Scientists Look to Small Probes To Gain Big Returns on Mars


PASADENA, Calif. — Inside NASA’s Radiation Belt Storm Probes (RBSP), a dual satellite mission slated to launch later this month, an engineering experiment is masquerading as ballast, an idea gaining traction as scientists try to innovate their way out of a budget crunch that is squeezing future Mars exploration.

“Sometimes in order to look to future missions, we try to put on very cheap new technology subsystems just to test them out in flight,” RBSP project scientist Barry Mauk told Space News. “We take advantage of the fact that the mission has a little bit of extra capability to fly a little bit of extra mass.”

In place of some tungsten to balance the probes so they spin like tops, an engineer at Johns Hopkins University Applied Physics Laboratory lobbied to install passive radiation monitors to measure total dosages behind various thicknesses of shielding inside the spacecraft. NASA and managers approved, allowing him to spend a few hundred thousand dollars of program reserve funds for the engineering equipment.

“You need to let people be a little more adventurous in terms of bypassing the normal things. There are ways to go about doing that,” Applied Physics Lab planetary scientist David Lawrence told participants at NASA’s Mars exploration planning conference in Houston in June.

Piggybacking payloads and experiments on bigger spacecraft is just one way thinking small can pack in more science bang for the buck.

Washington State University is working on a project called BOLD — Biological Oxidant and Life Detection — which would follow up NASA’s 1970s-era Viking Mars missions. It entails flying six pyramid-shaped probes that would crash-land, pointy end down, to penetrate 10 to 20 centimeters into the soil. Each of the battery-powered probes would conduct experiments to analyze the chemistry of the soil and look for life with a sensor that can ferret out a single molecule of DNA or other nucleotide, the building blocks for life on Earth.

Scientists estimate the cost of the mission, which could be ready to fly in 2018, at about $300 million.

The Massachusetts Institute of Technology is developing a martian miniprobe that could be used to explore lava tubes — tunnels in the ground created by underground lava flows — and other environments too treacherous for rovers. The idea is to bounce, roll and hop a swarm of baseball-sized probes, each powered by a fuel cell, to explore a wide swath of remote or rocky terrain on Mars.

Another idea is to outfit cubesat satellites with sensors to make radiation measurements on Mars. The probes, which could be deployed from a Mars orbiter, would be outfitted with a nanolander system. In addition to radiation dosimeters, a suite of payloads could be developed including biological and chemical sensors to collect data that would be of interest not only to scientists but also to engineers planning future human missions to Mars, according to a paper written by NASA Ames Research Center scientist Orlando Santos and colleagues that was presented at the Houston planning conference.

Recommendations from conference participants are being folding into an upcoming report to NASA officials outlining options for Mars exploration beyond next year’s planned launch of the Maven Mars atmospheric probe, said Doug McCuistion, who oversees the Mars exploration program at NASA headquarters in Washington.

In addition to proposals for possible missions in 2018 and beyond, the report is expected to address enabling technologies and small-satellite initiatives.



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