Growing Food for Space and

Earth:NASA’s Contributions to Vertical Agriculture

Raymond M. Wheeler

NASA Exploration Research and Technology Directorate

Kennedy Space Center, Florida, USA

American Society of Horticultural Science

Aug. 4-7, 2015

https://ntrs.nasa.gov/search.jsp?R=20150015991 2020-07-05T16:51:02+00:00Z

food

(CH2O) + O2 CO2 + H2O

Clean Water Waste Water

Plants for “Bioregenerative” Life Support

HUMANSMetabolic

Energy

food

(CH2O) + O2*+ H2O CO2 + 2H2O*

Clean Water Waste Water

PLANTS

Light

NASA’s Bioregenerative Life Support Testing

1980 1990 2000

CELSS Program ALS / ELS Program

Algae Closed Systems Salad Machine

Wheat (Utah State)

Purdue

NSCORT

Potato (Wisconsin)

Lettuce (Purdue)

Soybean (NC State)

Sweetpotato / Peanut (Tuskegee)

Uni

vers

ities

Rutgers

NSCORT

Ames

Kennedy Large, Closed System NFT Lighting Waste Recycling Salad spp. Space Expmts.

Solid Media Pressure Human / IntegrationJohnson

N-Nutrition (UC Davis)

Gas Exch. / Ethylene (Utah State)

Purdue

NSCORT

MIR Wheat Studies

STS-73

Potato

Leaves

BIO-PlexNever

Completed

Biomass Production Chamber

Alliums (Texas Tech)

Hypobaria (TAMU)

ISS Mizuna

3

ISS Wheat

Lunar Grnhse (U AZ)

Crop Considerations for Space

• High yielding and nutritious (CHO, protein, fat)

• High harvest index (edible / total biomass)

• Horticultural considerations

– planting, watering, harvesting, pollination, propagation

• Environmental considerations

– lighting, temperature, mineral nutrition, CO2

• Processing requirements

• Dwarf or low growing types

Recirculating Hydroponics with Crops

Conserve Water & Nutrients

Eliminate Water Stress

Optimize Mineral Nutrition

Facilitate HarvestingWheat / Utah State

Soybean

KSC

Sweetpotato

Tuskegee

Rice / Purdue

Wheeler et al., 1999. Acta Hort.

Root Zone Crops

in Nutrient Film

Technique

(NFT)

Wheeler et al., 1990. Amer. Potato J. 67:177-187; Mackowiak et al. 1998. HortScience 33:650-651

0

2

4

6

8

10

12

0 20 40 60 80 100

Days After Planting

Wat

er U

se (

L m

-2d

-1)

Second Study865 mol m-2 s-1 PAR

First Study655 mol m-2 s-1 PAR

Fig. 7

Evapotranspiration from Plant Stand (potato)

Wheeler. 2006. Potato Research 49:67-90.

Water, Nutrient, and pH Control

Wheeler et al. 1999. Acta Hort.

High Yields from High Light and CO2 Enrichment

Wheat - 3-4 x World Record

Potato - 2 x World Record

Lettuce-Exceeded Commercial

Yield Models

Utah State

Univ.

Wisconsin Biotron

NASA Kennedy

Space Center

Bubgee, B.G. and F.B. Salisbury. 1988. Plant Physiol. 88:869-878.

Wheeler, R.M., T.W. Tibbitts, A.H. Fitzpatrick. 1991. Crop Science 31:1209-1213.

Potential Energy Conversion to Biomass

From Loomis and Williams. 1963. Crop Science 3:67-72

Assuming a maximum 12% conversion efficiency from PAR to biomass1

1.6 g dry mass / mol PAR

1 Radmer and Kok. 1977. BioScience. Actual instantaneous conversion efficiencies

of ~10% reported from some controlled environment studies ; e.g., Wheeler et al., 1993.

Crop Sci.; Gerbaud et al., 1998. Physiol. Plant.

Some Upper Limits to Energy Conversion and Productivity

Field Crops Observations1

Crop Productivity Photosynthetic Energy

Conversion Efficiency 2

-----------------------------------------------------------------------------------------------(g DM m-2 d-1) (%)

Tall Fescue 43 7.0 (UK)

Maize 40 6.8 (US)

Sudan Grass 52 6.0 (US)

-----------------------------------------------------------------------------------------------

CEA NASA Studies

Crop Productivity Radiation Use Efficiency

-------------------------------------------------------------------------------------------------(g DM m-2 d-1) ( g DM mol-1 PAR)

Wheat 61 1.44 Utah State3

130 0.67 Utah State4

Potato (12⇨24 h photoper.) 45 0.97 Univ. Wisc.5

(12 h photoper. only) 38 1.15 Univ. Wisc.5

-------------------------------------------------------------------------------------------------1 D.O. Hall. 1976. FEBS Letters2 Original data based on total solar irradiance; table data reflect efficiency based on PAR (400-700 nm)3 Monje and Bugbee. 1998. Plant Cell Environ (estimated) 4 Bugbee and Salisbury. 1988. Plant Physiol.5 From Wheeler, 2006. Potato Res. (assumes transplanting to increase PAR absorption).

Closed Systems Issues

NASA Ames

Research Center

NASA Johnson

Space Center

Purdue

Univ.

NASA

KSC

Canopy CO2 Uptake / O2 Production(20 m2 Soybean Stand)

Wheeler. 1996. In: H. Suge (ed.) Plants in Space Biology.

