Communications Lost with Chandrayaan-2 Just Before Landing on Moon – UPDATED

India’s Chandrayaan-2 lander/rover failed to successfully land on the Moon today (EDT).  Communications were lost 2.1 kilometers before the expected touchdown.  Speaking to the Chandryaaan-2 team hours later, India’s Prime Minister Narendra Modi called the mission an “amazing journey” and assured them “the best is yet to come.” [UPDATED September 8, with news about locating it on the surface.]

Chandrayaan-2 was launched on July 22 and arrived in lunar orbit on August 20. The spacecraft has three parts:  orbiter, lander, and rover.   The lander/rover separated from the orbiter on Tuesday and conducted a series of maneuvers to lower its orbit and, today, descend to the surface.

The lander is named Vikram after Vikram Sarabhai, the father of India’s space program.  It incorporates the rover, Pragyan (Wisdom in Sanskirt) which was to roll off the lander and conduct independent scientific investigations.

The landing was broadcast live and the spacecraft’s radio signals were monitored by astronomers in other countries as well. It became apparent that something was amiss during the final minutes of descent after the spacecraft completed a set of “rough braking” engine burns and was in the “fine braking” phase. Cees Bassa, an astronomer in the Netherlands, tweeted Doppler curves of the radio frequencies showing that they disappeared before landing.

It looks like the @isro #Chandrayaan2 Vikram lander has crashed. After the rough braking phase the Doppler curve from @radiotelescoop shows some wiggles, and then, at 20:20:01UTC the signals disappeared… pic.twitter.com/YQzriRslQ3

— Cees Bassa (@cgbassa) September 6, 2019

The Indian Space Research Organisation (ISRO) later confirmed that communications were lost at an altitude of 2.1 kilometers and “data is being analyzed.”

This is Mission Control Centre. #VikramLander descent was as planned and normal performance was observed up to an altitude of 2.1 km. Subsequently, communication from Lander to the ground stations was lost. Data is being analyzed.#ISRO

— ISRO (@isro) September 6, 2019

Modi was present at the control center in Bengaluru during the attempted landing and offered encouragement to the scientists and students gathered there once it was apparent something was awry.  He returned several hours later and gave a formal speech reiterating his pride in the scientists working on the mission and the Indian space program as a whole.

“We came very close, but we will have to cover more ground in the times to come,” but “we are full of confidence” and “the best is yet to come. … To our scientists I want to say — India is with you.”  Narendra Modi

UPDATE:  The head of ISRO, K Sivan, told local news outlets on September 8 that the Chandrayaan-2 orbiter had taken a “thermal image” of the Vikram lander and it “must have been a hard landing” but it is “premature to say anything” about its status.  The image had not been released as of press time.  The orbiter carries an imaging infrared spectrometer. 

The details of what went wrong are not yet known, but India is the second country this year to experience a disappointing ending to a lunar landing attempt.  An Israeli spacecraft, Beresheet, crashed in April.

So far, the Soviet Union, the United States and China are the only countries to successfully land on the Moon.  Only the United States has landed not only robotic spacecraft, but humans, on the lunar surface.  This year is the 50th anniversary of the first human lunar landing, Apollo 11, on July 20, 1969.  Five more American crews landed on the Moon through 1972.  NASA is currently planning to return American astronauts to the Moon by 2024 — the Artemis program.

Despite the fate of the lander/rover, the Chandrayaan-2 orbiter continues with its mission.  It carries eight scientific instruments including a terrain mapping camera, large area soft x-ray spectrometer, solar x-ray monitor, orbiter high-resolution camera, imaging infrared spectrometer, dual frequency synthetic aperture radar, atmospheric compositional explorer, and dual frequency radio science experiment.

 Note: this article was updated on September 6 EDT after PM Modi addressed the Chandrayaan-2 team at 10:30 pm EDT (September 7, 8:00 am Indian Standard Time), and again on September 8 EDT with news about locating the lander on the surface.