| MISSION_DESCRIPTION |
One-sentence Mission Result Summary
===================================
The small changes in comet 9P/Tempel 1 between two observed perihelia,
in 2005 by Deep Impact and in 2011 by Stardust-NExT, were most obvious
in the vicinity of smooth flows [VEVERKAETAL2011].
Mission overview
================
Stardust-NExT was an extended mission that used the Stardust (SDU)
spacecraft to effect a flyby of comet 9P/Tempel 1 at 178 km on
15 February, 2011 (40 days post perihelion) and obtain high-resolution
images of the coma and nucleus, as well as measurements of the
composition, size distribution and flux of dust emitted into the coma.
The SDU spacecraft had been launched in 1999 and had already flown by
comet 81P/Wild 2 in January, 2004 as part of the prime Stardust mission
([BROWNLEEETAL2003] [SEMENOVETAL2004A], [RYNOETAL2004A]
[SEMENOVETAL2008]).
The 2005 impact by the Deep Impact (DI) mission on 9P/Tempel 1 excavated
ejecta with an optical depth such that the cameras on the DI flyby
spacecraft could not image the surface in the impact area. Therefore the
size of and character of the crater that had been excavated could not be
determined ([AHEARNETAL2005A], [AHEARNETAL2005B]) by the DI mission.
Mission activities included a plan to update knowledge of the rotational
phase of the comet sufficiently well to view significant portions of the
hemisphere studied by Deep Impact in 2005 and imaging the crater
excavated by the impactor [BELTONETAL2011] [MEECHETAL2011].
Stardust-NExT was a low-cost, low-risk mission to complete and expand
the investigation of comet Tempel 1 initiated by Deep Impact, and for
the first time assess the changes in the surface of a comet between two
successive perihelion passages. It provided important new data that
may be used to assess how Jupiter family comets (JFCs) evolve and how
they were formed 4.6 billion years ago.
The investigation of comets addresses each of the three strategic
objectives for solar system exploration enunciated in NASA's Space
Science Enterprise Strategy (SSES) 2003:
To learn how the solar system originated and evolved to its current
state.
To understand how life begins and determine the characteristics of
the solar system that led to the origin of life.
To catalog and understand the potential impact hazard to Earth from
space.
([WEILERETAL2003])
Stardust-NExT contributed significantly to the first and last of these
objectives. Stardust-NExT was designed to obtain essential new data,
capitalize on the discoveries of earlier missions to determine how
cometary nuclei were constructed at the birth of the solar system,
and increase our understanding of how they have evolved since then.
The investigations on the Stardust-NExT mission included:
Cometary coma and nucleus imaging (Navigation Camera a.k.a. NAVCAM,
[NEWBURNETAL2003])
Comet particle composition measurements (Cometary and Interstellar
Dust Analyzer a.k.a. CIDA [KISSELETAL2003])
Dust flux measurements (Dust Flux Monitor Instrument a.k.a. DFMI,
[TUZZOLINOETAL2003])
The Sample Return Capsule (SRC) had been returned to Earth in 2006 and
was no longer part of the in-flight spacecraft [FARNHAM&SEMENOV2006].
Mission phases
==============
Based on NAVCAM activities, and particle instruments' general inactivity
before and after the Tempel 1 encounter, there were four logical mission
phases for Stardust-NExT: CRUISE; APPROACH; ENCOUNTER; DEPARTURE.
N.B. Because of differences in sensing range between the imaging and
particle instruments, these logical mission phases correspond only
approximately to instrument-specific operational data collection
periods or subphases as defined in instrument data catalogs for the
Stardust-NExT data sets.
For the particle instruments, CIDA and DFMI, there are only
two phases: CRUISE and ENCOUNTER. APPROACH and DEPARTURE, as
defined here, are combined and considered to be CRUISE.
