EEEEEEEEEEE   U         U    V           V   EEEEEEEEEEE
          E             U         U     V         V    E
          E             U         U      V       V     E
          EEEEEEE       U         U       V     V      EEEEEEE
          E              U       U         V   V       E
          E               U     U           V V        E
          EEEEEEEEEEE      UUUUU             V         EEEEEEEEEEE
Vol. 7, No. 12             23 December 1997                  ISSN 1065-3597
	  (C) 1997, Regents of the University of California

Notes from the Editor
   by Brett A. Stroozas, EUVE Mission/Flight Director

   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 Public GO/RAP Data Release for 1 January 1998
    1.2 Abstracts of Recently *Accepted* EUVE-Related Publications
 2. EUVE Satellite Mission Operations News
    2.1 EUVE Observes U Gem as TOO
    2.2 Recent Science Observations Pose Operational Challenges
    2.3 FOT Conducts Engineering Calibrations/Tests
    2.4 Ground System Engineer Resigns
    2.5 GO Support Being Folded Into Operations
    2.6 On-Line Access to EUVE
 3. EUVE Outsourced Extended Mission Status Report
    3.1 PACOR Replaced: Final Outsourcing Objective Completed
    3.2 UCB/CEA Eliminates DDCS Communications Line
    3.3 EUVE Leading Way On NASCOM's IP Transition

To comment on or make suggestions for the EUVE electronic newsletter,
please send e-mail to (Internet).

   The EUVE observatory continues to perform extremely well.  During
November and the first half of December 1997 the EUVE observatory
completed and/or began observations of a number of Guest Observer (GO)
and Right-Angle Program (RAP) targets as listed below.  For each
target is given its name, spectral type (generally from the SIMBAD
database), the observation start day/time (day-of-year:hours:minutes),
name of the Principal Investigator (PI), observation type/priority,
and any relevant notes:

  Target          SpT         GMT Start        PI         T  Notes
Saturn           Planet  298:02:00 (25 Oct)  Gladstone    1  EGO,MOV,MU1,TCO
epsilon CMa      B2Iab:  308:06:30 (04 Nov)  Vallerga     1  PID
MBM 12           MolCld  310:01:03 (06 Nov)  Berghoefer   2  EGO,MU2,TCO
BATSE 2852       GRB     310:01:03 (06 Nov)  Hurley       3  RAP
U Gem            DwfNova 311:18:20 (07 Nov)  Mauche       1  EGO,TOO
Moon             Moon    318:09:28 (14 Nov)  Flynn        1  PID,CF1,MOV,MU3,SCA
Moon             Moon    318:14:12 (14 Nov)  Edelstein    1  PID,CF2,CO1,MU4,MOV
NGC 6434         AGN     318:14:12 (14 Nov)  Fruscione    3  RAP
Moon             Moon    318:15:47 (14 Nov)  Flynn        1  PID,CF1,MOV,MU3,SCA
Diffuse Bkgd     Bkgd    318:18:50 (14 Nov)  Lampton      1  EGO,CF3,TCO
RE J2107-05      CV:AM   318:18:50 (14 Nov)  Howell       1  RAP
Hale-Bopp        Comet   321:22:32 (17 Nov)  Mumma        1  EGO,CO2,MOV,TCO
beta Cas         F2IV    327:01:33 (23 Nov)  Ayres        1  EGO
NISM Downwind    NISM    341:06:21 (07 Dec)  Flynn        1  EGO,CF4,MU5,TCO
Slew Tests       ----    341:18:46 (07 Dec)  ------       -  EN1
Survey           ----    342:02:37 (07 Dec)  ------       -  EN2
NISM Downwind    NISM    342:07:36 (08 Dec)  Flynn        1  EGO,CF4,MU5,TCO
EUVE J1137+510   NOID    342:07:36 (08 Dec)  Lampton      3  RAP
MBM 12           MolCld  342:18:39 (08 Dec)  Berghoefer   2  EGO,ALT,MU6,TCO
ALEXIS Transient NOID    345:17:34 (11 Dec)  Bloch        1  EGO,MU7
2EUVE J0632-05.0 WD:DA   346:17:15 (12 Dec)  Wolff        1  EGO
EUVE J0113+624   NOID    346:17:15 (12 Dec)  Lampton      3  RAP
  Key to Notes:

