News Warner Logo

News Warner

Photophoretic Propulsion Enabling Mesosphere Exploration

Photophoretic Propulsion Enabling Mesosphere Exploration

  • Photophoretic Propulsion Enabling Mesosphere Exploration (PPEMSE) is a NASA-funded concept that aims to explore Earth’s upper atmosphere using no-moving-parts flying vehicles.
  • The concept utilizes photophoretic levitation and propulsion, which creates lift in structures that absorb light on the bottom yet stay cool on the top, maximizing payload capabilities.
  • The proposed system can operate in a range of ambient pressures (0.1-1000 Pa) ideal for Earth’s mesosphere and Mars’ low gravity and thin atmosphere, allowing for longer flight times than conventional airplanes or balloons.
  • Phase 2 of the proposal focuses on scalable fabrication of Knudsen pump structures to enable kg-scale payloads in the mesosphere and trajectory control with 1 m/s velocity control in existing stratospheric balloon vehicles.
  • The PPEMSE concept was selected as a 2025 NASA Innovative Advanced Concepts (NIAC) award winner, demonstrating its potential for advancing space technology and exploration capabilities.

2 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

Labeled diagram depicting Photophoretic Propulsion
Artist concept highlighting the novel approach proposed by the 2025 NIAC awarded selection of Photophoretic Propulsion Enabling Mesosphere Exploration concept.
NASA/Igor Bargatin

Igor Bargatin
University of Pennsylvania

We propose to use the photophoretic levitation and propulsion mechanism to create no-moving-parts flying vehicles that can be used to explore Earth’s upper atmosphere. The photophoretic force arises when a solid is heated relative to the ambient gas through illumination, inducing momentum exchange between the solid and the gas. The force creates lift in structures that absorb light on the bottom yet stay cool on the top, and we engineered our plate mechanical metamaterials to maximize this lift force and payload. The levitation and payload capabilities of our plates typically peak at ambient pressures in the 0.1-1000 Pa range, ideal for applications in Earth’s mesosphere and Mars’s low gravity and thin atmosphere. For example, in the Earth’s mesosphere (i.e., at altitudes from ~50 to ~80 km), the air is too thin for conventional airplanes or balloons but too thick for satellites, such that measurements can be performed for only a few minutes at a time during the short flight of a research rocket. However, the range of ambient pressures in the mesosphere (1-100 Pa) is nearly optimal for our plates’ payload capabilities. Phase 2 of the proposal focuses on the scalable fabrication of Knudsen pump structures that will enable missions with kg-scale payloads in the mesosphere as well as trajectory control with 1 m/s velocity control in existing stratospheric balloon vehicles.

2025 Selections

Details

Last Updated

May 27, 2025

Editor
Loura Hall

link

Q. What is Photophoretic Propulsion Enabling Mesosphere Exploration?
A. It’s a concept proposed by Igor Bargatin and his team to use photophoretic levitation and propulsion mechanism to explore Earth’s upper atmosphere.

Q. How does the photophoretic force work?
A. The photophoretic force arises when a solid is heated relative to the ambient gas through illumination, inducing momentum exchange between the solid and the gas.

Q. What kind of structures can benefit from this lift force?
A. Structures that absorb light on the bottom yet stay cool on the top can create lift in these structures.

Q. Where are the proposed flying vehicles suitable for exploration?
A. The mesosphere (altitudes from ~50 to ~80 km) and Mars’ low gravity and thin atmosphere are ideal locations for these vehicles.

Q. What is the range of ambient pressures that is nearly optimal for the plates’ payload capabilities?
A. The range of ambient pressures in the mesosphere (1-100 Pa) is nearly optimal for the plates’ payload capabilities.

Q. What is Phase 2 of the proposal focused on?
A. Phase 2 focuses on the scalable fabrication of Knudsen pump structures to enable missions with kg-scale payloads and trajectory control.

Q. How much velocity control can be achieved in existing stratospheric balloon vehicles?
A. The proposed system will provide 1 m/s velocity control in existing stratospheric balloon vehicles.

Q. What is the goal of this research?
A. The goal is to explore Earth’s upper atmosphere using no-moving-parts flying vehicles that can carry payloads and navigate through the mesosphere.

Q. Who awarded the proposal in 2025?
A. Igor Bargatin’s team received a 2025 NIAC award for their proposed concept, Photophoretic Propulsion Enabling Mesphere Exploration.