Ulysses
Ulysses
Ulysses, with more than six and a half years of highly successful scientific operations behind it, continues to perform extremely well. Following the first-ever passes over the Sun's northern and southern polar regions in 1994 and 1995, Ulysses is now well into the second phase of its exploratory mission. The ultimate goal of the new mission phase, referred to as the 'Ulysses Solar Maximum Mission', is the study of the Sun's polar regions under conditions of high solar activity, culminating in a second set of polar passes in 2000 and 2001.
By early September of this year, Ulysses will have reached a position 5 degrees north of the solar equator at a distance of 5 AU from the Sun. The current phase of the Ulysses orbit, as the spacecraft approaches aphelion, is characterised by relatively slow changes in latitude and radial distance. From this quasi-stationary, low-latitude vantage point, Ulysses is well-placed to monitor transient solar-wind features such as Coronal Mass Ejections (CMEs) that have moved out from the Sun, past the orbit of Earth. A number of CME events are being studied in collaboration with other spacecraft (e.g. SOHO and Wind), including the well-publicised CME that passed the Earth in mid-January 1997, possibly causing damage to a telecommunications satellite.
The Ulysses science team continues to be prolific, with more than 600 publications to date. In addition to many individual papers in the literature, there have been eight coordinated publications. The latest is a comprehensive collection of papers describing the results obtained during the pole-to-pole transit and northern polar passage that appeared as a special issue of Astronomy and Astrophysics in December 1996.
All nine proposals that were received in response to the ESA Announcement of Opportunity (AO) for the Ulysses Guest Investigator Programme were recommended for selection, and the Guest Investigators formally joined the Ulysses science team at the last Science Working Team meeting, held at ESTEC in April.
Happily, all continues to go very well with the in-orbit operations of ESA's Infrared Space Observatory (ISO) satellite. The spacecraft, the instruments and the ground segment all continue to perform excellently. Some of ISO's scientific results receiving very detailed attention are its detections of water in many different targets, such as in the giant planets in our solar system, around newly-forming stars, in the envelopes of dying stars, and around the centre of our galaxy.
In early April, the capability of ISO to respond fast to unexpected astronomical events was graphically demonstrated. The Italian-Dutch satellite, BeppoSAX, reported detecting an intense burst of gamma rays - these enigmatic 'Gamma Ray Bursts', lasting only a few tens of seconds, are currently one of astronomy's greatest puzzles as there is no consensus as to what they are. Thus observations as soon as possible after the initial detection are critical. Within 40 hours of notification, ISO was making detailed observations with its camera and photometer of the area around the suspected position.
The second station-keeping (or orbit- correction) manoeuvre was successfully conducted on 14 May at 00.30 UT. A 'burn', lasting 3 minutes and 12 seconds, was made using the hydrazine reaction control system. This altered the satellite's velocity by 0.7 m/s and increased the apogee height by some 20 km. The result is that the eastward drift of the satellite has been stopped and a small westward drift induced. The third (and probably last) manoeuvre is being planned for 11 December 1997.
During this manoeuvre, a second direct measurement was made of the quantity of liquid helium coolant remaining on-board ISO. This is of critical interest as it deter- mines ISO's in-orbit lifetime. The measurement was made by using heaters to inject a precisely-known quantity of heat into the liquid and by measuring the temperature increase. This May measurement gave a remaining mass of 116 kg. Combining the results of the May 1997 and September 1996 measurements yields a best estimate of 10 April 1998 (± 2.5 weeks) for the exhaustion of ISO's liquid helium. This additional lifetime, some 10 months above the required 18, is of great scientific value, not only because of the increase in the number of observations to be made, but specifically because it permits ISO to spend time examining the Taurus/Orion region of the sky, one of the most exciting and violent regions of star birth in our Galaxy.
The Cluster fleet
Following the Science Programme Committee's (SPC) decision on 3 April to approve the Cluster II mission, the prime contract with Dornier Satellitensysteme (D) has been successfully kicked-off. Procure-ment of long-lead items has been initiated and detailed discussion with all subcontractors has started.
