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ELECTRONIC NEWSLETTER OF THE EUVE OBSERVATORY
---------------------------------------------------------------------------
Vol. 6, No. 12 27 Dec 1996 ISSN 1065-3597
---------------------------------------------------------------------------
(C) 1996, Regents of the University of California
---------------------------------------------------------------------------
Notes from the Editor
=====================
by Brett A. Stroozas, EUVE Flight Operations Manager
Welcome to the electronic newsletter for NASA's Extreme Ultraviolet
Explorer (EUVE) satellite, compiled and published monthly by the
Center for EUV Astrophysics (CEA) at the University of California,
Berkeley (UCB). The contents of this issue of the EUVE electronic
newsletter are as follows:
1. EUVE Science News
1.1 Upcoming Release of Cycle 5 NRA
1.2 Call for Proposals for EUVE RAP Program
1.3 Abstracts of Recently *Accepted* EUVE Papers
2. EUVE Science Operations News
2.1 New Contact Information for EUVE Observatory
2.2 Public Release Begins for Cycle 4 Observations
2.3 Public GO/RAP Data Release for 1 Jan 1997
2.4 On-Line Access to EUVE
3. EUVE Outsourced Extended Mission Status Report
3.1 OEM Management
3.2 EPOC Ground Systems Development
3.3 EPOC Systems Testing
To comment on or make suggestions for the EUVE electronic newsletter,
please send e-mail to ceanews@cea.berkeley.edu (Internet).
*********************************************
***** CEA/EUVE WISH YOU AND YOUR FAMILY *****
*** A MERRY CHRISTMAS AND A HAPPY NEW YEAR **
*********************************************
The EUVE observatory performed well throughout the month of Nov
1996, conducting observations of the following Guest Observer (GO) and
Right-Angle Program (RAP) targets (name and spectral type information
taken from the SIMBAD or internal CEA databases; "NOIDs" are
unidentified objects):
=======================================================================
Target EUVE Spectral Observation
Name Name Type GMT Date(s) Notes
=======================================================================
beta CMa tunnel -------- Bkgd 31 Oct - 04 Nov 1996 EGO,SCN
EUVE J1629+780 EUVE J1629+780 WD:DA 04 Nov - 08 Nov 1996 EGO
EUVE J0205+093 EUVE J0205+093 NOID 04 Nov - 08 Nov 1996 RAP
WD 0455-28 EUVE J0457-28.1 WD:DA 08 Nov - 14 Nov 1996 EGO
II Peg EUVE J2355+28.6 K0V... 08 Nov - 14 Nov 1996 RAP
Survey -------- ---- 14 Nov - 14 Nov 1996 ENG
Diffuse -------- Bkgd 14 Nov - 18 Nov 1996 EGO,MUL,TCO
0946+09 -------- NeutSt 14 Nov - 18 Nov 1996 RAP
V471 Tau EUVE J0350+17.2 WD 18 Nov - 21 Nov 1996 EGO,TCO,COO
EUVE J2027+52.5 EUVE J2027+52.5 NOID 18 Nov - 21 Nov 1996 RAP
gamma Tau -------- K0III 21 Nov - 23 Nov 1996 EGO
EUVE J2112+501 EUVE J2112+501 WD 21 Nov - 23 Nov 1996 RAP
beta CMa Tunnel -------- Bkgd 23 Nov - 27 Nov 1996 EGO,SCN,MUL
Sirius B EUVE J0645-16.7 WD:DA 27 Nov - 06 Dec 1996 EGO,SPI
=======================================================================
Key to Notes:
EGO = Guest Observer observation
RAP = Right-Angle Program observation
SCN = Imaging observation with scanning telescopes
ENG = Engineering survey period to calibrate star trackers
MUL = Multiple pointings
TCO = Time-critical observation
TOO = Target of Opportunity
SPI = Spiral dithered observation
1. EUVE Science News
====================
1.1 Upcoming Release of Cycle 5 NRA
-----------------------------------
by Dr. Ron Oliversen, EUVE Deputy Project Scientist (GSFC)
The EUVE Guest Observer (GO) NASA Research Announcement (NRA) for
Cycle 5 will be released on 30 Dec 1996, with a proposal deadline of
28 Feb 1997. This NRA will not request budget information; however,
about $400k is expected to be available to fund Cycle 5 programs. The
NRA proposal process will be conducted by NASA and the proposal peer
review will take place within one month of the proposal deadline.
