Space Telecommunications, Astronomy, and Radiation Lab

The Microwave Radiometer Technology Acceleration CubeSat (MiRaTA)

Kerri Cahoy, J.M. Byrne, T. Cordeiro, P. Davé, Z. Decker, A. Kennedy, R. Kingsbury, A.

Marinan, W. Marlow, T. Nguyen, S. Shea MIT STAR Laboratory

William J. Blackwell, G. Allen, C. Galbraith, V. Leslie, I. Osaretin, M. DiLiberto, P. Klein,

M. Shields, E. Thompson, D. Toher, D. Freeman, J. Meyer, R. Little MIT Lincoln Laboratory

Neal Erickson, UMass-Amherst Radio Astronomy

Rebecca Bishop, The Aerospace Corporation

This work is sponsored by the National Oceanic and Atmospheric Administration under Air Force Contract FA8721-05-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the United States Government.

ESTF 2015- 2 KC, WJB 6/15/2015

Outline

•  Introduction and Motivation •  MiRaTA Goals

–  Microwave Radiometer –  GPS Radio Occultation

•  MiRaTA Status –  MicroMAS lessons learned –  MiRaTA status

•  Next Steps

MicroMAS Launched July 13, 2014

Orb-2 Antares/Cygnus Deployed March 4, 2015

International Space Station Courtesy NASA/NanoRacks

ESTF 2015- 3 KC, WJB 6/15/2015

Suomi NPP Satellite Launched Oct. 2011

Microsized Microwave Atmospheric Satellite

(MicroMAS) Deployed Mar. 2015

NASA/GSFC

Advanced Technology Microwave

Sounder (ATMS)

4.2 kg, 10W, 34 x 10 x 10 cm

New Approach for Microwave Sounding

85 kg, 130 W instrument

•  Miniaturized microwave sensor aperture (10 cm)

•  Broad footprints (~50 km), modest pointing requirements

•  Relatively low data rate (kbps) •  Perfect fit for a CubeSat! 2200 kg spacecraft

NPP: National Polar-orbiting Partnership

ESTF 2015- 4 KC, WJB 6/15/2015

Outline

•  Introduction and Motivation •  MiRaTA Goals

–  Microwave Radiometer –  GPS Radio Occultation

•  MiRaTA Status –  MicroMAS lessons learned –  MiRaTA status

•  Next Steps

ESTF 2015- 5 KC, WJB 6/15/2015

Microwave Radiometer Technology Acceleration (MiRaTA)

•  Two science instruments on a 3U CubeSat:

•  Tri-band microwave radiometer -  Temperature (~60 GHz, V-band) -  Water vapor (~183 GHz, G-band) -  Cloud ice (~207 GHz, G-band) -  Absolute calibration better than 1 K

•  GPS radio occultation receiver (GPSRO) -  Called the Compact TEC Atmospheric GPSRO System (CTAGS) -  Atmospheric temperature, pressure profiles -  Ionospheric electron density and Total Electron Content (TEC)

•  Goal: Demonstrate both payloads and use GPSRO to calibrate the radiometer by sounding overlapping volumes of atmosphere.

•  Calibration proof of concept using limb measurements and GPS-RO –  Observe coincidental radiometric and GPS-RO atmospheric density

information –  Enabled by high-performance COTS GPS receivers with low size,

weight, and power

•  Funded by NASA Earth Science Technology Office (ESTO)

ESTF 2015- 6 KC, WJB 6/15/2015

MiRaTA Space Vehicle

Acronym key: CTAGS, NovAtel OEM-628 + LNA PIM Payload Interface Module IFP Intermediate Frequency Processor EPS Electrical Power System LNA Low Noise Amplifier for GPSRO MAI-400 Maryland Aerospace Inc. ADCS Attitude Determination and Control EHS Earth Horizon Sensors

MAI-400 (ADCS)

Bus Stack

CTAGS LNA

PIM

IFP

Radiometer Assembly

3U Double-Deployable Solar Panels

Cadet Radio

Motherboard

Batteries

EPS

CTAGS, NovAtel OEM-628

EHS

ESTF 2015- 7 KC, WJB 6/15/2015

Overlapping GPSRO and Radiometer

N(h, lat, lon) DN(q, f, lat, lon)

Modification of image from Lidia Cucurull

Progression of the tangent point for an ingress (setting) occultation

ESTF 2015- 8 KC, WJB 6/15/2015

MiRaTA Calibration Maneuver

~ 20 minute maneuver 0.5° / sec rate

ESTF 2015- 9 KC, WJB 6/15/2015

Radiometer and GPSRO Simulation

•  Single set of GPS SV tracks over 24 hrs as rx’d by MiRaTA. •  Plot area is anti-ram FOV of MiRaTA GPS antenna array (85° x 30° full beamwidth) •  Post-LNA gain (dB) shown for L1. Goes to 5 dB at 81 km tangent height. •  Green bands show where radiometer field of view overlaps with GPSRO measurements.