The Cluster II mission consists of four identical spacecraft, which will be Iaunched at approximately the same time: the Phoenix spacecraft, built from spares from the original Cluster programme, and three new satellites. At the time of the Cluster II decision, integration of the Phoenix spacecraft had just been completed and it had successfully passed all functional and electromagnetic (EMC) tests. The Phoenix programme was then halted and its environmental test phase will now be held nearer the launch date.
The payload for the original Cluster mission was funded directly by the
Member States. However, as near-term budgets had already been fully committed, the SPC requested the Agency to partially fund the European scientific instruments for Cluster II.
System studies relating to the proposed Soyuz launch for Cluster II are being conducted with the help of the Starsem Consortium. The present baseline is to use the Fregat upper stage, which will have its maiden flight in 1999. The four Cluster spacecraft would be launched in mid-2000 in two pairs on separate launches approximately one month apart.
The ground system (ESOC, JSOC and CSDS) has been put on hold with reduced manpower, in order to maintain some continuity and also to study the new launch scenarios. The build-up of resources needed nearer to the launch is currently being defined with a view to minimising costs.
The XMM satellite
The integration of the spacecraft's structural and thermal model is progressing well. All of the necessary elements have been delivered to Dornier (D). The focal-plane assembly is fully assembled and mated with the upper element of the telescope tube. This complete 'upper module' is now ready to undergo the first alignment and light-tightness tests.
Integration of the Reaction Control System (RCS) pipework at BPD (I) has been completed and the complete subassembly has arrived at Dornier for further integration with the remaining elements of the service module. Deliveries of engineering models at equipment level are continuing.
Acceptance testing of the Attitude and Orbit Control (AOCS) subsystem is in progress at Matra Marconi Space (UK). Integration of the electrical model of the spacecraft is proceeding in parallel at Dornier.
The measured performance of the first two flight mirror modules tested at CSL (B) is very good and confirms the high expecta- tions. The test campaign for the first module is now complete. The second module has been delivered for the RGS experiment flight detector and grating calibration campaign at the Max Planck Institute's Panter facility (D). The ground-segment development work has progressed according to plan and the final Ground Segment Definition/Design Review Board meeting was successfully completed in June.
The redefinition of XMM's orbit has been finalised, with the adoption of a southerly orbit with an inclination of 40°.
The XMM launch contract was formally signed on 16 June.
The spacecraft prime contractor Alenia (I) has been busy preparing for the Detailed Design Review, following lower-level reviews at each subcontractor. The Data Package has been delivered and the review is expected to be completed by early June. The first deliveries of electrical ground-support equipment and software needed early in the programme to support the payload teams have been completed.
The payload teams met key milestones during the reporting period. The contractor for the spectrometer anti-coincidence system has been selected and is expected to meet the required delivery dates. The contract with the Imager prime contractor has been clarified and full development-phase support should now be available, but the payload schedule nevertheless remains tight.
A first round of preliminary studies regarding the Iaunch of Integral on the Proton vehicle has been completed and the results are promising. The technical interfaces between the spacecraft and the launcher have been clarified and the feasibility of a shorter coast phase has been demonstrated.
Definition of the ground segment is progressing. The allocation of specific NASA or European ground stations is still under review, and so the project is proceeding on the basis of generic ground-station performance.
The design phase (Phase-B) started on 3 March with Dornier Satellitensysteme (D) as prime contractor, after agreement had been reached on the contractual aspects of Phase-B and the main development phase (Phase-C/D).
The Invitations to Tender (ITTs) for the first two major procurements at system level were released in May, according to plan (i.e. major subcontractor avionics and platform).
The Experiment Conceptual Design Reviews have been conducted for all instruments, with no major technical problems being identified.
Definition of the ground requirements has started and is progressing according to plan.
Satellite
The Artemis structural model is currently in testing at CASA (E) to verify that the micro-vibration environment of the space-craft is compatible with the requirements of the Silex optical communications terminal.
lntegrated system testing and tests to demonstrate electromagnetic compatibility and robustness to electrostatic discharges have been successfully carried out on the engineering-model spacecraft. Activities using this development model have now been completed.
The flight-model primary structure, fully equipped with the propulsion subsystem, has been delivered by BPD (I) to A!enia Aerospazio in Rome for satellite-level integration activities. The main elements of the S-band/Ka-band data-relay repeater have also been delivered to Alenia by Bosch Telecom (D) and Alcatel Espace (F).