The NRA will be accessible directly from the Office of Space
Science World Wide Web (WWW) HomePage at the URL
http://www.hq.nasa.gov/office/oss/
in the "Research Opportunities" menu. Relevant proposal material will
also be made public on 30 Dec 1996 at the CEA ftp site at
ftp.cea.berkeley.edu
in the directory /pub/nra96.
1.2 Call For Proposals for the EUVE RAP Program
-----------------------------------------------
by Dr. Roger Malina, CEA and EUVE Observatory Director
With the NASA decision to turn over operations of the EUVE
Observatory to the University of California, Berkeley, a decision has
also been made to extend EUVE operations into 1999. As a result the
EUVE Observatory is issuing a call for proposals for use of the EUV
photometer instruments via the Right Angle Program (70-700 A). These
instruments have been used effectively to detect faint new EUV
sources, to carry out long term monitoring (e.g., of cataclysmic
variables and active late-type stars), and to map diffuse sources
(e.g., the interstellar medium and interplanetary medium). Proposals
can be submitted at any time (they are reviewed and approved on an
on-going basis) by filling out the WWW submission form at
http://www.cea.berkeley.edu/Science/rap_proposers.html
Further information on the RAP program is available at
http://www.cea.berkeley.edu/Science/rap.html
No funding is associated with this program so GOs should seek funding
through other mechanisms (e.g., the NASA ADP program).
1.3 Abstracts of Recently *Accepted* EUVE Papers
------------------------------------------------
Included below are abstracts of EUVE-related papers recently
*accepted* for publication. For those papers authored by CEA
personnel, the CEA publication numbers are indicated. Unless
otherwise noted, researchers may obtain preprints of the CEA papers by
sending an e-mail request containing the publication number(s) of
interest to pub@cea.berkeley.edu.
Researchers are encouraged to contribute *accepted* EUVE-related
abstracts for inclusion in future editions of this newsletter;
abstracts will also be posted under the CEA WWW site. Please send all
abstracts to archive@cea.berkeley.edu.
--------------------------------------------------------------
DAMPING-UNDAMPING STRATEGIES FOR THE LEVENBERG-MARQUARDT NONLINEAR
LEAST-SQUARES METHOD
M. Lampton
To appear in Computers in Physics. [CEA publication #769]
The speed of the Levenberg-Marquardt (LM) nonlinear iterative
least-squares method depends upon the choice of damping strategy when
the fitted parameters are highly correlated. Additive damping with
small damping increments and large damping decrements permits LM to
efficiently solve difficult problems, including those that otherwise
cause stagnation.
--------------------------------------------------------------
DIFFUSION OF SILICON IN THE ENVELOPES OF HOT DA WHITE DWARFS
P. Chayer, G. Fontaine, and C. Pelletier
To appear in White Dwarfs, ed. J. Isern, M. Hernanz, & E. Garcia-Berro
(Dordrecht: Kluwer), 1997. [CEA publication #770]
We present the results of time-dependent diffusion calculations for
silicon in the presence of radiative levitation, mass loss, and
accretion in a H-rich white dwarf model using a mass of 0.5 M_sun, log
g = 7.4, and T_eff = 60,000 K. For a mass loss rate M_dot <= 1E-18
M_sun/yr, the silicon abundance profile is essentially given by the
equilibrium radiative levitation theory after 4.7E+06 yrs of evolution
(the age of the model), though, for 1E-16 <= M_dot <= 1E-14 M_sun/yr
the outermost silicon reservoir predicted by radiative levitation is
completely depleted. A mass loss rate of M_dot = 5E-13 M_sun/yr,
however, is sufficient to maintain relatively large values of the
silicon abundance throughout the envelope. Accretion in solar
proportion of interstellar matter or of stellar wind coming from a
close companion, at rates ranging from 1E-17 to 5E-16 M_sun/yr, can
maintain a silicon abundance of -6.5 <= log N_Si/N_H <= -5.0 in the
atmosphere of our white dwarf model.
