SNIP Plenary Meeting Minutes
for 3/13, 16-17/95
(FINAL COPY 6/8/95)
SNIP PLENARY MEETING - TOKYO & OKINAWA, JAPAN
MARCH 13 & 16-17, 1995
ATTENDANCE
Name Organization/Address Telephone/Address
Telemail
D. Fahnestock NASA-GSFC/Code 500 (301) 286-8767
T. Ryan NASA-GSFC/Code 501 (301) 286-9406
TRYAN
Fax: (301) 286-1700
CC: tryan@gsfcmail.
gsfc.nasa.gov
R. Stanley NASA-GSFC/Code 515 (301) 286-2401
RSTANLEY
Fax: (301) 286-1602
E. Ambrose NASA/LORAL-Code (301) 794-2552
EAMBROSE
Phone: (301) 794-2552
Fax: (301) 794-7208
CC: Ed.Ambrose@ccmail.
gsfc.nasa.gov
Anthony Sersen* NASA/RMS (301) 805-3447
ASERSEN
Fax: (301) 805-3447
R. Brockdorff* NASA/StEL Corp- (301) 286-5955
Code 531.1 Fax: (301) 286-1770
CC: ronnaa@class.
gsfc.nasa.gov
A. Chang Code O Rep/NASDA Hq Tsukuba Space Center
2-1-1 Sengen, Tsukuba
Ibaraki-ken
305 Japan
Phone:81-298-52-2325
* Did not attend Okinawa Plenary Meeting.
K. Lenhart ESA/ESOC Robert Bosch Strasse 5
D64293 Darmstadt,
Germany
Phone: 49-6151-902227
Fax: 49-6151-90-3402
M. Schmidt ESA/ESOC Robert Bosch Strasse 5
D64293 Darmstadt,
Germany
Phone: 49-6151-90-2012
Fax: 49-6151-90-0495
K. Falbe-Hansen ESA/ESTEC P.O. Box 299
2200 A.G. Noordwijk,
The Netherlands
Phone: (31) 1719 83152
J. Gerner ESA/ESTEC-XRT P.O. Box 299
2200 A.G. Noordwijk,
The Netherlands
Phone: (31) 1719 84473
Jun Gomi NASDA Hq/T&DA World Trade Center
Bldg 2-4-1
Hamumatsu-cho,
Minato-ku
Tokyo 105 Japan
Phone: 81-3-5470-4318
N. Hotta MELCO 325, Kamimachiya
Kamakura, Kanagawa
247 Japan
Phone: 81-467-47-2136
Fax: 81-467-47-1874
M. Fuda NASDA Hq/TACC Tsukuba Space Center
2-1-1 Sengen, Tsukuba
Ibaraki 305 Japan
Phone:81-298-52-2326
* Did not attend Okinawa Plenary Meeting.
T. Fujiwara MELCO 8-1-1, Tukaguchi-
Honmachi, 661, Japan
Phone: 81-6-497-6081
Fax: 81-6-497-6311
Y. Tsuneoka NEC Corp. 4035 Ikebe-cho
Tsuzuki-ku, Yokahama
City 224 Japan
Phone: 81-45-939-2401
Fax: 81-45-939-2404
S. Matsuo* NASDA Hq/T&DA 2-6-1 Hamumatsu-cho
Minato-ku, Tokyo
Japan 105
Phone:81-3-5470-4319
Fax: 81-3-5470-4327
K. Kikuchi NEC Corp. 4035 Ikebe-cho
Tsuzuki-ku, Yokahama
City 224 Japan
Phone: 81-45-939-2401
Fax: 81-45-939-2404
S. Hunter* ATSC/PAP-Code 501 (301) 805-3300
HUNTERS
Fax: 301) 805-3309
CC: trsrah@atscv1.
atsc.allied.com
W. Fetterer ATSC/PAP-Code 501 (301) 805-3070
WFETTERER
Phone: (301) 805-3070
Fax: (301) 805-3309
* Did not attend Okinawa Plenary Meeting.