  ALT = Alternate target observed instead of beta Cas to avoid
	thermally "hot" spacecraft attitude
  CF1 = Non-standard payload configuration: only Scanners B and C on,
	XY mode, only quadrant 3 unblanked, widened countrate shutdown
  CF2 = Non-standard payload configuration: only long-wavelength
	spectrometer on, XY mode, widened countrate shutdown
  CF3 = Non-standard payload configuration: Scanners A, B, and C off
  CF4 = Non-standard payload configuration: Scanner C off, XY mode
  CO1 = Observation coordinated with EURD satellite
  CO2 = Observation coordinated with ground-based telescopes
  EGO = EUVE Guest Observer observation
  EN1 = Engineering slew tests (low- and high-rates)
  EN2 = Engineering star tracker calibration observation
  MOV = Moving target
  MU1 = Multiple pointings (18) required for this observation
  MU2 = Multiple pointings (30) required for this observation
  MU3 = Multiple pointings (35; 7 pointings for each of 5 orbits)
	required for this observation
  MU4 = Multiple pointings (7 pointings, 1 orbit) required for this
  MU5 = Multiple pointings (15) required for this observation
  MU6 = Multiple pointings (15) required for this observation
  MU7 = Multiple pointings (3) required for this observation
  PID = PI Discretionary observation
  RAP = Right-Angle Program observation
  SCA = Scanning telescope (imaging) GO observation
  TCO = Time-critical observation
  TOO = Target of Opportunity observation

Note that this issue of the EUVE electronic newsletter will be the
last published on a monthly basis; beginning in 1998 distributions
will be continued as events warrant (e.g., on a quarterly basis).
This publication change is in response to the continued shrinking of
available EUVE mission staffing and budgetary resources.

We at the EUVE Project hope you had a wonderful Thanksgiving and wish
you a wonderful Holiday Season:

	    *****   M E R R Y   C H R I S T M A S   *****
	    *****              A N D   A            *****
	    *****  H A P P Y   N E W   Y E A R !!!  *****

1. EUVE Science News

1.1 Public GO/RAP Data Release for 1 January 1998
        by Dr. Nahide Craig, EUVE Scientist

   The table below lists the GO/RAP observations that become public on
1 January 1998.  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 assigned data identification code (GO
and RAP data are marked accordingly).  As of 22 November 1997 all
public data sets must now be ordered from NASA's Space Science Data
Center (NSSDC) via e-mail ( or WWW

   The data rights policies for observations state that PIs have
proprietary rights to their 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; note that RAP targets observed as of 15 Mar 1997 do *not*
have associated proprietary periods.  See the UCB/CEA WWW site
(address below) for a complete list of publicly available EUVE data

   Target         ~Exp    GMT Observation Dates   SpT      DataID
    Name         (ksec)    Start           End


		     ***** Cycle 4 Targets *****

  V711 Tau          184   09 Oct - 16 Oct 1996    G9V      go0631 *
  V711 Tau          184   16 Oct - 23 Oct 1996    G9V      go0632 *
  VY Ari             80   23 Oct - 25 Oct 1996    K0       go0633 *
  V815 Her           44   25 Jun - 26 Jun 1996    G5       go0634 *
  TUNNEL #1          11   31 Oct - 01 Nov 1996    Bkgd     go0635 *
  TUNNEL #1          11   01 Nov - 01 Nov 1996    Bkgd     go0636 *
  TUNNEL #1          11   01 Nov - 01 Nov 1996    Bkgd     go0637 *
  TUNNEL #1          11   01 Nov - 02 Nov 1996    Bkgd     go0638 *
  TUNNEL #2          11   02 Nov - 02 Nov 1996    Bkgd     go0639 *
  TUNNEL #2          11   02 Nov - 03 Nov 1996    Bkgd     go0640 *
  TUNNEL #2          11   03 Nov - 03 Nov 1996    Bkgd     go0641 *
  TUNNEL #2          11   03 Nov - 03 Nov 1996    Bkgd     go0642 *
  TUNNEL #3          12   23 Nov - 24 Nov 1996    Bkgd     go0643 *
  TUNNEL #3          12   24 Nov - 24 Nov 1996    Bkgd     go0644 *
  TUNNEL #3          13   24 Nov - 25 Nov 1996    Bkgd     go0645 *
  TUNNEL #3          13   25 Nov - 25 Nov 1996    Bkgd     go0646 *
  TUNNEL #4          11   03 Nov - 04 Nov 1996    Bkgd     go0647 *
  TUNNEL #4          11   04 Nov - 04 Nov 1996    Bkgd     go0648 *
  TUNNEL #4          17   25 Nov - 26 Nov 1996    Bkgd     go0649 *
  TUNNEL #4          17   26 Nov - 27 Nov 1996    Bkgd     go0650 *

