Sittler
CUALeon Ofman
JPLNeil Murphy
CaltechDick Mewaldt
APLRalph McNutt
SwRIDave McComas
U of Delaware /BartolBill Matthaeus
WWU-MuensterIngrid Mann
GRC/NASAGeoffrey Landis
SwRIDon Hassler
U of WalesShadia Habbal
U of MarylandGeorge Gloeckler
LANLBill Feldman
SAICRay Dirling
MPIVolker Bothmer
CNRSMarianne Balat
Montana State ULoren Acton
2-3 March 2004 McComas - 3COSPAR – Paris 2004
Solar Probe History
New STDT in line of studies dating back to “Simpson’s Committee” of the Space Science Board (National Academy of Sciences) (24 October 1958)
2-3 March 2004 McComas - 4COSPAR – Paris 2004
Top Priority Science
NRC “Decadal Survey” (Highest Priority Science)•“Basic to understanding the genesis of the heliospheric system is the determination of the source of the solar wind, which will be provided of the solar wind, which will be provided by the Solar Probe mission. Because of the importance of this objective to the overall understanding of the solar-heliospheric system, as well as to other stellar systems, the Solar Probe should be implemented as soon as possible.”
NASA Sun-Earth Connection “Road map”•“The SEC mission roadmap contains some missions that are outside of the typical funding limitations of Solar Terrestrial Probes and Living With a Star mission cost caps. One of these missions is Solar Probe, which is a very high priority mission that accomplishes SEC science that is not possible with any other mission. For this mission and some others, NASA needs to be flexible in determining overall mission cost caps.”
2-3 March 2004 McComas - 5COSPAR – Paris 2004
Goals of Current Study
• Demonstrate outstanding and compelling science– Review previous studies– Incorporate more recent results and theories
• Develop achievable mission concept and plan– Maintain focus on critical observations– Identify additional science opportunities– Prioritize core vs supporting science
• Build consensus in committee and community• Adapt to evolving political environment
2-3 March 2004 McComas - 6COSPAR – Paris 2004
Evolution of Science
2-3 March 2004 McComas - 7COSPAR – Paris 2004
A Solar Flyby Mission
-6 h
-2 h
+4 h
-8 h
+2 h
-4 h
0 h
4.6 RS
4.6 RS
4.0 RS
9.0 RS
7.4 RS
5.9 RS
5.9 RS
7.4 RS
-30 d-20 d
-10 d-5 d
+30 d+20 d+10 d
+5 d
-1 d
+1 d
215 RS(1 AU)165 RS
(0.8 AU)104 RS(0.5 AU)
20 RS(0.1 AU)
65 RS(0.3 AU)
Near-Sun Trajectory (view from Earth)
Pole to pole flyby 14 hours within 9 RPole to pole flyby 14 hours within 9 RSSPP--10 d to P+10 d within 0.5 AU10 d to P+10 d within 0.5 AUPP--30 d to P +30 d within 1 AU30 d to P +30 d within 1 AU
+6 h
2-3 March 2004 McComas - 8COSPAR – Paris 2004
Example: Polar Plumes
At 30 solar radii, Solar Probe is already embedded in the polar structures (i.e. polar plumes). Important to simultaneously connect in-situ observations of coronal structures through which the S/C is flying with their source regions below.
2-3 March 2004 McComas - 9COSPAR – Paris 2004
Solar Probe Thermal Protection System
The Basic Problem
C1, C3, C5
C2, C4
2.364 MW
2.360 MW
<2.5 mg/s
≈ 100 W
2-3 March 2004 McComas - 10COSPAR – Paris 2004
Solar Probe Design Evolution 1982 - 1999
2-3 March 2004 McComas - 11COSPAR – Paris 2004
2002 APL Study Movie
2-3 March 2004 McComas - 12COSPAR – Paris 2004
2002 APL Study
Sun
Jupiter
Earth
LaunchMay 26, 2010C3: 127 km2/s2
Solar Orbit 4 RS × 5.0 AU
Earth at Perihelion(at quadrature)
AphelionJul 19, 2015
JGA FlybyAug 23, 2011C/A range: 7 RJ
1st Sun Encounter, Jul 18, 20132nd Sun Encounter, Jul 18, 2017
• Short time of flight to Sun (3.1 years)• Repeated solar flyby every 4 years – accomplish 2 flybys within
7.1 years and 3 flybys within 11.1 years• Favorable Earth quadrature at all perihelion passages• Trajectory adjustment maneuver outside 0.8 AU
2-3 March 2004 McComas - 13COSPAR – Paris 2004
Evolution of Instrumentation
2-3 March 2004 McComas - 14COSPAR – Paris 2004
Current Baseline Observations
• Solar Wind Package (SWP)– Fast solar wind electrons, protons, and alphas– Ion composition– Nadir viewing TBD
• Energetic Particles Package (EPP)– Suprathermal and energetic particles– Solar neutrons, gamma rays and hard x-rays– Coronal dust
• Waves and Fields Package (WFP)– Magnetic fields– Plasma waves
• Remote Sensing Package (RSP)– Hemispheric white light– Polar imager (EUV & magnetograph channels)
2-3 March 2004 McComas - 15COSPAR – Paris 2004
Polar Imager(EUV & Magnetograph)
Observations into ~20 Rs with failsafe S/C periscope mirror
2-3 March 2004 McComas - 16COSPAR – Paris 2004
Plasma Viewing (1)
• NV Part of ‘99 baseline mission requirements• Very strong driver of S/C requirements
