1. Mars Sustainability Workshop Kennedy Space Center February 8, 2018
In Situ Resource Utilization (ISRU)
for Mars
Mars Sustainability Workshop Kennedy Space Center February 8, 2018
Introduction.
Standing in for Rob M. who had a family emergency and had to travel back to Germany on short notice.
Going to give a very brief overview of ISRU as a space exploration technology and its challenges.
The concepts in this presentation were developed in collaboration with several NASA centers and academic partners.
Jason Schuler
Rob Mueller
Surface Systems Lead
Senior Technologist
Applied Science & Technology
Exploration Research and Technology Programs
Ascentech Inc.
NASA
Kennedy Space Center, Florida, USA

2. The need for ISRU 30 Days 500 Days Credit: NASA DRA 5.0
The two most likely scenarios for a Mars mission are : A Conjunction class mission (low energy) or a opposition class mission (high energy). There are several advantages/disadvantaged but this boils down to surface time: 500 days or 30 days.
Since this workshop is about Mars Sustainability lets consider the 500 day case.
To live on Mars for 500 days, we will need some level of Earth Independence.
In Situ Resource Utilization (ISRU) is “living off the land” and it’s a crucial technology to enable humans to survive on mars for 500 days.
30 Days
500 Days
Credit: NASA DRA 5.0

3. We wouldn’t have gotten far if we couldn’t use the local resources
Settling the West
We wouldn’t have gotten far if we couldn’t use the local resources
ISRU is not a new idea.
Without ISRU we would not have been able to leave the coast and settle the west.
Here is a fun example calculation of how far we could have gone of we had to bring all our resources with us.
100 miles.
200 LB
Credit: NASA Jerry Sanders

4. Leverage (Gear) ratios using ISRU
Mars mission
Oxygen only 75% of ascent propellant mass; 20 to 23 mT
Methane + Oxygen 100% of ascent propellant mass: to 29.6 mT
Regeneration of rover fuel cell reactant mass
Every 1 kg of propellant made on Mars saves 7.4 to 11.3 kg in LEO
1 kg propellant on Mars
1.9 kg used for EDL
Potential mT launch mass saved in LEO
= 3 to 5 SLS launches avoided per Mars Ascent
10 Mars Missions = 30 to 50 SLS launches avoided
2.9 kg prior to Mars EDL
Mars
ISRU’s future gets a bit more technical than muleDays but the concept is the same.
Our concern is getting to Mars …. and preferably getting back
#### Explain gear ratio table and maybe show calc ####
If we have to bring everything we need on Mars all the way from Earth, our mission gets very expensive.
Consider our return trip. For every kilogram of propellant we put on the surface of Mars for our flight home, we need to put about 11kg in LEO.
We will need about 30mT of propellant for that trip. Back that up through the gear ratio and that means we need 330 mT in LEO, which will take 3 – 5 SLS launches. $1billion per launch)
8.4 kg used for TMI propulsion
226 kg on Earth
Earth Orbit
11.3 kg in LEO
Estimates based on Aerocapture at Mars

5. Evolvable Mars Campaign: Minimum Lander Size vs ISRU option
ISRU propellant production makes Mars EDL easier
Atmospheric ISRU
Only
(LOx)
18t Payload
43t Lander
16.1m
No ISRU
40t Payload
90t Lander
23 m
ALL ISRU
(LCH4 + LOx)
15t Payload
33t Lander
15.1 m
Entry Configuration
Entry decent and landing is one of the most challenging aspects of sending humans to Mars.
If we can make some of our consumables on the surface we reduce the mass of our entry vehicle and drastically reduce the EDL challenges.
(Why methane and not liquid Hydrogen? Thermal issue to carry the cold hydrogen…)

6. What is In Situ Resource Utilization (ISRU)?
ISRU involves any hardware or operation that harnesses and utilizes ‘in-situ’ resources to create products and services for robotic and human exploration
Resource Assessment (Prospecting)
Resource Acquisition
Resource Processing/ Consumable Production
In Situ Manufacturing
In Situ Construction
In Situ Energy
So what does ISRU involve?
6 major areas in consideration:
Prospecting, Acquisition, Processing, Manufacturing, Construction, Energy.
‘ISRU’ does not exist on its own. By definition it must interface with users/customers of ISRU products and services

7. Mars ISRU Depends on Resource of Interest
Mars Atmospheric Resource Processing
Strengths
Atmospheric resources are globally obtainable (no landing site limitations)
Production of O2 only from carbon dioxide (CO2 ) makes >75% of ascent propellant mass
Significant research and testing performed on several methods of atmospheric collection, separation, and processing into oxygen and fuel; including life support development
Weaknesses
Production of methane delivery or hydrogen (H2) from Earth which is volume inefficient or water from the Mars soil (below)
Mars optimized ISRU processing does not currently use baseline ECLSS technologies
Mars Soil Water Resource Processing (ties to Lunar Ice & Regolith)
Surface material characteristics studied from Mars robotic landers and rovers
Water (in the form of hydrated minerals) identified globally near the surface
Lunar regolith excavation and thermal processing techniques can be utilized for Mars
Low concentrations of water in surface hydrated mineral soil (3%) still provides tremendous mass benefits with minimal planetary protection issues
Risk associated with the complexity of the required surface infrastructure needs must be evaluated. Significant autonomous ops required.
Local/site dependency on water resource concentration and form
Concerns from planetary protection and search for life with water extraction at higher concentrations

8. Resources/Technologies
This chart shows the types of resources that are common in the solar system and the technologies that are associated with their utilization.
Some of these technologies are in their infancy. And some of these technologies are fairly well developed for earth applications.
But the common challenge between all of these is lifetime. These systems will need to operate around the clock (in some cases) for years with virtually no maintenance.
Challenges: dormancy, different states of matter during processing, corrosive materials, power needs (kilopower)

9. Evolvable Capability This is a capability that will evolve over time.
We will start with the lowest hanging fruit of propellants and then start to expand into consumables, manufacturing, construction
And eventually this will grow to large scale mining operations with resources returning to earth (think rare materials, or power) ## economic reasons…###