--------------------------------------------------------------
EXTREME ULTRAVIOLET LIGHT CURVE AND PHASE-RESOLVED SPECTROSCOPY OF THE
HOT WHITE DWARF IN V471 TAURI
J. Dupuis, S. Vennes, P. Chayer, S. Cully, and T. Rodriguez-Bell
To appear in White Dwarfs, ed. J. Isern, M. Hernanz, & E. Garcia-Berro
(Dordrecht: Kluwer), 1997. [CEA publication #771]
We present an analysis of the spectroscopic data obtained with the
Extreme Ultraviolet Explorer (EUVE) of the binary V471 Tauri. This
system comprises a hot white dwarf and a K dwarf star with an orbital
period of 12.5 hours and is believed to be a precursor of a
pre-cataclysmic variable. The EUV emission from the system is
completely dominated by the hot white dwarf and exhibits a temporal
variability at the period of 9.25 minutes previously detected by
EXOSAT (Jensen et al. 1986, ApJ, 309, L27) and the WET consortium
(Clemens et al. 1992, ApJ, 391, 773). Because the EUVE data are
time-tagged, we produce light curves phased on the 9.25 minute period
for the three spectrometer ranges (SW, MW, and LW). By comparing the
pulse shape of the three light curves, we notice that the pulse
amplitude is the strongest in the SW, noticeably weaker in the MW, and
virtually undetected in the LW. This suggests that we are, indeed,
looking at an opacity effect. To further explore this question, we
extract spectra during the low and high phases of the 9.25 minute
phase and find that, indeed, most of the absorption happens shortward
of 250 A. We attempt to constrain the composition of the spots on the
white dwarf photosphere by fitting a combination of pure hydrogen and
metal-blanketed models. We discuss implications of the possible
accretion mechanisms on the white dwarf.
--------------------------------------------------------------
MODELING EXTREME ULTRAVIOLET SPECTRA OF WHITE DWARFS WITH
HIGH-METALLICITY LTE MODELS
P. Chayer, S. Vennes, J. Dupuis, P. Thejll, and A.K. Pradhan
To appear in White Dwarfs, ed. J. Isern, M. Hernanz, & E. Garcia-Berro
(Dordrecht: Kluwer), 1997. [CEA publication #772]
We present Extreme Ultraviolet Explorer (EUVE) spectra of the hot
metal-rich DA white dwarf stars MCT 0455-2812, RE 2214-492, RE
0623-377, G191-B2B, and Feige 24, in the portion of the spectrum 200 A
<= lambda <= 370 A. Each spectrum contains strong lines that can be
interpreted as individual lines or blends of many lines. The
strongest features are present in all spectra and suggest that the
chemical composition of these stars is very similar. We also present
abundance analyses of heavy elements using metal line blanketed LTE
model atmospheres which include contributions of trace of heavy
elements such as C, N, O, and Fe.
--------------------------------------------------------------
EXTREME ULTRAVIOLET SPECTROSCOPY OF EUVE J0720-317 AND EUVE J0723-277
J. Dupuis, S. Vennes, and S. Bowyer
To appear in White Dwarfs, ed. J. Isern, M. Hernanz, & E. Garcia-Berro
(Dordrecht: Kluwer), 1997. [CEA publication #773]
We present Extreme Ultraviolet Explorer (EUVE) and optical spectra
of the DAO member of the close binary EUVE J0720-317 and of the hot DA
EUVE J0723-277. A comparison of density measurements of the local
interstellar medium (ISM) toward EUVE J0720-317 and EUVE J0723-277
(only 4 deg apart) reveals large variations in ISM ionization
properties. We speculate that the line of sight toward the close
binary EUVE J0720-317 is contaminated with circumbinary material or by
unsuspected structures in the local ISM.
--------------------------------------------------------------
PERFORMANCE OF THE EUVE IMAGING TELESCOPES
M.M. Sirk, J.V. Vallerga, R.F. Malina, P. Jelinsky, and D.S. Finley
To appear in Astrophysical Journal Supplement. [CEA publication #775]
The Extreme Ultraviolet Explorer (EUVE) observatory, successfully
launched on 1992 June 7, provided astronomers with the first
observatory dedicated to observation in the extreme ultraviolet. The
scientific objectives of EUVE include an all-sky survey in four
spectral bands, a deep survey in two spectral bands, and a
spectroscopic survey carried out through a NASA guest observer
program. We describe here the hardware components of the four
telescopes used to carry out both the all-sky survey and the deep
survey, and we present the imaging and photometric performance
characteristics of the instruments as determined from ground
calibration and in-orbit data.
