- Title: Dispelling the myth of robotic efficiency: why human space exploration will tell us more about the Solar System than will robotic exploration alone
- Authors: Ian Crawford
- First author’s institution: Department of Earth and Planetary Sciences, Birkbeck College London, Malet Street, London, WC1E 7HX
Although many astronomers enjoy films and books like Apollo 13 and The Right Stuff, the majority of astronomers seem to favor robotic exploration over manned spaceflight. The most common argument is that robotic exploration is simply more efficient and cost-effective than human exploration. A recent paper by Ian Crawford challenges this view by arguing that the increased mobility, flexibility, and efficiency of human exploration outweigh the added cost of sending people into space.
Crawford bases his analysis on the American Apollo program, field studies in analog environments, and current trends in robotic exploration. He points out five major advantages of human space exploration:
- Humans can make spur of the moment decisions and react well to sudden changes.
- Humans can travel more quickly over uneven terrain. (Apollo 17 astronauts covered more distance in three days than the Mars Exploration Rover Opportunity has covered in eight years!)
- Humans are better at selecting diverse samples and a manned mission is automatically a sample return mission.
- Humans are better suited to conducting complex tasks like drilling.
- Human spaceflight has enabled space-based astronomy. Think of all of the fantastic science that was enabled by the space shuttle servicing missions to the Hubble Space Telescope.
Crawford addresses the first four bullet points by comparing the performance of the Apollo astronauts with the performance of robotic missions to the Moon and Mars. The disparity between the manned and robotic missions is striking: the Apollo astronauts collected and returned 382 kg of samples from more than 2000 different sampling locations while the Luna sample return missions returned only 0.32 kg of Moon rocks. In addition, many more referred scientific papers have been written about the Apollo data than about data from robotic missions. As shown in the figure below, scientists have written over 2500 refereed publications about the Apollo data, roughly 500 publications about the Luna sample return data, and fewer than 500 papers about data from the Lunokhods, Surveyors, and Mars Exploration Rovers. Interestingly, the rate of papers about Apollo is still rising despite the fact that the last Apollo astronauts left the Moon in 1972.
Although the scientific rewards of the Apollo missions are impressive, the cost of the Apollo program was significantly higher than the cost of the robotic missions to the Moon and Mars. Crawford states that the Apollo program would cost $175 billion in 2012 dollars while the most expensive of the robotic missions (the Mars Science Laboratory, currently en route to Mars) cost $2.5 billion. However, Crawford projects that the cost of robotic missions will continue to increase as planetary scientists design rovers to accomplish more complicated tasks. The figure below illustrates that point by comparing the cost of Pathfinder, the Mars Exploration Rovers, the Mars Science Laboratory, and a proposed Mars Sample Return mission. With each generation, the rovers became bigger and better able to explore the Martian surface. Unfortunately, the increase in scientific capability comes with an increasing price tag. Crawford questions whether future science budgets will have enough cash to pay for bigger and bigger rovers given the current issues funding robotic space exploration.
In Crawford’s opinion, the solution around the increasing cost of robotic exploration is to piggyback science on politically-motivated missions that are primarily funded through non-science avenues. For instance, the bulk of the $175 billion spent on Apollo would have been spent regardless of whether there was any science associated with the race to the Moon. Crawford states that the added science cost of the Apollo program is only $2.09 billion in 2012 dollars: nearly $0.5 billion less than the Mars Science Laboratory. In order to advance scientific understanding of the Solar System, Crawford argues that astronomers should participate in human exploration of the Solar System such as the program outlined by the world’s space agencies in the Global Exploration Roadmap.
What do astronomers at your institution think about human exploration of the solar system? Should astronomers actively support sending humans to the Moon and Mars? Please share your opinions in the comments section.
To get the conversation started, check out this neat list of human and robotic advantages. The sections on human maintainability and response time are particularly amusing.