According to our current understanding of physics, electromagnetic (EM) waves, such as light, travel at a constant speed in a vacuum, which is approximately 299,792,458 meters per second (or about 186,282 miles per second), denoted as "c." This speed is a fundamental constant in the theory of relativity and is commonly referred to as the speed of light.
In outer space, where there is a lack of significant matter or obstacles, EM waves can travel without being significantly impeded. Therefore, they propagate at this constant speed of light between two points in outer space.
It's important to note that while the speed of light is constant in a vacuum, it can be affected by the presence of different media, such as gases, liquids, or solids. When EM waves pass through a medium other than a vacuum, their speed can be reduced, and they can experience refraction or other interactions.
In summary, in the absence of any significant medium or obstacle, EM waves, including light, will travel at the same constant speed in outer space as they do in a vacuum, which is approximately 299,792,458 meters per second.