--------------------------------------------------------------
ETOOLS: TOOLS FOR PHOTON EVENT DATA
M. Abbott, T. Kilsdonk, C. Christian, and E. Olson
To appear in Proceedings of the Sixth Annual Conference on
Astronomical Data Analysis Software and Systems (ADASS), ASP
Conference Series, 1997. [CEA publication #776]
We present an overview of the ETOOLS project and describe some of
the design features of the ETOOLS system.
--------------------------------------------------------------
CASE STUDY OF RDBMS USE ON THE EUVE MISSION
E.C. Olson
To appear in Proceedings of the Sixth Annual Conference on
Astronomical Data Analysis Software and Systems (ADASS), ASP
Conference Series, 1997. [CEA publication #777]
The Extreme Ultraviolet Explorer satellite (EUVE) mission has
employed a Relational Database Management System (RDBMS) in several
ways. Shortly after the launch of EUVE in 1992, an indexing scheme
for the EUVE telemetry was implemented to facilitate access to the
calibration, in-flight, and supplemental telemetry data. The RDBMS
has been used for tracking EUVE observations and other administrative
information. Over time it has evolved into the central data
repository of the distributed EUVE data reduction system. A number of
experimental systems also used the RDBMS. In 1992 EUVE began
participating in the Astrophysics Data System, using the RDBMS as the
repository for the EUVE bright source list and additional, ancillary
information. With the advent of the World Wide Web, EUVE used its
RDBMS to publish dynamic information for use within the project and
across the Internet. More recently, EUVE has created prototype client
programs to facilitate use of relational databases for scientific
applications.
--------------------------------------------------------------
2. EUVE Science Operations News
===============================
2.1 New Contact Information for EUVE Observatory
------------------------------------------------
by Michael Gunter, EUVE/CEA Project Manager
As mentioned above, the EUVE EP operations are currently being
transferred from NASA GSFC to CEA at the University of California,
Berkeley. As a result, organizational changes are occurring within CEA.
The following is an updated summary of contact information and
personnel for the EUVE Observatory.
o Center for EUVE Astrophysics
Telephone: 510-643-7043
o EUVE Observatory Director: Dr. Roger F. Malina
Telephone: 510-643-5636
E-mail: rmalina@cea.berkeley.edu
o EUVE Observatory Deputy Director: Dr. John Vallerga
Telephone: 510-643-5666
E-mail: jvv@cea.berkeley.edu
o EUVE Project Manager: Dr. Michael Gunter
Telephone: 510-642-0835
E-mail: gunterm@cea.berkeley.edu
Beeper: 510-310-1487
o EUVE Business Manager: Kevin Kaier
Telephone: 510-643-5640
E-mail: kaier@cea.berkeley.edu
o EUVE Scheduling Information: Dr. Damian Christian
Telephone: 510-642-9908
E-mail: damian@cea.berkeley.edu
o EUVE GO/GI/Archive Information: Dr. Nahide Craig
Telephone: 510-643-7273
E-mail: ncraig@cea.berkeley.edu
or, for general information:
Telephone: 510-642-3032
E-mail: egoinfo@cea.berkeley.edu (GO Program)
archive@cea.berkeley.edu (Archive Program)
o EUVE Flight Operations Manager: Brett Stroozas
Telephone: 510-643-7312
E-mail: bretts@cea.berkeley.edu
2.2 Public Release Begins for Cycle 4 Observations
--------------------------------------------------
by Dr. Nahide Craig, EUVE User Support Scientist
Cycle 4 GO observations, which have a six month proprietary period
(versus the 12-month period associated with observations from Cycles
1-3), begin going public on 1 Jan 1997 (see list in section 2.3
below). Due to delays in getting the funds to GOs at the beginning of
1996, the Project Office at GSFC has granted an additional two months
of proprietary time to those observations carried out early in Cycle
4.
