Advanced Life Support Research and Technology Development Metric

Breakdown of ISS ECLSS Equivalent System Mass Components by SystemSystemAssumedMass[kg]ResupplyMass[kg/yr]AssumedVolume[m³]ResupplyVolume[m³/yr]AveragePower[kW]AverageCooling[kW]Crew Time[per•hr/yr]Percentageof TotalECLSSESM[kg ESM]Air 1,233.5 385.6 201.657 0.562 4.73 4.73 11.5 19,567 13.2%Clothing 0 4,114.5 0 3.857 0 0 0 43,717 29.6%Food 0 5,708.6 0 0 1.61 1.61 0 57,291 38.7%Waste 0%Water 797.0 1,772.0 0 5.542 0.49 0.49 80.0 22,674 15.3%Other 0 0 69.230 0 0.25 0 0 4,637 3.1%Advanced Life Support System Technology BaselineThe ALSS technology baseline is an example of an ALS Program LSS fromJohnson Space Center (Lin, 1997), with additional components added for completenessand comparability to the ISS case. The selections presented in this particular baselinearose from a preliminary study of a life support configuration for a transit vehicle for amission to Mars using a TransHab-style inflatable structure for the crew module. Theunderlying reference mission, which differs from the DRM and the reference mission forthe Metric, assumed a single vehicle would transport the crew from Earth orbit to Marsand then back to Earth again. Separate vehicles would transfer the crew to the surface ofMars and provide a habitat once there. As such, the technology selection process did notconsider surface operations. While systems designed to function in microgravity generallyare not gravity sensitive and will function on a planetary surface, overall such anequipment selection may not be optimal. Finally, because the systems included are underdevelopment and not flight-ready, the physical attributes are less precise than the valuesfor the USOS equipment. Thus, the ALSS baseline should be considered representative,but not necessarily optimal, for the reference mission.Thus, the ALSS case is extrapolated from ALS Program values developed atJohnson Space Center. The original ALSS values (Lin, 1997) have been updated withmore recent values (Hanford, 1998) where possible. The ALSS here is primarily aphysicochemical system with a biological primary water processor and very limitedbiological food production. The system is defined in detail in the tables below. Itrepresents an advance over ISS technology, and is for a 400-day outbound and returntransit. As noted above, similar technology should work on the surface, and should beindependent of the mission scenario. This scenario does include a small plant growthchamber. The mass allocated is 120 kg. This is adequate for about a half square metergrowing area. Half a square meter could produce as much as 1% of the food for the crewwith a high productivity cereal crop, or as low as 0.1% for a low productivity crop.Food, clothes, and laundry are not covered by these references, and have beenadded. These masses are large compared to other equipment. Nevertheless, these itemswill be important issues when comparisons to bioregenerative options are eventuallyundertaken. Radiation protection could also be an issue when considering transit vehicles,but it can be ignored as a first approximation.Food cost is taken from Hanford (1997). This value is 12% lighter than the figureused for ISS technology case. This is reasonable assuming a greater use of dehydratedfood for longer-duration trips and the availability of a small quantity of fresh food.