The Capricornio program was formally cancelled during 2000 amid alleged foreign political pressure, competition from other launchers, and INTA's desire to focus on other endeavours.

[3] The first phase of activity on the Capricornio programme centred upon the development of solid motors, which included the use of both the INTA-100 and INTA-300 sounding rockets from the El Arenosillo test range in southern Spain.

During June 1997, it was announced that the American manufacturer Thiokol was to supply the Castor 4B solid rocket motor that would power the first stage of Capricornio.

[2][7] For the second phase of the programme, it was intended to use both the second and third stages of Capricornio as the Argo sounding rocket; it was originally planned to fly sometime in late 1998 or early 1999.

Development of the launcher had been formally suspended during 1998, one year prior to the planned launch; one claimed reason for this outcome was that INTA had decided to redirect its resources into other endeavours.

[3] The aerospace author Brian Harvey, speculated the competition from Arianespace's Vega launcher had made the role of Capricornio less clear.