I. INTRODUCTION
A. Mr. J. Gomi, NASDA SNIP co-chairman and host, convened the
meeting and requested that members introduce themselves, identi-
fying areas of SNIP expertise and/or program responsibilities.
Before reviewing the Plenary Planning and Working Group (WG)
agendas he briefed members on Splinter meetings and facility
tours. He also explained logistics for the Plenary meeting in
Okinawa.
B. ESA requested that a briefing on the Artemis Configuration/
Schedule and Ground segment be added to the agenda, as well as a
status presentation on Ground Communications between NASA and
ESA. This was agreed to. (Attachment 1.)
II. ACTION ITEM REVIEW - NASA/ESA/NASDA (ATTACHMENT 2)
The status of action items issued at the July '94 Plenary was
reported as follows:
No./Agency Action Response
1. ESA Contact CCSDS for avail- ESA to provide updated
able Signalling I/F copy at future date
Document list, for in- for distribution.
clusion in meeting (Open.)
minutes.
2. NASA Develop additional SNIP To be discussed in de-
Master Schedule covering tail at this Plenary.
Experiment prep/develop (Closed.)
dates for inclusion in
meeting minutes.
3. NASA Send Test Fish Inter- To be discussed in de-
operability Matrix to tail at this Plenary.
ESA/NASDA for update and (Closed.)
inclusion in meeting
minutes.
4. NASA Review/update SNIP pro- Updated presentation
grams/accomplishments made at Greenbelt
from ESA menu-driven (U.S.) Space Ops Confer-
diskette and comment at ence. (Closed.)
next Plenary.
III. TDRSS STATUS - NASA (ATTACHMENT 3)
A. The present configuration of TDRS satellites (TDW, TDE,
and TD-Spare showed downlinks to STGT and the Extended TDRSS
Ground Terminal (ETGT). A configuration of the Space Segment
current TDRS constellation was shown. An antenna polarization
and operational status of KSA and SSA Forward and Return links
was also presented. The current operational NCC interfaces
showing scheduling data flow, as well as TLM/CMD and vector in-
formation, were also explained.
B. The WSGT has shut down operations for 1 year during up-
grading. The fully automated STGT has prime responsibility for
controlling TDRS satellites. The ETGT is responsible for opera-
tion of the GRO Remote Relay Terminal (GRTS) at the White Sands
Complex (WSC). Current TDRS's have only S-/Ku-band capability,
but planned follow-on SC; i.e., TDRS-H, -I, -J, will also be
equipped with Ka-band.
C. Future planning was described, as follows:
1. The T-16 Build (ETGT) will have two TT&C antennas for
contingency operations, and to support the F-1 GRTS/ETGT opera-
tions as well as TDRSS TT&C (via two S-band RF links).
2. The F-7 launch aboard STS-70 is scheduled for June '95.
3. The TDRS-H, -I, -J contract was awarded to Hughes in
February '95. The SC will be functionally similar to present
TDRS's, but with Ka-band and enhanced MA capability.
D. A detailed description of GRTS/TDRS elements and comm
interfaces, RGRT Normal Ops Space-to-Ground Link (SGL) config-
urations, and GRTS GRO service support, was presented.
E. An explanation of processes/documentation users must fol-
low in order to obtain SN services was provided.
F. NASA Responses to NASDA and ESA queries proceeded as fol-
lows:
1. Will NASA continue to recommend Ku-band use after Ka-
band frequency is initiated aboard -H, -I, -J satellites? Though
NASA currently has no Ka-band users, it is expected that future
users will request Ka because of the quality of data and better
protection from RFI. Ku-band affords service to many users and
is expected to remain for an indefinite period.
2. What is the size/weight of Ka- versus Ku-band antennas?
TDRS-H,-I,-J and follow-on SC will be equipped with smaller and
lighter antennas. TDRS-H.-I,-J will be launched from Expendable
Launch Vehicles (ELV) rather than Space Shuttle.
3. How long will GRTS facility remain in use? GRTS has to
support the GRO satellite and will likely remain open to close
ZOE for other users.
4. What is the status of "stored" TDRS SC? The stored
SC (TDRS-6) is being controlled at S-band Telemetry, Tracking,
and Command (TT&C). The S-band user services have been turned
off. A decision will be made to re-locate TDRS-3 SC to the ZOE.
