By Ken Bignell

Following the First World War a new Department of Aeronautics was created at IC in 1920, and, recognising the urgency of gaining expertise in those aspects of meteorology which were relevant to the rapid developments in aviation, the Air Ministry and the College recommended the inclusion of facilities and staff for training in the subject in the Aeronautics Department, then housed at No.1 Lowther Gardens, on the corner of Exhibition Road and Prince Consort Road.

Sir Napier Shaw, FRS, just retiring from the Directorship of the Meteorological Office, was appointed to a (part-time) professorship of Meteorology in the new Department from 1 September 1920, this being the first professorial appointment in the subject in the UK. Space being hard to find in College at the time, accommodation and facilities were made available in the South Kensington section of the Met. Office then housed in the large building on the south-west corner of Exhibition Road and the present-day Imperial College Road. The first (post graduate) course opened in October 1920, staffed by Sir Napier Shaw and his technical assistant Miss E. Austin, and visiting lecturers Mr. D. Brunt from the Met. Office and Mr. C. T. R. Wilson from Cambridge University.

Increasing pressure on space within the Met. Office steadily eroded the accommodation available to IC, and eventually the Office gave notice that the arrangement would be terminated in September 1924. Accordingly an Advisory Committee was set up in late 1923 to advise on the whole matter of Meteorology at IC, particularly the problems of space and finance. The Committee met on 15 November 1923 and recommended that provision for teaching and research should be maintained, at a total annual expenditure of £1250 (something like £100K today?). The report also implied that Meteorology should become a sub-department of Physics, rather than Aero.; but it emerged that space could not be found in Physics. In the event it turned out that Aero were moving into the old RCS building (then known as the Huxley Building) opposite the Science Museum in Exhibition Road , and it was here that Meteorology found its new quarters, though still under the wing of Aeronautics.

In October 1924, Shaw having just retired, Sir Gilbert Walker FRS, who was retiring from a distinguished career in the Indian Meteorological Service , was appointed the new (part-time) head of Meteorology at IC. Walker and one administrative assistant (but no academic assistance) ran the sub-department, teaching a comprehensive course to students from Physics, Aeronautics, and the Meteorological Offices of the UK and India. Together with help from some of his students, Walker continued work started in India on the problem of the Indian Monsoon, extending its scope to the subject of World Weather. He also initiated a series of experimental investigations on the problems of convection in a fluid heated gently from below, and the effects of vertical shear-matters which later became to be of great importance in the interpretation of the evolution of natural clouds.

Walker retired in 1934 and College decided to appoint a full-time professor in Meteorology. Mr. D. Brunt (later Professor Sir David Brunt, FRS) was appointed, and at the same time the sub-department was placed under the wing of Physics, though still housed in the Huxley Building. Academically, however, Meteorology remained a single-handed enterprise until 1939, when, with the approach of war, funds recently granted from the University facilitated the appointment of a Reader, namely, Mr. P. A. Sheppard from the Met Office. At the beginning of the 1938-39 session Meteorology had finally become an independent Department, whilst Brunt and Sheppard enjoyed the services of two visiting lecturers and those of Professor L. W. Pollak from Prague.

A small experimental hut was erected at the College Sports Ground at Harlington for field investigations of the turbulent transfer of heat, momentum and water vapour from the ground to the atmosphere.

At the same time, the University and the Royal Meteorological Society, with the support of the Air Ministry, made a case to the University Grants Committee for the provision of funds to foster the development of Meteorology at IC. These representations were successful to the extent that UGC increased their allocation by £1250 p.a. for research fellowships and technical assistance from the 1939-40 session, together with a non-recurrent grant of £10,000 for the creation of a meteorological laboratory at IC. All these plans were however suspended until after the 1939-45 war; Brunt and Sheppard were seconded to the Air Ministry in September 1939. Brunt returned to College in June 1940, but Sheppard served until 1945 organising a large programme of upper-air observations by radio-sonde and aircraft.

Courses resumed for the 1945-46 session with Brunt and Sheppard teaching the most comprehensive syllabus yet offered for the DIC and MSc programmes. More space became available when Zoology moved out of Huxley, providing space for laboratories and a Library.

In October 1947 Mr. E. G. Jennings was appointed as Chief Technician to set up and develop workshops to support current and planned experimental programmes.

