(35S) - Mars Lander

[Roberto Volpi]

INTRODUCTION

In the '70s and '80s one of the very first games possible on a programmable calculator was the Moon Lander, and its popularity came also from the fact that the conquest of the moon still was a recent accomplishment.
Now, space explorations aim to Mars, so it is a good opportunity to revisit this classic, using the metric system.
As height and fuel are freely chosen at every play, there is more replay value.

Enjoy!


INSTRUCTIONS:

"GTO L ENTER" to reset the program
Input height value, press "ENTER", input fuel value and press "R/S"
Height and Velocity are displayed after "HEIGHT-SPEED" panel
Fuel available after "FUEL" and "CONSUPTION" after display
Pilot must hit "R/S" within 1 seconds after INPUT BR and adjust burn rate
The aim is to land at less that 3m/s, otherwise the lander will crash, and the crew will die in it.
Cycle repeats until the message "ON MARS" or "CRASH" is displayed



L001 LBL L
L002 SF 10
L003 STO F
L004 X<>Y
L005 STO H
L006 -50
L007 STO V
L008 0
L009 STO B
L010 STO A
* L011 (EQU) HEIGHT - SPEED
L012 PSE
L013 RCL H
L014 X≤0?
L015 GTO L060
L016 RCL V
L017 PSE
L018 (EQU) FUEL
L019 PSE
L020 VIEW F
L021 PSE
L022 (EQU) CONSUMPTION
L023 PSE
L024 VIEW B
L025 PSE
L026 RCL B
L027 (EQU) INPUT BR
L028 PSE
* L029 STO B
L030 10
L031 X<Y?
L032 STO B
L033 RCL B
L034 RCL F
L035 X<Y?
L036 GTO L056
L037 X<>Y
L038 STO F
L039 RCL B
L040 2
L041 X
L042 4
L043 -
L044 STO A
L045 2
L046 /
L047 RCL H
L048 +
L049 RCL V
L050 +
L051 RCL A
L052 STO+V
L053 R DOWN
L054 STO H
L055 GTO L011
* L056 (EQU) PARTIAL BURN
L057 PSE
L058 RCL F
L059 GTO L029
* L060 -3
L061 RCL V
L062 X>Y?
L063 GTO L065
L064 (EQU) CRASH
* L065 (EQU) ON MARS
L066 RTN


Variables:
H=Height (m), V=Velocity (m/s), A=acceleration (m/sec2)
F=FuelTank (Litres), B=Burn Rate (L/s)
Approaching velocity is negative. It is -50 m/sec at start