POEM-4

POEM-4 Latest News

Recently, POEM-4 re-entered the Earth's atmosphere and impacted the Indian Ocean, as monitored by ISRO’s IS4OM (System for Safe and Sustainable Space Operations Management).

What is POEM-4?

• POEM-4, or PSLV Orbital Experiment Module-4, is a space research platform developed by ISRO that utilizes the spent fourth stage (PS4) of the PSLV rocket as an orbiting experimental module in space.
• It is part of the SpaDeX (Space Docking Experiment) mission and represents the fourth deployment of the POEM series, following POEM-3.
• POEM-4 has a three times larger payload capacity than its predecessor, POEM-3, marking a major advancement in reusing upper rocket stages for scientific research.
• Total of 24 payloads were hosted on POEM-4: 14 payloads from ISRO and 10 payloads from non-government entities (NGEs) including start-ups and academic institutions
• Notable payloads include:
  • Walking Robotic Arm (RRM-TD): A robotic manipulator capable of inchworm-like motion, aimed at enabling inspection and servicing tasks in space.
  • Debris Capture Robotic Manipulator: Developed by Vikram Sarabhai Space Centre (VSSC), this innovation assists in space debris collection and manipulation, aligning with global efforts in space clean-up.
  • Gradient Control Reaction Wheel Assembly (RWA): Designed by ISRO Inertial Systems Unit (IISU), this system enhances attitude control and stabilization of the POEM platform using reaction wheels.

Launch and Mission Details

• POEM-4 was launched on December 30, 2024, aboard PSLV-C60, which also carried twin SPADEX satellites to a 475 km altitude.
• After satellite deployment, the PS4 upper stage was reconfigured as POEM-4 and continued in a nearby orbit, serving as an experimental platform.
• POEM-4 was then de-orbited by restarting its engine and brought to a circular orbit at 350 km altitude with a 55.2° inclination.
• The stage was passivated (leftover fuel vented) to prevent accidental break-up and ensure safe operations in orbit.

POEM-4 FAQs

Q1. What is POEM-4?
Ans. POEM-4 (PSLV Orbital Experimental Module) refers to the use of the spent fourth stage of ISRO's PSLV-C60 rocket as an orbital platform for conducting scientific experiments in space.

Q2. What were the objectives of the POEM-4 mission?

Ans. The mission aimed to conduct various scientific experiments, including the germination of cowpea seeds in microgravity and the operation of India's first space robotic arm.

Q3. When was POEM-4 launched?

Ans. POEM-4 was launched on December 30, 2024, as part of the Space Docking Experiment (SpaDeX) mission. 

Source: TH