BILI Aims to Sniff for Life on Mars
November 2, 2016
A sensing technique that the U.S. military currently uses to remotely
monitor the air to detect potentially life-threatening chemicals,
toxins, and pathogens has inspired a new instrument that could “sniff”
for life on Mars and other targets in the solar system -- the
Bio-Indicator Lidar Instrument, or BILI.
This artist’s rendition shows how a proposed laser-fluorescence
instrument could operate on Mars.
Branimir Blagojevic, a NASA technologist at the Goddard Space Flight
Center in Greenbelt, Maryland, formerly worked for a company that
developed the sensor. He has applied the technology to create an
instrument prototype, proving in testing that the same remote-sensing
technology used to identify bio-hazards in public places also could be
effective at detecting organic bio-signatures on Mars.
BILI is a fluorescence-based lidar, a type of remote-sensing instrument
similar to radar in principle and operation. Instead of using radio
waves, however, lidar instruments use light to detect and ultimately
analyze the composition of particles in the atmosphere.
Although NASA has used fluorescence instruments to detect chemicals in
Earth’s atmosphere as part of its climate-studies research, the agency
so far hasn’t employed the technique in planetary studies. “NASA has
never used it before for planetary ground level exploration. If the
agency develops it, it will be the first of a kind,” Blagojevic said.
A Rover’s ‘Sense of Smell’
As a planetary-exploration tool, Blagojevic and his team, Goddard
scientists Melissa Trainer and Alexander Pavlov, envision BILI as
primarily “a rover’s sense of smell.”
Positioned on a rover’s mast, BILI would first scan the terrain looking
for dust plumes. Once detected, the instrument, then would command its
two ultraviolet lasers to pulse light at the dust. The illumination
would cause the particles inside these dust clouds to resonate or
fluoresce. By analyzing the fluorescence, scientists could determine if
the dust contained organic particles created relatively recently or in
the past. The data also would reveal the particles’ size.
“If the bio-signatures are there, it could be detected in the dust,”
The beauty of BILI, Blagojevic added, is its ability to detect in
real-time small levels of complex organic materials from a distance of
several hundred meters. Therefore, it could autonomously search for
bio-signatures in plumes above recurring slopes — areas not easily
traversed by a rover carrying a variety of in-situ instruments for
detailed chemical and biological analysis. Furthermore, because it could
do a ground-level aerosol analysis from afar, BILI reduces the risk of
sample contamination that could skew the results.
“This makes our instrument an excellent complementary organic-detection
instrument, which we could use in tandem with more sensitive, point
sensor-type mass spectrometers that can only measure a small amount of
material at once,” Blagojevic said. “BILI’s measurements do not require
consumables other than electrical power and can be conducted quickly
over a broad area. This is a survey instrument, with a nose for certain
vWith such a tool, which also could be installed on an orbiting
spacecraft, NASA could dramatically increase the probability of finding
bio-signatures in the solar system, he added. “We are ready to integrate
and test this novel instrument, which would be capable of detecting a
number organic bio-signatures,” Blagojevic said. “Our goal is increasing
the likelihood of their discovery.”
Blagojevic hopes to further advance BILI by ruggedizing the design,
reducing its size, and confirming that it can detect tiny concentrations
of a broad range of organic molecules, particularly in aerosols that
would be found at the ground level on Mars.
“This sensing technique is a product of two decades of research,”
Blagojevic said, referring to the technology created by his former
employer, Science and Engineering Services, LLC..
Blagojevic and his team used NASA’s Center Innovation Fund, or CIF, to
advance the technology. CIF stimulates and encourages creativity and
innovation within NASA, targeting less mature, yet promising new