It would be the most precious cargo since the Apollo astronauts returned Moon rocks to Earth. In 2033, humans would arrive in Mars orbit in order to pick up and return to Earth a canister containing the hopes and dreams of Mars scientists: a small collection of Mars rocks that would have been previously collected and put into orbit.

An internal NASA study group, tasked with replanning the agency’s beleaguered Mars programme, revealed on Tuesday that it was using this working scenario and date as a goal. The group has been tasked with finding ways of getting the human and robotic sides of NASA to work together more. In return for supplemental funds from the human programme and the technology office, the robotic science missions might, for instance, include experiments useful for the human programme, such as radiation detectors or optical communication demonstrations.

While the administration of President Barack Obama has said before that it would like to put humans in the vicinity of Mars by the early 2030s, this is the first articulation I’ve seen of a specific, shared date for the key goal of both the human and robotic sides. Orlando Figueroa, a former NASA official leading the study group, presented the working plans on Wednesday to a newly convened committee of the National Academies responsible for astrobiology and planetary science.

Some of the committee members weren’t too thrilled to be wedded to the human programme. Some pointed out that the technological challenges in getting people to Mars are much greater — and much more expensive — than sending a robot. Such a long mission not only requires new rocketry to get there, but also new materials that would shield astronauts from the intense radiation that exists outside the comfortable environment of the Earth and its magnetosphere. Figueroa says that a robotic retrieval mission could be sent instead in 2033.

Figueroa also mentioned four possible scientific pathways that could define the new Mars programme. My distillation of them are as follows:

1) Proceed, as quickly as the budget allows, with the existing plans for the first stage of a Mars sample return mission: sending a rover to a specific site to identify and cache intriguing samples that would later be lifted into orbit and returned.

2) Do surface science at as many as three sites — increasing the time before samples are returned but increasing the probability that one of the sites has preserved life.

3) Shift away from the singled-minded focus on sample return and perform more generalized Mars “system science”, which could include atmospheric and interior investigations.

4) Consider the possibility that the Curiosity rover, due to land at Gale Crater in August, makes a breakthrough discovery that motivates an intense and immediate follow-up study.

Figueroa’s group is supposed to submit its final report to NASA later this summer.