		     ***** Cycle 3 Targets *****

  TUNNEL #4          17   26 Nov - 27 Nov 1996    Bkgd     go0651 *
  TUNNEL #1          13   28 Nov - 29 Nov 1995    Bkgd     go0652 *
  TUNNEL #1          13   29 Nov - 29 Nov 1995    Bkgd     go0653 *
  TUNNEL #1          15   29 Nov - 30 Nov 1995    Bkgd     go0654 *
  TUNNEL #1          17   30 Nov - 30 Nov 1995    Bkgd     go0655 *
  TUNNEL #1          17   30 Nov - 30 Nov 1995    Bkgd     go0656 *
  TUNNEL #2          37   27 Jan - 28 Jan 1996    Bkgd     go0657 *
  TUNNEL #2          37   27 Jan - 28 Jan 1996    Bkgd     go0658 *
  TUNNEL #3          37   28 Jan - 29 Jan 1996    Bkgd     go0659 *
  TUNNEL #3          37   28 Jan - 29 Jan 1996    Bkgd     go0660 *
  TUNNEL #4          18   29 Jan - 30 Jan 1996    Bkgd     go0661 *
  TUNNEL #4          18   29 Jan - 30 Jan 1996    Bkgd     go0662 *
  TUNNEL #4          18   30 Jan - 30 Jan 1996    Bkgd     go0663 *
  TUNNEL #4          18   30 Jan - 30 Jan 1996    Bkgd     go0664 *

  Note: "*" indicates Scanning Telescope imaging GO observation.



			 ***** N O N E *****


1.2 Abstracts of Recently *Accepted* EUVE-Related Publications
	by Brett A. Stroozas, EUVE Mission/Flight Director

   Included below are abstracts of EUVE-related papers recently
*accepted* for publication.  For those papers authored by UCB/CEA
personnel, the UCB/CEA publication numbers are indicated.  Unless
otherwise noted, researchers may obtain preprints of the UCB/CEA
papers by sending an e-mail request containing the publication
number(s) of interest to

   Researchers are encouraged to contribute *accepted* EUVE-related
abstracts for inclusion in future editions of this newsletter and for
posting under the UCB/CEA/EUVE WWW site.  Please send all abstracts to


S.M. Rucinski
To appear in Astronomical Journal.

   EUVE satellite spectroscopic observations (SW, MW and LW bands
covering 80-160, 170-350 and 450 A with resolutions 0.5, 1 and 2 A)
and photometric observations (Deep Sky Survey, broad-band 70-140 A)
have been obtained for two contact, 44i Boo B and VW Cep, and one
detached, ER Vul, close binary stars.  All three systems have orbital
periods shorter than one day and thus are expected to show "saturated"
levels of chromospheric, transition-region and lower-corona emissions.
The spectroscopic data were of sufficient quality for an attempt at an
emission-measure determination only for 44i Boo B.  This
determination, based entirely on iron lines, and utilizing Singular
Value Decomposition formalism developed by Schmitt et al. (1996)
indicates lack of any dominating temperature regime with the emission
measure rising from log T about 6 to log T about 7.2.  However, strong
dependence of the resulting emission-measure curve on the inclusion of
individual lines formed at high temperatures casts some doubts about
the quality of the solution.  A comparison of the line strengths have
been made for selected strongest chromospheric, transition-region and
lower-coronal emission lines; it included the data for the single,
rapidly-rotating star AB Dor which is the only such star with the
rotation period shorter than one day which has been observed with the
EUVE.  If the single-epoch observations are representative, the
results indicate that AB Dor is under-active relative to the three
binary stars which show similar levels of activity.


