Research and Applications Objectives

This AO is directed at research and applications in all areas that can benefit from the mission opportunity described in the previous section, in particular:

• Space Science

• Earth Observation

• Space Technology

• Radiation Biology and Exobiology

The above list of disciplines should not be considered exhaustive. Other fields of research or applications (e.g. physical experiments in microgravity) that can benefit from the space-environment exposure offered for external payloads through this AO will be considered, and no discipline will be favoured a priori.

Space Science

When preparing ESA's Horizon 2000 Programme, the Survey Committee addressed the possible use of the Space Station as a complement to the free-flying missions, to take advantage of the unique potential offered by the Station's external payload accommodation sites, which could include:

• Long-term monitoring of known astronomical sources over a wide spectral range (UV/X-rays/gamma-ray burst sources). Such observa-tions could be carried out with small multipurpose telescopes, which could also be used to observe targets of opportunity.

• Continuous space-based measurements of the solar total and spectral irradiance from the ultraviolet to the infrared. The International Astronomical Union (IAU) is strongly encouraging such an activity, which could be carried out by an international set of instruments dedicated to these measurements in the various wavelength bands.

• Continuous monitoring of the Space Station environment with the aim of studying the distribution of natural particles and artificial debris.

• Validation and qualification of enabling technologies for next-generation high- energy-astrophysics instrumentation.

In preparation for this AO a set of solar-physics experiments previously flown on Spacelab and Eureca has been analysed with respect to accommodation onboard the Space Station. It has been demonstrated that such a set of instruments, when placed on a suitable pointing device (described in more detail in the Technical Annex (Ref. 1), can maintain the necessary orientation towards the Sun for at least 15 minutes per orbit.

In this Early Utilisation phase, it is intended to make maximum use of instruments that have been flown before and would require only limited refurbishment and adaptation to allow their accommodation on the Express Pallets and interfacing with the operations infrastructure.

In addition, new instruments in planning or under development for other missions (e.g. spares of SOHO experiments) can be considered, provided they are adequately supported by national funding.

In order to benefit from truly international developments, co- operation with scientists from the International Partner countries - the USA, Canada, Japan and Russia - is strongly encouraged.

The ESA point of contact for the Space Science domain for this AO is:

Mr H. Olthof
ESTEC, PU
Keplerlaan 1
NL-2200 AG Noordwijk
The Netherlands

Earth Observation

General Objectives

The Agency has identified four main underlying objectives for its Earth Observation Programme, contributing to:

• The study and monitoring of the Earth's climate and environment on various scales, from local or regional to global.

• The monitoring and management of the Earth's resources, both renewable and non-renewable.

• The continuation and improvement of the service provided to the worldwide operational meteorology community.

• Furtherance of our contribution to the understanding of the structure and dynamics of the Earth's crust and interior.

Together, these objectives span all four of the primary Earth Observation research and application areas, i.e. atmosphere, land, ocean/ice and geodesy/geophysics. There is also a fifth objective, namely the initiation and consolidation of services for application communities with emerging needs for Earth Observation space data, which focusses specifically on applications.

Based on a set of candidate mission profiles addressing Earth Observation user requirements beyond the year 2000, two general classes of Earth Observation mission have been identified:

Earth Explorer Missions - these are research/demonstration missions with the emphasis on advancing understanding of the different Earth-system processes. The demonstration of new observing techniques would also fall within this category.

Earth Watch Missions - these are pre- operational missions addressing the requirements of specific Earth Observation application areas. Responsibility for this type of mission would eventually be transferred to operational (European) entities and the private sector. To ensure such a scenario, data continuity over a period of at least ten years would be required.

Nine Earth Explorer missions have been identified which combine to address research requirements for the post-2000 era: a gravity-field and steady-state ocean-circulation mission, an Earth-radiation mission, a land-surface processes and interactions mission, an atmospheric-dynamics mission, a chemistry mission, a magnetometery mission, a precipitation mission, an atmospheric profiling mission and a topographic mission. Four of these have been selected for Phase-A study.

In parallel, five candidate Earth Watch missions are being investigated, in addition to the existing collaboration with EUMETSAT: coastal zones, ice monitoring, land surface, atmospheric chemistry and open oceans.

Suitable Candidates for ISS

The mainstay of ESA's Earth Observation Programme is a series of Sun- synchronous polar missions and there is little point in looking to non-Sun-synchronous missions to duplicate what has already been well-covered by these missions (or by Meteosat and Meteosat Second Generation). However, there are areas where non-Sun- synchronous missions have the potential to make unique contributions to ESA's Earth Observation Programme, particularly vis-a-vis low-latitude processes that are dependent on the diurnal cycle. Four of the most important topics in this respect are:

• atmospheric-oceanic dynamics

• thermodynamics of the lower latitudes

• Earth's radiation balance at lower latitudes

• chemistry of the lower latitudes.