Silex LEO terminal
The Silex LEO terminal has been integrated on Spot-4 for satellite-level testing.
Ground segment
The Design Review for the Artemis operational ground segment has been completed and full development is now underway.
Future strategy
In order to prepare for discussions at the Council Meeting to be held at Ministerial Level in 1998, an ESA Earth Observation Strategy Task Force has been established to reflect on and prepare a strategy for future programmes. It includes representatives of the main European players in Earth Observation. In paraIlel, an Industrial Ad Hoc Working Group will ascertain industry's point of view regarding future Earth-observation programmes. The Strategy Task Force's report will be available in October.
Future programmes
At the Earth Observation Programme Board meeting on 27 May, the eleven countries participating in EOPP Extension 2 agreed to initiate the programme with just a 46.21% level of subscription, as a temporary and exceptional measure. This has allowed some new activities to be initiated, but is not yet sufficient for initiating the Earth Explorer Phase-A studies. The situation will be reviewed in September.
In-house work has been started on the preparation of both the Earth Watch and Earth Explorer Programme elements.
Campaigns
The final EMAC workshop took place on 14 - 16 April and that for POLRAD on 28/29 April. The corresponding workshop for INDREX is in preparation.
Envisat-1 system
The Envisat Mission System Critical Design Review (EMS-CDR) has been conducted successfully, confirming that the design, development and integration plans are compliant with the mission requirements.
Significant progress has been achieved in the definition of the Data Policy. The Announcement of Opportunity for scientific data exploitation and pilot projects is in preparation.
The first meeting for the preparation of the High Level Operations Plan (HLOP) was held in April, with the programme participants represented by their DOSTAG-committee experts.
An Envisat Web site has been established which provides detailed mission information. It is accessible via the ESA Home Page.
Polar Platform (PPF)
The Polar Platform Critical Design Review (PPF-CDR) has been successfully completed within the framework of the Envisat Mission System Critical Design Review (EMS-CDR). The overall develop- ment status is well advanced and generally satisfactory. Few problems were identified and these are currently being resolved.
The spacecraft structural-model activities have been successfully completed . The vibration tests were conducted at ESTEC (NL) using the newly developed HYDRA test facility (longitudinal axes), and the Multi-Shaker (lateral axes). Following final alignment checks, the spacecraft was then shipped back to the prime contractor, Matra Marconi Space (Bristol, UK), where the refurbishment of the Payload Module structure to flight standard has been initiated.
Following its integration at Matra Marconi Space in Toulouse (F), the flight-model Service Module was delivered to Matra Marconi Space in Bristol.
The engineering-model (EM) activities have continued with the mating of the flight-model Service Module with the Payload Module equipped with five EM instruments or breadboard models.
Integration of the flight-model Payload Equipment Bay is continuing at DASA/Dornier (D).
Envisat-1 payload
All engineering-model instruments have been delivered for integration onto the Polar Platform EM payload model, with the exception of MERIS and ASAR. The MERIS EM model is expected to be delivered at the beginning of July, closely followed by the Central Electronic Assembly (CESA) of the ASAR instrument.
Following the EMS-CDR, a number of actions were initiated with industry to fully resolve a few non-compliances. Emphasis is now focussing on flight-model instrument manufacture and testing. A large number of flight-model subassemblies have been delivered and integration of the flight-model instruments has begun.
Envisat-1 ground segment
The Payload Data Segment (PDS) Detailed Design Review was successfully held in parallel with the EMS-CDR. The Flight Operation Segment (FOS) and Payload Data Segment (PDS) development efforts are progressing according to plan.
Simulated payload data have been delivered for the acceptance testing of the PDS front-end and the ASAR processors, which are nearing development completion and factory acceptance testing.
Expert Support Laboratories (ESLs) are assisting the Agency by providing valuable guidance in the PDS processor development. They provide reference test data as well as answering specific PDS contractor questions. MIPAS Level-2 ESL documentation is planned to be delivered in July, allowing the corresponding PDS processor development to be kicked-off.