B. Flynn, J. Vallerga, F. Dalaudier, and G.R. Gladstone
To appear in Journal of Geophysical Research.

   We present results from EUVE measurements obtained during the
all-sky survey of interplanetary and geocoronal HeI 584 Angstroms
emission.  The data consist of count rates from the Long Wavelength
Spectrometer and long wavelength photometric band (520-750 Angstroms)
of Scanner C obtained over a 1-year period from July 1992 to July
1993.  During this period, EUVE was in survey mode so that the
scanners made 5X360 degrees sweeps of the sky in a plane perpendicular
to the Sun-Earth line, while the spectrometers were aligned with the
anti-solar direction.

   The interplanetary HeI signal is morphologically consistent with
previous observations with similar observing geometry, such as Prognoz
6 (Dalaudier et al. 1984).  However, unlike the Prognoz 6 data, the
EUVE measurements were made from low Earth orbit (520 km) and so
contain geocoronal emission as well.  As a result, along sight lines
where the relative speed between the interplanetary wind and the Earth
is at a minimum, extinction of the interplanetary signal through
resonance scattering by the He geocorona occurs.  We believe this to
be the first detection of line extinction of the local interstellar
He wind emissions by the geocorona.

   We find that the geocoronal extinction signatures provide a new
means of determining the interstellar He wind vector and emission line
profile, and add further constraints on the values of other
interplanetary and solar He parameters and the morphology of the He
geocorona.  Based upon model fits of the observed interplanetary
emission and geocoronal extinction, we determine values for the
interplanetary wind ecliptic longitude (76.0 +/- 0.4 deg), latitude
(-5.4 +/- 0.6 deg) (downwind direction), speed (26.4 +/- 1.5 km/sec),
and temperature (6900 +/- 600 K).  In addition, assuming an
interplanetary He density of 0.01 cm^(-3), we determine an average
solar HeI 584 Angstroms line center flux of (1.4 +/- 0.3)E+10
photons/cm^2/sec/Angstrom for the data analyzed here.


2. EUVE Satellite Mission Operations News
	by Brett A. Stroozas, EUVE Mission/Flight Director

   The last six weeks have been *extremely* busy ones for EUVE mission
operations personnel.  During that time the EUVE Observatory conducted
22 total observations of 18 separate targets: 11 for Guest Observers,
five for the Right-Angle Program, four as Director's Discretionary
Time, and two engineering tests (a star tracker calibration and some
high-rate slew tests).  Of these observations four required special
payload configurations, two were coordinated with other satellites
and/or with ground-based observatories, one was a moving target, seven
required multiple pointings, seven were time-critical, one was a
Target of Opportunity, and one was an alternate target (to avoid a
thermally undesirable spacecraft attitude).  In addition, on 31
October EUVE completed its 30,000th orbit, and on 28 November its
2000th day in orbit!  The following subsections describe some of the
recent operations highlights in more detail.

2.1 EUVE Observes U Gem as TOO

   In the early morning hours (~5:20am local pacific time) on 7
November the EUVE Project called a Target of Opportunity (TOO) to the
dwarf nova star U Gem.  Within five hours the FOT had EUVE on target
and observing the TOO, not a bad response time considering that for
the first two hours after the TOO was called none of the FOT members
had yet started work for the day (note that for budgetary
considerations the FOT supports TOOs only during regular business
hours)!  The extreme EUV-brightness of the source posed a potential
safety hazard to the deep survey (DS) imaging instrument, prompting
engineers to turn off the DS for most of the observation, which was
completed successfully on 14 November.

2.2 Recent Science Observations Pose Operational Challenges

  Of the various observations conducted during this period a number
required multiple pointings; of those, a few -- the Moon, the Diffuse
Background, and the NISM Downwind -- posed additional challenges to
the FOT.

