India’s first three-axis stabilised geostationary communication satellite Identify India’s first three-axis stabilised (3-axis controlled) geostationary communication satellite used for experimental telecom/TV relay.

Introduction / Context:
Satellite attitude control is critical for pointing antennas and solar arrays. Early Indian spacecraft evolved from spin-stabilised to three-axis stabilised platforms. Knowing which satellite first achieved 3-axis stabilisation in geostationary orbit is important in India’s spaceflight history.

Given Data / Assumptions:

• The candidates include early Indian satellites: Aryabhata, Rohini, Bhaskara and the experimental geostationary payload APPLE.
• Three-axis stabilisation is required for precise payload pointing and efficient power generation.
• The query focuses on the first Indian example at geostationary altitude.

Concept / Approach:

APPLE (Ariane Passenger Payload Experiment), launched in 1981, was India’s first experimental geostationary communication satellite. It used a 3-axis stabilisation scheme and enabled India’s initial experiments in TV/telecom relay from geostationary orbit, paving the way for the INSAT series.

Step-by-Step Solution:

Verification / Alternative check:

Standard ISRO retrospectives describe APPLE as India’s first 3-axis stabilised GEO experimental communication satellite used for TV/telecom link trials.

Why Other Options Are Wrong:

Rohini/Aryabhata/Bhaskara were not 3-axis geostationary communication spacecraft; INSAT-1D is later and not the first.

Common Pitfalls:

Confusing first GEO satellite experiments (APPLE) with first operational INSAT satellites; mixing LEO science missions with GEO comsats.

Final Answer:

APPLE