The four Cluster spacecraft, being readied for launch
A major milestone was achieved in mid-February when the SOHO spacecraft was successfully injected into its halo orbit. This injection manoeuvre was followed by a series of spacecraft commissioning tests, which have all confirmed the very good performance of the spacecraft.
A first coordinated scientific mini-campaign has already taken place, with simultaneous observations being made by some SOHO instruments together with those of the Japanese solar spacecraft Yohkoh and several ground observatories throughout the world. The specific features of the Sun explored during this campaign were 'polar plumes in the south coronal hole'.
The preparation of two modifications to the on-board software that will enhance the robustness of some system features (particularly attitude and orbit control) was completed in mid- March. Following thorough ground testing with the ESA, NASA and industry simulators, these software patches have been successfully uploaded and tested on the orbiting spacecraft.
The ERS-2 satellite celebrates its first year in orbit on 21 April 1996. The tandem operations with ERS-1 continue to provide unique interferometric images of the Earth based on the Synthetic Aperture Radar (SAR) instrument. The Commissioning of the ERS-2 Scatterometer is nearing completion and full operational status is expected by mid-May 1996.
Advantage has been taken of the tandem operations to achieve a very precise cross-calibration between the ERS-2 and ERS-1 Radar Altimeters (RAs). Full exploitation of the ERS-1 instrument's twin geodetic phase data has provided a marine geoid with an unprecedented high resolution.
The Global Ozone Monitoring Experiment (GOME) is demonstrating a stable in-orbit performance. The complex ground processing system is still being optimised, the resulting instrument data products being compared with ground-based validation stations. General release of GOME data products is anticipated from April 1996 onwards.
Operation of the Infrared Radiometer (IRR) of the Along-Track Scanning Radiometer (ATSR-2) was interrupted in late 1995 following anomalous behaviour of the radiometer's scanning mechanism. As a result of a series of short in-orbit tests conducted to diagnose the scanning anomalies and to recover the IRR, the performance of the scanning mechanism has improved considerably. IRR operations are therefore expected to resume in April 1996, although close monitoring of in-orbit data and further analysis of the anomaly will continue.
Data from the ERS-2 Precision Range and Range-Rate Equipment (PRARE) is now considered operational, whilst full deployment of the ground stations continues.
The ERS-1 and ERS-2 spacecraft performances remain stable and the next highlight will be the completion of the fifth year of ERS-1 operations on 17 July 1996.
The four Cluster spacecraft, being readied for launch
The four spacecraft have been fuelled and are undergoing final thermal-hardware integration at the Kourou launch site. Battery conditioning has started and integration and final thermal hardware closeout will commence after Easter. The four spacecraft will be totally readied for a launch on 30 May, as currently foreseen for the first Ariane-5 flight (V501).
The Mission Flight Readiness Review (MFRR) was held at ESTEC at the beginning of March to assess the readiness for launch of all mission elements: spacecraft, scientific payload, ground segment, data dissemination system, Joint Science Operations Centre and launch-vehicle interfaces. All elements had previously successfully undergone individual acceptance reviews and the MFRR Board unanimously agreed the launch-readiness of all elements.
The qualification status of the spacecraft against the greater than expected shock loads coming from fairing separation was the only open point which required further attention. As a result of two test programmes using the spacecraft structural model (equipped during the first test with flight-spare equipment and payload), the Ariane-5 design authority had agreed to install shock attenuators between each spacecraft stack and the launch- vehicle interface. The results of both tests have been evaluated by a Shock Working Group consisting of Agency and Industry experts, which has now cleared Cluster for flight on V501 using the attenuators.
All other support systems are now in 'readiness-for-flight' configuration in anticipation of a launch on 30 May or shortly thereafter.
Following launch, the four Cluster spacecraft will undergo a three-month commissioning and evaluation phase, before being handed over to the scientific community for their two-year scientific mission.
A number of incidents that occurred and decisions that were taken at the end of 1995 and early in 1996 have, together, produced a programme perspective rather different from that last reported in these pages. The conclusions of the studies of the effects of pyrotechnic shocks have resulted in the introduction of a pyrotechnic shock test into the flight-model Probe acceptance testing sequence, while the investigations into the performance of the Probe descent module's foam thermal insulation have determined the need to re-perform the 'Titan entry' test with the modified foam.
