Site: European Space Research and Technology Center (ESTEC)
P.O. Box 299
2200 AG Noordwijk
The Netherlands

Date Visited: June 22, 1992

Report Authors: C. Mahle and J. Pelton



C. Bostian
W. Brandon
V. Chan
M. DeHaemer
R. DePaula
B. Edelson
P. Hager
N. Helm
R. Jennings
C. Mahle
E. Miller
J. Pelton
L. Riley


Edward Ashford

Head, Communications Satellite Dept.

Carl B. von Stieglitz

Advanced Systems and Technology
Program Manager

Pierre Bartholome

Head, Bureau de Bruxelles

Hans-Hermann Fromm

Fixed Communications and Broadcasting
Systems Manager

Manfred Wittig

Communications Payloads Engineer

Bertram Arbesser-Rastburg

Head, Wave Interaction and Propagation Section

Anton Jongejans

Mobile Communications Systems Engineer


Ed Ashford gave an overview of ESTEC's origin and charter. In 1975, the European Space Research Organization (ESRO), which started in 1964 as an organization to launch scientific satellites, and the European Launcher Development Organization (ELDO) merged. At that time the charter was augmented to include application satellites -- in particular, telecommunications and remote sensing satellites. Scientific satellites are still a mandatory part of their "basic" program. Application satellites are "optional," i.e., the member countries do not have to contribute and participate. No military technology or satellites are allowed. The "basic" programs are funded by contributions of all members according to GNP; the optional programs are funded on an ad hoc basis. Other optional programs are earth observation, space transportation (Ariane), space station, and microgravity space plane (HERMES). The distribution of contracts by ESA to industry is by geographic (GNP or ad hoc) rationale; each country is supposed to get its fair share of what it paid in.

Telecommunications satellites launched: 1978: OTS; 1981, 84: Maritime European Communications Satellite (MARECS); 1983, 84, 87, 88: ECS; 1989: OLYMPUS (which started out as L-Sat). As technology matures, programs are taken over by other operating entities. For example, the Inmarsat organization uses MARECS and now funds and operates its second generation Mobile Satellites; EUTELSAT uses ECS and funds EUTELSAT 2 satellites.

ESA headquarters in Paris has 314 people; ESTEC, 1,165 plus about 400 contractors. ESOC (the Operations Center at Darmstadt) has 312 people, ESRIN (Research at Frascati, Italy) 120. The HERMES program employs 57. The total ESA staff is 2,018 people. The Telecom Directorate is headed by Rene Collette, located in Paris, to whom Ed Ashford reports. The ESTEC Directorate, headed by M. Le Fevre, has the largest staff and the most facilities.

Funding is quoted in MAU (million accounting units; the "accounting unit" is equal in value to the ECU at the middle of the previous year). Total ESA funding in 1991: 2,367 MAU (about $2.5 billion U.S. at $1.06 million/MAU). The distribution is space transportation (Ariane) 49.5%, telecom (including DRS) 9.8%, space platform 12.9%, science 10%, earth observation 5.8%, G&A 6.2 + 3.3%, other 2.5%.


ESA takes into account the needs of such entities as Inmarsat and EUTELSAT in its telecom R&D planning. However, no more satellite development is being performed directly on behalf of either EUTELSAT or Inmarsat. ESA is not supposed to compete with industry either in R&D work or testing services. They can do only work authorized by charter. Therefore, no specific major new technologies are being developed on site at ESTEC. Nevertheless, ESTEC initiates, directs and supports (by funding) R&D in the industries of member countries.

The ESTEC mission include studies, development of test hardware and satellites (proof of concept), technical support, and reliability and quality assurance (R&QA). It has a test center equipped with a large thermal-vacuum chamber, solar beam capability,and antenna test facility. ESTEC could integrate a spacecraft, but has not done so. The book value of these facilities (buildings and equipment) was 300 MAU book value in 1991.

ESA's Current and Future Telecom Programs

ESA is currently working on PSDE, ARTEMIS, EMS, and DRS. Future (proposed) programs include Minisat and ARCHIMEDES. The overall Agency long term plans were not approved at the Munich ministerial conference of 1991 and are to be re-considered at another such conference in Spain in the autumn of 1992.