Turning to the Processing and Archiving Centre (PAC) activities, the development effort for the French PAC (F-PAC) has begun. Finalisation of the Statements of Work for the other PACs is in process.
The Preliminary Design Review (PDR) for the SEVIRI (Scanning Enhanced Visible and Infrared Imager) scanning assembly is still in progress and the SEVIRI scheduling remains on a critical path.
The satellite primary structure for the Structural and Thermal Model (STM) has been delivered to the prime contractor Aérospatiale in Cannes (F), where the various subsystems and equipment items will be integrated during the rest of the year.
The development of the MSG-1 spacecraft and the procurement of MSG-2 and -3 are on schedule, with engineering and thermal/mechanical-model production in progress at equipment and subsystem level. The launch of MSG-1 remains on schedule for October 2000, with MSG-2 to be launched in 2002 and MSG-3 to go into storage in 2003.
As of June, it has proved impossible to achieve the level of subscription for the Metop main development phase (Phase-C/D) needed to allow the release of those advanced activities seen as necessary to preserve the programme cost and schedule objectives. The consequent effects on the programme are critical and its survival is threatened, unless formerly announced subscriptions by Belgium, France, Spain and United Kingdom materialise.
The Metop Phase-C/D Request for Quotation (RFQ) was released in early April. Industry is currently preparing its offer for submission in late summer. In response to the programmatic situation, industry will be entering a hibernation phase as soon as the Phase-C/D offer is complete.
The Meteosat SEVIRI instrument's passive cooler
The Meteosat Transition Programme (MTP) spacecraft has been fully integrated and all the major environmental tests have been completed. The final performance testing has also been completed.
Although a launch date has not yet been confirmed, the spacecraft will be transported to Kourou in early July, allowing a launch between end-August and mid-September.
Once launched, the spacecraft will be operated by Eumetsat to provide the regular weather pictures over Europe which are currently being provided by Meteosat-5, with Meteosat-6 as the in-orbit spare. Both these spacecraft were provided under ESA spacecraft supply contracts.
The extension of ERS operations (Phase-E1) has been approved. Subscriptions still outstanding from Belgium, Italy and Spain threaten full continuation of operations due to insufficient financial coverage.
ERS-2 satellite operations remain stable with continued high availability of payload science data. Uploading of a software patch for the satellite platform, providing improved surveillance and recovery in case of attitude-control anomalies, is imminent. Close monitoring of the gyro package, following the recent unit failure, has shown that the remaining five gyros are stable and that satellite pointing is within requirements. It is anticipated that, based on the evaluation of the remaining gyros, a piloting triplet selected for the next period should allow almost full recovery of the pointing performance that was achieved with the original gyro configuration.
ERS-1 is being maintained as a back-up for ERS-2. ERS-1ís performance, particularly that of the attitude and orbit control, thermal and power subsystems, remains stable. The payload check-out performed in the third week of May showed that instrument functionality is unimpaired.
ERS-1 will be re-activated for special campaigns over Japan and Australia planned for July/August this year.
The International Space Station
Columbus Orbital Facility (COF)
The COF preliminary design phase is nearing completion. Many equipment-level and subsystern-level PDRs have been successfully concluded, and the system PDR is planned for the fourth quarter of this year. The overall configuration
mock-up has been assembled and is being evaluated for subsystem, harness and piping layout, access and maintainability. This mock-up will be put into a neutral-buoyancy facility this summer for crew activity tests. Several equipment breadboards and development models have been completed and are under test. The technical and programmatic aspects of possibly adding an External Payload Accommodation capability to the COF are under study.
Consolidation of the industrial consortium to reflect the final levels of Member State contributions to the Programme has been completed. Rider 1 to the Prime Contract incorporating all amendments has been signed by both parties.
Following a re-assessment of the overall Space Station Assembly Sequence, necessitated mainly by funding problems in Russia, all of the International Partners have participated in a Space Station Control Board (SSCB) to baseline a revised Station Assembly Sequence (up to mid-2002). The sequence of flights thereafter is under detailed multilateral evaluation, with one of the major goals being the launch of COF by the Space Shuttle to the Station in the second half of 2002. The SSCB plans to meet again in September/October to baseline all assembly flights after mid-2002.
