BioSentinel - DigitalCommons@USU
Transcript of BioSentinel - DigitalCommons@USU
Brian Lewis
Systems Engineer
NASA Ames Research Center
BioSentinel: Monitoring DNA Damage
Beyond Low Earth Orbit on
a 6U Nanosatellite
BioSentinel
Mission Goals and Objectives
• Conduct life science studies relevant to human exploration – 1st biological study beyond LEO in over 40 years
– BioSentinel uses DNA double strand break frequencies to calibrate radiation damage in space
– Validate biological radiation damage models in space
– Demonstrate “biosentinel” science concept
• Design payload with sensors for multiple environments – BioSensor, LET Spectrometer, TID Dosimeter
– Secondary payload on Space Launch System (SLS) EM-1 in late 2017
– Instrument on ISS at similar time to EM-1 launch
– Ground controls in lab and at radiation beam facilities
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BioSentinel
• Quantify DNA damage from space radiation environment – Space environment cannot be reproduced on earth
– Omnidirectional, continuous, low flux with varying particle types
– Health risk for humans spending long durations beyond LEO
– Radiation flux can spike 1000x during a solar particle event (SPE)
• Correlate biologic response with TID and LET data – BioSensor payload uses engineered S. cerevisiae
– Measures rate of double strand breaks (DSBs) in DNA
– LET spectrometer measures particle energy and count
– TID dosimeter measures integrated deposited energy
• Yeast assay uses microfluidic arrays to monitor for DSBs – Three strains of S. cerevisiae, two controls and an engineered strain
– Wet and activate multiple sets of microwells over mission lifetime
– DSB and associated repair enable cell growth and division of the engineered “biosentinel” strain
– Activate reserve wells in event of an SPE
BioSentinel Science Concept
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BioSentinel
• Freeflyer launched as a secondary payload on EM-1 – Exploration Mission 1: 1st flight
of NASA’s Space Launch System
• Final orbit of secondaries to be determined
• Will likely be Earth-interior, heliocentric orbit
• Far outside the LEOs typically occupied by CubeSats
– Range to Earth of 0.73 AU at 18 months
– Far outside the protective shield of Earth’s magnetosphere
A representative orbit that BioSentinel might occupy
Launch
Artist’s rendering of the Space
Launch System
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Mission Orbit BioSentinel
Orbit
BioSentinel
5
nogamma
25Gy
50Gy
100Gy
~180Gy
nogamma
25Gy
50Gy
100Gy
~180Gy
SCmedium(viability)
SC-LEUmedium
3daysat23°C
~2x106
cells/well~2x102
cells/wellNocells
Payloads and Data Products
LET Spectrometer Chip
Teledyne dosimeter Typical LET Spectrometer Frame
Prototype Fluidic Card
• 3 color optical system per well
• Colorimetric and optical density assay
• Pressure, RH and temp sensors in payload volume
• Selective downlink of spectrometer data
• Active monitoring of LET and TID to trigger SPE response
BioSentinel
Spacecraft Design
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PharmaSat carried a microwell and fluidics system similar to that which will be used in
BioSentinel
Avionics Transponder
Payload
Deployable Solar Arrays
Propulsion System
Batteries
Star Tracker
• Extend ARC biological nanosats to 6U form factor – Port application-based LADEE flight software to capable, reliable avionics
– Support autonomous guidance, navigation, attitude control, and propulsion
– Generate sufficient power for transponder over long link distances
BioSentinel
Electrical Power • Deployable solar arrays
– 31 W generated at end of life
• 3s2p Li-Ion Battery pack – 5100 mA-hr capacity
• Required for detumble after deployment
• Required for momentum management
• Evaluating cold gas and electric propulsion systems
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Propulsion
0 50 100 150 200 250 300 350 400 450 500-8
-6
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2
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time (sec)
de
g/s
ec
Body Rates
x
y
z
Detumble controller simulation
BioSentinel
Guidance, Navigation and Control • GNC Functions
– Detumble
– Pointing for communications, power generation, and safe mode
– Autonomous momentum management
• 3 axis controlled system
– Reaction wheels and star tracker for nominal operations
– Sun sensors and inertial measurement unit for contingencies
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GN&C Development Testbed
Simulated Controller Performance 0 5 10 15 20 25 30
0
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60
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time (min)
err
or
(arc
se
c)
Angular Attitude Error
unfiltered
EKF
BioSentinel
Communications • X-Band Coherent Transponder
– Command and Telemetry
– Ranging and Nav Support
– 100 – 4000 bps telemetry
• 20 dB medium-gain antenna and 6 dB low gain antenna
• Deep Space Network 34m ground station
• 2 – 8 hours aperture time per week
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0
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100 200 300 400 500 600
Po
ssib
le D
ata
Rat
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kb/s
]
Mission Elapsed Time (Days)
Achievable Downlink Data Rate During Mission
6dB link margin
3dB link margin
BioSentinel
Structures / Thermal • 6U volume nanosatellite
• BioSensor payload maintained at 1 atm pressure
• Payload cold biased to 4 C for yeast viability
• Active microfluidic “tile” maintained at 23 °C for growth
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Payload Thermal Variability
Spacecraft Internal Temperatures
BioSentinel
• 1st NASA biology studies beyond LEO in 4 decades
– Enabling comparison across multiple radiation & gravitation environments
• 1st 6U CubeSat to fly beyond LEO
– Challenges for communications and attitude control
– Collaboration with sister missions reduces risk
• 1st CubeSat to combine a biology science payload with capable C&DH and FSW
– Payload includes autonomous measurement response to SPEs
BioSentinel (Potential) Firsts and Challenges
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Support : NASA Human Exploration and Operations Mission Directorate (HEOMD)
Advanced Exploration Systems Division – Jitendra Joshi, Jason Crusan Program Execs.
Affiliations : NASA ARC, NASA JSC, NASA GRC, Loma Linda U. Med. Center, Univ. Saskatchewan