09:30 〜 09:45
[PPS04-08] Phantom: A New Frontiers-class Aerobot Mission to the Venus Skies
★Invited Papers
The Phantom Mission: Phantom is an ambitious New Frontiers-class (US$1B+) mission concept under development at the Jet Propulsion Laboratory, and features an aerial robot (aerobot) paired with an orbiter to address these and other science objectives from within the Venus clouds. The Phantom aerobot is a variable-altitude balloon and gondola able to traverse an altitude range of 52–62 km with an instrument payload of ~25 kg. Operating in the middle cloud layer and with materials and construction methods to resist the high-acidity environment, the aerobot circumnavigates Venus in 5–7 Earth days. To minimize battery power consumption, most science operations will be performed on the day side where solar power is available; the nominal lifetime of the balloon exceeds 30 Earth days.
Supporting the operations of the aerobot is an orbiter that also carries a science payload. The orbiter will assume an inclined, elliptical orbit about Venus to permit synoptic imaging of the Venus atmosphere, serve as a communications relay to Earth, and track the aerobot. The orbiter’s lifetime is measured in years, offering continued valuable science at Venus long after the aerobot phase of the mission ends, and operating as a radio relay for subsequent aerial and lander missions.
The Phantom Theme: Phantom addresses Decadal-level questions by taking as its core science focus the theme of “volatiles.”
This theme encompasses investigations of the chemical and physical properties and processes of terrestrial planet atmospheres; how terrestrial atmospheres are lost to space; the rates and nature of volatiles released from rocky mantles; the chemical and physical properties with which rocky planets form; the history of volatiles in the evolution of terrestrial planets; and the role of volatiles in developing and maintaining habitable environments.
To address this wealth of science investigations centered on the “volatiles” theme, the Phantom mission has seven primary science objectives: 1) Establish if the Venus clouds are habitable; 2) Characterize the nature of aerosols there; 3) Determine how volatiles are transported to, in, and through the cloud layer; 4) Establish how radiative flux drives convection, circulation, and microphysics in the Venus atmosphere; 5) Search for a modern magnetic field or evidence for an ancient record of intrinsic Venus magnetism; 6) Test whether volcanic eruptions inject volatiles into the atmosphere; and 7) Assay atmospheric species lost to space.
Technology Development: Although the middle Venus atmosphere is a far more benign environment than the surface, key technical challenges remain. For instance, the Venus clouds are primarily composed of sulfuric acid droplets, requiring the use of acid-resistant materials on the outer balloon envelope, gondola, and solar panels. Further, the requirement that the aerobot be capable of traversing a range of altitudes has motivated the design of a balloon-within-a-balloon design. The Phantom aerobot therefore features an outer, metallized, unpressurized balloon that is coated in Teflon, which protects against sulfuric acid cloud droplets and sunlight, and which encompasses an inner, super-pressure balloon reinforced with Vectran; exchanging helium between the inner and outer balloons modulates the aerobot’s buoyancy and thus altitude.
A one-third-scale aerobot prototype successfully demonstrated this design during a set of flight tests in Black Rock Desert, NV in July 2022. These tests validated the use of variable-altitude balloon technology in temperature–pressure conditions similar to those the full-scale aerobot would encounter in the middle Venus atmosphere, and provided crucial flight data for simulation models of full-scale aerobot operations at Venus. Work continues to develop ever-higher-fidelity balloons with materials and seams able to withstand the chemical and physical conditions that characterize the Venus clouds, together with ongoing development of instrumentation capable of addressing the Phantom mission science objectives.
Outlook: The timing and scope of NASA’s next New Frontiers competition remain uncertain. Nonetheless, with coupled aerobot and orbiter flight elements, the Phantom mission addresses Decadal-level planetary science questions in a way not possible from orbit or via a single descent profile. And, as Venus sits at the intersection of key questions of planetary formation, atmosphere gain and loss, dynamic habitability, and the evolution and fate of Earth-size worlds, Phantom enables the planetary, exoplanetary, and heliophysics communities to take the next giant leap in our understanding of the Solar System and beyond.
Supporting the operations of the aerobot is an orbiter that also carries a science payload. The orbiter will assume an inclined, elliptical orbit about Venus to permit synoptic imaging of the Venus atmosphere, serve as a communications relay to Earth, and track the aerobot. The orbiter’s lifetime is measured in years, offering continued valuable science at Venus long after the aerobot phase of the mission ends, and operating as a radio relay for subsequent aerial and lander missions.
The Phantom Theme: Phantom addresses Decadal-level questions by taking as its core science focus the theme of “volatiles.”
This theme encompasses investigations of the chemical and physical properties and processes of terrestrial planet atmospheres; how terrestrial atmospheres are lost to space; the rates and nature of volatiles released from rocky mantles; the chemical and physical properties with which rocky planets form; the history of volatiles in the evolution of terrestrial planets; and the role of volatiles in developing and maintaining habitable environments.
To address this wealth of science investigations centered on the “volatiles” theme, the Phantom mission has seven primary science objectives: 1) Establish if the Venus clouds are habitable; 2) Characterize the nature of aerosols there; 3) Determine how volatiles are transported to, in, and through the cloud layer; 4) Establish how radiative flux drives convection, circulation, and microphysics in the Venus atmosphere; 5) Search for a modern magnetic field or evidence for an ancient record of intrinsic Venus magnetism; 6) Test whether volcanic eruptions inject volatiles into the atmosphere; and 7) Assay atmospheric species lost to space.
Technology Development: Although the middle Venus atmosphere is a far more benign environment than the surface, key technical challenges remain. For instance, the Venus clouds are primarily composed of sulfuric acid droplets, requiring the use of acid-resistant materials on the outer balloon envelope, gondola, and solar panels. Further, the requirement that the aerobot be capable of traversing a range of altitudes has motivated the design of a balloon-within-a-balloon design. The Phantom aerobot therefore features an outer, metallized, unpressurized balloon that is coated in Teflon, which protects against sulfuric acid cloud droplets and sunlight, and which encompasses an inner, super-pressure balloon reinforced with Vectran; exchanging helium between the inner and outer balloons modulates the aerobot’s buoyancy and thus altitude.
A one-third-scale aerobot prototype successfully demonstrated this design during a set of flight tests in Black Rock Desert, NV in July 2022. These tests validated the use of variable-altitude balloon technology in temperature–pressure conditions similar to those the full-scale aerobot would encounter in the middle Venus atmosphere, and provided crucial flight data for simulation models of full-scale aerobot operations at Venus. Work continues to develop ever-higher-fidelity balloons with materials and seams able to withstand the chemical and physical conditions that characterize the Venus clouds, together with ongoing development of instrumentation capable of addressing the Phantom mission science objectives.
Outlook: The timing and scope of NASA’s next New Frontiers competition remain uncertain. Nonetheless, with coupled aerobot and orbiter flight elements, the Phantom mission addresses Decadal-level planetary science questions in a way not possible from orbit or via a single descent profile. And, as Venus sits at the intersection of key questions of planetary formation, atmosphere gain and loss, dynamic habitability, and the evolution and fate of Earth-size worlds, Phantom enables the planetary, exoplanetary, and heliophysics communities to take the next giant leap in our understanding of the Solar System and beyond.