TDRS-3 is expected to bgin its drift phase in late April 1995.
IV. DRS PROGRAM STATUS - ESA (ATTACHMENT 4)
A. The status of ESA's Data Relay Tracking Mission (DRTM)
and related programs was summarized as follows:
1. The Artemis and DRS are scheduled for Dec '97 and mid-
2000 launches, respectively.
2. DRS users, SPOT-4 (ESBT) and ENVISAT, are scheduled
for early '98 and mid-1999 launches, respectively.
3. Potential DRS users have been identified; i.e., Colum-
bus Orbiting Facility (COF), METOP, and ATV/CTV.
4. NASDA users of the ESA/Artemis will be ADEOS (launch:
early '96), ETS-VII (launch: Aug '97), and OICETS (launch: Aug
'98).
5. The COF will be attached to Space Station.
B. Summarized for Splinter information were S-/Ka-band user
Space Terminal activities: These include the European S-band
Terminal integrated on SPOT-4, SBS (aboard ENVISAT), and the
Small User Transponder (undergoing development). Ka-band User
Space Terminal activities include the KBS experiment, integrated
with ENVISAT, and the Advanced Ka-band Transponder scheduled for
development in the near future. A listing of DRTM program pro-
curements was also summarized.
C. From ESA's perspective, their DRS Decentralized Ground
Segment configuration reflects the way ESA and client/user views
the Ground interfaces. NASA remarked that their equivalent or-
ganizations to ESA's DRS Mission Control Facility (MCF) and DRS
OCC are the GSFC/NCC and White Sands/WSC. The MCF location will
be either at ESOC (Germany) or Redu, Belgium. The DRS OCC is
located in Rome, Italy.
D. A separate briefing on DRS/Artemis Ground Segment develop-
ments discussed the issuance of pertinent documentation and the
Ground Definition Phase (attachment 5). Key points were high-
lighted, as follows:
1. ESA's Central Earth Terminal (CET) concept is uuder-
going review. Users located close to ESOC will be provided with
limited facilities; i.e., a small terminal and in-orbit test
facility.
2. An Artemis Flight Readiness Review is tentatively
scheduled for Oct '97.
3. The Artemis Ground Segment schedule showed major mile-
stones for hardware/software deliverables to ESOC, Simulator
development, Preparation for Operations, and Routine Ground
Segment operations for procurement, integration, and system
component testing.
V. SPACE NETWORKS STATUS - NASDA (ATTACHMENT 6)
The NASDA SN is presently made up of the following elements:
A. DRS:
1. Launched by the H-II vehicle in August 1994, ETS-VI
failed to reach geostationary orbit and is currently in a 3-day
recurrent orbit. Satellite equipment, including S-/Ka-band inter-
satellite communications, is working nominally as designed.
2. The COMETS launch is scheduled for Feb 1997. A system
Critical Design Review (CDR) was held March 6 - 7, 1995. The
inter-satellite communications Prototype Flight Model (PFM) is
under development.
3. The DRTS Phase A study is ongoing, and Phase B is ex-
pected to start in 1995. Launches of DRTS-1W and -1E are
expected in 2000 and 2001, respectively, taking into account a
6-month launch delay.
B. New User SC: This is an HTV/H-II Transfer Vehicle (2001
launch) proposed as a Space Station logistic resupply vehicle,
similar to ESA's ATV. The Space Station would interface with the
HTV RVD within 4 days following HTV launch.
C. SN Ground Station:
1. The ETS-VI station was completed in June '94 and the
ETS-VI SN experiment begun in Dec '94.
2. The COMETS Ground station (CGS) CDR was completed in Jan
'95, and full-up capability is expected by Oct '96. An RF Com-
patibility test between ADEOS and COMETS Ground system is expec-
ted in March '96.
3. The DRTS ground station investigated in 1995 will be
budgeted in the FY '96 budget. Configuration specifications were
provided.