Initially, the PTTs were not interested in using regional satellites in Western Europe. So ESA provided OTS, and let the PTTs play with it. Subsequently, the PTTs ordered five more such communications satellites and eventually formed EUTELSAT. OTS-2 was used until 1991 as a test bed; ESA learned how to "solar sail" for attitude control to save fuel; the spacecraft operated for 12 years. Future programs also are to be used as a "push" to users (start with a demonstration, operate the initial system, then turn the system over to a user-formed operating entity).

In a similar vein, MARECS A (1981) and MARECS B (1984) were leased to Inmarsat (currently in a 5 degrees inclined orbit, at 22 degrees E, MARECS A is still used for demonstrations). The ECS series has four active satellites (1, 2, 4, and 5) launched from 1983 to 1988. All are used by EUTELSAT. ESA will operate them until 1994. ECS-1 is now in inclined orbit.

Initial planning for OLYMPUS started in 1977. It was launched in 1989. (Comment: Big programs seem to take a long time.) It has 14/12 GHz and 30/20 GHz communications channels, two DBS TV channels, and beacons at 12, 20 and 30 GHz. OLYMPUS is currently located at 19 degrees W. Its solar array was designed to supply 7 kW max., and sized for 3.6 kW at end-of-life (EOL); the bus was sized to dissipate a thermal load of 7 kW. The actual OLYMPUS launch mass was 2,432 kg. The spacecraft lost a solar array drive in 1990 and lost attitude control in May 1991. Temperatures went to as low as - 100 degrees centigrade. It was recovered after 50 days, and is now back in operation. Everything but one high power DBS channel (230 W TWT reduced to 180 W before launch) is still in operation. New technology used included 230 W TWTAs and surface tension fuel tanks (in cooperation with a U.S. manufacturer). The micro-g acceleration environment on-board OLYMPUS was also measured. There is no high speed data (2 Mbits/sec) on demand in Europe, except by reservation (very expensive).

New Programs

Telecom Long Term Plan (TLTP). The objective is to develop, test and demonstrate advanced satellite communications systems and technology, new earth stations and support. The proposed budget is 200-300 MAU/year from 1992-2005 (minimum expected is 200 MAU/year). In the latter part of the 1970s, Germany and France partially withdrew from the TLTP program to support their own programs, but after TV-Sat and TDF they rejoined the ESA efforts. The PSDE program is part of TLTP. It comes in six segments (support + studies, payload, experiment and demonstration with existing satellite, industry cooperative phase, to be determined (TBD) OBP/Minisat, TBD ARCHIMEDES).

Present TLTP Projects:

  1. Advanced Relay and Technology Mission (ARTEMIS). Alenia Spazio is the prime contractor. It carries the SILEX package built by MATRA, S- and Ka-band transponders built by Alcatel and Alenia Spazio, and an L-band package built by Alenia Spazio to be used for Land Mobile Satellite Services (LMSS) with spot beams covering Europe. It has electrical propulsion using two types of xenon ion thrusters. ARTEMIS will be launched in the 1995/1996 time frame on an Ariane 5 APEX flight.
  2. European Mobile Satellite (EMS) Package. Alenia Spazio is again prime contractor. It supports L- and Ku-band packages. EMS will fly on ITALSAT F2 at the end of 1994 or early 1995. It will provide 42 dBw over Western Europe, and its coverage extends over a good part of Eastern Europe, as well. EMS is designed to provide service for up to 600 simultaneous voice channels and 75,000 users, Its payload is funded at 53 MAU as part of the second segment of PSDE.
  3. Data Relay Satellite (DRS). Two operational satellites are planned, for geostationary orbit slots at 59 degrees E and 44 degrees W. The DRS will have S-band, Ka-band and GEO-LEO optical ISLs as a complement to ARTEMIS. They will be interoperable with TDRS and ATDRS and DRTS (Japan). The program is funded at 740 MAU, with launches scheduled for 1998 and after 2000. Users will include the polar orbit earth monitor (POEM), COLUMBUS, HERMES and other Western European programs.

