April 10, 2020
April 22, 2020
Your title's a bit vague.
I doubt they using instruments to specifically spot alien UFO's. The equipment on board that's designed to observe space would likely catch these things inadvertently.
The space station exists to observe a number of things and it's a bit sensational to act like that have tools specifically for spotting alien vessels. The ISS has just as much reason to monitor and detect UFO's in case they happen to be terrestrial military vessels.
I sincerely doubt they have something that specifically detects aliens. It's likely that they have tools that record a lot of ambient data that are also capable of spotting potential alien activity.
It's worth noting that the space station is not that well equipped to do far-reaching observation of space. I mean, it's in a better position than pretty much all observatories on earth, but the technology for observation is not so surprisingly limited, though I suspect we are going to see an investment in this with the return of star wars (not the movie series).
The Hubble Space Telescope would likely be the best "alien android ufo detector" we have and it's woefully unprepared for this task. There are many reasons for this: chief among them being that the Hubble's design is pretty obsolete compared to what's being produced.
The Hubble Telescope, though a great astronomical tool, has many limitations that astronomers would like to see changed. There is more distortion in images than scientists would like and the older reflective materials used to capture light in the Hubble aid this problem.
Our tools for observing space are essentially light and gravity. We have relatively poor tools for measuring gravitational changes when compared to traditional Hollywood aliens' depictions. Many kinds of wavelengths of light are lost on Earth before reaching our eyes. The Hubble Telescope helps to minimize this but its design does not capture enough detail.
Currently, the next best "detector" I could think of is NASA's latest design for an orbiting telescope. This scope is known as the "James Webb Space Telescope". ( https://www.jwst.nasa.gov/ )
NASA is thankfully rather open about the goals of this device, though likely withholding potential military applications for obvious reasons. The newer scope is comprised of hexagonal golden plates are better and reflecting various wavelengths of light when polished. This allows the telescope to dynamically compensate for distortions in light/images and correct them. Simply put, lets scientists see more stuff in space.
This is likely the best "alien detector" we'll have for a while. Assuming alien ufo's have some means of manipulating light on an advanced level, and have been close enough to potentially be spotted by the Webb scope, there's a chance we could detect something.
I would be skeptical of a "detector" device being on the ISS purely for aliens. It is most likely intended for terrestrial threats but the gov't does try to plan for the unknown. It's likely that they'll try, but there are more immediate threats (e.g. like China blowing up satellites and sending debris flying through orbit at thousands of miles a second) that those tools are likely being used for.
Wait for the Webb Scope and we'll see what we see. Space is very large and our tools for observing it are akin to ancient people using sun dials to tell time.