CO2 Exchange Rates of Soybean Stands

-20

-10

0

10

20

30

40

50

0 10 20 30 40 50 60 70 80 90 100

Time (days)

CO

2E

xchange R

ate

(µ

mol m

-2s

-1)

Photosynthesis

Night Respiration

815 µmol m-2 s-1

HPS Lamps

477 µmol m-2 s-1

MH Lamps

Canopy Lodged

Harvest

High Temp

Event

14

Wheeler et al., 2004. EcoEngineering.

0

5

10

15

20

25

30

35

40

45

50

0 200 400 600 800 1000 1200 1400 1600

CO2 (mol mol-1)

CO

2E

xchange R

ate

(

mol m

-2s

-1)

CO

2C

om

pe

nsa

tion

Po

int

Fig. 6

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

90 100 110 120 130 140 150

CO2 Compensation Point

y = 0.15 x - 14.6

R2 = 0.99

CO2 (mol mol-1)

CO

2 E

x.

(m

ol m

-2 s

-1)

(97)

Effect of CO2 Concentration on Photosynthesis (potato)

Similar results for

wheat and soybean

Optimal Concentration

Wheeler. 2006. Potato Research 49:67-90.

Canopy / Stand Ethylene Production

Wheeler et al. 2004. HortScience 39:1541-1545.

Ethylene Production - Tomato cv. Reimann Philipp

0

100

200

300

400

500

0 10 20 30 40 50 60 70 80

Time (days)

Eth

yle

ne

(p

pb

)

Light Cycle

Dark Cycle

Harv

ests

Wheeler et al. 2004. HortScience 39:1541-1545.

Ethylene in Closed Systems

Epinastic

Potato Leaves

at ~40 ppb

Epinastic

Wheat Leaves

at ~120 ppb

NASA’s Biomass Production Chamber (BPC)An Attempt at Vertical Agriculture !

Control Room

External View - Back

Hydroponic System

20 m2 growing area; 113 m3 vol.; 96 400-W HPS Lamps;

400 m3 min-1 air circulation; two 52-kW chillers

NASA’s Biomass Production Chamber (BPC)

Wheat(Triticum aestivum)

planting

harvest

Soybean(Glycine max)

Lettuce(Lactuca sativa)

Potato(Solanum tuberosum)

Automation

Technologies

for CEA

ALSARM Robot in NASA

Biomass Production Chamber

25

0

10

20

30

40

50

0 10 20 30 40 50 60 70 80

Photosynthetically Active Radiation (mol m-2 d-1)

Cro

p Y

ield

(g m

-2d

-1)

Total

Biomass

Edible

Biomass

Studies

Include:

Wheat (4)

Soybean (4)

Potato (4)

Lettuce (3)

Tomato(2)

Effect of Light on Crop Yield

Wheeler et al. 1996. Adv. Space Res .

Electrical Power for BPC

• 96 400-W HPS lamps with dimming ballasts

• Two 30 kW blowers (400 m3 min-1)

• Two 15-ton (52 kW) chillers for cooling

• 100 kW water heater for air re-heat

→ Not designed for energy efficiency!!

The Importance of Lighting--Electric Lamp Options

Lamp Type Conversion* Lamp Life* Spectrum

Efficiency (hrs)

• Incandescent/Tungsten** 5-10% 2000 Intermd.

• Xenon 5-10% 2000 Broad

• Fluorescent*** 20% 5,000-20,000 Broad

• Metal Halide 25% 20,000 Broad

• High Pressure Sodium 30% 25,000 Intermd.

• Low Pressure Sodium 35% 25,000 Narrow

• Microwave Sulfur 35-40%+ ? Broad

• LEDs (red and blue)**** >40% 100,000 ? Narrow

* Approximate values.

** Tungsten halogen lamps have broader spectrum.

*** For VHO lamps; lower power lamps with electronic ballasts last up to ~20,000 hrs.

**** State-of-Art Blue and Red LEDs most efficient.

LED Studies

Red...photosynthesis

Blue...photomorphogenesis

Green...human vision

Some NASA Related References:

Bula et al. 1991. HortSci 26:203-205.

Barta et al. 1992. Adv. Space Res.

12(5):141-149.

Tennessen et al. 1994. Photosyn. Res.

39:85-92.

Goins et al. 1997. J. Exp. Botany

48:1407-1413.

Kim et al. 2004. Ann. Bot. 94:691-697.

Solar Collector / Fiber Optics For Plant Lighting

2 m2 of collectors on solar

tracking drive (SLSL Bldg, NASA KSC)

Up to 400 W light delivered to chamber

(40-50% of incident light)

Takashi Nakamura, Physical Sciences Inc.

30

Nakamura et al. 2010. Habitation

Human Habitats and

Crops for

Supplemental Food

Habitat Demonstration Unit (HDU) Test 2011

HDU Test 2012

NASA’s HDU at Desert Test Site

Plant Atrium

or Growing

Shelf

Plant Growth on the International Space

Station—VEGGIE Plant Chamber.

32

Some Lessons Learned from NASA

CEA / Vertical Ag work

• Over half of maintenance / upkeep time dedicated to nutrient system

management

– If condensate water is retrieved, pay attention to elemental content

• Extensive work for optimizing hydroponic solution replenishment

recipes

– We made no attempts to reduce nitrate in tissue

• Consider ability to reach all sections of the growing area; it was not

easy for use to inspect the back of our trays; consider shelf-to-shelf

height

• Initially we sanitized hydroponic hardware following crops, but later

abandoned in favor of thorough cleaning

• Consider innovative means for improving energy efficiency, e.g., if

possible use heat from lamps and power supplies for air “re-heat”

• Worker safety—consider sunglasses for working around bright red and

blue LEDs 33

Agriculture in Space

As we explore sustainable living for space, we will

learn more about sustainable living on Earth

34

KSC Advanced Life Support Team, Hangar L, KSC 1994