On Wednesday, NASA announced that it had made major changes to its plan to return samples from the surface of Mars in the early 2030s. Currently collected by the Perseverance rover, the samples are expected to be moved to Earth by a rover and rocket relay. Now, inspired by the success of the Ingenuity helicopter, NASA says it can lose one of the rovers, replacing it with a pair of helicopters instead.
The plan to return the samples from Mars involves a lot of challenges, but one of the main ones is that the samples are currently in Perseverance, but must eventually end up in a rocket that takes off from the surface of Mars. This means that Perseverance will have to get close enough to the rocket landing site – which we can’t choose precisely – to swap the samples, possibly diverting it from scientific purposes. It also cannot be too close when the rocket lands since landing the rocket and its associated hardware could pose a risk to the rover and its samples.
The original plan included a contingency. The perseverance would approach after the rocket landed and the samples would be transferred directly. If that didn’t work for some reason, a second rover sent to Mars by ESA would act as a go-between, visiting a site where the samples had been cached, retrieving them, and then delivering them to the rocket.
In the new plan, this second rover has been eliminated. In its place? Two helicopters. These will be delivered as part of the same payload as the rocket carrying the samples into orbit. As a result, the new plan involves only one lander (beyond the one that delivered Perseverance) that will carry both the rocket and the helicopters, greatly reducing the risk of the overall plan.
These helicopters, naturally, will be based on the design of Ingenuity, which was sent to Mars as a test vehicle and far exceeded expectations, completing 29 flights in a year. Given this experience, NASA is confident that helicopters can be designed to carry small payloads and potentially make multiple flights between the return rocket and where the samples are, either on Perseverance or in a location cache.
After that, the plan remains the same. The samples will be loaded into a container placed on the Mars Ascent Vehicle designed by NASA to transport them into orbit. There, the container will be transferred to the Earth Return Orbiter, built by ESA, which will bring them back to Earth in 2033, when they will fall into the atmosphere to be recovered and studied.
The next step will be approval by ESA, after which the two agencies will begin the preliminary design phase, which will handle all the details of the various vehicles that will be needed. Meanwhile, Perseverance has already collected about ten samples from the surface of the red planet.