In the context of the COF launch barter agreement with NASA, an enabling letter has been signed between ESA and the Italian Space Agency (ASI) giving industry an Authorisation to Proceed with the development of ISS Nodes 2 and 3. Industry has also been authorised to begin the production of extra DMS equipment and to perform sustaining engineering for the NASA Software Verification Facility.
Automated Transfer Vehicle (ATV)
The main development phase (Phase-C/D) Request for Quotation (RFQ) was formally released to the prime contractor Aérospatiale (F) on 19 March, and the Proposal submission is now targeted for early September. The Executive's objective is to present the associated Contract Proposal to the 26 November meeting of the Agency's Industrial Policy Committee (IPC). The Executive plans to extend the current Phase-B2 contract from March to end-November in order to secure the Phase-C/D schedule by starting advanced C/D activities and to ensure industrial team continuity.
In terms of Space Station interfaces, a key event has been the signature of the trilateral decision paper by ESA, RSA and NASA on the ATV's capabilities and mission.
The second ARP demonstration flight has been completed successfully in conjunction with the STS-84 Shuttle mission. Initial indications are that the essential mission objectives have been achieved, but with some data loss occurring in the GPS experiment. This anomaly is under investigation.
Crew Rescue Vehicle/Crew Transfer Vehicle (CRV/CTV)
Lifting-body concept for CRV/CTV
Taking into account the considerable progress made in the definition of the lifting-body CRV/CTV, thanks to excellent cooperation with NASA, a proposal for continuing this cooperative effort through the end of 1998, in parallel with completion of the capsule-type CTV study, has been presented to the Manned Space Programme Board. The latter endorsed reorientation of the on-going CTV studies to accommodate continuation of ESA/NASA cooperation until the end of 1997, with a final decision concerning work in 1998 to be taken in September. The System Requirements Review (SRR) for the CTV capsule concept was successfully completed during April.
Atmospheric Re-entry Demonstrator (ARD)
The ARD qualification effort was success-fully completed in April. The ARD will be kept operational until the launch-preparation activities can be resumed, which is dependent on the final date established for the Ariane-503 launch.
Operations and ground segment
ATV operational and performance data and annual ESA up-/download requirements have been used by NASA/JSC as inputs to a Mixed Fleet Traffic Analysis. The study report, released in April, shows the ATV integrated with all other ISS Fleet resources. Based on this data, a preliminary ATV manifest has been generated as an input to the ESA/RSA implementation arrangements.
A definition study of the COF/ATV Operations Control Functions and Facilities was begun in April, as well as a study related to the definition of the associated ground communications infrastructure.
The following month, the detailed definition study for the COF/ATV Operations Support Functions and Facilities was also kicked-off. Each study will take approximately six months.
Utilisation
Since the finalisation of the Memorandum of Understanding (MOU) with NASA on Early Opportunities on Space Station for Europe and the subsequent issue by ESA last December of the Announcement of Opportunity (AO) for External Payloads to 6000 addressees in all ESA Member States, the Executive has received notifications of interest from about 150 potential proposers.
In the context of the discussions with NASA concerning the pressurised Early Opportunity payloads, it has been agreed to implement the Protein Crystallisation Diagnostic Facility (PCDF) and the Modular Cultivation Facility (MCF) as Express Rack payloads.
Astronauts
The major mission event of late was the participation of ESA Astronaut J.-F. Clervoy in the STS-84 Shuttle mission from 15 to 24 May. This was the first time that an ESA Astronaut had been assigned as Payload Commander aboard a Shuttle docking with the Mir space station. The fact that the experienced Russian Astronaut Elena Kondakova was also a member of the same crew underlined the truly international nature of the STS-84 mission.
Early deliveries
Data Management System for the Russian Service Module (DMS-R)
The Russian Service Module team has requested additional DMS-R software changes. Rather than fully using the DMS-R software system services, they have opted to build these services themselves by reusing significant amounts of software developed for a Russian satellite, in order to safeguard the Service Module schedule.
All qualification- and engineering-model hardware has been manufactured, and the qualification programme is proceeding towards its planned completion by the end of July. Flight-unit manufacture has also been initiated, and the agreed delivery date of August remains feasible.