   On the 14 November EUVE conducted two independent Moon
observations: one (for Dr. Jerry Edelstein) sandwiched between parts
of another (for Dr.  Brian Flynn).  These combined observations, which
were conducted over a period of six orbits, all during the unstaffed
hours at UCB/CEA, required 42 total slews (7 slews/orbit) and two sets
of completely different non-standard payload configurations.  For the
first three orbits EUVE was to conduct a scanning telescope (imaging)
observation, with the payload reconfigured such that all instruments
were off except Scanners B and C, the telemetry mode switched to XY,
only one of the each detector's four quadrants unblanked, and widened
countrate shutdown parameters.  During the fourth orbit the spacecraft
was to be slewed 90 degrees and the payload reconfigured such that
only the long-wavelength spectrometer detector was on, XY telemetry
mode, and widened countrate shutdown parameters.  Finally, for the
fifth and sixth orbits the spacecraft was slewed 90 degrees back to
its initial Moon orientation and payload configuration to complete the
Scanner observation.

   The combination of implementing the required multiple slews and the
various payload configurations, all at the proper times and during the
unstaffed off-shift hours, provided the FOT with a logistically
challenging set of observations.

  The problem of supporting the many slews required during UCB/CEA's
off-shift hours was solved using Absolute Time Commands (ATCs), which
are time-tagged commands that are loaded on-board the spacecraft and
later automatically executed by the on-board computer (OBC) at the
proper times.  At the end of the day shift the FOT would load a new
slew table for the off-shift slews; ATCs would then confirm (i.e.,
make active) these new slews, which would then autonomously execute at
the proper times.  This "confirm by ATC" strategy was successfully
tested on 12 November and then operationally implemented a few days
later for the actual Moon observations.

   On the payload end, engineers built, tested, and patched into the
ground systems some new payload commands that were required for the
Moon observations.  The final commanding timeline was then verified to
ensure that the payload would be configured properly at the proper
times for each of the three pieces of the two different Moon
observations.  All time-critical reconfiguration commands were then
also scheduled for autonomous on-board execution via ATC.

   These Moon observations were executed successfully and exactly as
planned.  Immediately upon their completion the EUVE satellite was
then slewed to conduct an observation of the diffuse background that,
like its predecessors, required a different non-standard payload
configuration -- all Scanners off and WSZ telemetry mode; these
reconfigurations were also successfully executed via ATC.

   Finally, on 7-8 December EUVE observed the NISM Downwind
observation (i.e., near-interstellar medium in the "downwind"
direction).  This observation required 15 individual pointings and a
non-standard payload configuration (Scanner C off, XY telemetry mode).
Once again, ATCs were used to successfully carry out these

   Upon completion of the NISM Downwind observation, and in order to
mitigate the thermal effects on the spacecraft's communications
subsystem, the FOT decided not to return to the "hot" attitude of the
beta Cas observation (which was already 91% complete) as was
originally planned.  Instead, on 8 December the FOT slewed the
spacecraft to an alternate target, MBM 12, an observation that easily
fit the scheduling timeline and that required a spacecraft attitude
(within 30 deg of the sun-line) that promoted spacecraft cooling.

   Throughout all of these observations, the combination of multiple
slews, varying payload configurations, the specific timing of the
events, and the off-shift hours during which the observations were
executed, all added up to some challenging and fun times for EUVE FOT

2.3 FOT Conducts Engineering Calibrations/Tests

   On 7-8 December the FOT conducted two engineering observations: a
series of engineering slew tests and a brief transition to survey mode
to calibrate the star trackers.  Combined, these observations required
a fair amount of preparation by the FOT.

   The slew tests consisted of a series of single-axis slews
(X-Y-Z-Y-X) in both low- and high-rates, first using the current
gyroscope parameters and then using some newly updated ones generated
from analysis of recent reaction wheel assembly test data.  The
purpose of these slew tests was twofold: to operationally check out
the effects of the newly updated gyroscope parameters; and as initial
preparatory work for the upcoming March 1998 Venus observation, which
will require high-rate slews (which have only been previously employed
on EUVE for survey mode, and never for inertial mode observations).

   For the star tracker calibration the spacecraft was commanded to
survey mode and spun up to three revolutions per orbit (~0.2 deg/sec),
where it then accumulated star tracker data before being spun back
down and then slewing back to the NISM Downwind attitude.  As usual,
the accumulated data was then forwarded to GSFC's Flight Dynamics
Facility (FDF) for analysis.

