Ice Melting Heater
Resistive/Microwave Ice-to-Liquid Heater
The resistive/microwave ice-to-liquid heater converts extracted lunar ice batches into liquid water for downstream processing by supplying the 334 kJ/kg latent heat of fusion alongside sensible heating. Operating at 90 percent efficiency, the 2,000-watt unit delivers a melt rate of 5 kilograms per hour using microwave dipole coupling and resistive elements. Engineering the system for lunar operation requires vacuum-rated pyrolytic boron nitride or Inconel-clad heating elements, continuous thermal control above 5 °C to prevent reservoir refreezing, and pump-driven fluid recirculation to manage heat transfer and phase separation under one-sixth gravity.
Resistive/microwave heater melting captured ice batches into liquid water for processing.
Purpose
Resistive/microwave heater melting captured ice batches into liquid water for processing.
Context
Child of L2-WTR-MELT in L1-WTR water processing chain
Principles
- ▸Latent heat of fusion 334 kJ/kg + sensible heat above 0 C set energy demand
- ▸Microwave heating couples directly to water dipole (faster than resistive)
- ▸Cold-start protection keeps reservoir >5 C to prevent re-freeze
- ▸Multi-zone heating handles batch arrival timing variations
- ▸Tolerance to trace mineral content avoids fouling
Typical implementations
- ▸NASA Glenn LADI water-handling thermal stages
- ▸ISS Water Recovery System heated reservoir
- ▸Microwave-augmented water release studies (PMC 12308065, 2025)
- ▸ESA PROSPECT water recovery heater concepts
Lunar considerations
- ▸Vacuum-rated heater elements (PBN or Inconel-clad) for long life
- ▸Power source from waste-heat scavenging via L1-TCS where possible
- ▸Long-duration operation in 1/6 g may need pump-driven recirculation
Specifications
Functional
| primary function | Resistive/microwave heater melting captured ice batches into liquid water for processing. |
| melt rate kg per hour | 5 |
| heater efficiency percent | 90 |
Physical
| mass kg | 8 |
| materials | Inconel 718 jacket, PBN heater elements, 316L SS reservoir |
| vacuum compatibility | True |
Operational
| power consumption w | 2000 |
| thermal range c | -40, 70 |
| lifetime years | 15 |
| mtbf hours | 60000 |
Interfaces
Provides
- Liquid water for collection
Requires
- Solid ice from cold trap
- Heater power up to 2 kW
Cite this entry
Lunar Ark Codex. "Ice Melting Heater" (L3-WTR-MELT-HEAT). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-WTR-MELT-HEAT
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.