– Substantial heat load back to S/C– Difficult electroptics– Strong driver of mission risk
• Any NV appendage must be S/C supplied• Examining science requirement and effects• Partially mitigated by aberration & turbulence• Detailed simulations w/ various BCs
2-3 March 2004 McComas - 17COSPAR – Paris 2004
Plasma Viewing (2)
P+
He++
S Polar Pass
2-3 March 2004 McComas - 18COSPAR – Paris 2004
S Polar Pass – Electrons
2-3 March 2004 McComas - 19COSPAR – Paris 2004
Plasma Viewing (3)
• Nadir viewing not required for electrons• Continued study of NV requirements for ions
– Additional simulations– More BCs and assumptions
• Study of primary plasma viewing and options– Aft axial boom oversubscribed & risky– Examining side moving arm to track umbra
• Single pixel NV ion deflector may be needed– Engineering team studying resources/risk
• Expect to reach near full consensus of STDT
2-3 March 2004 McComas - 20COSPAR – Paris 2004
Coordinated Solar Observations (1)
• SP Sun-viewing not possible at perihelion– Risk and complexity of high heat load– Soda straws not viewing footpoints
• Hemispheric white-light provides context• Perihelion positioned on disk seen from Earth
– Full suit of Earth and near-Earth observations– Not required but all available should be used– Coordinated campaign mode
2-3 March 2004 McComas - 21COSPAR – Paris 2004
Coordinated Solar Observations (2)
East Limb at quadrature
West Limb at quadrature
East Limb at 30° off quadrature
West Limb at 30° off quadrature
Solar Probe trajectoryPerihelion
Earth orbit30°
30°
• Placement ~15 deg from limb optimum– Close enough for coronagraphs– Adequate surface viewing for other solar observations– Real-time communication lost away from quadrature
2-3 March 2004 McComas - 22COSPAR – Paris 2004
Initial Trade Study Flow
1.Organize &
Bound Trade SpaceDefine Products
2.Redefine Thermal
ShieldCharacteristics
4.Perihelion
Adjustment Trades
STDT #2
6.Off-Quadrature
Trades
STDT #3
12.Spacecraft
Accommodation
STDT #5 & 6
8.Propulsion
SizingTrades
3.Minimum Perihelion
Trades
STDT #1
13.Perform off-pointing
Trades
STDT #4
5.Aphelion
AdjustmentTrades
STDT #2
9.Mission Trade
Synthesis
10.Define Nadir
Viewing ImagerSuite Concept
STDT #5
11.Define Particle
DeflectionInstrument
Concept
STDT #6
7.Thermal
Shield SizingTrades
14.Documentation
& MeetingPreparation
July 7, 2004 Solar Probe STDT Engineering Trade Studies – Preliminary Data Yanping Guo-23
6 Rs5 Rs
4 Rs
Near Sun Flyby Trajectory
0 h
-4 h
-6 h
+2 h
+4 h
+6 h
-2 h
25 hours6 Rs
19 hours5 Rs
14 hours4 Rs
Encounter Time from Pole to Pole
Range (Rs)
13.1+14 h
11.811.8+12 h
10.510.4+10 h
9.29.09.0+8 h
8.07.67.4+6 h
7.06.45.9+4 h
6.35.44.6+2 h
6.05.04.00 h
6.35.44.6-2 h
7.06.45.9-4 h
8.07.67.4-6 h
9.29.0-8 h
10.5-10 h
6 Rs5 Rs4 Rs
Time ticks every hour
Ongoing Perihelion Study
July 7, 2004 Solar Probe STDT Engineering Trade Studies – Preliminary Data Yanping Guo-24
Launch Year SensitivityLaunch Oppertunities
Solar Probe Launch Opportunities 2010 - 2018
12.9
12.7
12.3
12
11.9
11.7
11.6
7
C/A Range to Jupiter (RJ)
4
4
4
4
4
4
4
4
Final Orbit Period (yr)
330
370
390
380
350
310
270
50
DSM** at P+20d (m/s)
4.552021/March2018/January
4.622020/February2016/December
4.662019/January2015/November
4.652018/December2014/October
4.592017/November2013/September
4.512016/October2012/August
4.452015/August2011/July
3.932013/July2010/May
Initial Orbit Period (yr)
Sun Arrival* Year/Month
Launch Opportunity Year/Month
*Favorable quadrature at perihelion passage** Deep Space Maneuver (DSM) for adjusting orbit period
2-3 March 2004 McComas - 25COSPAR – Paris 2004
Large ∆V Penalty Mission Design
• 1st Perihelion ~15 deg off E limb– Realtime science data– On-disk solar viewing from Earth
• 2nd Perihelion ~20 deg off W limb– Store/dump science data (looking at some RT) – On-disk solar viewing from earth
• 1-2 additional extended mission Perihelia– Store/dump science data– Back side perihelia – no viewing from Earth
2-3 March 2004 McComas - 26COSPAR – Paris 2004
Additional S/C AIs
• Dust environment and protection• Largest practical science data volume• Updated radiation environments• Thin axial wave antenna extending from
axial boom• Effects of launch, charging, and dust on
thermal coatings.
2-3 March 2004 McComas - 27COSPAR – Paris 2004
Community Outreach
• Community input & consensus is critical• Your input is important to us!
– Science inputs– Measurement ideas– Anything relevant to Solar Probe
• Contact STDT members who you know• STDT Website
http://solarprobe.gsfc.nasa.gov/