D. ETS-VI Experiment: A successful test of the DSS/ETS-VI
Ground station link has been confirmed on S-/Ka-band. The experi-
ment window with NASA/UARS is planned for approx. 2 hours/day
during the experiment period. ETS-VI must maintain attitude con-
trol (during experiment) for antennae pointing. Experiment test
items were listed for information, as were revised experiment
schedule milestones. A complete list of SN interoperability test/
experiment dates was also presented, along with COMETS/ETS-VI and
DRTS Operations configurations. NASDA responded to several NASA
queries/concerns, as follows:
1. What is the apogee/perigee of ETS-VI ? Apogee is higher
than geosynchronous; perigee is 2000 - 3000 km.
2. Is there potential scheduling conflict with EUST test
of ETS-VI and UARS (at ESA and NASA) in May '95 ? Probably not,
because ESA's ETS-VI/EUST testing lasts only 1 day.
VI. ETS-VI EXPERIMENT STATUS - NASDA (ATTACHMENT 7)
A. The spacecraft was launched by an H-II on Aug 28, 1994.
Apogee engine failure was the reason it failed to achieve a
geostationary orbit. Due to degradation of solar power, the SC
life is expected to be shorter than originally anticipated (Jan
'96 because of Van-Allen belt effects).
1. The ETS-VI experiment with DSS conducted from Dec '94
has confirmed SN/S-band Inter-satellite Communications (SIC) and
Ka-band Single Access (KaSA) capability. The functions of both
were summarized and explained.
2. There was no indication that transponder characteris-
tics; i.e., I/O, frequency, spurious, etc., had degraded. Charts
demonstrating Spurious Return Link Radiation and SIC Return Fre-
quency and Ka-band/SA Return I/O Characteristics were presented
along with SIC Forward/Return link evaluations.
B. NASDA made the decision to reschedule the COMETS ground
system modifications from Dec '95 to June '96. The ETS-VI ex-
periment is expected to be completed by the end of Nov '95, and
an additional 4 months extension has been granted for this
activity.
VII. DRTS STATUS - NASDA (ATTACHMENT 8)
The FY 1995 Phase A budget for DRTS study and development of the
Breadboard Model (BBM) has been approved. However, the budget for
Phase B design was not approved. The BBM budget, Phase A, will
be used to start development of the frequency synthesizer. Re-
scheduling of the program based on current budget conditions is
as follows:
A. Two DTRS will be developed: 1)DRTS-W @ 90 degrees E;
launch is Aug (vice Feb) 2000, and 2) DRTS-E @170 degrees W;
launch is Aug (vice Feb) 2001.
B. Design Phase:
Activity New Schedule Former Schedule
Phase A July - Dec '94 July - Oct '94
Phase B Apr '95 - Mar '96 Mar - May '95
Phases C/D Apr '96 June '95
C. Described for members information was the overall DRTS-E/-
W configuration, as well as configurations for services to Earth
Observation (EOS) mission, service to the rendezvous/docking mis-
sion, and human life information support. Domestic feeder link
antenna electronic characteristics were also described, and the
status of international cooperation with respect to technical
parameters, frequency plan, NASA Ka-band installation on future
TDRS's, and polarization requirements explained.
D. Responses to ESA/NASA questions about tracking and data
handling were as follows:
1. The Masuda GT will be used for DRTS tracking data. The
Hatoyama GT described in the DRTS configuration will assume the
same role as WSGT in processing/recording of mission data, and
TKSC will coordinate the distribution of data to users.
2. NASDA confirmed that two Control Center systems will
operate DRTS-E/-W satellites. ESA recommended that normal config-
urations of 170- and 90-degrees be separated even further to
avoid RFI, but NASDA replied this probably cannot be done.
VIII. GROUND STATION DATA EXCHANGE - ESA (ATTACHMENT 9)
Presented for information were several configuration charts il-
lustrating Ground system interfaces used for data exchange.
These included Nominal Columbus Orbital Facility Communications
Support, IGS Communications Support During Spacelab Mission
IML-2 (1994), EUROMIR-95 Baseline Communications Concept, Comm
Resources to Support COF and ATV, and Possible ETE Video Confer-
encing between Shuttle and SS/MIR. The Russians reportedly have
a DRS with limited capability, and have asked to join SNIP WG
discussions to learn more about being compatible with S-/Ka-band
systems.
