Souvenirs de SohoSouvenirs de Soho

Roger-Maurice BonnetRoger-Maurice Bonnet

Orsay 19 avril 2006Orsay 19 avril 2006

Souvenirs de SohoSouvenirs de Soho

The History of the Soho MissionThe History of the Soho MissionMCE Huber, RM Bonnet, D. Dale, M. Arduini, C. Fröhlich, V. MCE Huber, RM Bonnet, D. Dale, M. Arduini, C. Fröhlich, V. Domingo, 1996, ESA Bulletin 86Domingo, 1996, ESA Bulletin 86

Disco Disco ISO ISO

Science TeamScience Team: : A. Balogh, RM Bonnet, P.Delache,A. Balogh, RM Bonnet, P.Delache,C. Fröhlich, et C. HarveyC. Fröhlich, et C. HarveyESTEC Team: ESTEC Team: D. Wynn-Roberts, V. DomingoD. Wynn-Roberts, V. Domingo

Soho: Rapport de Phase-ASoho: Rapport de Phase-A

Objectifs scientifiques originauxObjectifs scientifiques originaux

Lancement de SohoLancement de Soho

Soho original Model PayloadSoho original Model Payload

Soho original Model PayloadSoho original Model Payload

EITEIT

SumerSumer

Planning prévuPlanning prévu

Sélection de la CU:juin 88. Lancement de Soho: 2 décembre 95

Venise, Juin 1994Venise, Juin 1994

Horizon 2000Horizon 2000

Garmisch-PartenkirchenGarmisch-Partenkirchen

Garmisch-PartenkirchenGarmisch-Partenkirchen

Février 1986: Autorisation de démarrage Février 1986: Autorisation de démarrage par le SPC du STP (Soho-Cluster)par le SPC du STP (Soho-Cluster)

• The Committee was giving scientific priority to the STP (solar-terrestrial physics) The Committee was giving scientific priority to the STP (solar-terrestrial physics) programme and agreed to the inclusion of this in ESA’s scientific programme, thus programme and agreed to the inclusion of this in ESA’s scientific programme, thus starting on implementation of the Horizon 2000 long-term programme.starting on implementation of the Horizon 2000 long-term programme.

• The STP programme should be carried on within the financial constraints The STP programme should be carried on within the financial constraints mentioned at the top of page 22 of ESA/SPC(85)11, i.e. within the limits of a 400 mentioned at the top of page 22 of ESA/SPC(85)11, i.e. within the limits of a 400 MAU envelope (at 1984 economic conditions) plus a contingency margin.MAU envelope (at 1984 economic conditions) plus a contingency margin.

• This decision is not to constitute a precedent for implementing the other This decision is not to constitute a precedent for implementing the other cornerstones which, under the terms of ESA/SPC(85)11, have to be carried out cornerstones which, under the terms of ESA/SPC(85)11, have to be carried out within an overall envelope of 400 MAU at 1984 economic conditions that includes within an overall envelope of 400 MAU at 1984 economic conditions that includes the contingency margin.the contingency margin.

• The STP programme should be carried out on a timetable compatible with an The STP programme should be carried out on a timetable compatible with an optimised and cost-efficient development programme, with the constraints resulting optimised and cost-efficient development programme, with the constraints resulting from the availability of free launches in 1993-1994, and finally with the need not to from the availability of free launches in 1993-1994, and finally with the need not to compromise the start-up of other missions that form part of the Horizon 2000 compromise the start-up of other missions that form part of the Horizon 2000 programme.programme.

• On the basis of the foregoing, the Committee unanimously approved the Director On the basis of the foregoing, the Committee unanimously approved the Director General’s proposal contained in section 3 of ESA/SPC(85)11.General’s proposal contained in section 3 of ESA/SPC(85)11.

De Disco à Soho!De Disco à Soho!

Comment réduire le CaC de 275 MauComment réduire le CaC de 275 Mau

• By November 1987, the complete package of science descoping/rationalisation, By November 1987, the complete package of science descoping/rationalisation, expanded international cooperation, together with the APEX opportunity for Cluster, expanded international cooperation, together with the APEX opportunity for Cluster, offered a real opportunity for cost reductions within STSP, resulting in an estimated offered a real opportunity for cost reductions within STSP, resulting in an estimated cost to ESA of 500 MAU, including launch vehicles: a saving of some 250 MAU! cost to ESA of 500 MAU, including launch vehicles: a saving of some 250 MAU! However, the problem still remained of how to meet the SPC limit of 400 MAU. However, the problem still remained of how to meet the SPC limit of 400 MAU.

