On December 4th 2012, it was announced that NASA intends to launch another rover to Mars in 2020. The successful landing and science conducted by the Mars Science Laboratory (MSL) Curiosity rover has renewed the confidence of the agency to replicate its success. Utilizing the same basic design as MSL and over $200 million worth of flight ready hardware leftover from development, NASA hopes this will reduce mission costs by almost a billion dollars.
What the 2020 rover will be designed to investigate has yet to be announced. Many speculate, and hope, that this mission will be a chance to fulfil the highest priority of the 2010 Planetary Science Decadal Survey. Every ten years, the National Research Council prepares a document listing the highest priority goals listed by scientists from various fields, and in the case of planetary science, the report was published in 2010. The Decadal Survey listed a Mars “sample return” mission as the most sought after goal of the planetary science community.
Few mission concepts have endured like the tantalizing prospect of collecting a sample from the surface of Mars and returning it to Earth for study. Numerous studies have been performed, landing vehicles designed, and funding sought. The technical challenges would be immense. Prohibitive costs have always been cited as the greatest challenge, however.
The task of retrieving a Martian rock sample will be difficult and more than a little complicated. During the Apollo missions, astronauts were able to simply collect lunar regolith samples in a bag and return to Earth for study in their command module capsule. Unfortunately, there won’t be any astronauts on Mars to attempt a similar method of sample collection for years to come. This means NASA and its partners will need to develop a robotic vehicle to operate in the place of human astronauts.
Presently, a Mars sample return mission would require a series of vehicles in order to complete this “holy-grail” of planetary science goals. A three-tiered mission architecture is envisioned; one vehicle to collect and cache a sample, a second to launch and fly to Martian orbit, and a third to collect it from the orbiter and return to Earth where it would re-enter the atmosphere and land so the sample could be extracted. The 2020 rover could, if chosen to do so, could become the first leg of this journey.
This is not the first time a sample return mission has been proposed. For as long as the world’s space agencies have launched interplanetary probes, studies have been done to determine the feasibility of collecting a sample for return and examination on Earth. While technologically difficult, it is not without precedence – the Japanese Hayabusa probe successfully collected a microscopic surface sample of the asteroid Itokawa in 2010. The Russian space Agency Roscosmos attempted to launch a similar mission to Phobos, the larger of Mars’ two moons, but the probe was lost following a launch vehicle anomaly.
NASA recently selected the members of the Science Definition Team (SDT) from a list of hundreds of potential candidates, who together will determine the mission and goals of the 2020 rover. With selection complete, the process of choosing instrumentation and science teams can now begin. One can expect that a number of instruments will be designed to identify potential elements that may have sustained life, if it ever existed on Mars. Many hope that this team will decide upon sample-return as the 2020 rover’s primary mission. Both the Planetary Society and the American Astronomical Society’s Division for Planetary Sciences (DPS) have endorsed the proposal to conduct a sample return mission.
However, the 2020 rover (which has yet to acquire a name similar to rovers that preceded it) will likely be the only “flagship” mission for planetary science in the next decade. Reductions to the planetary science budget, sequestration, and the rising costs of other NASA projects have forced planetary scientists to focus on smaller, less-expensive and shorter-term missions in order to study the moons and planets of our Solar System. Even exploration of the red planet, which has seen an armada of probes and rover in the last decade, will see fewer mission directed toward its study.
Because of the reduced spending on planetary science missions, NASA may decide it will be more prudent to equip the 2020 rover with instrumentation for analysis on Mars, as MSL and MER currently do. The possibility that the “return” legs of the sample return mission profile might not be adequately funded (or worse, cancelled) could lead to an expensive mars rock collecting rover with no way to deliver its cargo to Earth for study. Like Curiosity, the 2020 rover might carry a range of remote sensing and contact instruments to study geology and potential astrobiology.
How likely is it that the 2020 Mars rover will be part of a greater sample return architecture? That remains to be seen. NASA will face a number of annual budget cycles before the rover’s construction must be completed for the intended launch window. In that time, Administrations will change, NASA leadership will change, and the agency will also be conducting the most ambitious beyond-low-Earth-orbit (BLEO) human exploration missions since the Apollo Lunar missions ended in 1972. How much commitment the planetary science community gives to Mars sample return may depend on how well the budget supports other missions, particularly the lagging exploration of the outer planets.
At the annual Lunar and Planetary Science Conference (LPSC), held in Woodlands, Texas this year, it was noted that future efforts toward studying the gas giant planets and their multitude on moons will be diminished because of the budget for Flagship-class missions. NASA’s Science Mission Directorate (SMD) continues to support Discovery-class missions to the outer planets, but the price cap on mission costs will make such endeavors unlikely. Is this indicative of a Mars-bias? Some scientists think so, but that would be in-line with the agency goals of eventually supporting human missions to Mars in the 2030 timeframe.
Indeed, 2 more missions were announced just prior to the announcement of the 2020 rover. Mars Atmosphere and Volatile Evolution, or MAVEN, an orbiter designed to study the Martian atmosphere will launch next year- and InSight (which stands for Interior exploration using Seismic Investigations, Geodesy, and Heat Transport) , a lander based on the successful 2008 Phoenix mission, which will use a drill device to probe the planet’s crust, will launch in 2016. Taking advantage of the 2018 launch window will be the joint European Space Agency (ESA) and Russian space agency (Roscosmos) ExoMars rover mission. The ExoMars mission will incorporate an ambitious plan to utilize an orbiter and a rover for a planned multi-year study. These missions, as well as the NASA rovers Opportunity and Curiosity, are adding to our knowledge of Mars over the coming decade.
While Mars exploration continues with the rovers presently on the surface and the orbiters overhead, the question remains as to whether NASA’s 2020 rover will play any role in a sample return mission. The planetary science community looks forward to the decisions made by the SDT. In either case, the coming decade will be an interesting one to watch when it comes to the 4th planet in our solar System.
Casey Stedman (@Stedman_casey) is affiliated with ERAU-Worldwide Campus