ESTF 2015- 10 KC, WJB 6/15/2015

Radiometer (UMass Amherst & MIT LL)

Components of the same color are in the same block. UMass Amherst has fabricated prototype blocks

Ultra-compact IF Spectrometer (V-band)

Wideband G-band RFE

Calibration load

V-band RFE

ESTF 2015- 11 KC, WJB 6/15/2015

Science Payload Antennas

•  CTAGS GPSRO Patch Array Antenna fabricated –  Successful mechanical inspection completed –  Electrical testing ongoing

•  Radiometer Reflector Antenna Fabricated –  Successful mechanical inspection completed –  Electrical testing complete; data under analysis

Radiometer Reflector Antenna

CTAGS Patch Array Antenna

ESTF 2015- 12 KC, WJB 6/15/2015

Science Payload Modules

EDU PIM Board EDU PVRM Board

FM G-RFE-1 Module FM V-RFE Internal Layout V-RFE Mechanical Module

•  Designs implemented; boards fabricated and testing of payload hardware is ongoing

•  Engineering Design Units fabricated for critical payload components

FM DRO Module

ESTF 2015- 13 KC, WJB 6/15/2015

Outline

•  Introduction and Motivation •  MiRaTA Goals

–  Microwave Radiometer –  GPS Radio Occultation

•  MiRaTA Status –  MicroMAS lessons learned –  MiRaTA status

•  Next Steps

ESTF 2015- 14 KC, WJB 6/15/2015

MicroMAS Debrief: Intro

•  MicroMAS 3U CubeSat -  34 x 10 x 10 cm, 4.252 kg -  10 W average power -  118 GHz radiometer payload

•  3D atmospheric temperature

•  MicroMAS deployed March 4, 2015 -  Successful downlinks March 4, 5, 9 -  Radio transmitter issue -  Unable to validate radiometer -  Panels and antenna deployed -  Power system and battery nominal -  Obtained ADCS sensor data: IMU,

magnetometer, EHS, sun sensors -  Turned on MAI-400, reaction wheels

•  Wheels responded but unable to validate ADCS algorithms

ESTF 2015- 15 KC, WJB 6/15/2015

MicroMAS Earth Horizon Sensors while tumbling

18:54:00 18:54:43 18:55:26 18:56:09 18:56:520

500

1000

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2500

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3500

4000

ADC

Cou

nt

EHS A (Side) Measurements

LimbSkyEarthWide FOV

18:54:00 18:54:43 18:55:26 18:56:09 18:56:520

500

1000

1500

2000

2500

3000

3500

4000

ADC

Cou

nt

EHS B (AntiRam) Measurements

LimbSkyEarthWide FOV

Side-­‐looking  EHS  is  on  the  same  side  as  panel  YN  

Room  Temp  ~1400  counts  

Sun  

Space  

ESTF 2015- 16 KC, WJB 6/15/2015

MicroMAS lessons learned

•  Redundant radio needed –  Implementing low-rate UHF radio

on MiRaTA in addition to Cadet

•  TLEs for ISS-deployed CubeSats not as good as predicted –  Compare Riesing (SmallSat 2015)

to Coffee et al., 2013

•  Flight spares are a good idea •  Ensure all ADCS sensor

parameters are tunable in case they are mis-labeled in code or have biases

•  Power reset management is important tool

•  Increased battery heating

ESTF 2015- 17 KC, WJB 6/15/2015

MiRaTA Status

•  Procurement of major COTS components nearly complete –  Have Cadet radios, Pumpkin motherboard, Clyde Space EPS –  Expecting Clyde Space solar panels, batteries, MAI-400 reaction wheel

assembly and Earth Horizon sensors (MAI-400 electronics boards complete)

•  Custom bus and payload components nearing completion –  Have prototype avionics and interface boards –  Have engineering unit payload modules –  Flight model radiometer and GPSRO antennas fabricated

•  Build of Mass Mockup and Ground Support Equipment for functional and environmental testing is underway

•  Critical Design Review was June 1-3, 2015

•  Still do not know what our launch/orbit will be (NASA CSLI) –  Hoping for an SSO opportunity, but could work with ISS deployment

ESTF 2015- 18 KC, WJB 6/15/2015

MiRaTA / MicroMAS Testing

4-coil Merritt design Helmholtz cage

Payload Calibration

TVAC

Payload Spin Balance

ADCS Suspension Test

“Piñata”

3-Axis Air Bearing Test

ESTF 2015- 19 KC, WJB 6/15/2015

Payload TVAC for Radiometric Calibration

•  Detailed simulations of payload thermal (cyan) and radiometric environment (red, green, blue)

•  Assessments were made of: –  Sensitivity –  Absolute accuracy –  Linearity –  Stability

Variable target

Motor and reflector

Payload

Cold target

Ambient target

ESTF 2015- 20 KC, WJB 6/15/2015

MicroMAS Radiometer Performance Accuracy and Precision

1 2 3 4 5 6 7 8 90

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Channel

NED

T (K

)

ATMS equivalent spot size; 250 K payload temperature

3!

