It was not the case, and our species was able to ultimately determine that it was simply another celestial rock. Alright, maybe not just any celestial rock, as this object, named Oumuamua, is now officially recognized as “the first confirmed object from another star to visit our solar system.” Yes, it is not of this world, but rather originates from a location beyond our own star, a place that we will likely never be able to identify.
Just imagine the excitement if we were able to send a spacecraft to this interstellar object and collect a sample for closer examination. What secrets might it hold? What marvels could it reveal?
We have the capability to send spacecraft to other celestial bodies to accomplish such tasks. We have already achieved this multiple times, most recently with the OSIRIS-Rex spacecraft and the Bennu asteroid.
However, Bennu is a local rock and we already possess a significant amount of knowledge about it. Oumuamua is different. Unlike Bennu, it is not trapped in an orbit, and with an average speed of 59,000 mph (95,000 kph), the window of opportunity for a potential encounter with it is very brief.
As it currently stands, none of our existing methods of space propulsion are capable of enabling a spacecraft to reach the necessary speeds to approach and catch up with such a passing interstellar object.
And even the methods currently under research do not provide a solution. For example, solar sails have the ability to propel spacecraft deep into space on long-duration missions, but they lack the capability to perform propulsive maneuvers in space.
Spaceships powered by nuclear energy could potentially be the answer, but they are currently prohibitively expensive to produce and may prove to be too large for practical use.
In the course of time, NASA’s Innovative Advanced Concepts (NIAC) program has discovered several alternative propulsion methods that may meet the requirements for a rendezvous with an interstellar object. In 2021, a proposal was made for a radioisotope-electric-propulsion spacecraft.
This year, another proposal was accepted in Phase 1 of the NIAC program. Conceived by James Bickford from the Charles Stark Draper Laboratory, it involves utilizing the momentum generated by the natural decay of a radioactive isotope to generate thrust.
The scientist envisions a device known as the Thin Film Isotope Nuclear Engine Rocket (TFINER), which consists of thin sheets of radioactive isotope. How thin? Well, approximately 10-microns thick, which is roughly the length of a typical bacterium.
The radioactive isotope in question is Thorium-228. This substance has a half-life of 1.9 years, but more importantly, its decay chain produces additional alpha emissions, which have lifetimes ranging from 300 nanoseconds to three days.
Photo: NASA
The isotope engine has the potential to generate propulsion by coating one side of a thin film with a absorber that captures forward emissions. Bickford suggests that combining multiple stages of longer half-life isotopes could optimize velocity over extended mission durations. This configuration not only increases delta-V and spacecraft lifespan, but also enables active thrust vectoring and maneuverability.
As explained by the mastermind behind this concept, approximately 30 kilograms (66 pounds) of radioisotope could be distributed across a 250 square meter (2,690 square feet) area, allowing a spacecraft to achieve a maximum speed of 150,000 mph (540,000 kph). This scalability ensures adaptability to the needs of space exploration.
Considering the above information, it is conceivable that such a spacecraft could rapidly venture into deep space and catch up with various celestial objects.
The scientist has not disclosed any additional numerical data regarding the potential application of this system in a spaceship. However, NASA has shown interest in the idea by including it in this year’s NIAC Phase 1.
Although tangible results from this research are not guaranteed, it highlights the numerous possibilities available to expand our understanding of space.
Bickford envisions the system being utilized not only for rendezvous with passing interstellar objects, but also as a propulsion method for multi-target observations at the solar gravitational focus.
We will closely monitor the progress of this technology, as we do with all other concepts from the NIAC program, and provide updates if any noteworthy developments occur.
According to the Source autoevolution.com