2.3 Public GO/RAP Data Release for 1 Jan 1997
---------------------------------------------
by Dr. Nahide Craig, EUVE User Support Scientist
The table below lists the GO/RAP observations that become public on
1 Jan 1997. For each observation is given the target name, the
approximate exposure time in ksec, the GMT start/end dates, the
target's spectral type, and the data identification code (GO and RAP
data are marked accordingly). All public data sets can be ordered
from the archive via WWW and electronic or postal mail (see addresses
below). Please be sure to include in your order the DataID(s) of
interest. Processed data sets are shipped via postal mail on 8mm tape
or (if requested) on CD-ROM.
The data rights policies for observations state that Principal
Investigators (PIs) have proprietary rights to the data for a given
period of time from the date (s)he receives it. It is often the case
that long observations are broken up over many months; e.g., an
observation approved for 60 ksec may actually be observed for 10 ksec
one month, 20 ksec the next, and 30 ksec three months later. In such
cases the proprietary period begins after the PI is sent the final
piece of the completed observation.
===============================================================
Target ~Exp Observation Dates SpT DataID
Name (ksec) Start End
===============================================================
GO DATA SETS AVAILABLE 1 JAN 1997:
V1159 Ori 43 07 Feb - 09 Feb 1996 DwNova go0445 *
V1159 Ori 46 23 Feb - 24 Feb 1996 DwNova go0446 *
V1159 Ori 25 25 Feb - 25 Feb 1996 DwNova go0447 *
V1159 Ori 25 25 Feb - 26 Feb 1996 DwNova go0448 *
V1159 Ori 35 10 Mar - 11 Mar 1996 DwNova go0449 *
V1159 Ori 35 11 Mar - 12 Mar 1996 DwNova go0450 *
Capella 133 03 Mar - 07 Mar 1996 G5e go0451 *
LHS 2065 95 16 Mar - 20 Mar 1996 M go0452 *
PSR J1024-0719 40 20 Mar - 21 Mar 1996 Pulsar go0453 *
PSR J1024-0719 56 25 Mar - 27 Mar 1996 Pulsar go0454 *
EUVE J1746-706 100 27 Mar - 30 Mar 1996 WD:DA go0455 *
EUVE J1746-706 100 30 Mar - 03 Apr 1996 WD:DA go0456 *
EUVE J1746-706 63 03 Apr - 05 Apr 1996 WD:DA go0457 *
EUVE J0729-388 130 05 Apr - 10 Apr 1996 B5Vp go0458 *
EUVE J0729-388 130 10 Apr - 14 Apr 1996 B5Vp go0459 *
ALEXIS Transient 4 11 Apr - 11 Apr 1996 NOID go0460 *
Jupiter 77 14 Apr - 17 Apr 1996 SolSys go0461 *
MRK 421 182 17 Apr - 23 Apr 1996 BLLac go0462 *
MRK 421 182 23 Apr - 30 Apr 1996 BLLac go0463 *
V824 Ara 71 30 Apr - 03 May 1996 K1Vp go0464 *
NGC 4051 5 06 May - 06 May 1996 AGN:Sy go0465 *
VW Hyi 223 07 May - 14 May 1996 DwNova go0466 *
MRK 421 5 10 May - 11 May 1996 BLLac go0467 *
PKS 2155-304 147 15 May - 20 May 1996 BLLac go0468 *
NGC 4051 124 20 May - 24 May 1996 AGN:Sy go0469 *
NGC 4051 124 24 May - 29 May 1996 AGN:Sy go0470 *
RE J0317-853 62 03 Jun - 05 Jun 1996 NOID go0471 *
LHS 2924 110 07 Jun - 11 Jun 1996 NULL go0472 *
Coma Cluster 36 11 Jun - 12 Jun 1996 GalClust go0473 *
AU Mic 86 12 Jun - 15 Jun 1996 M0Ve go0474 *
II Peg 100 23 Oct - 26 Oct 1995 K0V go0475
II Peg 96 26 Oct - 30 Oct 1995 K0V go0476
UX Ari 84 07 Nov - 10 Nov 1995 G5IV go0477
IRAS Cloud 100 11 Nov - 14 Nov 1995 Bkgd go0478
IRAS Cloud 100 14 Nov - 18 Nov 1995 Bkgd go0479
IRAS Cloud 36 18 Nov - 19 Nov 1995 Bkgd go0480
UX Ari 92 19 Nov - 22 Nov 1995 G5IV go0481
UX Ari 74 22 Nov - 25 Nov 1995 G5IV go0482
1ES 0921+52.5 21 25 Nov - 26 Nov 1995 AGN go0483
EUVE J0003+243 4 26 Nov - 26 Nov 1995 NOID go0484
Note: "*" indicates Cycle 4 targets (see 2.2 above)
RAP DATA SETS AVAILABLE 1 JAN 1997:
1607-0032 147 15 May - 20 May 1996 Pulsar rap0067
1455-3330 144 29 May - 03 Jun 1996 Pulsar rap0068
EUVE J1436-38.2 369 17 Apr - 06 May 1996 NOID rap0069
EUVE J1521-16.8 223 07 May - 14 May 1996 NOID rap0070
