The cost of NASA’s Mars Sample Return project has risen from a projected US$5.3 billion to US$11 billion, prompting many to question if the mission is worth continuing. In response, the space agency has turned to its field centres for cost cutting ideas, with any mission delayed until 2035 at the earliest.
If this cannot be done (the life of the Perseverence rover, already on Mars, is an issue), then it seems likely that the mission will be cancelled, and money will be channelled to other NASA programmes, most probably the human lunar and Mars landing and return efforts.
Artist’s impression showing Mars Ascent Vehicle (MAV) lifting off from lander carrying sample for return to Earth. Courtesy: NASA-JPL
The original plan
Although samples from the surface of asteroids, comets, and the Moon have all been brought to Earth, humans are yet to retrieve one from a planet. It was this missing piece that brought forth the decision to attempt a remotely controlled sample return mission from the surface of Mars.
NASA and the European Space Agency (ESA) combined efforts to create a plan to recover samples drilled from the Martian surface by Perseverance, the rover already on the planet. The original plan had a Mars return vehicle – the Earth Return Orbiter (ERO) – orbiting the planet and a landing craft – the Entry, Descent and Landing system (EDL) – that would attempt to land in the early 2030s. After reaching the surface, the lander would receive samples from Perseverance via another ‘Fetch Rover’ and these would be placed into a 2.7 m long two-stage rocket dubbed the Mars Ascent Vehicle (MAV), being developed under a NASA contract by Lockheed Martin. This would lift off, taking the rock and soil samples back into Mars orbit. The ‘Orbiting Sample’ is then picked up by the ERO return craft (finding it by its radio beacon) and placed into another sealed capsule before beginning its return to Earth. Just before its arrival ERO would release the capsule so it could make a direct entry into Earth’s atmosphere, followed by a parachute arrested landing on a desert floor. Then, if all things went to plan, the capsule, still hermetically sealed, would be taken to a laboratory for its contents to be released and examined.
So what went wrong?
The Mars Sample Return project’s cost has risen from the original estimate of US$5.3 billion, then to a projected US$8 billion, and most recently to a figure of US$11 billion with US$3 billion already spent. This has resulted in many querying whether the mission is now worth doing. A commissioned independent review which estimated the latest cost estimate noted that a series of missteps had been made. This included an under appreciation of the technology and timeline required to develop such a mission. There was also an over complexity of the mission architecture including five different types of spacecraft/rover vehicles including a rather complicated rendezvous and docking procedure. Finally, and most importantly, there was general mismanagement of the project involving several field centres within NASA.
Apart from the current plan’s cost and complexity, a separate concern about the mission has been voiced by scientist. Biological threats to Earth have long been a staple of science fiction but have also been underlined more recently in the wake of the Covid-19 pandemic. The Mars sample return mission could expose our planet to such a threat, through a potential breach of the sample capsule during the landing process, or due to a less than adequate quarantine system. The scientists’ fears are not unjustified: a parachute failure led to the crash landing and a breach of the Genesis capsule carrying solar wind particles back to Earth.
Suggestions so far
With the project in financial trouble NASA Administrator Bill Nelson has now tasked the agency’s various field centres with to come up with a cheaper plan. One possibility is for the sample size to be reduced to about one third of what was originally envisaged to be returned. This would significantly reduce the size and complexity of lander and ascent system needed.
Another is that the mission could do away with the sample return aspect altogether and instead replace this with a specialist laboratory lander to do in situ analysis of the samples on the surface of Mars.
Comment by David Todd
The Mars Sample Return mission – attractive as it seems – is now so prohibitively expensive, and its delays so pronounced, that it should be scrapped and its funding spent elsewhere.
For example, only a small portion of the US$11 billion saved could be channelled into NASA’s science budget to save the venerated Chandra X-ray observatory. It still has a few years of good observations left if it is allowed to live. On a grander scale, such was the success of the small robotic helicopter Ingenuity on Mars that NASA plans to fly one on Saturn’s Moon Titan called Dragonfly. And it needs more funding as its own projected costs have ballooned to over US$3.3 billion.
Similarly, if NASA wants to get to the Moon before the end of the decade it needs to direct some cash to develop a small storable propellant human-carrying lunar lander and transfer stage for the early Artemis landing missions. The cryogenic efforts of SpaceX and Blue Origin for the currently planned Human Landing System (HLS) just won’t be ready in time.
Finally, some of the savings should be used to start designing a human Mars mission which could be flown by the late 2030s if NASA ever gets its act into gear. If such a mission was made in good time, it would make any Mars robotic sample return mission redundant.
