At the moment, our spacecraft relies on a two-way relay system that needs to bounce signals to and from Earth-based atomic clocks to figure out where it is and where it's going. It uses the time it takes to send a signal and to receive a response to calculate for its location, path and velocity. The process could take anywhere from a few minutes to a few hours, depending on how far the spacecraft is from our planet. That's why we need a technology that will allow astronauts to know where they are and to change course quickly if we want to see more of the universe.
The Deep Space Atomic Clock was designed live onboard a spacecraft and calculated for its location and route using only signals it receives from Earth ̵
The test clock will remain in space for a year to help NASA figure out whether it can remain stable in the orbit. If all goes well, it could be used for missions as early as the 2030s. You can watch the first Deep Space Atomic Clock leave Earth aboard and Falcon Heavy on June 24th through NASA's live stream. SpaceX is aiming for an 11:30 PM launch, so the broadcast will begin shortly before