ALTIUS

{{Short description|Satellite}}

{{Infobox spaceflight

| name = ALTIUS

| names_list =

| image = ALTIUS mission logo.png

| image_caption = ALTIUS BISA logo

| image_alt = ALTIUS logotype

| image_size =

| mission_type = Earth Observation

| operator = European Space Agency

| Harvard_designation =

| COSPAR_ID =

| SATCAT =

| website = https://www.esa.int/Applications/Observing_the_Earth/Altius

| mission_duration = >3 years (design lifetime)

| distance_travelled =

| orbits_completed =

| suborbital_range =

| suborbital_apogee =

| spacecraft = ALTIUS

| spacecraft_type =

| spacecraft_bus = PROBA

| manufacturer = QinetiQ Space

| launch_mass = {{convert|266|kg}}{{cite web |url=https://www.esa.int/Applications/Observing_the_Earth/Altius |title=Altius |publisher=ESA |access-date=10 November 2021}}

| BOL_mass =

| landing_mass =

| dry_mass = {{convert|254|kg}}

| payload_mass =

| dimensions =

| power =

| launch_date = {{start-date|2026}} (planned){{cite web |url=https://www.esa.int/Applications/Observing_the_Earth/Altius |title=ALTIUS - ESA's ozone mission |access-date=4 May 2024 |work=ESA}}

| launch_rocket = Vega-C

| launch_site = Kourou ELV

| launch_contractor = Arianespace

| deployment_from =

| deployment_date =

| entered_service =

| disposal_type =

| declared =

| deactivated =

| destroyed =

| last_contact =

| recovery_by =

| recovery_date =

| decay_date =

| landing_date =

| landing_site =

| orbit_reference = Sun-synchronous orbit

| orbit_regime = Low Earth

| orbit_longitude =

| orbit_slot =

| orbit_semimajor =

| orbit_eccentricity =

| orbit_altitude = ≈668 km

| orbit_periapsis =

| orbit_apoapsis =

| orbit_inclination =

| orbit_period =

| orbit_RAAN =

| orbit_arg_periapsis =

| orbit_mean_anomaly =

| orbit_mean_motion =

| orbit_repeat = 3 days

| orbit_velocity =

| orbit_epoch =

| orbit_rev_number =

| apsis =

| instrument_type = payload

| telescope_name = ALTIUS instrument

| telescope_type = Multi-channel tuneable spectral imager

| telescope_diameter =

| telescope_focal_length =

| telescope_area =

| telescope_wavelength = UV: 250-355 nm (tuneable)
VIS: 440-675 nm (tuneable)
NIR 600-1020 nm (tuneable)

| telescope_resolution = 1 to 3 km (vertically)

| instruments =

| programme =

| previous_mission =

| next_mission =

| insignia = ALTIUS mission patch.png

| insignia_caption = ALTIUS mission logo

| insignia_alt = ALTIUS mission patch

| insignia_size =

}}

ALTIUS (Atmospheric Limb Tracker for Investigation of the Upcoming Stratosphere) is a satellite mission proposed by the Belgian Institute for Space Aeronomy and currently under development by the European Space Agency.{{cite journal |last1=Fussen |first1=Didier |last2=Dekemper |first2=Emmanuel |last3=Errera |first3=Quentin |last4=Franssens |first4=Ghislain |last5=Mateshvili |first5=Nina |last6=Pieroux |first6=Didier |last7=Vanhellemont |first7=Filip |date=3 August 2016 |title=The ALTIUS Mission |journal=Atmospheric Measurement Techniques Discussions |pages=1–40 |doi=10.5194/amt-2016-213 |doi-access=free}}{{cite web |url=https://events.oma.be/indico/event/20/page/0 |title=First ALTIUS Symposium |date=2017-05-02 |website=Space Pole Events |publisher=Belgian Institute for Space Aeronomy |access-date=11 June 2018 |archive-date=2018-06-12 |archive-url=https://web.archive.org/web/20180612141219/https://events.oma.be/indico/event/20/page/0}}{{cite web |url=https://www.esa.int/About_Us/Ministerial_Council_2016/Earth_Observation_Programmes |title=Earth Observation Programmes |date=2016 |website=ESA Ministerial Council 2016 |publisher=European Space Agency |access-date=11 June 2018 |quote=ALTIUS: Develop and operate a small mission dedicated to the operational monitoring of stratospheric ozone profiles.}}

Its main objective is to monitor the distribution and evolution of stratospheric ozone in the Earth's atmosphere. The industrial consortium is led by QinetiQ Space, acting as mission prime.{{cite web |last=Henry |first=Caleb |url=https://spacenews.com/qinetiq-to-build-ozone-monitoring-satellite-for-european-space-agency/ |title=QinetiQ to build ozone-monitoring satellite for European Space Agency |work=SpaceNews |date=27 January 2020 |access-date=27 January 2020}} The satellite design is based on the PROBA small satellite bus. The payload, developed by OIP Sensor Systems, is an innovative UV, visible and NIR instrument.{{cite web |url=http://www.oip.be/en/detail_66.aspx |title=ALTIUS |website=OIP Sensor Systems |access-date=11 June 2018 |archive-date=2018-06-12 |archive-url=https://web.archive.org/web/20180612140923/http://www.oip.be/en/detail_66.aspx}}

The mission is scheduled for launch in 2026 from the Guiana Space Centre on Vega-C together with another Earth-observing satellite, FLEX.{{Cite web |title=Ride into space on Vega-C secured for FLEX and Altius |url=https://www.esa.int/Applications/Observing_the_Earth/FutureEO/FLEX/Ride_into_space_on_Vega-C_secured_for_FLEX_and_Altius |access-date=2025-03-03 |website=www.esa.int |language=en}}