SMILE (spacecraft)

*Solar wind Magnetosphere Ionosphere Link Explorer*
	Artist's impression of the SMILE spacecraft
Mission type	Magnetospheric mission
Operator	ESA-CAS
Website	cosmos.esa.int/web/smile/links
Mission duration	3 years (nominal)
Spacecraft properties
Manufacturer	Airbus (payload module)
Launch mass	2200 kg
Dry mass	708 kg
Power	850 W
Start of mission
Launch date	Q4 2025 (planned)
Rocket	Vega-C
Launch site	Kourou
Contractor	Arianespace
Orbital parameters
Reference system	Geocentric
Regime	Highly elliptical orbit
Perigee altitude	5,000 km
Apogee altitude	121,182 km
Inclination	70° or 98°
	; Official insignia for the SMILE mission Cosmic Vision ← JUICE PLATO →

Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) is a planned joint venture mission between the European Space Agency and the Chinese Academy of Sciences. SMILE will image for the first time the magnetosphere of the Sun in soft X-rays and UV during up to 40 hours per orbit, improving our understanding of the dynamic interaction between the solar wind and Earth's magnetosphere.^[3]^[4] The prime science questions of the SMILE mission are

What are the fundamental modes of the dayside solar wind/magnetosphere interaction?
What defines the substorm cycle?
How do coronal mass ejection-driven storms arise and what is their relationship to substorms?

As of April 2024, SMILE is expected to launch in late 2025.^[2]

^ Cite error: The named reference SMILE-Overview was invoked but never defined (see the help page).
^ ^a ^b "Smiles all round: Vega-C to launch ESA solar wind mission". ESA. 30 April 2024. Retrieved 27 June 2024.
^ Branduardi-Raymont, G.; Wang, C.; Escoubet, C.P.; et al. (2018). ESA SMILE definition study report (PDF) (Technical report). European Space Agency. pp. 1–84. doi:10.5270/esa.smile.definition_study_report-2018-12. S2CID 239612452. ESA/SCI(2018)1. Archived (PDF) from the original on 22 April 2023.
^ "SMILE: Summary". UCL Mullard Space Science Laboratory. Retrieved 19 December 2018.

[SMILE-Overview-1] Cite error: The named reference SMILE-Overview was invoked but never defined (see the help page).

[esa-20240430-2] "Smiles all round: Vega-C to launch ESA solar wind mission". ESA. 30 April 2024. Retrieved 27 June 2024.

[ESAdefinitionstudyreportSMILE-3] Branduardi-Raymont, G.; Wang, C.; Escoubet, C.P.; et al. (2018). ESA SMILE definition study report (PDF) (Technical report). European Space Agency. pp. 1–84. doi:10.5270/esa.smile.definition_study_report-2018-12. S2CID 239612452. ESA/SCI(2018)1. Archived (PDF) from the original on 22 April 2023.

[smile-mssl-4] "SMILE: Summary". UCL Mullard Space Science Laboratory. Retrieved 19 December 2018.

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