    Future TLTP Projects:

  4. Minisat. Minisat will mass about 800 kg, generate about 1 kW DC power and accommodate a 150 to 180 kg payload, possibly the OBP package. The OBP payload would mass about 100 kg, use 600 W and its budget is projected to require 150 MAU. The OBP package is projected to provide seven beams over Europe, working into 1.8 m diameter earth stations. The five-year program includes a master control station and seven traffic sites, with launch in 1996 or later. The Minisat concept projects launches every two to three years in contrast to large programs which can take up to 15 years to reach launch.
  5. ARCHIMEDES (Advanced Research High Inclined Orbit Satellite) HEO. ESA has studied high inclination orbits with 24 hour, 12 hour and n X 8 hour periods, as well as Molnyia orbits. Payload is to be determined. ESA looks for cooperation with NASA and NASDA. Archimedes could possibly share a bus with a Minisat, with a launch date of 1998 or later. Possible users include sound broadcast, mobile, and a navigation payload with GPS overlay. Currently no hardware has been built; only studies have been conducted. Phase A and Phase B studies have been completed and/or are underway. Matra Marconi Space (MMS) came up with the modular satellite concept.
  6. AOTS (launch after 2000). AOTS is yet to be defined. ESA is looking for bus improvements, for instance a robot arm to aid in deployment.

The ASTP Program. ASTP has been running since 1978, with Mr. Stieglitz in charge since 1983. It is divided into four-year segments, the current segment being 1990-1994. It is funded at 200 MAU total, 118 MAU having been contributed since 1990. Program content is FSS and Broadcast 36%, Common Technologies (bus) 20%, Data Relay Services 15%, Mobile, Navigation, Aeronautical service technology 12%, Telematics (Protocols, Ground Data Handling, TT&C) 19%. ESA has placed about 200 related contracts (both hardware developments and studies). The average contract value is 600-700 KAU (minimum 50 KAU to maximum 2.5 MAU). Only Germany has not participated (reason: no money contributed). It is a favorite program for small countries.

ASTP is the basis under which technologies are developed. It is followed by PSDE which is the umbrella for spacecraft and payload development (originally including SILEX). ARTEMIS and DRS were removed from PSDE for political reasons. The detailed work ongoing in elements of ASTP are shown in Table ESTEC.1.

Semiconductor Intersatellite Link Experiment (SILEX). Built by MATRA, SILEX links LEO to GEO at a data rate of 50 Mbits/sec; the return link, GEO to LEO, operates at a maximum rate of 2 Mbits/sec. The first application is to be SPOT-4 which will have an optical PASTEL terminal (OPAL terminal) transmitting to ARTEMIS. The GEO terminal has a beacon for acquisition only. The LEO terminal has a 25 cm diameter telescope and masses 125 kg. LEO terminal development started in early 1991 at MMS. The GEO terminal contract is at the proposal phase. Completion is anticipated in 1995. ESA has tested optical earth stations in the Canary Islands using 10 cm diameter telescopes at 2.4 km altitude at 140 km separations. They have also performed propagation measurements. An optical ground station will also be tested in the Canaries, for GEO terminal check-out. It will use a 1 m diameter telescope.

Table ESTEC.1
Ongoing Work in Elements of ASTP

The GEO beacon beamwidth is 700 mrad, the communications beam 8 mrad. Laser diodes were obtained from SDL. There is up to 300 Hz motion compensation using a control loop and mirror. Coarse pointing is done using two PLL loops of about 3 Hz bandwidth. A third control loop can move the beam for pattern measurements. Acquisition uses a 280 x 280 matrix of charge-coupled devices (CCDs) with a 30 Hz readout rate; tracking uses CCDs in a 14 x 14 matrix with a 1 kHz readout rate. Both are made by Thomson CSF. The microprocessor is a 1,750 Marconi. The package masses 140 kg and draws 250 W max.


The program began in the mid-1980s. The uplink operates at low rates (64 kbits/sec to 2 Mbits/sec using frequency division multiple access [FDMA]); the downlink employs TDMA at 33 Mbits/sec. The earth station will use an antenna about 1 m in diameter and a 10 W HPA. Details were published by Fromm, Bella, and Garofalo in the AIAA 1992 ICSC Proceedings. ESA has developed ASICs under industry contract for the time/time-space-time (T/TST) switch. A breadboard was tested in double loop over a EUTELSAT satellite. The final T stage should be completed by the end of 1992. The development of the demod will then be initiated. The ASICs are being built by SIC Italy and Alcatel.