   For both the slew tests and the star tracker survey observation the
FOT again used ATCs for all reconfigurations and for the confirmation
of slew table loads during the off-shift hours.  And, once again,
everything was executed successfully and as planned.

2.4 Ground System Engineer Resigns

   On 1 December the FOT lost the services of its Ground Systems
Engineer, Sriram Chelluri.  Sriram was with the EUVE Project for just
over a year, coming on-board in the Fall of 1996 and subsequently
playing a pivotal role in the successful outsourcing of EUVE
spacecraft operations from GSFC to UCB/CEA; for this we offer to him
our most appreciative and enthusiastic "thanks"!  With the bulk of the
challenging systems work completed at UCB/CEA, Sriram offered his
resignation, having decided to move on to a commercial company in the
San Jose/Silicon Valley area in order to pursue his software
development goals.  We were very sorry to lose Sriram but wish him all
the best in his new job and in his future career!

2.5 GO Support Being Folded Into Operations

   On 10 December UCB/CEA began transferring to the FOT the
responsibility for supporting EUVE Guest Observers (GOs).  This
transfer is the result of further cost-cutting measures within the
EUVE Project.  UCB/CEA's most recent budget projections indicate that
the current EUVE funding will run out earlier than expected: in early-
instead of mid-1999.  In response, UCB/CEA has decided to try to
further extend the mission lifetime by laying off additional personnel
-- scientists, staff, and students -- by early 1998.  Most of these
cuts will affect the GO Program, although the FOT is losing all of its
undergraduate student support.

   The current work of the positions identified for lay-off will
either be cut entirely (i.e., fewer services to the community) or will
be folded into operations with the FOT.  Now that EUVE operations have
become relatively routine and well understood, and now that operations
personnel are fairly well cross-trained, the FOT members now have
spare time that can be filled with other tasks.  Therefore, UCB/CEA
has decided to fold all GO services into operations.  The FOT has
begun the necessary training and should be handling all of the GO
services by mid-January 1998.  As an additional note, the FOT is also
training to take on more of the computer systems support work.

2.6 On-Line Access to EUVE

   Listed below are the various methods for on-line access to EUVE:


 o anonymous FTP:

 o EUVE Electronic Newsletters

     Past issues -- available via the UCB/CEA WWW site
     Subscriptions -- mail ("subscribe

 o GS 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?  Do you
     lack sufficient disk space and/or CPU power in your EUVE data
     analysis?  If you answer "yes" to any of the above, the Guest
     Scientist (GS) Program at UCB/CEA can help YOU!  For more
     information see the UCB/CEA WWW site or contact the EUVE Science
     Archive (

 o Public RAP

     The Public 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 UCB/CEA WWW site (address below) or contact the EGO Center
     (  Mail all proposals to

 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)

3. EUVE Outsourced Extended Mission Status Report
	by Brett Stroozas, EUVE Mission/Flight Director

   Work continues to clean up the few remaining open issues from the
outsourcing of EUVE Explorer Platform (EP) spacecraft operations from
GSFC to UCB/CEA.  The following subsections describe some of the
recent outsourcing highlights.

3.1 PACOR Replaced: Final Outsourcing Objective Completed

   Since the launch of EUVE, GSFC's Packet Processor (PACOR) facility
has routinely routed EUVE data to UCB/CEA.  With the outsourcing of
spacecraft operations from GSFC to UCB/CEA in March of this year,
there was no longer any compelling need for continued PACOR support
for EUVE.  At that time UCB/CEA began developing new software systems
to replace the three PACOR functions: processing of realtime and tape
recorder dump data, and the weekly delivery of spacecraft attitude
data to FDF.

   In early November UCB/CEA assumed the final PACOR responsibility:
that of delivering the weekly batch of attitude data to FDF; since
October UCB/CEA had handled the other two PACOR functions.  UCB/CEA's
new software systems continue to perform well and there have been no
major problems.  As a result, at 00:00 GMT on 15 November UCB/CEA
officially terminated PACOR support for the EUVE mission.  GSFC can
now decommission the PACOR facilities and personnel that were
supporting the EUVE mission, which should yield to GSFC some
additional cost savings.

