Why is the Ascension Mentioned in the Canon of the Mass?

Dom Gueranger reflects in his unparalleled Liturgical Year as to why the Ascension is always mentioned in the Canon of the Mass. Here he expresses similar noteworthy sentiments:

The feast of the Ascension shows us the work of God in its completion. Hence it is that the Church, in her daily offering of the holy sacrifice, thus addresses the eternal Father: the words occur immediately after the consecration, and contain the motives of her confidence in the divine mercy: ‘Wherefore, O Lord, we Thy servants, as also Thy holy people, calling to mind the blessed Passion of Christ Thy Son our Lord, His Resurrection from the dead, and His admirable Ascension into heaven, offer unto Thy most excellent Majesty a pure, holy, and unspotted Host.’ 

It is not enough for man to hope in the merits of his Redeemer’s Passion, which cleansed him from his sins; it is not enough for him to add to the commemoration of the Passion that of the Resurrection, whereby our Redeemer conquered death; man is not saved, he is not reinstated, except by uniting these two mysteries with a third: the Ascension of the same Jesus who was crucified and rose again.