I guess i'm trying to understand how a photon could measure velocity of an object with mass as an expansion of the universe if a photon itself contains no mass.

I mean theoretically gravity could be the lens that describes everything we see thus giving the appearance of expansion or contraction based upon the fluctuations of that gravitational lens.

Could you theoretically test this by say launching a spacecraft as far out and as fast as voyager towards a redshifted galaxy and then get a spectral analysis of the incoming photons at the currently velocity of the expansion and thus repeat the process until humanly possible to measure any increasing or decreasting velocity thereof relative to the observers point.

I mean technically if you achieve the expansion velocity and its still redshifted wouldn't that mean that the light you are observing is forever gravitationally shifted and entirely upon the frame of view vs redshifted because of a doppler/cosmological effect?

sorry if i'm running off on tangets.. i haven't researched the measured velocity of expansion so i'm taking a wild guess on how you would test the redshift thereof against a body moving it at the same speed/direction thereof.