For the NAVCAM, operational mission subphases were defined as CO
(CHECKOUT), C5 and C6 (CRUISE 5 and 6), and TE (TEMPEL ENCOUNTER),
and those two-letter acronyms were used in the NAVCAM PRODUCT_IDs
and FILE_NAMEs. C6 was not intentional but was added when the
NAVCAM image ID was reset during C5, temporarily causing duplicate
FILE_NAMEs in the ground data system for NAVCAM images taken at
different times. An earlier mission phase, C4 (CRUISE 4) was
defined but no NAVCAM data were taken during that phase. Details
of the two-letter NAVCAM 'subphase' designations have been
provided in the NAVCAM data set.
CRUISE
------
Performed instrument checkout and calibration activities: All
instruments were in CRUISE configuration when turned on: NAVCAM and
DFMI were off except for calibrations; CIDA was on nearly continuously.
Minimal science data were taken except for CIDA. NAVCAM activities
included characterization of photometric (stars), geometric (star
clusters), bias and dark (shutter closed), and post-decontamination
(post-bake) behaviors. Navigation maneuvers were performed including
Tempel 1 time of arrival adjustment in February, 2010 to maximize the
probability of optimizing imaging of both previously seen and unseen
comet surface including the DI crater.
Mission Phase Start Date 2007-01-17 (2004-02-12 for CIDA)
Mission Phase Stop Date 2010-12-16
Spacecraft Operations Type CRUISE
Target Names CALIBRATION, INTERSTELLAR PARTICLES,
NON SCIENCE
APPROACH:
---------
Performed NAVCAM imaging of coma for science and navigation starting
sixty days before Encounter (E-60d) closest approach through two days
before encounter. All instruments were in cruise configuration when
turned on. CIDA was off. DFMI was off except for calibration.
NAVCAM coma observations started with eight-image sets every 2-6 days,
increasing later to up to ~100 images per day, interrupted only for
calibration and decontamination. Significant scattered light was
observed for most of these images, due to the spacecraft attitude and
mirror angle used, which prevented coma detection. The coma was first
detected in summed images at E-28d when the sequences were modified to
use a spacecraft attitude which minimized scattered light. Approach
phase ended with a two-day standdown of instrument operations to
prepare for ENCOUNTER phase (below). Because of the standdown, there
is a discontinuity (gap) between the APPROACH stop date and the
ENCOUNTER start date.
Mission Phase Start Date 2010-12-17
Mission Phase Stop Date 2011-02-13
Spacecraft Operations Type CRUISE
Target Names 9P/TEMPEL 1 (1867 G1), CALIBRATION,
INTERSTELLAR PARTICLES, NON SCIENCE
ENCOUNTER
---------
Performed close-up science measurements of comet 9P/Tempel 1 on
15 February, 2011; all instruments were in encounter configuration
when turned on. NAVCAM took seventy-two high-spatial resolution
brightness-compressed images over T +/- ~4minutes; four of these were
coma observations for which the comet nucleus was intentionally
overexposed. CIDA was on continuously. DFMI was on for T +/- ~20
minutes. Auto-navigation software performed flawlessly and kept the
bulk of the comet nucleus in all NAVCAM images. Before and after the
encounter, the spacecraft was in two-day standdowns of instrument
operations to downlink data. Because of the standdowns, there are
discontinuities (gaps) between the APPROACH stop date and the
ENCOUNTER start date, and betwee the ENCOUNTER stop date and the
DEPARTURE start date.
Mission Phase Start Date 2011-02-15
Time of Closest Approach 2011-02-15T04:39:10
Mission Phase Stop Date 2011-02-15
Spacecraft Operations Type ENCOUNTER
Target Names 9P/TEMPEL 1 (1867 G1), NON SCIENCE
DEPARTURE
---------
Performed NAVCAM imaging of coma for science, similar to APPROACH phase
above. All instruments were in cruise configuration when turned on.
CIDA was off. DFMI was off except for a final calibration. NAVCAM
imaging was stopped at E+10d after the coma was determined to be too
faint for further scientific utility. Remaining spacecraft fuel was
burned to exhaustion on 26 March in a final maneuver to allow
validation and/or calibration of fuel estimation techniques used on
this and other missions. The Stardust spacecraft was left in a safe
orbit (it will not come near Earth for the foreseeable future) and will
boot to a safe configuration in the event the solar panels supply power
to the processing unit.