================================================================
2.4 On-Line Access to EUVE
--------------------------
Listed below are the various methods for on-line access to EUVE:
o CEA World Wide Web (WWW)
URL http://www.cea.berkeley.edu/
telnet www.cea.berkeley.edu 200 (for those without a WWW browser)
o anonymous FTP
ftp ftp.cea.berkeley.edu
Name: anonymous
Password: type_your_full_e-mail_address
o anonymous gopher
gopher ftp.cea.berkeley.edu
o EUVE Electronic Newsletters
Past issues -- available via the CEA WWW site
Subscriptions -- mail majordomo@cea.berkeley.edu ("subscribe
euvenews")
Post message (moderated) to all subscribers:
mail euvenews@cea.berkeley.edu
o GI Program
Are you interested in finding out about or using EUVE data? Do
you need help in understanding EUVE data sets? Do you need help
in using the available EUVE data analysis software tools? If you
answer "yes" to any of the above, the Guest Investigator (GI)
Program at CEA can help YOU! For more information see the CEA
WWW site or contact the Archive (archive@cea.berkeley.edu).
o Public RAP
The Public Right Angle Program (RAP) is a simple and easy method
for researchers to propose for long-exposure EUVE imaging data.
For more information on the Public RAP and the simple proposal
process see the CEA WWW site or contact the EGO Center
(egoinfo@cea.berkeley.edu). Mail all proposals to
euverap@cea.berkeley.edu.
o Contact information for the EUVE Science Archive or EGO Center:
Center for EUV Astrophysics
2150 Kittredge St.
Berkeley, CA 94720-5030
510-642-3032 (voice)
510-643-5660 (fax)
archive@cea.berkeley.edu
egoinfo@cea.berkeley.edu
3. EUVE Outsourced Extended Mission Status Report
=================================================
by Brett Stroozas, EUVE Flight Operations Manager
Work continues to outsource EUVE EP operations from GSFC to the
EUVE Platform Operations Center (EPOC) at CEA. Upon completion of the
operations handover, which is currently scheduled for Feb 1997, will
the EUVE Outsourced Extended Mission (OEM) will commence. The
following sections describe some of the outsourcing highlights from
Nov 1996.
3.1 OEM Management
------------------
One major managerial focus during the month was the continued
hiring and training of the members of the new EPOC Flight Operations
Team (FOT). All but one of CEA's eight-person FOT has been hired, and
five members completed two months of training duty at GSFC with their
counterparts from the incumbent Lockheed-Martin FOT. One additional
EPOC FOT member remained at GSFC to complete his training, while the
final member will begin training at GSFC when hired.
Another major managerial focus for the month was to begin the
establishment of contractual arrangements for external flight anomaly
and hardware/software maintenance support. CEA began talking to and
negotiating with various external companies regarding possible support
contracts.
The final major managerial focus was the preparation by CEA for the
Mission Operations Review Meeting (MORM) to be held on 6 Dec. The
purpose of the MORM was for CEA to present to GSFC detailed plans on
the OEM including CEA's operations concept, flight operations
management plan, EPOC implementation and systems test plan, master OEM
schedule, and the performance criteria that CEA must meet in order for
the operations handover to occur. Brett Stroozas and George Kaplan
from CEA traveled to GSFC to present this material. At this time the
handover of EP operations from GSFC to CEA is still on schedule for
Feb 1997; see section 3.1 ("Schedule Milestones") of the previous
newsletter (Vol. 6, No. 11; 30 Nov 1996) for more details on the major
OEM milestones.