In each case, the processes involved include, to varying degrees, a component of the diurnal cycle. Instruments capable of measuring the necessary parameters (radiation balance, precipitation and wind field) to address the climate objectives could also, in many instances, make significant contributions to operational meteorology, which also suffers from a shortage of data from these regions, particularly over the oceans.

Importantly, the range of latitudes overflown by the International Space Station contains some of the most volcanically and seismically active areas of the globe, as well as most of the mapped magnetic anomalies. Investigations at such latitudes could therefore prove to be of great importance to such research disciplines as vulcanology, seismology, tectono-physics and geodesy. Candidate instruments for the Space Station include those for the observation and monitoring of volcanic ash-plumes, volcanic thermal budgets, moving lava flows, seismic deformations, etc.

A key attribute of the International Space Station is the potential for in-orbit servicing, repair, upgrading and replenishment, as well as retrieval, making it well-suited to the development and validation of new concepts, techniques and technologies.

Potential candidate experiments therefore include:

• technological or conceptual experiments intended to pave the way for later missions

• tests of new calibration techniques.

Reflight of existing Earth-Observation instruments from previous missions might also be envisaged for this AO, particularly in view of the tight schedule constraints.

Possibilities for International Cooperation

In addition to proposing self-standing European experiments, there is considerable interest in joint collaborative experiments, especially where international collaboration could provide the means to realise an experiment which might otherwise be prohibitively expensive. One such potential experiment is a Doppler Wind Lidar for observing winds three-dimensionally in the troposphere, a large and expensive instrument with very exacting resource needs in terms of viewing requirements and data transmission. Challenges of this type are unlikely to be met without the active support and cooperation of our International Partners.

The ESA point of contact for the Earth Observation domain for this AO is:

Mr C. Readings
ESTEC, VR
Keplerlaan 1
NL-2200 AG Noordwijk
The Netherlands

Space Technology

Objectives

The main objectives of the European Technology R&D Programmes are to:

• ensure effective technological preparation for Europe's future space programmes through the development of critical technologies, first by demonstrating feasibility and then by demonstrating flight suitability for specific future missions

• advance the state-of-the-art of technology and enhance the competi-tiveness of European industry in space systems.

Such demonstrations are an essential prerequisite for programmes to be able to include advanced technologies with an acceptable degree of risk.

In this context, ESA invites the technology community to propose experiments for the International Space Station falling into three categories:

(i) In-Orbit Validation of New Technologies
This category includes, but is not limited to, experiments in the following technology domains:

• power and energy conversion

• thermal control and life support

• structures, mechanisms and pyrotechnics

• propulsion

• antennas, electromagnetic effects

• spacecraft control and data systems

• robotics and automation

• instrument technology

• micro/nano-technologies for space

• space communication technologies.

The Space Station is a well-suited in-orbit test-bed for the development to maturity of these technologies and their routine application in follow-on projects, offering substantial resources over an extended period in space and allowing experiments to be returned to Earth.

(ii) Space Materials, Coatings, and Environmental Effects
This category includes new materials and coatings for long- duration exposure in Low Earth Orbit (LEO). It would also include experiments addressing propulsion contamination, the synergistic effects of combined exposure to atomic oxygen, radiation and thermal environments, micro-meteoroid and debris detection, radiation monitoring and electrostatic-discharge- phenomena investigations.

(iii) Space Engineering Data Acquisition
This category typically includes experiments aimed at validating mathematical models, component testing, and the in-orbit calibration of new instruments and detectors.

Space Technology Proposal Evaluation and Selection

Space Technology proposals received in response to this AO will be evaluated by Technical Review Boards. Those proposals considered to have the greatest technical merit and application relevance will be further reviewed for engineering compatibility and compliance with the available Space Station accommodation. Based on these reviews, and taking into account the recommendations of an external Assessment Board, a prioritised list of technology experiments to be endorsed by its Industrial Policy Committee (IPC) will be established.

The ESA Technical Directorate will organise the evaluation of technology experiments proposed, respecting the confidentiality of the information contained in the proposals and protecting ownership of the ideas proposed. The proposals will be evaluated and selections made on the basis of the criteria defined in Section Evaluation Criteria.

In addition, the following criteria will apply for the two categories of technology users:

Category I: 'Industrial Users', who rely on their own R&:D funding for developing and qualifying their experiments

Selection criteria:

• Evidence that the space product has a market.

• Evidence that the flight demonstration will lead to an increased reliability, or an increased performance of the space product, or will make the product more readily available on the market.

• Compatibility of the flight- demonstration schedule with the application opportunities.

Category II: 'ESA and National Users Experiments', who rely on ESA and National Agency R&D funding for developing and qualifying their experiments

Selection criteria:

• The experiments address a technology that supports a European space programme or the industry's global competitiveness.

• Confidence that the validation of the system in orbit significantly reduces the risk associated with the technology's application.