Mission Phase Start Date 2011-02-17
Mission Phase Stop Date 2011-02-25
Spacecraft Operations Type CRUISE
Target Names 9P/TEMPEL 1 (1867 G1), CALIBRATION,
INTERSTELLAR PARTICLES, NON SCIENCE
[AHEARNETAL2005A] A'Hearn, M.F., M.J.S. Belton, W.A. Delamere, J. Kissel,
K.P. Klaasen, L.A. McFadden, K.J. Meech, H.J. Melosh, P.H. Schultz, J.M.
Sunshine, P.C. Thomas, J. Veverka, D.K. Yeomans, M.W. Baca, I. Busko, C.J.
Crockett, S.M. Collins, M. Desnoyer, C.A. Eberhardy, C.M. Ernst, T.L.
Farnham, L. Feaga, O. Groussin, D. Hampton, S.I. Ipatov, J.-Y. Li, D.
Lindler, C.M. Lisse, N. Mastrodemos, W.M. Owen, J.E. Richardson, D.D.
Wellnitz, and R.L. White, Deep Impact: Excavating Comet Tempel 1, Science,
310, 258-264, 2005, doi:10.1126/science.1118923,
http://www.sciencemag.org/content/310/5746/258.abstract,
http://www.sciencemag.org/content/310/5746/258.full.pdf.
[AHEARNETAL2005B] A'Hearn, M.F., M.J.S. Belton, A. Delamere, and W.H. Blume,
Deep Impact: A Large-Scale Active Experiment on a Cometary Nucleus, Space
Science Reviews, 117, 1-21, 2005, doi:10.1007/s11214-005-3387-3.
[BELTONETAL2011] Belton, M.J.S., Meech, K.J., Chesley, S., Pittichova, J.,
Carcich, B., Drahus, M., Harris, A., Gillam, S., Veverka, J., Mastrodemos,
N., Owen, W., A'Hearn, M.F., Bagnulo, S., Bai, J., Barrera, L., Bastien, F.,
Bauer, J.M., Bedient, J., Bhatt, B.C., Boehnhardt, H., Brosch, N., Buie, M.,
Candia, P., Chen, W.-P., Chiang, P., Choi, Y.-J., Cochran, A., Crockett,
C.J., Duddy, S., Farnham, T., Fernandez, Y.R., Gutierrez, P., Hainaut, O.R.,
Hampton, D., Herrmann, K.A., Hsieh, H., Kadooka, M.A., Kaluna, H., Keane, J.,
Kim, M.-J., Klaasen, K., Kleyna, J., Krisciunas, K., Lara, L.M., Lauer,
T.R., Li, J.-Y., Licandro, J., Lisse, C.M., Lowry, S.C., McFadden, L.,
Moskovitz, N., Mueller, B., Polishook, D., Raja, N.S., Riesen, T., Sahu,
D.K., Samarasinha, N., Sarid, G., Sekiguchi, T., Sonnett, S., Suntzeff, N.B.,
Taylor, B.W., Thomas, P., Tozzi, G.P., Vasundhara, R., Vincent, J.-B.,
Wasserman, L.H., Webster-Schultz, B., Yang, B., Zenn, T., Zhao, H.,
Stardust-NExT, Deep Impact, and the accelerating spin of 9P/Tempel 1, Icarus,
Volume 213, Issue 1, May 2011, Pages 345-368.
http://dx.doi.org/10.1016/j.icarus.2011.01.006
[BROWNLEEETAL2003] Brownlee, D. E., P. Tsou, J. D. Anderson, M. S. Hanner, R.
L. Newburn, Z. Sekanina, B. C. Clark, M. E. Zolensky, J. Kissel, J. A. M.
McDonnell, S. A. Sandford, and A. J. Tuzzolino, Stardust: Comet and
interstellar dust sample return mission, J. Geophys. Res., 108, (E10), 8111,
2003
[FARNHAM&SEMENOV2006] Farnham, T.L., Semenov, B., STARDUST DUST COLLECTOR
GEOMETRY, SDU-C-SRC-6-GEOMETRY-V1.0, NASA Planetary Data System, 2006.