The ESTEC laboratories were visited in the company of M. Lopriore. They are well equipped. Hardware not developed at ESA is being tested there. They have an array antenna with 32 MIC elements (with phase and amplitude control by external computer) under test. It is not sophisticated. Engineers at ESTEC design MMIC circuits using four European foundries for fabrication. Their compact antenna range is excellent. A 6 m x 10 m reflector built by CASA (Spain) is very accurate. The range has 38 to 40 dB Xpol performance. It is large enough to accommodate entire satellites.


(Roles of EC, ESA and ESTEC)

The EC in Brussels is comprised of 12 countries of which Luxembourg, Portugal,and Greece do not participate in ESA. At the time of the NASA/NSF panel's visit, ESA included Austria, Czechoslovakia, Sweden, and Norway, which are not as yet in the EC, for a total of 13 countries. There is considerable overlap in countries. ESA funding runs about 2.5 billion ECU per year; EC R&D at about 80 billion ECU.

In 1984, EC started to coordinate research and development. Telecommunications research has been coordinated since 1987. At first there was no satellite-related work included by EC. It needed a "push" by ESA and industry (ESA told industry to complain to their governments). The "3rd framework" program, running from 1990 to 1994 contains a few satellite-related topics. The "4th" program (1994-1998) is in planning and will have topics of interest to ESA.

Satellite communication policies were directed toward liberalization of the market in 1987, although the relevant "green paper" had no satellite-specific terms. The "2nd green paper" contained satellite telecommunications provisions, approved in 1990. These mandated:

  1. Space segment provision to be competitive (now PTTs and EUTELSAT are a monopoly). New entrants are likely.
  2. Free access to satellite capacity; full commercial freedom.
  3. Earth segment to be fully liberalized.
  4. Network services to get Pan European licenses. (There is as yet no European equivalent to the FCC, but some national licenses are valid in all other countries.)

ESA and industry organized a working group on satellite communications policy. The PTTs are growing less interested in satellites and more interested in private industry and networks. The EC council talks to the PTTs while ESA talks to industry and tries to form a consensus. ESA functions as de facto space office for the EC and is seen as the interpreter of industry views.

The definition of new R&D programs by ESTEC seems to derive for the most part from their own technical studies rather than from PTTs or Inmarsat, or EUTELSAT. The one attempt at collaboration with Inmarsat, flying an experimental package, was not successful. In short, there are rather limited options for European R&D in satellite communications, namely ESA programs and individual projects of aerospace companies. The European Commission or the European Economic Commission both spend considerable monies on telecommunications-related research, but virtually none in the past on space communications, the overwhelming emphasis being on terrestrial systems.

In general, ESA R&D programs have been successful, with strong, even pivotal impact on the creation of EUTELSAT (OTS and ECS), as well as on Inmarsat's early operations (MARECS). Only the long delayed and politically difficult H-Sat/L-Sat/ OLYMPUS experimental DBS demonstration project has proven to be of limited impact on European communications services. In some respects, OLYMPUS seems to have experienced difficulties parallel to those experienced by the ACTS project in the United States. In both cases one might attribute at least part of the problem to an excessively distant relationship with the relevant industry groups.


As expected, the visit to ESTEC proved to be of critical importance, giving an overview of virtually all ongoing R&D for European satellite communications. Several billion dollars worth of European research in communications is, however, being carried out outside the context of ESA. Within ESTEC's R&D activities, monies are spent through defined programs such as ARTEMIS, SILEX or the technology oriented ASTP program. The PSDE Program seems to have created a flexible multi-year environment for developing technologies in the form of multiple missions or payloads. A full 10% of ESTEC's budget is committed to communications satellite research, in comparison to well under 1% for NASA.

In conclusion, ESA has a well thought out program to foster basic technology, for instance for SSPAs, and to demonstrate new technologies and satellite applications which have a chance of becoming a commercial venture in the long run. One such example is the development of FSS communication satellites, which were turned over to EUTELSAT for commercial operation. An example of new technology demonstration is the OBP program. A multi-phased, multi-year effort is under way to develop first the technology and the system application. It will then be incorporated into a demonstration satellite to show that it works in space and what its use would be if used commercially in an operational system.

Published: July 1993; WTEC Hyper-Librarian