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WHAT This Opportunity Is About


NASA MarsPort 2002 enables up to six teams of students to conduct engineering trade and design studies in support of a MarsPort Deployable Greenhouse (MDG) for operation on the surface of Mars. Scientific knowledge, hands-on educational experience, public outreach tools, and publicity for the students and their schools in the teams' hometown news media will be its principal benefits.

Why a MarsPort study?

Perhaps as soon as the second decade of this new millennium, a crew of spacefarers from Earth could land on the planet Mars. They will work, explore, and conduct science experiments on the surface of Mars before climbing back into the Mars Ascent Vehicle (MAV) for rendezvous with the Earth Return Vehicle (ERV) and the return trip home.

They and subsequent spacefarers will require a dependable infrastructure from which to sustain life and launch spacecraft from the Martian surface.

Objective

The NASA Marsport 2002 Engineering Design Student Competition will evaluate multiple configurations for a MDG to support human exploration of the Martian surface. The student teams will perform trade studies to derive an optimal configuration for the MDG. A systematic approach is essential in defining the MDG, and will require analyzing and trading options for the following elements: greenhouse structure, light collection, water and nutrient delivery, atmospheric controls, crop selection, harvesting and materials handling, and thermal management. The design shall include a minimal mass and lift-off volume approach. In addition, deployment options from the spacecraft and on the surface should be analyzed.

Mission Architecture

As outlined in the Mars Design Reference Mission (DRM) 3.0 (http://spaceflight.nasa.gov/mars/reference/hem/hem1.html), the first human mission to Mars will require several launches over a period of two years to establish a Base Camp for the crew on the Martian surface. A full description of this mission architecture is contained in the DRM 3.0 (including the 1998 addendum). These documents shall be considered the baseline for this competition, except where specifically identified.

The ERV will be put into orbit around Mars and the MAV along with its In-Situ Resource Utilization (ISRU) propellant and life-support production plant will be staged on the surface eighteen months prior to the crew lifting off from Earth. In that eighteen months the ISRU plant will produce all the propellants required for the MAV to lift the crew off the surface as well as a large cache of crew consumables, such as water and oxygen.

Two years later a second ISRU and MAV will be launched in conjunction with the first crew. This hardware will serve as the primary hardware for the second crewed mission, as well as a back-up system for the crew on the first mission.

To enable affordable human missions to Mars, producing crew consumables, utilizing Martian resources, and recycling waste products may be advantageous in reducing mission costs. Because of the transit time to Mars and limited launch window, resupply is not a good option, so crew self sustainability is critical. The MDG will aid in accomplishing these goals, but is not considered as part of the DRM 3.0. For the sake of this competition it should be considered as a change to the architecture as well as the following information. The MDG can be predeployed 2 years earlier than crew arrival or sent during the launch window when the crew departs. The MDG can be launched in a Magnum Launch Vehicle, as described in the DRM 3.0, or in another projected/existing launch vehicle. If the magnum is used another major payload should be assumed to accompany it. The amended architecture may take advantage of or augment the existing ISRU capability if practical.

Mars Environmental Constraints

Teams should rely on information set forth in the Mars environmental references (http://www.tsgc.utexas.edu/marsport/references.html) adopted for the MDG design effort. The proposal team may select the landing site, but for the purpose of this competition it shall be located within +/- 15 degrees of the equator.

Assumptions

All assumptions made by the teams that are not mentioned in this section are to be annotated in the front of the required documentation.

  1. The design life of the MDG shall be 20 years.
  2. Crew size is 6.
  3. Leakage rate of the MDG should be less than 1% of the volume per day at the target internal pressure.
  4. MDG crops will provide a diet augmentation (i.e., will not be used to supply more than ~25% of the crew food).
  5. Crop lighting will be provided using incident solar radiation with or without supplemental electric lighting.
  6. Crew ingress/egress is not a requirement.

Concept of Operations

A concept of operations will be developed to tie all phases of use of the MDG operation. These shall include: deployment from spacecraft, surface deployment, start-up, daily operations and maintenance (e.g., cleaning of dust), harvesting, replanting (for multiple crop scenarios), shutdown, and mothballing for a future crew. The concept shall identify hardware and procedures needed for the MDG operation - autonomous single crop, autonomous multi-crop, remote and man tended. The teams shall define a logistics methodology and sparing requirements for repair and maintenance of the subsystems in the MDG.

