Context: The Indian Space Research Organisation (ISRO) has successfully demonstrated space docking, utilising the indigenous Bharatiya Docking System.
Relevance of the Topic:Prelims: Space Docking Experiment (SpaDeX); Space Docking; Bharatiya Docking System
ISRO SpaDeX Docking Mission
- What is Space docking?
- Docking is a process by which two fast-moving spacecraft are brought to the same orbit, brought closer to each other manually or autonomously, and finally joined together.
- This capability is necessary for:
- carrying out missions that require heavy spacecraft that a single launch vehicle may not be capable of lifting off with.
- setting up a space station for which separate modules are joined in space.
- carrying crew and supplies to the space station.
- SpaDeX Mission:
- PSLV-C60 mission was launched on December 30, 2024.
- The PSLV rocket carried two satellites named Chaser (SDX01) and Target (SDX02), each weighing 220 kg.
- Successful space docking by ISRO:
- The two small satellites were brought within a distance of 3 metres from each other in orbit, their extended ring was joined with each other, retracted, and locked in space.
- ISRO also demonstrated giving commands to the two satellites as one composite object.
- Significance:
- The successful docking makes India the fourth country in the world — after the United States, Russia, and China — to have this capability.
- This paves the way for smooth conduct of ambitious future missions including the Bharatiya Antriksha Station, Chandrayaan 4 and Gaganyaan.
Also Read: PSLV-C60: SpaDeX & POEM
When was the first docking in space achieved?
- United States: In 1966, NASA’s Gemini VIII became the first spacecraft to dock with the target vehicle Agena. Gemini VIII was a crewed mission orbiting the Earth, commanded by Neil Armstrong, who in 1969 became the first human to set foot on the Moon.
- USSR: Soviet Union in 1967 demonstrated the first uncrewed, automated docking of the Kosmos 186 and Kosmos 188 spacecraft.
- China: China demonstrated its docking capability in 2011, when the unmanned Shenzhou 8 spacecraft docked with the Tiangong 1 space laboratory.
What happened during the docking experiment?
- ISRO carried out a series of manoeuvres to progressively bring “Chaser” satellite close to “Target” satellite.
- The satellites were allowed to drift close, and then their positions were held at around 5 km, 1.5 km, 500 m, 225 m, 15 m, and 3 m, before finally being joined together, at an orbit 475 kilometers (Low Earth Orbit) above the Earth.
- The space agency has demonstrated giving command to the satellites as a single composite object.
- ISRO will also demonstrate undocking, during which the satellites will separate and drift away to carry out their respective experiments over the two years of the mission’s life.
- The mission utilised the Bharatiya Docking System (BDS) indigenously devised by ISRO. This enabled the two Indian satellites to move precisely at the speed of 10 millimeters per second in docking, ensuring that they docked safely without risking a collision.
Bharatiya Docking System
- Spacecrafts that go to the International Space Station follow the International Docking System Standard (IDSS), which was first baselined in 2010.
- Bharatiya Docking System (BDS) being used by India is androgynous — meaning the systems on both the Chaser and Target satellites are identical.
- Advancements in BDS:
- BDS is similar to the IDSS used by other agencies, but uses two motors as compared to the 24 used in IDSS.
- BDS used several new sensors such as Laser Range Finder, Rendezvous Sensor, and Proximity and Docking Sensor to take precise measurements while bringing the two satellites closer and joining them.
- It also used a new processor based on satellite navigation systems to determine the relative position and velocity of the spacecraft.
- This is a precursor to a completely autonomous system for future missions that would be able to achieve docking without satellite-based navigation data.