Reduced-Graphene-Oxide-Based Thin Films: An Alternative Coating for Harsh Space Environments.

Area of Science:

• Materials Science
• Aerospace Engineering
• Surface Science

Background:

• Polymeric materials are crucial for spacecraft thermal control but degrade due to electrostatic charges in geostationary orbits.
• Environmental hazards, especially electrostatic discharge, pose significant risks to spacecraft components.

Purpose of the Study:

• To develop and evaluate a graphene-based coating for electrostatic dissipation on polyimide (Kapton®) for spacecraft applications.
• To assess the coating's durability and performance in simulated harsh space environments.

Main Methods:

• A reduced graphene oxide (rGO) coating (80-100 nm) was applied to Kapton® using a cost-effective spray technique.
• Spaceworthiness was tested via thermal cycling, thermal vacuum, humidity, adhesion, and aging.
• Electron bombardment and Kelvin probe force microscopy were used to evaluate electrostatic properties.

Main Results:

• The rGO coating maintained structural, optical, and electrical properties after rigorous space environment simulations.
• Electron bombardment tests showed significantly reduced charging on rGO-coated Kapton® compared to uncoated Kapton®.
• Kelvin probe force microscopy confirmed a substantial decrease in surface potential, from 300 mV to 60 mV.

Conclusions:

• The developed graphene-based coating demonstrates excellent durability and electrostatic dissipative properties for harsh space environments.
• This coating offers a promising, space-survivable solution for mitigating electrostatic discharge on spacecraft.
• The technique ensures minimal impact on essential thermo-optical properties for thermal control.