Gamma
...that Gamma, a gamma-ray telescope, was launched in 1990, 25 years after it was originally conceived?
...that <b id="mwEa0"><a href="./Gamma_(satellite)" id="mwEa4" rel="mw:WikiLink" title="Gamma (satellite)">Gamma</a></b>, a <a class="mw-redirect" href="./Gamma-ray_telescope" id="mwEa8" rel="mw:WikiLink" title="Gamma-ray telescope">gamma-ray telescope</a>, was launched in 1990, 25 years after it was originally conceived?