NASA researchers have proposed a tethered CubeSat mission to explore the Moon like never before. The concept would allow for a low-altitude study of the Moon to explore its extremely thin atmosphere.
The mission hopes to answer the mystery of the lunar swirls, light and dark swirling patterns that have been observed at over 100 locations across the surface of the Moon. The CubeSats, which would be made of 12 10-centimeter (4-inch) units, would measure magnetic anomalies and space weathering, which are believed to play a role in the formation of the swirls.
However, the intriguing part is that the two CubeSats would be tethered to each other by an extremely thin cable that stretches for 180 kilometers (112 miles). One of the satellites would be as low as 10 kilometers (6 miles) from the surface, while the other would be high above our natural satellite. The center of mass of the tethered system, known as BOLAS (Bi-sat Observations of the Lunar Atmosphere above Swirl) would be 100 kilometers (62 miles) over the Moon.
"The tension in the tether keeps the CubeSats in vertical alignment as they orbit," principal investigator of the mission Timothy Stubbs, from the NASA Goddard Space Flight Center, said in a statement. "The configuration, with the center-of-mass in a quasi-stable orbit, should enable the lower CubeSat to fly for long durations at low altitudes."
Low-altitude missions are a great way to study an airless body, as satellites are not slowed down by air resistance, which would make their orbit decay. Satellites usually need to spend a lot of fuel in course-correction maneuvers just to keep stable. The Moon's atmosphere is so tenuous that it’s actually considered an exosphere and yet its gravity is not uniform enough for low-altitude satellites. Tethering would solve this.
"This is an exciting concept," Michael Collier, a BOLAS co-investigator, added. "Candidly, I think it's groundbreaking. Tethered satellites are a very natural approach for targeting lunar science."
While the CubeSats might be small, they could be equipped with state-of-the-art instruments that could measure the lunar cycle of volatiles, like water and hydrogen, over the year-long mission. It could also study the magnetic fields around our satellite to work out if and how it affects the formation of the swirls.
Lunar swirls are thought to form in three possible ways: They are either the leftover material from cometary collisions, the effect of micrometeoroids, or weathered areas due to solar winds. In all these three scenarios, the magnetic field provides the curvy shape.
This mission could also be done with existing technology, according to researchers. It will be interesting to see if the program will be funded.