Possibly Royal Space Force: The Wings of Honnêamise. It was released in March of 1987.
These events culminate in the eventual space launch, which is taking place in a demilitarized zone, with the government's hope that the launch of the rocket will provoke the enemy nation into war. As planned, the Republic launches a vast combined arms invasion, resulting in a visually stunning finale as fighter planes duel high above an armored advance towards a defensive trench network. Despite calls to pull out, Lhadatt, already in the space capsule and determined to finish what he started, convinces the frightened and vulnerable ground crew to complete the launch. The spectacular launch stuns both sides into inaction as Lhadatt goes into orbit. With no more reference to the world below (beyond a slight suggestion that both nations' plans for war have been foiled), Lhadatt prays for humanity's forgiveness.
In a symbolic moment, Lhadatt's capsule is suddenly bathed in sunlight, and a montage of his own life and his world's history and achievements are shown. Meanwhile, on the planet's surface, Riquinni witnesses the first snow fall and gazes into the sky, thinking of Lhadatt.
Here's an image of one of their planes (note the Pusher configuration):
The swept wings are more visible in these models:
And a trailer for the film:
And the final scene with the launch and the sunlight hitting his capsule: