The Indian Space Research Organisation (Isro) is currently facing challenges with its SpaDeX satellite mission, which has enough fuel for docking but will be hindered by insufficient sunlight in the coming days as the docking window begins to shorten.
Isro Chairman V. Narayanan has, however, reassured stating, "We are not in any hurry. We will complete the mission successfully and we are moving forward with caution. No problem with being late; satellites have enough fuel."
The Chaser satellite (SDX01) has approximately 4.5 kg of propellant remaining, sufficient for two docking and undocking manoeuvres.
However, the operational window for these manoeuvres is limited. The opportunity to dock will close on January 20 and will not reopen until March 25, leaving a gap of 65 days.
As of January 15, 2025, Isro is closely monitoring the situation to ensure that the SpaDeX mission can proceed effectively despite the constraints.
The SpaDeX mission aims to demonstrate automated rendezvous and docking technology, a critical capability for future space missions, including those targeting the Moon and beyond.
This mission represents India's entry into an elite group of nations capable of mastering space docking technology, which includes countries like the United States, Russia, and China.
The delay in docking attempts is primarily due to the spacecraft's current position relative to sunlight exposure. The lack of adequate sunlight affects the solar panels' ability to generate the power necessary for operations.
As explained by former Isro scientist Manish Purohit, the Earth’s rotation shifts the spacecraft's footprint after each orbit, complicating tracking efforts.
With the satellites travelling at approximately 7 km/s, they complete an orbit in about 90 minutes, resulting in a limited time window for ground stations to maintain contact — typically just 15-20 minutes.
Isro officials have indicated that they are conducting thorough evaluations and simulations to ensure that all systems are ready for successful docking when conditions permit.
Despite these setbacks, Isro remains optimistic about the SpaDeX mission's objectives. The successful demonstration of docking technology will pave the way for future missions, including plans for a crewed space station orbiting the Moon by 2040 and a sample-return mission to the Moon's south pole by 2028.
Source: India Today