- August 31, 2023
Chandrayaan-3: Pragyan’s navigation cameras weigh just 125gm each, can tolerate high radiation, low temperature | India News – Times of India
The much-awaited pictures of India’s Vikram on the lunar surface has reached Earth, showing the Chandrayaan-3 lander that made the historic soft-landing on August 23 with the ramp that allowed the rover to roll out.
The photographs taken at at 7.3am and 11am Wednesday using the onboard cameras of Pragyan, the rover, also show two payloads — Instrument for Lunar Seismic Activity (ILSA) and Chandra’s Surface Thermo Physical Experiment (ChaSTE) — descending on to the lunar surface for in-situ experiments.
The second batch (taken at 11am) of photos Isro released was taken from just 15m from the lander. The Pragyan navigation cameras, the ones that guide the rover, were developed in a quiet lab called LEOS in Bengaluru.
The Laboratory for Electro-Optics Systems or LEOS had first developed these cameras as early as 2012 as part of preparations for Chandrayaan-2. The cameras were onboard the rover that went as part of the 2019 mission that failed.
“In 2019, a rover task group was formed with 12 people again. And the target set for me was to make light-weight cameras that could withstand lunar radiation and extreme temperatures. Each of the two cameras weigh only 125 grams. We’ve used LEOS’ own optics and miniaturised sensor and its great to see it work so well. The lander photo released today looks very clear,” Selvaraj P, former Isro group head, LEOS, and project manager of rover, told TOI.
These miniaturised digital cameras, Selvaraj said, use multi-element lenses and their image quality was verified through a host of tests on the ground.
“These cameras can withstand 50 megarad (radiation in space) which means unlike regular cameras that can get damaged in such conditions, these can perform for a really long time. The material and processes used also allow it to survive extremely low temperatures. We’ve tested it for -200° Celsius in vacuum. We expect it to survive the night and return to life when the sun rises again,” Selvaraj said.
These cameras are the eyes of Pragyan, allowing it to navigate on the lunar surface, while also sending in pictures. For every path planning, data from these navigation cameras need to be downloaded to ground where a digital elevation model (DEM) is generated. Then, the ground and mechanisms teams decide which path is best for Pragyan and uplink the command for the rover to follow.
The images taken by the rover further reiterate how smooth the landing was on August 23 and how firm Vikram is on Moon. Last week, PM Modi, who was briefed by Isro on the landing, had said: “…Our lander has firmly set its foot on the Moon like ‘Angad’ (from Ramayana). The entire world recognises India’s scientific spirit, technology and temperament.”
The photographs taken at at 7.3am and 11am Wednesday using the onboard cameras of Pragyan, the rover, also show two payloads — Instrument for Lunar Seismic Activity (ILSA) and Chandra’s Surface Thermo Physical Experiment (ChaSTE) — descending on to the lunar surface for in-situ experiments.
The second batch (taken at 11am) of photos Isro released was taken from just 15m from the lander. The Pragyan navigation cameras, the ones that guide the rover, were developed in a quiet lab called LEOS in Bengaluru.
The Laboratory for Electro-Optics Systems or LEOS had first developed these cameras as early as 2012 as part of preparations for Chandrayaan-2. The cameras were onboard the rover that went as part of the 2019 mission that failed.
“In 2019, a rover task group was formed with 12 people again. And the target set for me was to make light-weight cameras that could withstand lunar radiation and extreme temperatures. Each of the two cameras weigh only 125 grams. We’ve used LEOS’ own optics and miniaturised sensor and its great to see it work so well. The lander photo released today looks very clear,” Selvaraj P, former Isro group head, LEOS, and project manager of rover, told TOI.
These miniaturised digital cameras, Selvaraj said, use multi-element lenses and their image quality was verified through a host of tests on the ground.
“These cameras can withstand 50 megarad (radiation in space) which means unlike regular cameras that can get damaged in such conditions, these can perform for a really long time. The material and processes used also allow it to survive extremely low temperatures. We’ve tested it for -200° Celsius in vacuum. We expect it to survive the night and return to life when the sun rises again,” Selvaraj said.
These cameras are the eyes of Pragyan, allowing it to navigate on the lunar surface, while also sending in pictures. For every path planning, data from these navigation cameras need to be downloaded to ground where a digital elevation model (DEM) is generated. Then, the ground and mechanisms teams decide which path is best for Pragyan and uplink the command for the rover to follow.
The images taken by the rover further reiterate how smooth the landing was on August 23 and how firm Vikram is on Moon. Last week, PM Modi, who was briefed by Isro on the landing, had said: “…Our lander has firmly set its foot on the Moon like ‘Angad’ (from Ramayana). The entire world recognises India’s scientific spirit, technology and temperament.”