The situation with the flight-model experiments has deteriorated somewhat with some deliveries being further delayed and with failures occurring that necessitate some redesign and remanufacture. The flight-model Probe's test programme is being continued with electrical- or qualification-model experiment units where necessary, with the exchanges for full flight units planned at a later stage. Whilst this is not a desirable situation, technically it is not a major problem.
However, the combination of the above elements is resulting in additional work, double shift working and extended timelines, which will increase costs and delay the flight model's acceptance by six to eight weeks. However, the final delivery date to the launch site is not endangered.
Other aspects of the programme are satisfactory. The engineering- model Probe, now in a 'flight-look-alike' condition, will be delivered to the Jet Propulsion Laboratory in California in May as planned.
Ground-segment activities are proceeding normally, with preparations for the Ground Segment Implementation Review well in hand.
The NASA and Cassini mission activities are continuing normally, with a Launch Vehicle Critical Review successfully accomplished in February.
Following the Systems Requirements Review, special actions were initiated with the Prime Contractor, Alenia Spazio (I), to finalise the system specification which drives the design of the whole spacecraft. An acceptable level of definition having been reached, the procurement process for units and subsystems could be started. Due to the commonality between the Integral Service Module (SVM) and that of the Agency's XMM spacecraft, this process entails:
The first review of the payload instruments, the Instrument Science Verification Review (ISVR), was commenced with the aim of further assessing the scientific performance of the instruments and confirming the technical and management interfaces between the spacecraft and the payload.
Artist's impression of the Rosetta mission
The mission-definition phase for Rosetta is now coming to a close. The industrial system support studies are due to terminate at the end of March and each study group presented the results of their work to a meeting with European Industry on 28 March. The study notes produced during the support phase have been made available to all industrial groups.
At its February meeting, the ESA Science Programme Committee (SPC) debated the effect on Rosetta of the budgetary constraints imposed during last October's Council Meeting at Ministerial Level in Toulouse. The SPC capped the cost of the mission and excluded the provision of a scientific camera and payload-support items from the project budget. Provision of these would have caused the target project cost at completion to be exceeded by some 7%. The scientific camera is now under consideration as a conventional Principal-Investigator-funded instrument.
Also at its February meeting, the SPC endorsed the selection of the Rosetta Orbiter scientific payload, including two Surface Science Packages (SSPs) 'Champollion' and 'Roland'. Several of the proposed payload elements are either extremely complex or highly innovative, and consequently the interface definition with the spacecraft was somewhat vague. Because of the unique launch date, the SPC agreed that the proposed payload be pre-selected and subject to final confirmation after one year. During the confirmation phase, each instrument will have to demonstrate feasibility and its spacecraft interfaces must be firmed up prior to starting the industrial Phase-B.
The next phase of the project is the industrial-procurement phase, which will commence with the issue of the Invitation to Tender in June 1996. The procurement policy to be followed for Rosetta takes into account the recommendations of the SPC to endeavour to reduce all project element costs by at least 10%. Accordingly, a novel procurement policy involving maximum competitiveness at all levels has been proposed, and was agreed by the Agency's Industrial Policy Committee at its March meeting.
The definition phase for other mission constituents is continuing and a firm order has been placed with Arianespace for an Ariane-5 launch vehicle for January 2003. Rosetta's mass at launch has been agreed at 2900 kg, including a basic allocation of 220 kg for the scientific payload.
Future programmes
Preparation of the nine reports for assessment
for potential Earth Explorer missions has continued throughout
the reporting period. Each report has been supported by a mission
working group and industrial studies. The reports are to be
published in April and will be discussed at a dedicated workshop
at the end of May in Granada.
The declaration for the extension of EOPP for the period mid-1996 to 2001 was agreed at the February meeting of the Earth Observation Programme Board.
Campaigns
The preparations for a new campaign known as 'INDREX-
96' have been in progress. ESA is one of the project partners in
this campaign, aimed at the development of a 'Remote Sensing and
Monitoring System for Forest Management and Land Cover in
Indonesia'.
