It doesn’t matter how many times an astronaut has traveled into the unending darkness above the Earth; there is always a fear of ending up stranded. NASA recognizes this and is in the process of testing a “cosmic compass” which will guide space travelers back home.
The device is similar to a “sextant,” which uses the stars to measure precise angles to direct the user. Sextants, in history, have been extensively used by sailors in their sea voyages to get back on land. This device can help even astronauts in a very similar way. As they say, the readings of the stars could be put into a computer, and it could process out the precise location of their spacecraft’s position in space.
Though the concept resembles how the devices work on earth for positioning, there may be some logistical issues in space. As Greg Holt, NASA’s principal investigator said, “But particular challenges on a spacecraft are the logistics; you need to be able to take a stable sighting through a window.”
Sextants have been used in the past by NASA like in Apollo vehicles and Gemini missions, the first spacecraft to process sextant sightings. Right now, the space agency is focusing on feedbacks and innovations from astronauts involved in the investigation to produce the most accurate device possible.
Holt mentioned that since the plans for explorations and mission are “farther into space than ever before,” there is a need for a device which requires the least amount of energy to guide crews back to Earth. In case they lose contact with the on-Earth crew, they would require an autonomous navigation system as a backup.
Since the sextant device would be used as a backup when everything else fails, the device needs to be functional and stable in every regard. The accuracy of measuring angles between stars, planets, and moons are the last resort in the event of a breakdown of communication and other technology. This is the determinant of whether the crew will get back safe on earth, or wonder endlessly in space.
As a light of hope, Jim Lovell successfully proved that crews could use sextants for guidance back to earth in cases of communication breakdowns. Hence, there are efforts to develop this system to its best so no one in the dark ending world above us would end up somewhere we have no idea about.