There is no definitive answer to this question as the amount of mass in outerspace is constantly changing. However, we do know that there are billions of stars in the Milky Way galaxy, each of which contains a vast amount of mass. In addition to stars, there are also planets, moons, asteroids, comets, and other objects in outerspace, all of which contribute to the total mass. According to some estimates, the Milky Way galaxy alone contains about 100 billion stars, and the universe as a whole may contain as many as 100 trillion galaxies. If each galaxy contains an average of 100 billion stars, this means that there could be as many as 10^24 stars in the universe. The mass of a single star can range from a few tenths of a solar mass to several hundred solar masses, so the total mass of all the stars in the universe could be enormous.