The Polar Platform structural model
Envisat-1
Late 1995/early 1996 has been a very busy time for the
Envisat Programme. At the request of the Earth Observation
Programme Board Delegates, a number of detailed reviews
addressing the overall status and cost of the programme have
taken place, whilst the normal project work had to continue as
planned.
The development status of the payload and the Polar Platform has been the subject of one of these reviews (by the DOSTAG), with special attention being paid to instrument performance, critical technologies and overall programme schedule. It was concluded that a 'solid technical baseline exists for the Programme'.
The mission objectives have also been reassessed both with respect to the scientific use of the data and the support to operational and commercial applications by a high-level Scientific Task Force. It has confirmed that the payload constitutes a consistent set of instruments, none of which can be considered obsolete in the light of recent scientific results, and that it will indeed provide a unique Earth-observation capability.
The above reviews served to confirm the instrument development objectives baselined for the contract negotiations for the 120 subsystems that have taken place over the last 1.5 years. All negotiations for payload-instrument development were successfully finalised at the beginning of March. Whilst the payload instrument complement has been maintained, all other possibilities for cost savings are being pursued. Attention has focused on the consolidation of the technical baseline, and the streamlining of all development and test activities. The present programme schedule aiming at a mid-1999 launch is being maintained.
A fixed-price contract for the Advanced Synthetic Aperture Radar (ASAR), one of the Envisat payload's most demanding and critical instruments, has been agreed with Matra Marconi Space UK. Formal signature of the Mission Prime Contract is expected in the second quarter of 1996.
Polar Platform (PPF)
The structural-model programme has
progressed with integration at Platform level taking place in the
facilities of Matra Marconi Space in Bristol (UK). Preparations
are in progress for this model's transport to ESTEC in April for
subsequent mechanical testing. The structural-model programme has
been revised in order to make use of the HYDRA (the new ESTEC
hydraulic shaker test facility) for the forthcoming vibration
testing.
The proto-flight Service Module is under final integration at Matra Marconi Space in Toulouse (F). The electrical integration is well-advanced, but some difficulties remain in terms of timely availability of the dual-mode transponder.
Integration of the engineering-model Payload Equipment Bay (PEB) has been completed at Dornier (D) and functional testing and verification are currently in progress.
Several issues related to the interface with, and launch environment of the Ariane-5 vehicle are currently being addressed.
In response to the requests from the Member States participating in the programme to reduce costs still further, the Agency and industry have been making a substantial effort to identify cost reductions and to implement descopings in both hardware and future test activities, which lead, however, to additional development risk. On the basis of the results achieved, a coordinated proposal will be presented to the Earth Observation Programme Board in order to harmonise the present formal programme funding profiles of the Declarations with the actual needs of the programme.
Assembly and integration of the Meteosat Transition Programme (MTP) spacecraft has begun. Its launch is planned for early July 1997 on an Ariane-4 vehicle.
The MTP spacecraft design is the same as that of the Meteosat Operational Programme (MOP) spacecraft, the imaging instrument being a three-channel radiometer. This instrument will allow continuous imaging of the Earth with a resolution at the subsatellite point of 5 km in the infrared (two infrared channels) and 2.5 km in the visible (one visible channel) frequency spectrum.
The spacecraft assembly phase will be completed by the end of August, when the environmental test phase should begin. The final testing of the spacecraft will take place early next year, with the Flight Acceptance Review planned for mid-April 1997. The MTP launch campaign is expected to last two months, through May and June 1997.
The main development phase (Phase-C/D) continues to proceed on schedule with a series of Preliminary Design Reviews at subsystem and equipment level, releasing engineering-model manufacture and thermal/mechanical-model manufacture. The final system-level Preliminary Design Review (PDR) is planned for early April 1996.
Negotiations for the three-satellite procurement (MSG-1, 2 and 3) with industry are in process. The recurrent models MSG-2 and MSG-3, to be launched in 2002 and stored in 2003, respectively, are being fully financed by Eumetsat and are being procured on their behalf by ESA.