SNIP Plenary Meeting - Okinawa, Japan - March 16-17, 1995
Following brief introductions for the benefit of members not at-
tending the earlier Planning session, Mr. Gomi distributed the
continuing agenda for Plenary topics under consideration. There
were no recommended changes or new inputs. (Attachment 10.)
IX. REPORTS FROM SPLINTER GROUPS
A. SNIKaS (Attachment 11):
1. Closed were two action items from the June '94 Splinter
concerning IDRS/SS-alpha link freq/comm parameters (for RFI),
and DRS Polarization.
2. Two Ka-band items were discussed; i.e., changes to Pre-
face of Ka-band Recommendations and Defining Earth Station G/T
and EIRP in Link Budget. Two new action items were assigned.
Decisions on keeping the same polarization for Forward/Return
IOL frequency, and removing NASA/TDRS-H,-I,-J minimum EIRP, were
made. Listed also for information were the Ka-band data rate
specifications.
3. ESA/NASA took the action to review the NASDA-proposed
Interoperability Matrix. ESA presented their DRS service capa-
bility budget for review and comment. Conclusions were that all
pending actions would be closed by mid-April '95 and Ka-band Re-
commendations (Rev 2) will be signed by the end of May 1995.
NASA/Code 500 expressed concern that both S- and Ka-band final
documentation be finalized at the WG level in preparation for
TMM final approval (action item 1).
B. SNOPS (Attachment 12):
1. Two actions from the previous Splinter were closed;
i.e., NASDA presentation of Mapping Table between SNIP OCD and
DRTSS Strawman Documentation Tree, and ESA study results of SNIP
common signaling message approach.
2. There was discussion of information exchange require-
ments for NASDA (COMETS Scheduling and Pass Operation Scenarios,
User Interface Approach, and Compatibility Test Concept); ESA
(DRS/Artemis User Interface Status); and NASA (SN Operations
Lessons Learned). On the latter requirement, NASA and NASDA ac-
cepted new actions to provide detailed tutorials on lessons
learned for SN operations during ETS-VI/UARS experiments (action
items 2 and 3).
3. Recommended future activities include continuing infor-
mation exchange, document mapping approaches, and investiga-
ting common test message requirements. The next meeting will
attempt to identify a basic message set and data structure.
4. ESA requested that NASA provide a TDRS-H,-I,-J mission
overview and design status presentation by the next Plenary meet-
ing and NASA agreed (action item 4).
C. SNISS (Attachment 13): Four key meeting actions were sum-
marized, as follows:
1. NASDA/ESA to review NASA's definition/specification for
data bit jitter and jitter rate. (Due: May 31, 1995.)
2. NASDA/ESA to review/comment on NASA's Signal Group-B,
single data channel configuration (Due: May 31, 1995.)
3. NASA to provide jitter rate definition. (Due: Mar 31,
1995.)
4. NASA to finalize and distribute all changed pages for
S-band Parameters Document (due: May 31, 1995). Revisions invol-
ved the removal of Shuttle information. The signoff due date is
July 31. STGT implementations will probably be added to subse-
quent revisions.
D. SNITS (Attachment 14): NASA said the 6-Year Test Milestone
Schedule does not reflect ESA activity with either NASA or NASDA,
and ESA accepted an action item to "develop comments for inclu-
sion" (action item 5). EUST successful testing at GSFC (1992) and
the more recent planned ESBT test with TDRS-E are primary exam-
ples. The Splinter chairman summarized results of TRMM/COMETS
discussions, as follows:
1. All actions from the Nov '94 Splinter have been closed,
except one pertaining to CCB approval of TRMM/COMETS Docs Tree.
Twenty-seven new actions were assigned.
2. NASDA/COMETS Ground H/W and S/W CDR's were completed
between Aug '94 - Jan '95, and ETS-VI experiment will continue
throughout 1995, with the EGS upgraded to status of CGS. The
COMETS SN experiment plan is undergoing review and plans are to
have a 1-year experiment and 2 years of experimental operation.
