Their remarks came hours after communication between India's moon lander Vikram and the orbiter got snapped in a last minute snag with the former just 2.1 km away from its designated landing spot on the Moon's South Pole early on Saturday.
"Congratulations to the team at ISRO for their incredible work on the Chandrayaan 2 Moon Mission. Your passion and dedication is an inspiration to every Indian," Rahul Gandhi said in a series of tweets.
"Your work is not in vain. It has laid the foundation for many more path breaking and ambitious Indian space mission," he said.
Sonia Gandhi said in a statement: "We owe a great debt to ISRO and the brilliant men and women who staff it."
Hailing the work of the ISRO scientists, she said: "Chandrayaan 2's journey may take us slightly longer but ISRO's history is replete with examples of their determination in the face of seemingly hopeless odds.
"They never give up. I have no doubt that we will get there, if not today, then tomorrow; together as a nation."
Sonia Gandhi recollected that the scientists at ISRO have achieved incredible feats with 115 successful space missions and astounding successes with Chandrayaan 1 (India's first Moon mission) and Mangalyaan (Mars mission) and the nation was extremely proud of their immense successes.
She said that "no success is final and every obstacle is a stepping stone to future success".
"Chandrayaan 2 has laid the foundation for achieving greater feats and the entire country awaits in anticipation for traversing the next frontier of space," she said.
Meanwhile, Congress spokesperson Randeep Singh Surjewala also congratulated ISRO scientists, saying they have traversed the new frontiers of space and made every citizen proud.
"Chandrayaan-2 mission is a testimony that ISRO's scientists have traversed the new frontiers of space and made every Indian proud.
"We see it as a new opportunity to surge ahead and reach greater heights. Future is only brighter to achieve new feats and heights," Surjewala tweeted.
( With inputs from IANS )