• In dialogue with the SPC, it had been concluded that for the particular case of STSP, a In dialogue with the SPC, it had been concluded that for the particular case of STSP, a special Cornerstone target revision from the canonical 400 MAU to 460 MAU (1984 special Cornerstone target revision from the canonical 400 MAU to 460 MAU (1984 economic conditions) could be permitted, but further actions had to be undertaken to economic conditions) could be permitted, but further actions had to be undertaken to identify further reductions below the 500 MAU estimate. identify further reductions below the 500 MAU estimate.

• A very detailed and careful joint review of all project costs and cost-estimating A very detailed and careful joint review of all project costs and cost-estimating history was conducted, and several economies were introduced into the project team history was conducted, and several economies were introduced into the project team (manpower, other ESA facility and manpower costs, together with estimates for the (manpower, other ESA facility and manpower costs, together with estimates for the industrial elements). This resulted by end-1987/ early-1988 in a total STSP estimate industrial elements). This resulted by end-1987/ early-1988 in a total STSP estimate of 484 MAU (1984 economic conditions), compared with the SPC's revised limit of of 484 MAU (1984 economic conditions), compared with the SPC's revised limit of 460 MAU. 460 MAU.

• Working in close co-operation with Industry, the final cost estimate presented to the Working in close co-operation with Industry, the final cost estimate presented to the SPC amounted to 474 MAU, a figure that it found acceptable. The continuous SPC amounted to 474 MAU, a figure that it found acceptable. The continuous pressure on cost initiated in 1986 had resulted in a mission saving to ESA of pressure on cost initiated in 1986 had resulted in a mission saving to ESA of approximately 275 MAU and had provided a practical implementation opportunity for approximately 275 MAU and had provided a practical implementation opportunity for the first Cornerstone of Horizon 2000. the first Cornerstone of Horizon 2000.

EIT versus XIEIT versus XI

EIT versus XI (SPC Mars 88)EIT versus XI (SPC Mars 88)• The French Delegation supported the SSAC recommendation that… The French Delegation supported the SSAC recommendation that…

the payload had to be as intelligent as possible and it was therefore the payload had to be as intelligent as possible and it was therefore out of the question to decide against flying an imager, whether XI or out of the question to decide against flying an imager, whether XI or EIT.EIT.

• The Committee unanimously supported the provision of The Committee unanimously supported the provision of accommodation for an imager on board Soho, and asked the accommodation for an imager on board Soho, and asked the Executive to come back at its June meeting with an assessment of this Executive to come back at its June meeting with an assessment of this instrument’s prospects of being produced. Delegations were invited to instrument’s prospects of being produced. Delegations were invited to provide the Executive with al1 information that could assist it in this provide the Executive with al1 information that could assist it in this task.task.

• Following discussions among the French and German Delegations Following discussions among the French and German Delegations and the Executive , it was agreed that all Member States which and the Executive , it was agreed that all Member States which wanted an imager to be flown would be invited to take part in a wanted an imager to be flown would be invited to take part in a workshop on 15 April 1988. The German Delegation mooted the workshop on 15 April 1988. The German Delegation mooted the possibility of the imager being regarded as a basic instrument of the possibility of the imager being regarded as a basic instrument of the mission and developed under the responsibility of the Space Science mission and developed under the responsibility of the Space Science Department. Department.

Crises de dernières minutes Crises de dernières minutes

• Juin 94: Mama Kaput! XDL choisi en Juin 94: Mama Kaput! XDL choisi en remplacementremplacement

• Juillet 95: Roues à inertie: retard de 6 mois du Juillet 95: Roues à inertie: retard de 6 mois du lancementlancement

Non-conformant MaterialNon-conformant Material

The EOF at GSFCThe EOF at GSFC

The EOF at GSFCThe EOF at GSFC

Héliosismologie: avant et après SohoHéliosismologie: avant et après Soho

TSI : avant et après SohoTSI : avant et après Soho

18 juin 1998: 18 juin 1998:

““Roger, We have a problem…” Roger, We have a problem…” (P. (P. Wenzel, private communication)Wenzel, private communication)