NASDA has firmly identified 7 candidate test SC. The scheduling
philosophy for TRMM/COMETS events is to have TDRS-E/-W support 84
COMETS events (each 20 min. duration) during the test period.
3. ETS-VI CMD/TLM data flow and exchange of state vectors
are either in the planning stage or ongoing. TRMM/COMETS test
planning and interfaces are also being worked, as are proposals
for NASA testing with the NASDA ETS-VII SC. The next SNITS was
tentatively scheduled for Oct '95, coinciding with the next
Plenary meeting.
4. NASDA asked to present their proposal for a EUST/NASA-
TDRSS compatibility test at ESTEC (July '95), using GSFC and STGT
to test ESA's capability to make quick compatibility checks of
flight hardware. EUST testing will be performed with the French
transponder, and test planning/procedures will be similar to
those for NASDA's future ETS-VII test with SN/TDRS. ESA said most
of their future missions will be supported in S-band, and by a
DRS that will make use of descoped versions of EUST. The ESTEC
test will serve as an experimental check (rather than validation
test) and precursor to ESBT testing aboard SPOT-4 in 1998.
E. TRMM/COMETS FDF Splinter (Attachment 15): Vector exchanges
will be via IIRV format and the Geocentric Greenwich Rotating
Coordinate system will be used. A Orbit Determination WG has been
formed to address tracking data, force modeling/vector propaga-
tion, and vector exchange. Meetings were held at GSFC in July
1994 and at TKSC in Nov 1994.
F. ETS-VI/UARS Splinter (Attachments 16 and 17):
1. NASDA's requested extension of experiment duration to
July '95 (vice June) was agreed to. NASA and NASDA agreed with
the preliminary test configuration as presented. The key mile-
stone in the NASA/NASDA test schedule, said NASA, is that ETS-VI
compatibility with NASA's user SC was verified prior to launch.
2. The NASDA EGS improvement mods being investigated con-
sist of stripping 1-kb data from 32 kb and enabling Doppler com-
pensation at every SC pass. Visibility analyses were provided for
EGS, UARS/TDRS (Spare), and UARS/ETS-VI windows, with the conclu-
sion that a real test-day analysis is needed. It was agreed this
cannot occur until close to experiment start time.
3. A TDRS Spare can support the ETS-VI experiment if TDW
cannot.
4. The Test Outline is in signature cycle. The UARS project
Risk Analysis Assessment that ETS-VI support poses no risk is
undergoing NASA/GSFC Flight Assurance review. A Test Plan signa-
ture is planned for April 30, 1995.
G. ETS-VII/TDRSS Test Meeting (Attachment 18):
1. Test configurations were outlined for Phases 1 - 3 to
include Compatibility, TLM/CMD Data Flow, WSC-NCCDS Interface
Test, ETS-VII Simulator Operation (at TKSC), and ETS-VII/TDRS
Orbit testing. NASA Hq has approved test Phases 1/2, but Phase 3
is still under review.
2. NASDA took actions to review/comment on the NASA-
proposed ETS-VII/TDRSS Test Outline and Test Plan. A title page
for a high-level MOU between agencies covering "Exploration of
Space for Peaceful Purposes" was distributed. Its approval/signa-
ture is reportedly viewed as a precursor to initiation of any
binding requirements and Ops documents.
H. JESNITS Splinter (Attachment 19): A preparatory meeting
was convened at TKSC on March 10, 1995 to discuss the ETS-VI/EUST
test campaign. The dates anticipated are May 8 - 17, 1995. Three
action items were assigned ESA to provide names of test person-
nel, review the Compatibility Test Plan, and recommend a HP-8780
replacement. NASDA's actions included providing the DSS low-noise
amplifier (LNA) output signal, possible rental of HP-8780 hard-
ware, investigating the timing for EGS switch to coherent mode,
and study of C/No. Return link measurement.