Recruitment agreed in 1939 went ahead apace from 1946. Three appointments were made to new Lectureships; M. K. Miles (appointed Lecturer, October 1946) brought his war-time expertise in synoptic meteorology ; E. T. Eady , an eminent theoretical dynamical meteorologist, (appointed Lecturer, April 1948, then Reader in October 1949) ; B. J. Mason (appointed Lecturer, October 1948), experimental cloud physics.

In October 1949 Miles left, to be replaced by Dr. R. S. Scorer, an outstanding dynamical meteorologist. From October 1949-51, Mr. F. H. Ludlam, a distinguished cloud physicist, was a Leverhulme Research Fellow in the Department, on leave from the Met Office; he was appointed Lecturer in October 1951.

In 1952, Prof. Sir David Brunt retired, and Prof. P. A. Sheppard took over as Head of Department, heralding in a period of rapid expansion. In 1954 Dr. R. M. Goody was appointed Reader in Meteorology, initiating studies of atmospheric radiation. Greatly expanded new facilities at the Silwood Field Station provided a base for infra-red atmospheric spectroscopy and for radar investigations of precipitation from convective storms led by Ludlam.

In 1958 Dr. J. S. A. Green was successively appointed Assistant Lecturer, then Lecturer, who, with Eady and their research students, tackled problems of the amplification of various instabilities in atmospheric motion systems.

In the late 1950’s it was becoming clear that, for periods of a month or more ahead, it would be essential to correctly represent sea-surface temperatures in any future seasonal forecasting efforts, so it was appropriate that the Meteorology Department should have expertise in oceanographic matters. Accordingly, Dr. H. Charnock was appointed Reader in Physical Oceanography in 1958 (only briefly, as it turned out, because Charnock moved on to become Head of the National Institute of Oceanography the following year). These problems were taken up again by Green and his colleagues in the 1970’s and 80’s, by which time much more had been discovered about the vastly complicated dynamics of the oceans.

So it was in the 1960’s that the Met. Dept enjoyed its most buoyant period. Mr. J. R. Probert Jones joined the staff in the early 1960’s, bringing expertise in radar sounding of precipitation. About the same time, Dr. R. P. Pearce was appointed Reader, specialising in theory and numerical modelling of organised convection. Ludlam was appointed to a Personal Professorship in about 1965. The Department enjoyed a succession of short and long-term visits by the world’s most eminent meteorologists, providing valuable stimulus to the visitors and the Department alike.

In the mid-1970’s with the retirement of Sheppard approaching, the College faced a predicament. There were several problems. College was about to vacate the Huxley Building, so the Mathematics and Meteorology Departments would be competing for space in the new W2 Building with the Physics and Computing Departments. At that time small initiatives in meteorology were springing up in several universities, one in particular being the new department at Reading. Advice from the Met Office was that there was not room for two major departments of meteorology in the UK, and it was argued that the Reading department, being conveniently located close to the Met Office in Bracknell and the European Centre for Medium range Forecasts at nearby Shinfield Park, should be the one to survive. Accordingly, College decided that on Sheppard’s retirement the Meteorology Department would cease to exist; and that all its staff and facilities would be re-united with the Physics Department, with the new name ‘Atmospheric Physics Group’. The group would be accommodated on the top floors of the new W2 Building. These changes came about in 1975, marking the end of the pursuit of classical meteorology as an independent subject in Imperial College.

By André Balogh

The research group has been involved in scientific space missions since the early 1960s. It remains very active and has a programme which now stretches to beyond 2030. An overview of the group's involvement in missions over 50 years, from 1960 to 2010, is shown in the figure below. As I have been involved with the group's space programme since 1964, it is appropriate that I should give a brief historical overview.

The beginnings

The predecessor of the present Space and Atmospheric Physics Group, the Cosmic Ray and Space Physics Group, first participated in a space mission in 1962, when members of the group, led by Prof. Harry Elliot, built a cosmic ray detector for the first British scientific satellite, Ariel 1.