[KISSELETAL2003] Kissel, J., A. Glasmachers, E. Grun, H. Henkel, H. Hofner,
G. Haerendel, H. von Hoener, K. Hornung, E. K. Jessberger, F. R. Krueger, D.
Mohlmann, J. M. Greenberg, Y. Langevin, J. Silen, D. Brownlee, B. C. Clark,
M. S. Hanner, F. Hoerz, S. Sandford, Z. Sekanina, P. Tsou, N. G. Utterback,
M. E. Zolensky, and C. Heiss, Cometary and Interstellar Dust Analyzer for
comet Wild 2, J. Geophys. Res., 108, (E10), 8114, 2003
[MEECHETAL2011] Meech, K.J., Pittichova, J., Yang, B., Zenn, A., Belton,
M.J.S., A'Hearn, M.F., Bagnulo, S., Bai, J., Barrera, L., Bauer, J.M.,
Bedient, J., Bhatt, B.C., Boehnhardt, H., Brosch, N., Buie, M., Candia, P.,
Chen, W.-P., Chesley, S., Chiang, P., Choi, Y.-J. et al., 2011. Deep Impact,
Stardust-NExT and the Behavior of Comet 9P/Tempel 1 From 1997-2010, Icarus,
in press.
[NEWBURNETAL2003] Newburn Jr., R. L., S. Bhaskaran, T. C. Duxbury, G.
Fraschetti, T. Radey, and M. Schwochert, Stardust Imaging Camera, J. Geophys.
Res., 108, (E10), 8116, 2003
[RYNOETAL2004A] Ryno, J., B.V. Semenov, J. Kissel, J. Silen, and C.H. Acton,
STARDUST CIDA DATA, SDU-C/D-CIDA-1-EDF/HK-V1.0, NASA Planetary Data System,
2004.
[SEMENOVETAL2004A] Semenov, B.V., A.J. Tuzzolino, J.A.M. McDonnell, H.W.
Taylor, and C.H. Acton, STARDUST DFMI WILD 2 ENCOUNTER EDR DATA,
SDU-C-DFMI-2-EDR-WILD2-V1.0, NASA Planetary Data System, 2004.
[SEMENOVETAL2008] Semenov, B.V., R.L. Newburn, H.W. Taylor, C. Hash, and C.H.
Acton, T.L. Farnham, STARDUST NAVCAM IMAGES OF WILD 2,
SDU-C-NAVCAM-2-EDR-WILD2-V2.0, NASA Planetary Data System, 2008.
[TUZZOLINOETAL2003] Tuzzolino, A. J., T. E. Economou, R. B. McKibben, J. A.
Simpson, J. A. M. McDonnell, M. J. Burchell, B. A. M. Vaughan, P. Tsou, M. S.
Hanner, B. C. Clark, and D. E. Brownlee, Dust Flux Monitor Instrument for the
Stardust mission to comet Wild 2, J. Geophys. Res., 108, (E10), 8115, 2003
[VEVERKAETAL2011] J. Veverka, Klaasen, K., A'Hearn, M., Belton, M., Brownlee,
D., Chesley, S., Clark, B., Economou, T., Farquhar, R., Green, S., Harris,
A., Groussin, O., Kissel, J., Li, J.-Y., Meech, K., Melosh, J., Richardson,
J., Schultz, P., Silen, J., Sunshine, J., Thomas, P., Bhaskaran, S.,
Bodewits, D., Carcich, B., Cheuvront, A., Farnham, T., Sackett, S., Wellnitz,
D., Wolf, A., Return to Comet Tempel 1: Results from Stardust-NExT, Icarus
(tentative), May, 2011, in press.
[WEILERETAL2003] Weiler, E.J., 2003 Space Science Enterprise Strategy,
National Aeronautics and Space Administration, 01 October, 2003.
http://spacescience.nasa.gov/admin/pubs/strategy/2003/SpSciEntStrat(low).pdf
|
.png)
.png)
