NASA’s robotic Mars exploration program is in crisis. A recent review of the plan of its flagship Mars Sample Return (MSR) mission pegged its cost at $10 billion, a price tag that threatens to preclude funding every other exploration missions to the Red Planet for the following decade and a half.
While the decadal plan issued by a National Academy of Science committee identifies the MSR mission as the highest priority for NASA’s Mars exploration program, given the fee and schedule numbers now available, it’s time for the remaining of us to query whether this system of record still is smart.
Allow us to consider the choice. For a similar $10 billion now projected to be spent on the MSR mission over the following 15 years, we could send 20 missions averaging $500 million each in cost. These could include landers, rovers, orbiters, drillers, highly capable helicopters, and possibly balloons or other more novel exploration vehicles as well. As an alternative of being limited to 1 exploration site, these could possibly be targeted to twenty sites and carry an unlimited array of latest instruments provided by a whole bunch of teams of investigators from all over the world.
NASA claims that its Mars exploration program goals to look for all times. Nonetheless, the agency last flew a life detection experiment to Mars in 1976. With a strong program of this sort, we could fly a dozen life detection missions to numerous locations and never only test the surface soil in various latest ways for all times but drill right down to search way more life-favorable strata beneath the surface.
With a strong program of this sort, we could do many other things. Helicopters of other aircraft could carry sniffers to look for methane vents, and study 1000’s of surface locations every time they land. Such craft could also scan the subsurface of the planet for caverns and hydrothermal systems using ground penetrating radars (GPR). The ability of a radar return signal goes because the inverse fourth power of the space from the transmitter to the goal, providing an eight-order of magnitude advantage to aircraft over orbiters for this sort of exploration. Most of Mars is underground. We must always see what’s there.
These are only a few examples. For each instrument flown on Curiosity or Perseverance, there have been 10 other good ones proposed that needed to be excluded for lack of payload capability. With a strong program of this sort, many more instruments would get a likelihood to be flown. Not only that, but with plentiful missions within the queue, it could be possible to make use of the knowledge provided by early missions to enhance the engineering design of the exploration vehicles and discover the very best instruments and goal locations for follow-up investigations.
The science return from such a wealthy and varied program of this sort would vastly exceed that offered by returning a number of samples from one location on Mars. The authors of the National Academies of Science committee report apparently disagree. But there may be one other issue: Mission risk.
To be remotely competitive with the various program, the MSR needs to truly return the samples it collects to Earth. What’s the prospect that can occur?
Let’s take a look at the numbers. In its history, NASA has flown 25 spacecraft to Mars, of which (if we include the Ingenuity helicopter within the count) 20 have been successful. That could be a mission success probability of 0.8. The European Space Agency’s Mars spacecraft track record is 2 out of 4, for a mission success probability of 0.5. The MSR mission, as currently conceived, includes two latest NASA spacecraft (the sample return lander and the ascent vehicle), and one ESA spacecraft (the orbiter that can collect the sample in Mars orbit and return it to Earth.) If any of those three spacecraft fails, the mission fails. That signifies that to calculate the probability of mission success, one must put the success probability of every into series, and multiply them together. That signifies that, based on the person risk presented by each of the principal flight elements alone, the general probability of mission could be 0.8 x 0.8 x 0.5 = 0.32 or about one in three.
That estimate, nonetheless, doesn’t include the extra risk related to the interface between the flight elements, most significantly the success of the autonomous rendezvous and dock and sample transfer in Mars orbit between the Mars ascent vehicle and the sample return orbiter, which has never been done. Moreover, the 0.32 estimate for the probability of MSR mission success only includes technical risk. It ignores programmatic risk, which within the case of the ESA orbiter is incredibly high, as that program could easily be canceled should any one among a dozen governments have a change of heart about funding it any time over the following decade. Indeed, even when the ESA orbiter is funded, the probability is incredibly high that it won’t arrive on time, as witnessed by the continued travails of ESA’s Rosalind Franklin Mars rover, which, while originally planned for 2018 launch, is now scheduled for flight in 2028.
Briefly, the MSR program of record is incredibly high risk. It could thoroughly not produce any science in any respect.
In contrast, the success of the various program is virtually guaranteed. With 20 independent missions, each with a hit probability of 0.8, the chances are that at the least 16 of the 20 will succeed – most likely more, since later missions can reap the benefits of lessons learned on earlier flights.
Given these realities, it could be irresponsible for NASA to unquestioningly accept the National Academies of Science recommendations and put all its Mars exploration program eggs in the only high-risk basket of the sample return mission. On the very least, a study needs to be done comparing each the scientific return and risk of the MSR program of record against that of the various program, assuming each are funded at the identical level.
What’s the very best Mars exploration program that the American people should purchase for his or her $10 billion? All options needs to be on the table. Congress should insist that NASA provide the numbers.