Following the establishment of the European Space Research Organisation (ESRO) in 1964, in which Prof. Elliot played a prominent role, the Cosmic Ray Group built three scientific instruments for ESRO's first satellite, ESRO II, launched in 1967. These instruments measured cosmic rays and other energetic particles in near-Earth space. On HEOS-1 (launched in December 1968), the first European spacecraft to venture outside the Earth's magnetosphere, the group again contributed three instruments: one to measure cosmic rays, one to measure energetic particles, and one to measure magnetic fields in space. The Imperial College team involved in that mission was led by Prof. Elliot, and consisted of Bob Hynds (now Head of Imperial College's Computer Centre), Andrew Engel, Peter Hedgecock and André Balogh. The magnetometer on that spacecraft started a long involvement by the group in the measurement of magnetic fields in space.

In 1972, HEOS-2 was launched, again with an Imperial College magnetometer on board, led by Peter Hedgecock. Measurements by the two magnetometers on HEOS-1 and -2 contributed significantly to the mapping of the Earth's magnetosphere, in particular at high latitudes. The results obtained remain of great interest, and the data gathered over 25 years ago have been re-analysed recently by Malcolm Dunlop and Peter Cargill, still yielding new insights into the little understood high latitude region of the magnetosphere. 
 

The energetic particle telescope on the ISEE-3 mission

The next significant mission for us was ISEE-3. This was a NASA mission, launched in 1978 as one of the components of the three-spacecraft International Sun-Earth Explorer mission. Together with the Space Research Institute of Utrecht, the Netherlands, and the Space Science Department of the European Space Agency, we built an instrument to measure the fluxes of energetic particles in interplanetary space, as a function of energy and direction of propagation. The Principal Investigator of this instrument was Bob Hynds, of Imperial College, and the onboard Data Processing Unit was designed by André Balogh.

This spacecraft was the first to be launched to the L1 Lagrangian point in space, between the Earth and the Sun, where their gravitational pulls cancel. This type of orbit (since then succcessfully exploited by the SOHO solar observatory spacecraft) provides a good vantage point for observations in interplanetary space, in front of the Earth. ISEE-3 remained in that orbit for four years, through the maximum of solar activity cycle 21, and the observations of our energetic particle instruments led to studies (by André Balogh and Geza Erdos from Hungary) of the acceleration of 30 to 50 keV particles whith temporal and directional resolutions which remain unsurpassed.

Following this period at the Lagrange point, ISEE-3 was re-targeted to study the Earth's distant magnetospheric tail. Our particle instrument made the first observations of hot plasma bubbles ("plasmoids") being ejected down the magnetotail as a result of magnetospheric substorms. These studies were carried out by Stan Cowley and his students.

The third phase of the ISEE-3 mission was very spectacular. In 1983 the spacecraft was redirected, via a very close lunar flyby, to encounter the comet Giacobini-Zinner in September 1984. This was the first ever flyby of a comet by a spacecraft, but as there were no imaging instruments in the payload, no photos could be taken. However, the interaction of the comet with the solar wind was extensively studied, in particular by the ingenious use of our energetic particle telescope which was discovered to respond to cometary ions ! This work was also largely led by Stan Cowley. 
 

Ulysses: exploration of the heliosphere in 3D

In 1977, even before ISEE-3 was launched, the group initiated its participation in the joint ESA-NASA Out-of-Ecliptic mission which first became ISPM (International Solar Polar Mission) and was finally renamed the Ulysses mission. The Ulysses spacecraft was eventually launched in October 1990, onboard the Space Shuttle Discovery. Ulysses was first targeted to fly by Jupiter, to use the giant planet's gravitational force to place the spacecraft into a nearly polar orbit around the Sun. This mission has become phenomenally successful. The observations that it made in its first complete orbit around the Sun, under conditions of solar minimum activity, have already revolutionised our understanding of the heliosphere. In the next years, it will revisit the polar regions of the Sun under conditions of solar maximum activity. We expect an equally revolutionary view of the heliosphere at solar maximum to emerge from the observations of Ulysses in 1999-2001.

Our group leads the Magnetic Field Investigation on the Ulysses mission (Principal Investigator: André Balogh since 1984, before that, it was Peter Hedgecock). We provided the Fluxgate Magnetometer and the Data Processing Unit for that instrument, while our colleagues at the Jet Propulsion Laboratory (Lead Investigator: Ed Smith) provided the excellent Vector Helium Magnetometer sensor to measure accurately the very small magnetic fields in space, at large distances from the Sun. At Imperial College, much of the instrument was built by Trevor Beek; since launch, Bob Forsyth has played a central role in the analysis of the Ulysses magnetometer observations. At present, Geraint Jones looks after the Ulysses magnetometer data at Imperial College.  More details on the results of the magnetic field investigation can be found on the group's Ulysses pages and in the extensive publication list.

