Planetary scientists and engineers at the Jet Propulsion Laboratory (JPL) may get a chance to reprise the Mars Science Laboratory’s Curiosity rover, if Congress goes along with a NASA decision to develop another rover that would reach the planet’s surface using the “sky crane” technique that worked so well in August.

John Grunsfeld, the former astronaut who is NASA’s associate administrator for science, was set to announce today that the planned new rover would be launched in 2020 to cap a restructured U.S. robotic Mars exploration program.

Instrumentation for the new rover would be competed after a science team determines objectives for the 2020 surface mission. While NASA has said it continues to support the scientific priority of returning Mars samples to Earth for detailed analysis, it remains unclear how the new mission would support that objective.

The U.S. agency withdrew from a joint effort with the European Space Agency’s ExoMars program to begin caching samples for eventual return to Earth, and ESA has since joined the Russian space agency Roscosmos in continuing that plan.

Agency officials briefing lawmakers have said the new mission can be accommodated within the Obama administration’s fiscal 2013 budget request, which did not include funds to work with ESA. But it remains to be seen if Congress will appropriate funds for a new surface mission.

Curiosity is the largest payload ever landed on Mars. Its sky crane landing technique, which lowered the rover to a wheels-down landing on cables played out from a platform hovering on retro rockets, was untried until its Aug. 6 success inside Mars’ equatorial Gale Crater.

By using the same approach, NASA hopes to hold down development costs for the second rover, and maintain the skills at JPL that enabled the success with Curiosity.