Task Definition

External Structure: Design concepts for the external structure must be deployed from a manned or unmanned vehicle must have an internal frame structure such that it is stowed and can be stowed in a tight payload compartment, while also having the capability to be automatically deployed. The greenhouse external structure should accommodate connection ports to outside systems and habitats, anchoring capability, radiation and micrometeorite protection. Transparent materials can be considered as a good option because of the mass and power savings, but should allow maximum light (400-700 nm) transmittance and withstand ambient (Martian) UV radiation and other environmental parameters. Structural geometry should consider such factors as lighting harvesting efficiency, orientation with regard to solar movement across the sky, and capability to withstand pressure differentials (from inside to outside the greenhouse could range from 10 to ~50 kPa). Selection of operating pressures will not only affect structural design, but also management of the internal environment and gas leakage.

Water and Nutrient Delivery System: Solid media or fluid systems can be used for providing water and nutrients to the plant rootzone. Water must be conserved and recycled as much as possible within the system (e.g., recycling of condensed humidity). Management of mineral nutrients and root zone aeration should be considered.

Lighting System: Plants need light (400-700 nm) to sustain photosynthesis and growth. The incident light at the surface of Mars is half of what is available on Earth, and a number of lighting schemes might be considered. Innovative concepts for capturing and / or concentrating natural light along with supplemental electric lighting are sought in this design contest. A mid-day intensity of 125 W m-2 (400 - 700 nm), or about ~500 mmol m-2 s-1 photosynthetic photon flux (PPF) is sought, with minimal intensities of at least 50 W m-2 (~200 mmol m-2 s-1) maintained at least for a 12-h cycle each Martian day (minimum of ~2 MJ m-2 d-1 or 8 mol m-2 d-1).

Plant Growth Area Structures: Plant growth structures should provide adequate volume to accommodate crop growth and any projected materials handling, and be capable of withstanding the rigors of the Martian surface environment. Structural components should have minimal mass and be able to be stowed and deployed effectively. Inflatable materials and concepts might be considered. Structures do not need to be human rated or internally accessible, but human interfacing for collecting harvested biomass and any tending operations for non-autonomous systems should be considered.

Atmospheric Composition/Conditioning: Ventilation, temperature control, gas composition, relative humidity are important parameters in providing the appropriate environment for plant growth. All Design concepts must address the controls for providing a satisfactory environment. Atmospheric management will require separation and storage of photosynthetically-generated oxygen (O2), and systems or concepts for restoring carbon dioxide (CO2) consumed by the plants. Water (including water vapor) should be conserved and recycled, and contingencies for restoring water lost to leakage should be considered. Environmental parameters should be held within the following set-points:

Temperature:10 to 30°C
Relative Humidity:40 to 90%
CO2 Partial Pressure:0.1 to ~3 kPa
O2 Partial Pressure: >5 kPa
Inert Gas Composition:Optional
Ethylene Gas*: < 50 ppb equivalent at 100 kPa total pressure

(* Plants commonly produce small amounts of ethylene during growth and this ethylene gas must be removed or scrubbed to sustain acceptable growth).

Thermal Control: For a Mars deployable greenhouse, there will be both cooling and heating requirements. Extremely cold night temperatures may require supplemental insulation schemes, depending on structural characteristics (e.g., night time covers). There may be a need to reject heat from lighting system, while heat input maybe required during the dark cycles. Thus systems that can collect, store, and distribute waste heat should be included in the design concept.

Materials Handing: Depending on the management concept proposed, automation of plant harvesting and replanting might be required. Harvesting of crops would require removing plant materials for possible dehydration and storage. Edible materials might be separated and stored for crew arrival, or systems might be designed for human tending to reduce the need for automation. Similarly, replanting could be automated or operated as a human-assisted operation.

Mission Economics: Because of the high costs involved for space flight missions and hardware deployment, system mass and power consumption must be considered for assessing economic feasibility. Options dependent on high electrical power input would be limited to missions with sufficient electrical generating capabilities. Likewise, system risks and reliabilities must be considered and addressed in the design project overviews.

Missions might also consider the pre-deployment of autonomous structures prior to human arrival, or scenarios linked to human assisted construction following crew arrival at Mars.

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The NASA MarsPort Engineering Design Student Competition 2002 program is jointly sponsored by NASA and Science Applications International Corporation, and is jointly administered by the Florida Space Grant Consortium and the Texas Space Grant Consortium.


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Last Modified: Mon Dec 31, 2001
CSR/TSGC TeamWeb