Context:
A US-based startup, Reflect Orbital, has proposed using space-based reflective satellites to beam sunlight onto Earth at night to power solar farms after dusk, potentially reducing dependence on batteries and fossil fuels. However, experts warn of serious environmental, astronomical and regulatory concerns.
Key Highlights / Details
How the Technology Works
- Satellites equipped with giant mylar mirrors reflect sunlight to Earth.
- Operate in Sun-Synchronous Orbit (625–645 km altitude) along the day-night line.
- Each satellite illuminates ~7 km wide area on Earth.
- Capability: Reflect up to 20% of sunlight intensity (~200 W/m²).
- Requires a constellation of ~4,000 satellites by 2030, expanding later to 2,50,000 satellites.
Purpose
- Enable solar power generation after sunset.
- Reduce reliance on energy storage systems.
- Promote renewable energy continuity.
Major Concerns Raised
| Concern | Details |
| Light Pollution | Artificial illumination may brighten night sky, outshining the Moon. |
| Astronomy Risk | Reflected light interferes with telescopes and space observation. |
| Ecological Impact | Affects animal migration, circadian rhythms, mating cycles. |
| Space Debris Risk | Large satellite constellations increase collision risk (Kessler Syndrome). |
| Feasibility Issues | Each satellite stays over a location only for minutes—requires massive deployment. |
| Ethical/Social Impact | Impacts dark sky sanctuaries and indigenous cultures. |
Dhaweta Kulkarni (Dark Sky Defender Award): “Over 60% of invertebrates are nocturnal… removing night darkness will devastate ecosystems.”
Relevant Prelims Points
- Sun-Synchronous Orbit (SSO) – used for Earth observation satellites.
- Kessler Syndrome – chain reaction of satellite collisions due to orbital crowding.
- IAU – International Astronomical Union opposes excessive satellite brightness.
- Dark Sky Reserves – Recognised by IDA (International Dark-Sky Association) for astronomy conservation.
Relevant Mains Points
- Regulation of private space innovation vs environmental ethics.
- Importance of global space governance frameworks.
- Impact of technology on natural ecosystems and biodiversity.
- Conflict between energy innovation and sustainability.
- Outer Space Treaty 1967 – prohibits harmful contamination of space/celestial bodies.