How to add rocket jump functionality to this script?

It's a rocket launcher script, and I already tried, but I broke it. Anyway to add it without it breaking?

function blow(hit, missile)
    if missile  == nil then return end
    if swooshSound then swooshSound:stop() end
    explosion = Instance.new("Explosion")
    explosion.Position = missile.Position
    explosion.BlastPressure = 0
    explosion.BlastRadius = 5
    -- find instigator tag
    local creator = missile:FindFirstChild("creator")
    explosion.Hit:connect(function(part, distance) onPlayerBlownUp(part, distance, creator) end)
    explosion.Parent = game.Workspace   
    if explosionSound then explosionSound:Play() end
    wait(.1)
    if missile then missile:Remove() end
end