 Artist's rendering of the BOLAS concept. Vertical separation by the tether allows for a quasi-stable orbit and an extraordinary reduction in propellant requirement. | |
| Mission type | Reconnaissance, technology |
|---|---|
| Operator | NASA |
| Mission duration | ≥ 1 year (proposed) |
| Spacecraft properties | |
| Spacecraft type | Two tetheredCubeSats |
| Bus | 6U each |
| Dry mass | ≈15 kg (33 lb) each |
| Dimensions | 36×26×43 cm[1] |
| Moon orbiter | |
| Orbital parameters | |
| Periselene altitude | 10 km[2] |
| Aposelene altitude | 190 km |
| Inclination | 30°[3] |
Bi-sat Observations of the Lunar Atmosphere above Swirls (BOLAS) is a spacecraft mission concept that would orbit theMoon at very low altitude in order to study the lunar surface. The concept, currently under study byNASA, involves two small identicalCubeSat satellites connected vertically above the lunar surface by a 25 km longtether. The mission goal would be to understand the hydrogen cycle on the Moon, dust weathering, and the formation oflunar swirls.
BOLAS is a mission concept under study at NASA, with the goal of understanding the cycle of hydrogen on the Moon and to determine the formation mechanism of thelunar swirls. The mission would involve two smallCubeSat satellites connected with a 25 km (16 mi) longspace tether.[1] The lower CubeSat would orbit at an altitude of 10 km (6.2 mi) above the surface.[3][4] Without a tether system, a comparable low-altitude mission would need prohibitive amounts of fuel to maintain its orbit.[3] The two tethered spacecraft would be placed at a 30° orbit inclination and would remain stable for more than one year.[4]
The two CubeSats are 6 units each and would be equipped with nearly identical miniaturized instruments.[3] The mission would use the subsystems developed by Kentucky'sMorehead State University, which is leading NASA'sLunar IceCube mission.[3] The team from NASA'sGoddard Space Flight Center was selected in August 2017 to further mature the concept.
Abolas is a type of throwing weapon used by South Americangauchos made of weights on the ends of interconnected cords. Its application in aerospace is called space bolas ormomentum exchange tether.
The BOLAS mission would investigate the lunar hydrogen cycle by determining the mechanisms and dynamics of lunar hydrogen implantation, and their dependence on surface composition, regolith properties, local topography, plasma conditions, time-of-day, andcrustal magnetic fields.[4][1]
The second main objective is to understand the role that magnetic anomalies and space weathering could play in the formation oflunar swirls — enigmatic features found across the Moon's surface.[4][5] The mission would also study regolith, local topography,plasma conditions, and magnetic fields within thecrust.[3]
Scientists think the lunar swirls form as a result of magnetic fields in the lunar crust, which protect the lighter-colored regolith either by divertingsolar wind, or through the interaction with electric fields.[6][7]
The Principal Investigator for the BOLAS mission is Timothy Stubbs, at NASA'sGoddard Space Flight Center.[5]
The two CubeSats are 6 units each, measuring 36×26×43 cm[1] each, not including their deployable solar panels. The higher satellite is called BOLAS-H, and the lower one is BOLAS-L.[4] Both would operate independently and possess their own propulsion featuring twoBusek BIT-3 RFion engines each.[4] They would also feature anattitude control system (ACS), and anX bandtransponder for communication.[4]
The 25 kilometer longspace tether joining the two satellites is made of a commercially available high tenacity yarn with a thickness of 125 μm that is braided for redundant tensile strength.[4]
The two CubeSats are 6 units each and would be equipped with nearly identical miniaturized instruments:[1][4]