Design envelope

The instruments

Pressure and the areoid screens pressure against height above the areoid. Cabin gas screens the mass of a cabin mix and the inspired-oxygen line. Crew budget screens oxygen, food, and water for a number of people and days. Timekeeping on Mars screens solar longitude and mean solar time.

Oxygen from air screens the solid-oxide split of carbon dioxide. Propellant from air screens the net methane reaction on integer molar masses. Regolith shield screens the mass of piled soil. Solar resource screens sunlight. These are screening instruments sharing one constant file. The sentence on a page does not get its own private copy of a number.

Light time divides a distance you type by the defined speed of light. Landed mass stores two rolled rover masses. Dust and wheels keeps two dated wheel records. Ice to water refuses until you type the heat and the dirt. Pass volume divides two amounts you type. Methods is how a blank cell and a trust class should be read.

What a screen is not

A screen is not a forecast for a sol, a medical limit, or a clearance to fly. Regolith shield does not report a shielded radiation dose. Solar resource does not size a power system. Oxygen from air and Propellant from air do not size a crew plant. When a page and the constant file disagree, keep the file and fix the page.

The builder also writes that constant file to data/constants.csv. Each row is an id, a value, an SI unit, the display string, a trust class, and a bibliography id. Site dossiers compares six places and does not pick a winner. Subsurface ice names ice by the kind of evidence. Perchlorates is the oxidant measured at one landed site. Mission instruments names which flight a stored number came from.