I. ESBT/COMETS Test Meeting (Attachment 20): A NASDA/ESA
Test Outline was signed and will involve the ETS-VI, COMETS, and
other NASDA user SC, as well as Artemis, EUST, and ESBT. NASDA
was given the action to review/comment on ESA's ESBT (SPOT-4)/
COMETS Experiment Plan, and a generic test schedule was discus-
sed and agreed to. Joint actions to reevaluate test items, as
well as required on-orbit test period/passes, were levied.
J. NASDA User SC/Artemis Test Meeting (Attachment 21):
1. Under consideration is an Artemis/ADEOS Ka-band test, as
well as a future ETS-VII/Artemis test. Planning is underway for
an OICETS/Artemis test, and the entire range of optical issues
under consideration were described. To highlight these issues ESA
presented OICETS/Artemis status report, SILEX LEO/GEO Mission Re-
view, and OICETS LUCE Terminal H/W developments, plus the des-
cription of applicable Documentation Tree and system/Ground seg-
ment configurations (attachment 22).
2. The Ground data link between ESA and NASDA will be un-
dergoing interface testing with the In-orbit Infrastructure
Ground System (IGS) later this year. In response to a NASA ques-
tion about Viterbi decoder specs, ESA said it operates at 1/2
rate.
X. DRTS SPACE STATION SUPPORT - ESA (ATTACHMENT 23)
The DRTS comm link for NASA/SS, using the NASDA JEM SC in the
beginning of the DRTS mission period, is being investigated. A
development scenario for the Data Relay Satellite Program in
NASDA was presented. This covers the period 1994 - 2006. It in-
cludes the baseline comm test, data transmission via Ka-band
(1-way), network Ops experiment, a Ka-band (2-way) communica-
tions, and Optical Communications testing. Summarized also were
S-/Ka-band interorbit link specs, and data content proposed in
support of communications between DRTS and JEM during the cross-
support mission.
XI. HIGH DATA RATE TRANSPORT - NASDA (ATTACHMENT 24)
A. As a future SNIP objective, NASDA is proposing to study
the benefits and feasibility of a HDR transmission system using
inter-geostationary orbit communication (IOC). The goals are to
expand IOC to cover ZOE and eventually develop a global HDR com-
munications network. Items for study include data rate, GEO/GEO
link frequency (including optical link), and H/W implementation
requirements. Presented were comparisons of planned HDR transport
links/carriers, including optical and RF onboard equipment, and
a listing of key HDR transportation issues. NASDA's conclusion is
that a GEO/GEO optical link is a valid method for HDR transporta-
tion.
B. A number of concerns were raised, as follows:
1. ESA commented that getting HDR data to Ground elements
is the primary problem with the method proposed by NASDA, because
there are already problems in fine pointing data from GEO to Low-
Earth Orbits (LEO). Development of an optical link for sending
GEO/GEO data to Ground elements, and building a Ground system
data distribution system would prove too costly for interoper-
ability.
2. There was disagreement within ESA insofar as it was
suggested that optical link data might be downlinked from various
SC to Ground sites and separated via virtual channels. Both NASA
and ESA took an action item to conduct internal studies of the
GEO/GEO HDR transport requirement and report findings at the next
Plenary (action item 6).
3. NASA commented their HDR requirement is being reduced
because of official directives to compress data, and ESA said
they are faced with the same requirement. NASA is currently re-
quired to fly smaller SC with fewer instruments onboard; more-
over, no TDRS user has come close to using the 300-Mb max. data
rate.
XII. INTEROPERABILITY TEST FISH MATRIX - NASA (ATTACHMENT 25)
The list of interoperable SC candidates was distributed for
review and update. ESA and NASDA were asked to record agreed-
on changes based on a real-time review. Following these dis-
cussions NASA agreed to provide an updated chart for inclu-
sion with the meeting minutes (action item 7).
XIII. INTEROPERABILITY MASTER SCHEDULE - (ATTACHMENT 26)
SNIP Milestone Charts showing Interoperability Periods, DRS
Schedules/Decision Dates, and Experimental Interoperability
were distributed for review and update. A real-time review
noted all pertinent changes and text modifications required
since the last Plenary. NASA took an action to compile up-
dates and issue revised schedules with the Plenary meeting
minutes (action item 8). Some key changes and actions were
clarified, as follows:
A. "TDRSS Follow-on" is formally approved as TDRS-H,-I,
-J as of March 1, 1995. Following launch availability in
early 1999, a second TDRS must be ready for launch 1 year
later.