During the Preliminary Design Review (PDR) in December 1995/January 1996, a reference configuration, studied during Phase-B1, was evaluated. Evolution of the programmatic baseline during 1995, particularly regarding the payload complement which the Participating States wish to embark on the METOP series, remained incomplete at the time of the PDR. Consequently, the Review was followed by a holding phase during which industrial effort was kept to a minimum, focusing on those design elements that are independent of the payload complement.
The Participating States to both the ESA and Eumetsat programmes now appear to be converging on a payload definition. This retains the ASCAT and the other payload elements except ScaRaB which is removed, OMI which is realised as GOME, as flown on ERS-2, and MIMR, where provision is made for its possible re-embarkation if it should be offered as an Announcement of Opportunity instrument. In addition, a precision GPS system adapted to use the GPS signals for atmospheric sounding will be included. Assuming this becomes the baseline payload, Phase-B2 will be restarted in early April 1996.
International Space Station Programme (ISS)
In order to respect the financial ceilings of the approved ISS Programme, adjustment of the distribution of industrial tasks was investigated as part of a programme-wide assessment of the measures to be undertaken to achieve cost reductions equivalent to the 2.03% blocked amount in the Programme Declaration, and to meet the overall geographical-return targets. To this end, meetings have taken place with the Delegations of the main ISS Programme contributors to discuss the role of their Industry, and their aspirations with respect to the use of national facilities needed to support the operational phase. Particular attention has been paid to the special measures for Italy agreed at the Council Meeting at Ministerial Level in Toulouse last October.
COF
All technical non-compliancies against the ESA/NASA joint
requirements baseline have been resolved and the total work
content/price of the space-segment development contract has been
agreed. Industrial work in the domains of specifications/plans
finalisation, overall configuration design consolidation, ground
software avionics facility development and electrical ground-
support equipment development is underway. Furthermore, the
development models of some of the environmental-control and life-
support systems are being tested as part of the common COF/MPLM
procurement activity. Manufacture of the structural test unit of
the MPLM (on which the COF structure is based) has been completed
and it is being prepared for qualification testing.
Programmatically, the adjustment of the schedule to a launch date of November 2002 has been made, and fine tuning of the industrial worksharing is being finalised, with the goal of maximising European content wherever this is compatible with the price.
CRV/CTV
he parallel CRV/CTV Phase-A studies were completed as
planned by the end of 1995. A bridging phase from January to mid-
April 1996 will provide additional technical data in support of
open concept choices, such as the landing system. The Request for
Quotation for Phase-B, which is planned to start in September
1996, is in preparation and will consider the use of a single
contractor.
AT V
The system requirements and the system design as frozen at
the System Requirements Review (SRR1) in December 1995 remain
valid and will be finalised in May after completion of the Phase-
B Extension. A change of prime contractor after Phase-B is
envisaged and will be taken into account in the preparation of
Phase-C/D. The new prime contractor will be made familiar with
the overall programme, and in particular the ATV Rendezvous Pre-
development Programme, to the extent necessary to ensure that the
results are fully beneficial for the ATV Programme.
Discussions and studies with the Russian Space Agency (RKA) and the Russian contractors concerning the interfacing of the ATV with the Russian part of the Space Station for reboost have progressed well and all inherent technical aspects seem to have been addressed satisfactorily.
The Russian equipment that could be used on ATV has been defined and the profile of the first ATV demonstration flight has been worked out with the Russian contractor.
Technology and ARD
With few exceptions as far as ongoing ARD work
is concerned, all technology contracts have been committed and
are proceeding as planned.
Good progress has been made with the assembly and testing of the Atmospheric Reentry Demonstrator (ARD) in industry. The delay in the delivery of the ARD propulsion system was overcome by adapting the planning of the integration and test accordingly. Preparations are being made to repeat the failed balloon drop test, the necessary additional funds having been made available within the scope of the MSTP budget.
Preparations for the launch of the ARD in September 1996 on the Ariane-5 second demonstration flight have continued on schedule. Early deliveries Columbus Mission Data Base (MDB) The formal delivery and installation of the Columbus Mission Data Base into the NASA Mission Build Facility in Houston took place in December, thus concluding this phase of the activity in line with the schedule agreed with NASA in early 1994. Prototyping activities for further possible deliveries to NASA under a separate contract have been initiated.
