Researchers have studied two leading technologies that would enable us to take advantage of this unique opportunity and reach Sedna: a mysterious world on the edge of the Solar System.
Mysterious Sedna
Sedna was discovered in 2003. It has a diameter of 1,000 km. This body has one of the most extreme orbits known to us. At perihelion, Sedna approaches the Sun at 76 AU (2.5 times closer than Neptune), and at aphelion, it moves away to 937 AU. It takes more than 11,000 years to complete one orbit around the Sun.
However, Sedna is much bigger than just another distant rock. This is an object of a new orbital class, and its extreme orbit suggests that it may be the first known member of the inner Oort Cloud. Understanding Sedna may reveal the secrets of the early formation of the Solar System and the gravitational perturbations that shaped it.
In 2075–2076, Sedna will once again pass through the perihelion of its orbit, and then begin its long journey back into darkness. In an article posted on the arXiv preprint server, scientists looked at two promising technologies that would let us take advantage of this unique window of opportunity and reach Sedna.
Thermonuclear engine or solar sail
The first approach involves a direct fusion drive (DFD) — a conceptual power plant based on nuclear fusion, designed to produce both thrust and electricity. For DFD, researchers propose a 1.6 MW system with constant thrust and specific impulse, which represents a huge leap forward compared to current technologies.
The second approach involves an original variation on the solar sail. Instead of relying solely on solar radiation pressure, this concept uses thermal desorption. This is a process in which molecules or atoms adhering to a surface are released when that surface is heated, and it is this process that provides movement. The flight of the solar sail will be supported by gravitational maneuvers near Jupiter, which will act as a giant catapult.
The analysis showed that the DFD engine would allow Sedna to be reached in approximately 10 years. The combination of a solar sail and Jupiter’s gravity could complete the journey in seven years.
This difference in speed highlights the fundamental trade-offs in deep space exploration. The superiority of solar sails in terms of travel time is due to their ability to accelerate continuously without carrying heavy fuel. However, unlike the DFD engine, they do not allow the spacecraft to enter orbit around Sedna, but only ensure its flyby. In turn, the orbital mission is capable of conducting an extended study of the mysterious planetoid, mapping its surface, analyzing its composition, etc.
Both proposed technologies have a number of serious obstacles to their implementation. DFD remains largely a conceptual technology, requiring breakthroughs in fusion confinement and control that have eluded engineers for decades. Modeling shows that this technology could deliver a spacecraft weighing about 1,000 kg to Pluto in four years, but achieving such performance in reality remains uncertain.
An improved solar sail with thermal desorption represents a more evolutionary approach. The use of this technology, based on precisely calculated gravitational maneuvers and innovative materials, is associated with certain difficulties, but in the near future it may prove to be more realistic.
However, the window for reaching Sedna is quickly closing. Whether humanity will be able to cope with the task of exploring it depends on our willingness to invest in revolutionary engine technologies and accept the risks associated with expanding the boundaries of space travel.
According to Phys.org
