Will Smart Lander for Investigating Moon (SLIM) revolutionize lunar landing

Will Smart Lander for Investigating Moon (SLIM) revolutionize lunar landing

Subject : Science and Tech

Section: Space tech

Context: On December 25, Japan’s Smart Lander for Investigating Moon (SLIM) spacecraft entered into orbit around the moon and will land on January 19.

More on news:

• Japan will become the fifth country to soft-land a robotic craft on the natural satellite
• SLIM’s success or failure will also affect the upcoming Chandrayaan 4 mission.
• India succeeded with its Chandrayaan 3 mission in August 2023 to demonstrate end-to-end capability in safe landing and roving on the lunar surface.

About SLIM:

• Spacecraft: SLIM is a spacecraft built and launched by the Japan Aerospace Exploration Agency (JAXA) on September 7, 2023
• Low Weight: It weighed only 590 kg at launch(one-seventh of Chandrayaan 3 3,900 kg at launch).
• Counterparts:SLIM was launched with XRISM which is a next-generation X-ray space telescope which is onboarded an H-2A rocket.
• Other global missions: JAXA launched SLIM only two weeks after the surface component of India’s Chandrayaan 3 mission succeeded and Russia’s Luna 25 spacecraft failed.

 SLIM and its path to moon:

• 4 months: SLIM took four months because it followed a longer but more fuel-thrifty route based on weak-stability boundary theory.
• Kinetic energy:Once it is launched into an orbit around the earth ,SLIM will  swung around the planet multiple times in order to  build up its kinetic energy with each swing.
• Deflection in moon’s direction: On getting nearer to the moon,SLIM  instead of slowing down and being captured by the moon’s gravity, it allowed itself to be deflected in the moon’s direction .This deflection is the result of the combined forces exerted by the earth and the moon.
• About Hiten: Physicists worked it out in the late 1980s for another JAXA mission, called ‘Hiten’.

SLIM and its objective:

• Moon sniper: SLIM’s standout feature is its reputation as the “moon sniper” as it will try to land within 100 meters of its chosen landing site which is an unusually tight limit given the history of moon-landing missions.
• For example, the ‘Vikram’ lander of Chandrayaan 3 landed at a spot 350 meters away from a predetermined one.
• Soft land: SLIM will attempt to soft-land with the smallest ever area tolerance on the moon. The chosen site is near the Shioli Crater, at 13.3º S and 25.2º E., SLIM will use data from JAXA’s SELENE orbiter, which ended in 2009.
• Lower mass: Its lower mass ( only 120 kg excluding fuel) will help in this endeavor by rendering it more maneuverable while its small size will be a test of its economical design.
• Two rovers: SLIM will deploy two small rovers called Lunar Excursion Vehicle (LEV) 1 and 2.
• LEV-1, LEV-2, and SLIM will together study the lunar surface near the landing point, collect temperature and radiation readings, and attempt to study the moon’s mantle.

How will SLIM affect Chandrayaan 4?

The terrain near the moon’s poles is rocky, pocked with several craters, and full of steep slopes. Axiomatically, if there is a suitable landing spot for a (relatively) large landing module or rover, its downrange and cross-range limits will be lower than they were for Chandrayaan 3. The craft will have to land as close to the site as possible, if not at the site itself.