In view of the new launch date of December 1998 for the Service Module, the engineering support programme, which according to the ESA/RKA Arrangement terminates three months after the US Lab. launch, must now be extended by eight months.
European Robotic Arm (ERA)
The launch delay for the Russian Science and Power Platform (SPP), per Revision C of the Assembly Sequence, is eight months with respect to the current baseline. The consequences of this delay, together with the impact of the earlier change of launch vehicle from Proton to Shuttle are under review with industry, and a revised and consolidated plan for the completion of ERA development will be established during the summer.
At industry level, the manufacture of the subsystem engineering qualification models is progressing, with the first deliveries of hardware to the prime contractor. Assembly of the engineering model will lead to system functional testing by the end of the year, although there remains the potential for some delay due to design changes arising from the new launch configuration.
Laboratory Support Equipment (LSE)
The MELFI (Minus Eighty Degree Co-Laboratory Freezer) Preliminary Design Review (PDR) began in April with NASDA and NASA participating. The PDR kick-off meeting for the Microgravity Science Glovebox (MSG) was held in April at DASA in Bremen (D). The Request for Quotation (RFQ) for the Hexapod main development phase (Phase-C/D) was issued in April. The Invitation to Tender (ITT) for the Cryo-Freezer system has also been issued.
EMIR 1
The sixth and last flight of Biorack took place on the Shuttle mission to Mir from 15 May to 24 May. This STS-84 mission carried the Spacehab module, which contained not only the ESA Biorack but also the ESA MOMO instrument for the investigation of morphological transitions in model substances. Both instruments worked well. The Biorack carried not only the classical cell-biology experiments, but also an experiment on the vestibular biology of small amphibians and fish.
The Biopan, Biobox and FluidPac facilities are being prepared for flight on the Russian Foton 11 and Foton 12 capsules in September 1997 and November 1998, respectively.
Two short-duration sounding-rocket flights yielding 3 min of free-fall conditions are planned in November. The first one, Mini-Texus 5, will carry an experiment with a fluid at the critical point which will be submitted to oscillatory accelerations.The second, a Maser Technology mission, will flight-verify the new Maser service module with a technological experiment provided by CNES for studying the boiling and condensation of ammonia in microgravity.
EMIR 2
In conjunction with the STS-4 launch, negotiations were initiated with the Spacehab Corp. and NASA regarding ESA's participation in a possible additional series of three Spacehab missions to be carried out between 1998 and 2001. Candidate facilities for these flights are the Advanced Gradient Heating Facility (AGHF), the Advanced Protein Crystallisation Facility (APCF), the Morphological Transition in Model Substances (MOMO) facility, the Urine Monitoring System (UMS) and the Facility for Absorption and Surface Tension (FAST).
Discussions have continued with CNES regarding possible ESA participation, focussing on human-physiology research, in CNES missions to Mir scheduled for l998 and 1999.
MFC
The Microgravity Facilities for Columbus Programme was formally started on 1 January (see Bulletin 90, pages 6-20).
It includes the following multi-user facilities: Biolab, Fluid Science Laboratory (FSL), Material Science Laboratory (MSL) and European Physiology Modules (EPM).
The Biolab design phase (Phase-B) was completed in May and the results of the breadboarding have validated the design. The main development phase (Phase-C/D) is planned to start in September/October.
The FSL's Phase-B is in progress and will be completed in September, with its Phase-C/D planned to start in March 1998.
The current MSL Phase-B will be completed by December 1997, and Phase-C/D is planned for the second quarter of 1998. The cooperation with NASA to accommodate the MSL inside the US Lab will be finalised by the end of the year.
The EPM's study phase (Phase-A) will start in October.
Three important milestones in the schedule for the Ariane-502 planning have occurred:
Due to a problem encountered with the liquid-oxygen turbo-pump of the Vulcain engine of the cryogenic main stage destined for Ariane flight 504 (which is identical to the one fitted on 502), it has been decided to replace the complete Vulcain engine with the one intended for the flight 503 launcher. This activity, which will take two weeks, has been incorporated into the detailed launch-campaign planning.
The Ariane-502 launch is currently planned for 30 September.
ESA Bulletin Nr. 91