• Compatibility of the flight-demonstration schedule with the application opportunities.

The ESA point of contact for the Space Technology domain for this AO is:

Mr R. Aceti
ESTEC, FTD
Keplerlaan 1
NL-2200 AG Noordwijk
The Netherlands

Radiation Biology and Exobiology

Radiation Biology and Radiation Dosimetry

It has been recognised that it is highly desirable to perform a quantitative, as well as a qualitative, assessment of the radiation hazards to human beings in space, especially in view of the planned long-term stays aboard the International Space Station. This could include:

• Mapping of the radiation environment in space and its variation with time and orbital parameters, such as solar cycle, solar-flare events, inclination and altitude.

• Study of the modification of the radiation dose in space by mass shielding, leading to attenuation, buildup and/or activation.

• Study of the depth dose distribution of the radiation dose in a human body in space, e.g. during EVA. Emphasis will be put on the radiation exposure of critical organs, e.g. brain, gonads, bone marrow.

• Study of biological responses to the complex radiation environment in space and to the different components of the cosmic radiation field, such as protons, HZE particles and nuclear disintegration events.

• Study of the mechanisms of radiation damage in tissues, cells and sub-cellular systems.

• Study of the biological repair mechanisms for radiation damage.

Instruments that have been flown on previous missions on external platforms may be envisaged for reflight. For the studies of the effects of single HZE particles of cosmic radiation on dormant biological forms, e.g. spores and seeds, the BIOSTACK is a very suitable facility. As a new development, the construction of a human phantom, MATROSHKA, as part of the SEBA is planned, which will allow the depth dose distribution at the sites of critical organs to be determined. International cooperation with scientists from International Space Station Partner countries is encouraged.

Exobiology

The primary goal of the exobiological research is to achieve a better understanding of the processes leading to the origin, evolution and distribution of life in the cosmos. The following main objectives have been identified as being appropriate to exobiological studies conducted in Earth orbit:

• Study of the probabilities and limitations for life to be distributed among the bodies of our Solar System. Recent discoveries, e.g. on the Martian meteorite ALH84001, have provided new support to the idea of interplanetary transfer of rocks containing potential evidence of life. Emphasis will be placed on long-term studies of the responses of selected biological systems to the space environment (vacuum, solar radiation, cosmic rays, microgravity, extreme temperature) or selected parameters thereof.

• Study of the photochemical processing of organics in space. Emphasis will be placed on the study of the reactivity of simple organic molecules, e.g. in a simulated cometary environment, the stability of amino acids associated with minerals, and the simulation of organo-chemical processes in planetary atmospheres or the interplanetary/interstellar medium. The studies will contribute to the understanding of the relevance of extraterrestrial organic molecules to the emergence of life.

• Study of photo- biochemical/photo-biological processes in the simulated radiation environment climate of planets (e.g. early Earth, Mars, role of the ozone layer in protecting a biosphere).

• Collection of cosmic dust in a non-destructive mode to allow its mineralogical, chemical and isotopic analysis upon return to Earth. Of special importance to exobiology will be information on the distribution and behaviour of biogenic elements (C, H, O, N) and the identification of biological organic molecules.

Instruments that have flown on previous missions on external platforms may be envisaged for reflights. Photo-biological/photo- biochemical experiments require a suitable Sun-pointing device. Based on the ERA (Exobiology and Radiation Assembly) of Eureca, an exposure unit EXPOSE is planned to be developed as part of the Space Exposure Biological Assembly (SEBA) described below, which will allow samples to be exposed to solar ultraviolet irradiation in defined spectral ranges for defined periods under controlled environmental conditions (temperature, gas environment).

Proposers from different disciplines, which apart from biology could include astrophysics, planetary research, organic chemistry and paleontology, are encouraged to cooperate with scientists from International Space Station Partner countries, such as the USA, Japan, Canada and Russia.

SEBA

Figure 7. Conceptual SEBA layout and accomodation

ESA intends to develop a Space Exposure Biological Assembly (SEBA), as a new multi-user facility for space experiments in the fields of exobiology, chemical evolution, radiation biology and radiation dosimetry, SEBA consists of two dedicated experimental units:

(i) EXPOSE, which is a tray with environment-controlled compartments for photo-biological/photo-processing studies and which is mounted on a pointing device to the Sun

(ii) MATROSHKA, which is a tissue-equivalent phantom of the upper part of the human body for studies of the depth dose distribution of cosmic radiation, e.g. during EVA.

In addition, provisions for add-on experiments are foreseen.

SEBA is planned to be attached to a zenith-oriented Express Pallet on the International Space Station.

Researchers who would like their samples to be accommodated on SEBA should consult the more detailed description of this facility given in Reference 3.

The ESA point of contact for SEBA is:

Mr H. König
ESTEC, MSM-GP
Keplerlaan 1
NL-2200 AG Noordwijk
The Netherlands