Washington, April 29 (IANS) NASA has said that a crack that it detected in the Mars 2020 rover's heat shield will not change the mission's launch date.

The fracture, which occurred near the shield's outer edge and spans the circumference of the component, was discovered on April 12, after the shield completed a week-long test at a Lockheed Martin facility near Denver.

In a statement this week, NASA said it was working to build a replacement heat shield structure for the Mars rover.

"The situation will not affect the mission's launch readiness date of July 17, 2020," the statement added.

The test was designed to subject the heat shield to forces up to 20 per cent greater than those expected during entry into the Martian atmosphere.

The heat shield is part of the thermal protection system and aeroshell designed to encapsulate and protect the Mars 2020 rover and landing system from the intense heat generated during descent into the Martian atmosphere.

The structure was originally tested in 2008 and was one of two heat shields manufactured in support of the Mars Science Laboratory mission, which successfully landed the Curiosity rover on Mars in August 2012.

The current heat shield will be repaired in order to support the pre-launch spacecraft testing while a new heat shield structure is readied for flight over the next year, NASA said.

The Mars 2020 rover is designed to seek signs of habitable conditions on Mars in the ancient past, and also search for signs of past microbial life.