   The EUVE Project would like to publicly acknowledge and thank PACOR
for all of its efforts on behalf of EUVE.  With the successful
completion of the PACOR replacement UCB/CEA has successfully completed
its *final* outsourcing objective.

3.2 UCB/CEA Eliminates DDCS Communications Line

   The communications between UCB/CEA and the PACOR facility had been
conducted via GSFC's Data Distribution and Command System (DDCS)
network.  During the outsourcing of EUVE spacecraft operations from
GSFC to UCB/CEA, three other connections were *temporarily* moved to
the DDCS: with FDF, with the User Planning System (for scheduling data
uplink/downlink events), and with the Flight Software facilities at

   With UCB/CEA's recent elimination of PACOR support for EUVE,
UCB/CEA has been working with the NASA Communications (NASCOM) group
at GSFC to migrate the three remaining communications connections off
of the DDCS to their intended *permanent* home, a secure gateway on
the GSFC Mission Operations and Data Systems Directorate's
Operational/Developmental (hyperchannel) Network -- MODNET, for short.

   On 3 December GSFC and the FOT completed this migration work and
opened up the secure gateway for operational use in support of EUVE.
As a result of this migration, coupled with the termination of PACOR
support for EUVE, on 15 December UCB/CEA officially released the DDCS
line to NASCOM for decommissioning, which should result in further
mission operations cost savings at GSFC.

3.3 EUVE Leading Way On NASCOM's IP Transition

   For some time now GSFC's NASCOM group has been working on a large
project to convert the NASA mission ground system communications
protocol from the NASCOM-proprietary 4800-bit-block protocol to the
computer industry standard Transmission Control Protocol/Internet
Protocol (TCP/IP).  When complete, this so-call "IP Transition" will
result in a simplified communications infrastructure that will
significantly lower associated network development and maintenance
costs at GSFC.

   EUVE is leading the way as NASCOM's operational "guinea pig" in the
IP Transition effort.  During the last few months of 1996 UCB/CEA's
FOT supported numerous tests of NASCOM's Programmable Telemetry
Processors (PTPs), the devices used in converting between the
4800-bit-block and TCP/IP protocols.  EUVE helped to identify a number
of major bugs and problems with the PTPs, most of which have since
been resolved by NASCOM personnel.

   On 20 November NASCOM conducted a test of the EUVE IP connection
between White Sands Complex, NM (WSC -- the main data uplink/downlink
station for EUVE and many other NASA missions) and GSFC.  This
successful test verified that the IP connection between WSC and GSFC
was operating as expected.  A few days later, on 29 November, UCB/CEA
gave NASCOM the green light to switch to the new GSFC-WSC IP
connection for continuous "operational testing" with EUVE.  Since that
time we have been using this new connection/protocol with no
significant problems.  In fact, this transition has actually helped to
resolve some persistent annoying problems with the legacy system!

   The next step in the process is now underway.  NASCOM personnel
recently set up and configured the PTPs at UCB/CEA, which allowed us
to successfully test out the UCB-GSFC IP connection.  UCB/CEA is now
running the IP protocol through the full data downlink loop --
WSC-GSFC-UCB -- on our backup operational control string, and
everything is working well.  We expect that soon we will be able to
test out the final piece of the puzzle: the uplink path
(UCB-GSFC-WSC).  Once that is working properly EUVE will switch over
entirely to IP, being the first in a long line of missions to do so.


  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 Newsletter Editor: Brett
  Stroozas.  Funded by NASA/UCB Cooperative Agreement NCC5-138.  Send
  newsletter correspondence to

  The EUVE project is managed for NASA by UCB/CEA: Dr. Roger F.
  Malina, EUVE Observatory Director; Dr. John Vallerga, EUVE
  Observatory Deputy Director; Dr. Mike Gunter, EUVE Project Manager;
  Mr. Brett Stroozas, EUVE Mission/Flight Director; Mr. Rob Nevitt,
  EUVE Operations Manager.  NASA HQ: Dr. Guenter Riegler, Program
  Manager.  EUVE Science Advisory Board: Dr. Steve Howell (Chair).


[HomePage] [Email] [Search] [Glossary]

Page created by
Last modified 1/6/98