B. To complete SNIP/Phase 1 NASA agreed to provide NASDA
with the final S-band Specifications Document updates (Rev
1) (action item 11).
C. There was concern that Phase 1 recommendations/agree-
ment require OCD revisions regarding Ka-band. Members con-
curred that a three-agency review of the OCD was needed to
incorporate Ka-band agreed-on proposals (action item 9).
ESA was given the action to transmit updated Ka-band recom-
mendations to NASA and NASDA (action item 10).
D. It was agreed that the Phase 2 Interoperability decision
point was necessarily impacted by Ka-band Recommendation(s)
approval and signoff and a TMM decision to proceed.
E. ESA expects to have an operational DRS by the year 2000
to be followed a few months later by full-up interoperability.
F. At ESA's request, NASA accepted the action to develop a
SNIP Acronyms and Abbreviations List (action item 12). ESA and
NASDA agreed to assist by providing inputs.
XIV. SNIP INTERNET E-MAIL ADDRESS LIST (ATTACHMENT 27)
ESA presented an updated Internet/E-Mail list of key SNIP per-
sonnel addresses. Their presentation contained an explanation of
the address format and accession procedure, and referenced Net-
work Administrators available to provide E-Mail assistance. NASA
noted that the CCMail system will temporarily replace all GSFC-
Mail/NASAMail accounts at GSFC after Aug '95 (with possible ex-
ception of Codes 500 and 530) . They said GSFC CCMail user lists
would be provided to ESA as information was obtained.
XV. FUTURE MEETING
A. Agencies tentatively agreed on Oct 16 - 21 for convening
the next Plenary WG and SNIP Splinters, with a TMM meeting sched-
uled for Oct 23 - 24. It was suggested that sufficient time
between SNIP Plenary/Splinter meetings and the TMM should be
allotted (1 or 2 days) so that results/recommendations for TMM
can be prepared.
B. As host, ESA agreed to investigate available locations in
Europe. They commented that Redu, Belgium or ESTEC Hq (Noordwijk,
The Netherlands) were ideal for conducting work because of the
availability of conference rooms, but that availability of meet-
ing locations in Paris, France or Frascati, Italy will also be
considered.
XVI. ACTION ITEMS
The following action items were assigned:
Item/Agency Due Date Action
1. NASA/NASDA/ Next Plenary Deliver final SNIP Ka-band recom-
ESA mendations and S-band Specifica-
tions Document (Rev 1) to SNIP
Panel for presentation/approval at
next TMM meeting.
2. NASA Next SNOPS Present detailed presentation (tu-
Splinter and torial) on Space Network (SN) Op-
Plenary erations Lessons Learned.
3. NASA/NASDA Next Plenary Present an ETS-VI/UARS Experiment
tutorial on Lessons Learned.
4. NASA Next Plenary Present a TDRS-H,-I,-J overview
of mission status/design informa-
tion.
5. NASA/ESA Next Plenary Develop Master test schedule.
(ESA inputs due: May 1, 1995.)
6. NASA/ESA Next Plenary Study and clarify requirement for
GEO-to-GEO High Data Rate trans-
port, and present results of inter-
nal studies.
7. NASA Next Plenary Update Interoperability Matrix
chart based on Plenary discussions
and include with meeting minutes.
8. NASA Next Plenary Update Interoperability Master
Schedule based on ESA/NASDA inputs.
9. ESA/ May 31,1995 Review OCD and provide inputs to
NASDA NASA.
10. ESA May 31, 1995 Send updated Ka-band recommenda-
tions to NASA/NASDA.
11. NASA July 31, 1995 Send updates to S-band Specifica-
tions (Rev 1) Document to NASDA.
12. NASA Next Plenary Develop SNIP Abbreviations/Acron-
yms List and update after each
Splinter. (ESA/NASDA inputs to
NASA: July 31, 1995.)
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