The hunt to find signs of ancient life on Mars involves bringing back rock samples from the Red Planet — these are currently being collected by NASA’s Perseverance rover on the 45-km-wide Jezero Crater. The initial plan was to send a sample-return lander (SRL) by 2026 and get back the samples by 2031. But that timeline appears to have been pushed back. NASA has announced that the plan would now include an additional lander because of which the SRL launch date has been pushed back to 2028 and the sample return to 2033.Perseverance is working on the Jezero Crater as scientists believe it harboured a lake and a river delta billions of years ago. The rover is scratching beneath the surface to collect samples so that when they are brought back to Earth, scientists could have a closer look to figure out whether they hold any signs of ancient life.The mission was complex. For the 2026 launch plan, SRL was to carry a NASA Mars ascent vehicle (MAV) and an ESA-built fetch rover. The fetch rover was to pick the sample container from Perseverance and bring it to the MAV. The MAV would then have launched into Martian orbit with the samples. Then, an ESA-built Earth-return Orbiter to collect the samples from MAV and bring it back to Earth by 2031.But NASA is now planning to use a dual-lander architecture.“The development of a second lander necessitates a move to a 2028 launch date and 2033 sample return date and is consistent with the Mars Sample Return Independent Review Board’s finding that a dual-lander architecture may improve the probability of mission success,” stated NASA officials in a budget request proposalConsequently, the launch of the Earth-return orbiter has also been delayed, from 2026 to 2027.This is not the only mission that NASA has delayed. Its other ambitious plan — Artemis I— to return humans to the Moon has also been pushed back several times. Artemis I was originally scheduled to launch in November last year, but after several delays, NASA has said it is targeting summer this year for launching the first of the several Artemis flights.