BOLAS (spacecraft)
 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] |
| Moonorbiter | |
| 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 theMoonat very low altitude in order to study the lunar surface. The concept, currently under study byNASA,involves two small identicalCubeSatsatellites 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.
Overview[edit]
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 smallCubeSatsatellites 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 IceCubemission.[3]The team from NASA'sGoddard Space Flight Centerwas selected in August 2017 to further mature the concept.
Abolasis a type of throwing weapon used by South Americangauchosmade of weights on the ends of interconnected cords. Its application in aerospace is called space bolas ormomentum exchange tether.
Objectives[edit]
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 magneticfields.[4][1]
The second main objective is to understand the role that magnetic anomalies and space weathering could play in the formation oflunar swirls— Enigma tic features found across the Moon's surface.[4][5]The mission would also study regolith, local topography,plasmaconditions, 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]
Spacecraft[edit]
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 twoBusekBIT-3 RFion engineseach.[4]They would also feature anattitude control system(ACS), and anX bandtransponderfor communication.[4]
The 25 kilometer longspace tetherjoining 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]
Science instruments[edit]
The two CubeSats are 6 units each and would be equipped with nearly identical miniaturized instruments:[1][4]
- Energetic Neutral Atom Imager(ENAI) (lower CubeSat only) to detect neutralized solar wind.
- Ion spectrometer for measuring protons (H+).
- Magnetometerto measure local magnetic fields.
- Plasma Wave System(PWS) for measuring electron concentrations, electric fields, and dust impacts.
- Camera.
See also[edit]
- Lunar IceCube,a planned lunar CubeSat mission
- Lunar Polar Hydrogen Mapper,a planned lunar CubeSat mission
References[edit]
- ^abcdeUsing Paraffin PCM for Thermal Management of BOLAS Planetary CubeSats with Ion Thrusters.Michael K. Choi. NASA Goddard Space Flight Center. 2019.
- ^Tethered satellites could see the moon's weird swirls up close.Leah Crane,New Scientist.9 August 2017.
- ^abcdefJenner, Lynn (8 August 2017)."NASA Studies Tethered CubeSat Mission to Study Lunar Swirls".NASA.Retrieved10 September2018.
- ^abcdefghiBi-Sat Observations of the Lunar Atmosphere Above Swirls (BOLAS): Tethered SmallSat Investigation of Hydration and Space Weathering Processes at the Moon.(PDF) Stubbs, T. J.; Malphrus, B. K.; Hoyt, R., etal. 49th Lunar and Planetary Science Conference; 19–23 March 2018 at The Woodlands, Texa, USA.
- ^abA Miniature Lunar Sky Crane Could Help Solve the Mystery of the Moon's 'Tattoos'.Calla Cofield,Space.3 September 2017.
- ^L. L. Hood & G. Schubert (1980). "The Moon: Lunar magnetic anomalies and surface optical properties".Science.208(4439): 49–51.Bibcode:1980Sci...208...49H.doi:10.1126/science.208.4439.49.PMID17731569.S2CID42500916.
- ^Steigerwald, Bill (28 April 2016)."Lunar Tattoos: New Clues".NASA.Retrieved10 September2018.