2!

1!

0!

-1!

-2!

-3!

Accu

racy

(K)"

100! 150! 200! 250! 300! 350!Scene Temperature (K)"

Tropospheric channels

ESTF 2015- 21 KC, WJB 6/15/2015

Mission Operations Center

Mission Planning Mission Command

MiRaTA Ground & Data Segment

MiRaTA overpass

Wallops Flight

Facility (VA, USA)

High-Gain UHF Ground Station

Public FTP Site

JSpOC Two-Line Elements

MIT campus

Data Processing Center Data Product Derivation

and Archival Lvl 0 Lvl 1 Lvl 2

TLEs

TLEs

All Data

Commands

Low-rate UHF, 400 MHz: TLM

High-rate UHF, 468 MHz: TLM, DATA

Ground UHF, 450 MHz: CMD S/C Health

Commands

MIT LL and USU SDL

MiRaTA

LL

SDL

ESTF 2015- 22 KC, WJB 6/15/2015

Outline

•  Introduction and Motivation •  MiRaTA Goals

–  Microwave Radiometer –  GPS Radio Occultation

•  MiRaTA Status –  MicroMAS lessons learned –  MiRaTA status

•  Next Steps

ESTF 2015- 23 KC, WJB 6/15/2015

Summary and Next Steps

•  There remains a need for near real-time, persistent, high-resolution and accurate global measurements of weather systems –  Traditional aerospace approaches have budget and risk constraints

that are at odd with improving temporal and spatial sampling –  This directly compromises the science –  Discoveries are often made using oversampled data

•  Reveals effects, behaviors, dependences that are not captured in models

•  Tropical storms and hurricanes cause $5B of damage and property loss in the US alone each year –  Estimated losses of 10,000 lives each year globally

•  Nanosatellite sounding constellations will improve predictions and support more advanced and accurate warnings

•  MiRaTA demonstrates performance of radiometer and CTAGS –  MiRaTA EM functional testing Summer 2015 –  Flight SV Integration and Test activities Summer/Fall 2015

ESTF 2015- 24 KC, WJB 6/15/2015

Acknowledgments

This work is supported by NASA Earth Science Technology Office grant number NNX14AC75G and NASA Space Technology Research Grant NNX12AM30H. This work was also sponsored by the National Oceanic and Atmospheric Administration under Air Force contract FA8721-05-C-0002. One graduate student is supported by a National Science Foundation Graduate Research Fellowship under Grant No. 1122374. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. Opinions, interpretations, conclusions, and recommendations are those of the authors and not necessarily endorsed by the United States Government. Thank you to our full team of research staff, graduate students, co-ops, interns, undergraduates and support staff.

ESTF 2015- 25 KC, WJB 6/15/2015

Backup

ESTF 2015- 26 KC, WJB 6/15/2015

Architecture Studies Show Great Promise for Constellation Approaches

Latit

ude

Latit

ude

Longitude Longitude

Mean revisit tim

e (hours)

Mean revisit tim

e (hours)

3 Satellites, one per plane 24 Satellites, eight per plane

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ESTF 2015- 27 KC, WJB 6/15/2015

MicroMAS Operational Data Flowchart

Lvl0a Lvl0b Lvl0c

Data Product Description Level 0a Raw I/Q samples from USRP N210 containing L-3 Cadet packets

Level 0b Decoded & demodulated L-3 Cadet packets

Level 0c Ingested MicroMAS packets with units converted and timestamped

Level 1a Calibrated & geolocated antenna temperatures at native resolution

Decoded & Demodulated Cadet

Packets

Step 1

Step 2

Step 3

Step 4

ESTF 2015- 28 KC, WJB 6/15/2015

MiRaTA Space Vehicle

•  Payload –  Tri-band microwave radiometer –  GPS radio occultation receiver with

patch antenna array (on back)

•  Bus –  L-3 Cadet UHF radio* (3 Mbps) –  Low-rate backup UHF radio (2.4 kbps) –  Pumpkin PIC24F motherboard with

Salvo RTOS* –  Clyde Space EPS*, battery*, and

double-sided deployed solar panels –  MAI-400 reaction wheels + Earth

Horizon Sensors* –  Custom interface boards

*flown on MicroMAS