The MANTRA effort were a series of balloon flights performed over Canada between 1998 and 2004 to investigate changes in the concentrations of northern hemisphere mid-latitude stratospheric ozone, and of nitrogen and chlorine compounds that play a role in ozone chemistry.

Each mission carried several instruments in a single gondola to measure vertical concentration profiles of stratospheric trace gases, and made observations from a float altitude of about 35 km for one day. Several of these instruments were flown between 15 and 20 years before MANTRA and thus provided a link to historical data predating the onset of mid-latitude ozone loss.

The MANTRA mission was a collaborative effort between scientists in the Atmospheric Physics Group at the University of Toronto, the Meteorological Service of Canada, York University, the University of Waterloo, the University of Denver, and the Service d'Aeronomie of the Centre National de la Recherche from France.

All MANTRA flights were supported by the Canadian Space Agency ,under the First and Second Small Payloads Programs, and by the Meteorological Service of Canada. In addition, MANTRA 1998 received support from the Centre for Research in Earth and Space Technology, while MANTRA 2002/2004 missions were also supported by the Natural Sciences and Engineering Research Council of Canada.

Payload and launch support was provided by Scientific Instrumentation Limited (SIL) of Saskatoon, which performed all the missions from its balloon launch facility in rural Vanscoy, Saskatchewan.

The first balloon of the program which was launched in August 24th 1998, represented the first Canadian launch of a large high-altitude balloon in approximately fifteen years. Although not all of the instruments worked as intended, a useful dataset was collected. Also that mission received extensive coverage by Canadian and European media due to the fact that the balloon failed to terminate its mission and drifted across the Atlantic and the Arctic before landing in the Åland Islands, Finland, in the middle of the Baltic Sea, after a trip of near 9000 km along 9 days.

The following missions were performed succesfuly from that same site every two years achieving in August 29th 2000 a flight enduring 14 hours, on September 3rd 2002 with a duration of 18 hours, and in September 1st 2004, the last flight of the program with a duration of 13 hours. A fifth mission was intended on September 14th, 2004 but shortly after launch both termination systems fired prematurely and the flight was terminated.

More than 25 papers were published with the data obtained from the flights.

Launch base	Date	Flight Duration	Experiment	Payload landing place or cause of the failure
Vanscoy (SK)	8/24/1998	9 d	MANTRA (Middle Atmosphere Nitrogen TRend Assesment)	Near Mariehamn on the Aland Islands, located at Baltic Sea, Finland
Vanscoy (SK)	8/29/2000	14 h	MANTRA (Middle Atmosphere Nitrogen TRend Assesment)	East of Nipawin provincial Park, about 280 km northeast of the launch base.
Vanscoy (SK)	9/3/2002	18 h	MANTRA (Middle Atmosphere Nitrogen TRend Assesment)	At 52.276°N latitude, 100.208°W longitude, near Duck Bay in Lake Winnipegosis, Manitoba province.
Vanscoy (SK)	9/1/2004	13 h	MANTRA (Middle Atmosphere Nitrogen TRend Assesment)	At 51°33.85'N, 108° 7.5'W
Vanscoy (SK)	9/14/2004	8 m	MANTRA (Middle Atmosphere Nitrogen TRend Assesment)	1 km from the launch site