SPACE TRAVEL

THE CODE

menu=0
# Main menu function that loops if not given 1,2, or 3 and quits if given 4, and will loop after putting correct input and user wants to try new function
while menu != 4:
    print()
    print()
    print('Main menu:')
    print('1. Warp Speed')
    print('2. Cost to Launch')
    print('3. Time Dilation')
    print('4. Quit')
    menu = int(input('Choose a function: '))

# Calculates warp factor/ warp speed
    if menu == 1:
        #assigned variables
        warp_factor = -1
        speed_of_light = 299792458
        warp_exponent = 10/3
        #while not statement makes sure warp factor is greater than 0
        while not warp_factor >= 0:
            warp_factor = int(input('Enter warp factor: '))
            if warp_factor >=0:
                warp_speed = (warp_factor**(warp_exponent) * speed_of_light)
                print()
                print('Warp',warp_factor,'engage!')
                print ('You are now traveling at',"{0:,.2f}".format(warp_speed), 'meters/second')
# calculates cost to launch and lets you know how much you save whether using space x or ULA         
    elif menu == 2:
        #assinged variables for the while statements, and variables of the given rates for price per kilogram launched
        satellite_mass = -1
        satellite_cost = -1
        spacex_rate = 2720
        ula_rate = 14830
        spacex_insurance = .30
        #validates mass and oost of satellites then calculates
        while not satellite_mass > 0:
            satellite_mass = float(input('Enter satellite mass in kilograms: '))
            if satellite_mass > 0:
                while not satellite_cost > 0:
                    satellite_cost = float(input('Enter satelllite cost in dollars: '))
                    if satellite_cost > 0:
                            # calculates SpaceX insurance and adds it to total and calculates total for ULA
                            spacex_insurance *= satellite_cost
                            spacex_total = spacex_rate * satellite_mass + spacex_insurance
                            ula_total = ula_rate * satellite_mass
                            #Next few lines tell you how much you saved using the cheaper option
                            if spacex_total < ula_total:
                                spacex_saved = ula_total - spacex_total
                                print()
                                print('SpaceX will save you',"{0:,.2f}".format(spacex_saved),'on this launch')
                            elif ula_total < spacex_total:
                                ula_saved = spacex_total - ula_total
                                print()
                                print('United Launch Alliance will save you',"{0:,.2f}".format(ula_saved),'on this launch')
                            else:
                                print('SpaceX and ULA will charge the same') #Function if both produce the same output
# Calculates time on earth and time dilation from space
    elif menu == 3:
    # Assinged variables for while statements and for math used
        user_speed = 0
        user_distance = 0
        year = 365
        light_year = 9460730472580800
        speed_of_light = 299792458
        #while statements validate speed and distance
        while not (user_speed >0 and user_speed < 1):
            user_speed = float(input('Speed of space ship, expressed as a fraction of the speed of light: '))
        while not user_distance >0:
            user_distance = float(input('Enter travel distance in light years: '))
            #below statements till elif of earth calculate earth observer time
        earth_time = user_distance / user_speed
        earth_time *= year
        # if less than 1 year just prints total days
        if earth_time <365:
            print()
            print('An observer on Earth ages',"{0:,.0f}".format(earth_time),'days during the trip')
            print()
        #if more than a year prints amount of years and total days
        elif earth_time>=365:
            earth_days = earth_time % 365
            earth_years = (earth_time - earth_days) / year
            print()
            print('An observer on Earth ages',"{0:,.0f}".format(earth_years),'years and',"{0:,.0f}".format(earth_days),'days during the trip')
            print()

    #calculates time on space aka time dilation
            # the math may look weird but it calculates the square root and when multiplying velocity by c it cancels out
            # the bottoom c so you can just use speed as a fraction of the speed of light and still get the right answer
            # you then multiply the time dilation times total earth days and it gives you the answer
            #CALCULATIONS FOR TIME DILATION
        import math
        time_dilation = (math.sqrt((1 - (user_speed**2)))) * (earth_time)
        #if less than 1 years just prints days
        if time_dilation <365:
            print('A passenger on the ships ages',"{0:,.0f}".format(time_dilation),'days during the trip')
        # if more than a year prints out total years and days
        elif time_dilation >=365:
            space_days = time_dilation % 365
            space_years = (time_dilation - space_days) / year
            print('A passenger on the ship ages',"{0:,.0f}".format(space_years),'years and',"{0:,.0f}".format(space_days),'days during the trip')

#NOTHING FOR FUNCTION 4 BECAUSE IF USER INPUTS 4 IT SIMPLY QUITS