3.2 EPOC Ground Systems Development
-----------------------------------
Work continued on the installation and configuration of a new T1
communications line from GSFC to CEA. It is over this line that the
EPOC will command, control, and monitor the EP. The line was set up
and realtime data was successfully received from the spacecraft over
the line's "I" channel; clock-rate problems hampered proper operation
of the "Q" channel, which is used for tape recorder and on-board
computer dumps. NASA Communications (NASCOM) personnel continued to
work the Q-channel issue.
Preliminary interface testing of the various EPOC ground system
components also continued during the month. The major component
testing was with the Command Management System (CMS), which interfaces
with nearly all other EPOC system components. CMS is used for command
generation/management and the processing of observational science
plans, and is the central router and processor of nearly all
information required for satellite operations. Major progress was
made during the month and the EPOC CMS is nearly operational.
Excellent progress was also made in testing out and validating the
Transportable Payload Operations Control Center (TPOCC) system that
provides spacecraft command and control capabilities. The EPOC FOT
spacecraft controllers began to routinely monitor EP data during
realtime contacts with the spacecraft, in the process gaining valuable
experience in TPOCC operations.
3.3 EPOC Systems Testing
------------------------
Development and initial implementation of the EPOC systems test
plan was completed. An aggressive schedule was set forth that
provided for initial spacecraft commanding in early Dec and a
three-day EPOC "stress test" in mid-Dec. The goal is for the EPOC
systems to be completely tested and validated by the end of 1996.
Testing of the spacecraft scheduling functions was worked with
personnel from GSFC's Network Control Center (NCC) that schedules all
access to users -- like EUVE -- of NASA's Tracking Data and Relay
Satellite System (TDRSS). An engineering interface meeting was held
with the NCC Test Group in which various issues were discussed and
initial scheduling tests were set up for early Dec. The goal is to
complete scheduling testing and validation by the end of 1996. In
early Jan 1997 the Shadow Operations Period is scheduled to begin. In
its first phase, during the month of Jan, CEA will take over all
spacecraft scheduling functions with GSFC "shadowing" as a backup.
As mentioned above, the EPOC TPOCC system was configured to allow
for realtime operations testing via the processing and monitoring of
incoming realtime data from the EP. TPOCC was also set up to allow
CEA to begin successfully commanding of the EP simulator at GSFC. A
schedule was agreed upon that provided CEA with simulator access
during the week from 12-8pm PST, which coincides with the "prime"
operations shift at GSFC. Unfortunately, TPOCC testing progressed
slowly due to hardware problems with the simulator (Murphy's Law
states that timing is everything!), which were worked by GSFC
personnel from the Flight Software Group. The goal is to complete
realtime operations testing and validation by the end of Jan 1997.
The second phase of Shadow Operations is scheduled to being in early
Feb 1997, in which CEA will take over all realtime operations
functions (e.g., spacecraft command and control).
---------------------------------------------------------------------------
The EUVE Electronic Newsletter is issued by the Center for Extreme
Ultraviolet Astrophysics, University of California, Berkeley, CA
94720, USA. The opinions expressed are those of the authors. EUVE
Principal Investigators and Newsletter Publishers: Dr. Roger F.
Malina and Professor Stuart Bowyer. EUVE Flight Operations Manager
and Newsletter Editor: Brett A. Stroozas. Funded by NASA/UCB
Cooperative Agreement NCC5-138. Send newsletter correspondence to
ceanews@cea.berkeley.edu.
The EUVE project is managed by NASA's GSFC: Paul Pashby, GSFC
Project Manager; Dr. Yoji Kondo, Project Scientist; Dr. Ronald
Oliversen, Deputy Project Scientist; Mr. Kevin Hartnett, Mission
Director. NASA HQ: Dr. Guenter Riegler, Program Manager.
Information on the EUVE GO Program is available from Dr. Ron
Oliversen, Mail Code 681, GSFC, Greenbelt, MD 20771 at (301)
286-6290 or e-mail to euve@stars.span.nasa.gov.
END-----------EUVE------------ELECTRONIC---------------NEWS-------------END
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