PROBA

{{Short description|European Space Agency satellites from 2001}}

{{Infobox spaceflight

| name = PROBA-1

| names_list = PROBA, PROBA-1

| image =

| image_caption =

| mission_type = Experimental, Earth Observation

| operator = ESA

| website = {{URL|https://www.esa.int/Applications/Observing_the_Earth/Proba-1|Proba-1 applications}}

| COSPAR_ID = 2001-049B

| SATCAT = 26958

| mission_duration = Elapsed: {{time interval|22 October 2001 04:53|show=ymd|sep=,}}

| spacecraft_bus = PROBA

| manufacturer = QinetiQ Space (previously Verhaert Space)

| dry_mass = {{cvt|94|kg|lb}}

| launch_mass = {{cvt|94|kg|lb}}

| dimensions = {{cvt|0.6|x|0.6|x|0.8|m}}

| power = 90{{nbsp}}W

| launch_date = {{start date|2001|10|22|04|53|df=yes||Z}}

| launch_rocket = PSLV C3

| launch_site = Sriharikota FLP

| launch_contractor = ISRO

| disposal_type =

| deactivated =

| last_contact =

| decay_date =

| orbit_epoch = 22 October 2001 00:53:00 UTC

| orbit_reference = Geocentric

| orbit_regime = Sun-synchronous

| orbit_periapsis = {{cvt|553|km|mi}}

| orbit_apoapsis = {{cvt|677|km|mi}}

| orbit_inclination = 97.9 degrees

| orbit_eccentricity = 0.008866

| orbit_period = 97 minutes

| apsis = gee

}}

PROBA (Project for On-Board Autonomy), renamed PROBA-1, is a Belgian satellite technology demonstration mission launched atop an Indian Polar Satellite Launch Vehicle by ISRO on 22 October 2001.{{cite journal |last1=Ramakrishnan |first1=S. |last2=Somanath |first2=S. |last3=Balakrishnan |first3=S. S. |date=January 2002 |title=Multi-Orbit Mission by PSLV-C3 and Future Launch Opportunities |journal=IAF Abstracts |pages=936 |bibcode=2002iaf..confE.936R}}{{cite web |url=http://www.isro.org/pslv-c3/pslv-c3.aspx |title=PSLV-C3 |publisher=ISRO |date=22 October 2001 |archive-url=https://web.archive.org/web/20140325082903/http://www.isro.org/pslv-c3/pslv-c3.aspx |archive-date=25 March 2014 |access-date=25 October 2021 |url-status=dead}} The satellite was funded through the ESA's MicroSat and General Study Program with the objective of addressing issues regarding on-board operational autonomy of a generic satellite platform.{{cite web |url=https://www.esa.int/Applications/Observing_the_Earth/Proba-1/Overview |title=PROBA-1 - Overview |publisher=ESA |date=11 December 2012 |access-date=25 October 2021}}{{Cite web |title=PROBA-1 (Project for On-Board Autonomy - 1) |url=https://www.eoportal.org/satellite-missions/proba-1#proba-1-project-for-on-board-autonomy---1 |access-date=2022-12-28 |website=www.eoportal.org}} This small (60×60×80 cm; 95 kg) boxlike system, with solar panel collectors on its surface, hosts two Earth Observation instruments dubbed CHRIS and HRC. CHRIS is a hyperspectral system (200 narrow bands) that images at 17 m resolution, while HRC is a monochromatic camera that images visible light at 5 m resolution.

With an initial lifetime of one to two years, the satellite celebrated its 20th year of operations in 2021.{{cite web |url=https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Shaping_the_Future/Proba-1_Celebrates_20th_Birthday_In_Orbit |title=Proba-1 Celebrates 20th Birthday In Orbit |publisher=ESA |date=22 October 2021 |access-date=25 October 2021}} On 9 March 2018, it surpassed ERS-2 as ESA's longest operated Earth observation mission of all time.{{cite web |url=https://www.esa.int/Applications/Observing_the_Earth/Proba-1/Proba-1_sets_new_record |title=Proba-1 sets new record |publisher=ESA |date=8 March 2018 |access-date=11 March 2018}} ESA aims to deorbit the satellite through the ClearSpace-1 mission in 2026.{{cite web |last=Werner |first=Debra |url=https://spacenews.com/major-changes-approved-for-clearspace-1-mission/ |title=Major changes approved for ClearSpace-1 mission |work=SpaceNews |date=24 April 2024 |access-date=24 April 2024}}