Physics & Astronomy
closed ecological systems
100%
greenhouses
65%
mars
55%
life support systems
51%
crops
42%
recycling
42%
prototypes
37%
atmospheres
20%
hydroponics
19%
water
16%
Mars missions
15%
vegetables
13%
crews
13%
astronauts
13%
support systems
12%
biomass
12%
space missions
11%
concentrators
10%
food
10%
solar system
9%
cables
9%
membranes
6%
oxygen
5%
air
5%
estimates
5%
energy
2%
Earth & Environmental Sciences
Mars
43%
recycling
18%
crop production
17%
atmosphere
13%
hydroponics
10%
dietary intake
10%
solar power
10%
waste recycling
9%
organic waste
8%
production system
8%
food production
8%
solar system
8%
cable
8%
power generation
8%
vegetable
8%
cropping practice
7%
biological processes
7%
water
7%
crop
5%
food
5%
membrane
5%
oxygen
5%
biomass
4%
air
4%
program
4%
chemical
3%
energy
3%
analysis
2%
Engineering & Materials Science
Greenhouses
57%
Water recycling
39%
Crops
26%
NASA
21%
Energy Intake
12%
Solar concentrators
11%
Lunar missions
11%
Vegetables
10%
Solar system
9%
Recycling
7%
Biomass
7%
Power generation
6%
Membranes
6%
Earth (planet)
6%
Dynamical systems
6%
Oxygen
6%
Cables
6%
Air
4%