Core Data Management System for the Service Module (DMS-R)
The
ongoing development work in industry was complemented by a series
of technical meetings in Russia with the participation of the
Russian Space Agency, and the European and Russian industrial
partners, to negotiate open technical changes and revised
delivery dates, as agreed with NASA. Agreement was reached on all
points.
European Robotic Arm (ERA)
Negotiations with the ERA Prime
Contractor culminated in the signing of the contract for the ERA
Development Part 2. The final details of the subcontractor
arrangements remain to be settled. A competitive tender was
issued for provision of the ERA Mission Preparation and Training
Equipment.
Consideration is being given by NASA and RKA to a change in the International Space Station launch sequence whereby the Russian Scientific and Power Platform, on which the ERA is operated, would be launched on the Shuttle. The tasks of the ERA would remain substantially the same, but the implications of the new launch scenario are being assessed.
Laboratory Support Equipment
80°: Frezer
The Phase-B has
continued on schedule, although difficulties with the advanced
technology employed have given rise to some potential cost
increases for Phase-C/D. The programmatic review took place in
December and the development model test was initiated.
Microgravity Science Glovebox
Manufacture of the development
model has been initiated; integration and testing is planned for
the end of the first quarter of 1996. The Preliminary Design
Review foreseen for December 1995 was rescheduled for March 1996.
Hexapod
The first major review of the Phase-B, the system
requirements and design configuration review, took place in
December as planned. Overall, the Phase-B remains on schedule.
The EuroMir 95 mission was concluded on 29 February 1996, with the Microgravity Programme having contributed 18 life-science and 8 materials-science experiments, which were performed either as self-standing experiments or in three newly developed multi-user facilities. The total mass of the payload provided by the Microgravity Programme was approximately 350 kg.
On 2 March 1996, a fluid-physics payload designed to investigate the motion of gas bubbles in a well-defined thermal-gradient field in a fluid was successfully flown on the sounding rocket Texus 34, launched from Kiruna (S). This experiment was performed interactively in real time by the researcher located at his home institute in Naples (I).
1996 is a year of high activity for the Microgravity Programme, with the following launches:
In preparation for Space Station Utilisation, definition studies are being initiated for three major multi-user facilities: the Materials Science Laboratory (MSL), the Fluid Science Laboratory (FSL) and the Biolab (BL).
The EuroMir 95 crew in orbit: from left to right, cosmonauts Sergei Avdeev and Yuri Gidzenko, with ESA astronaut Thomas Reiter.
The EuroMir 95 mission came to a successful close at 11.42 h CET on 29 February 1996 with the safe landing of the Soyuz TM-22 spacecraft in the steppes of Kazakhstan. At the landing site, about 107 km northeast of the town of Arkalyk, ESA astronaut Thomas Reiter was welcomed back to Earth by backup astronaut Christer Fuglesang, his prime contact person at the Control Centre during the mission.
Less than seven hours later, Thomas Reiter and his Russian crewmates Yuri Gidzenko and Sergei Avdeev arrived at Star City's airport near Moscow, where they were greeted by Russian space authorities, top ESA officials, and numerous members of the EuroMir ground operations and management teams. First medical examinations confirmed the crew's excellent health after their 180 days in orbit aboard the Russian space station Mir.
After just one day of recovery, the crew were ready to give their first international press conference at Star City after their return. According to Thomas Reiter, the absolute highlights of mission for him were the two spacewalks that he made on 20 October 1995 and on 8 February 1996, the first ever undertaken by an ESA astronaut.
The accumulated data from the 41 experiments carried out onboard Mir is now in the hands of the scientists on the ground, who are analysing it together with the material returned and who will soon have their first briefings with the astronauts. The experiment programme spans the fields of life science, astrophysics, material science and technology. Thanks to the 45- day extension of the flight, all of the scientific experiments that had been scheduled could be conducted at least the requisite number of times, and sometimes more.
Thomas Reiter's post-flight programme, consisting of rehabilitation periods, medical examinations, debriefings and public appearances, etc. will continue until the end of June.
ESA Bulletin Nr. 86.