We also provided an energetic particle detector, called the Anisotropy Telecope (Imperial College Lead Investigators: Bob Hynds and André Balogh) to the group of cosmic ray and energetic particle detectors (COSPIN, Principal Investigator: Bruce McKibben of the University of Chicago, since 1996, previous to that the Principal Investigator was John Simpson).  Data from this instrument has been used extensively to study the flows of energetic particles in the jovian magnetosphere during the epoch of the Ulysses Jupiter flyby in February 1992 by Stan Cowely and his students. Work in progress now concentrates on the study of energetic particle fluxes associated with the recent increases in solar activity (André Balogh and Silvia Dalla).

Overall, Ulysses has been our most successful space mission to date, when measured by the number of scientific papers published by members of the group (over 200 papers), or by the number of students who have obtained their PhDs working on the Ulysses data. Tim Horbury (PhD 1996) won the Royal Astronomical Society's Blackwell Prize for the best thesis in his year, on the study of turbulence in the heliospheric medium. 
  
 

Cluster: magnetospheric processes and boundaries in 3D

The four-spacecraft Cluster mission of the European Space Agency has been called Europe's space fleet to the magnetosphere.  This mission concept arose from the need to determine the temporal and spatial aspects of small scale magnetospheric plasma processes and boundaries.  Simultaneous measurements at a minimum of four points are needed for this objective, a point recognised very early by Prof. Jim Dungey of Imperial College who proposed such a mission concept to ESRO in the mid 1960s (but he had called it  a "bunch").  The Space Physics Section (headed by Jim Dungey until 1983) of the old Cosmic Ray Group had a great deal of theoretical interest in magnetospheric phenomena; Jim Dungey's estwhile students, David Southwood (who became the Head of the new Space Physics Group in 1984) and Stan Cowley became very interested in the Cluster mission when ESA began seriosly considering it in the early 1980.  Their interests, allied with André Balogh's experimental interests in space magnetometry, naturally led to a proposal to undertake the Magnetic Field Investigation on Cluster.

A large international scientific team was gathered, including all the major research groups in Europe and in the USA with an interest in magnetic fields in space. The proposal was selected by ESA, with André Balogh as Principal Investigator. The Technical Manager was Ray Carvell; on his departure to Oxford, John Thomlinson became the Technical Manager, who then remained largely responsible for the FGM instrument (as the magnetic field investigation became known) until the launch disaster in 1996. The FGM technical team in Imperial College incuded, under John Thomlinson's leadership, Trevor Beek, Chris Carr, Ed Serpell and Bryan Wingfield. A considerable amount of scientific preparatory work, including the development of four-spacecraft data analysis tools and of in-flight calibration techniques, was undertaken mostly by Malcolm Dunlop.

After building breadboards, prototypes, Engineering Models, we built and delivered five sets of Flight Models of the FGM instrument for the four Cluster spacecraft in the period 1992-1994. This was a busy time for the Cluster team, building, testing and calibrating the FGM instruments, as well as taking part in the spacecraft integration ansd tests. Finally, in mid-1995, all four spacecraft were ready for launch and shipped to Kourou, French Guyana, to await the first test launch of Ariane-5.

The launch took place on 4 June 1996. We all remember that date only too well, as to our horror the launcher blew up some 40 seconds after lift-off. John Thomlinson and I watched, in the company of many other Cluster scientists and engineers, our work and plans blown out of the sky and scattered over the swamps of French Guyana, due to what turned out to be a stupid software error in the guidance control computer of Ariane-5. (See the Ariane 5 Failure Report.)

The explosion of the first Ariane-5 launch vehicle, and the destruction of the first Cluster mission: this is what happens when management shortcuts impose less than adequate testing of software !

Following the destruction of the four Cluster spacecraft in the explosion of Ariane-5, plans to rebuild the mission were immediately put forward to ESA. To cut a very long and nerve-racking story short, exactly 10 months after the distaster, ESA and the national agencies funding Cluster agreed to rebuild three spacecraft and refurbish a fourth one to make up the essential complement of four identical Cluster spacecraft. These, making up the Cluster-II mission, were launched in July-August 2000, onboard two Russian Soyouz launchers from Baykonur, Kazakhstan.