Final Project

Robert R.

Legislator:  John H. Shields, Representative

Mars/Pathfinder Intersection  

(Man to Mars)

Throughout the history of space travel, man has dared to venture across bounds of which he thought nearly insurmountable in the past.  As man now strives to push these bounds further on to Mars, he’ll go through feats that researches still question the means of today.  The journey to Mars consists of such feats as that of the physical, mental, mathematical, technological, emotional, and even spiritual realms of knowledge.  Of all these, physics plays a most interesting part to the whole in that it’ll have to get us there, and bring us back, safely.  But do the theories currently accepted prove to accurately get spacecraft to Mars routinely enough to risk loosing human life in an attempted manned mission?

The physics entailed in transporting man to Mars include such maneuvers as the Hohmann Transfer, which would successfully navigate spacecraft from Earths orbit to that of Mars.  The path would follow an elliptical outline of which the Sun would pose one of two foci points used to calculate travel distances and times.  The time of departure could theoretically be set for one of two orbit intersections Earth’s orbit shares with that of the Hohmann Orbit itself, but due to valuable time restrictions the point located furthest along the counter-clockwise path would pose most optimistic.  Taking into consideration the current speed limitations involved in recent space travel, the estimated round-trip travel time would consist of about fourteen months.  The time entailed would concern both the physical integrity of the spacecraft itself as well as the physical and mental abilities of the crew aboard.

The velocity of the spacecraft en route to the red planet can be calculated anywhere on the trail of its elliptical orbit using the vis-viva equation derived back in the 17^th century by German scientist Gottfried Leibniz.  It states that twice the quantity of a gravitational constant times the mass of the sun multiplied by the mass of the spacecraft plus an energy constant, divided by the distance from the Sun to Mars, divided by the mass of the spacecraft, all raised to the one half power equals the velocity of the moving object in orbit.  The planned intersection between the planet and the spacecraft itself must also be respectfully engineered.  The average orbital velocity of Mars comes out to around 24.4 kilometers per second, or about 54,500 miles per hour.  After calculation, the US Pathfinder’s velocity upon intersecting Mars’ orbit would be .663 kilometers per second, or about 1480 miles per hour.  The difference in velocities exist chiefly to provide the spacecraft with a minimal amount of maneuvering effort needed to attain stationary orbit around the planet.  Given the fact that many various logistical as well as human errors could occur along the way, the modifications needed to be made could mostly be done through prewritten software programs with minimal assistance from the control center.  The burns done by the craft could also be modified to make use of additional or insufficient amounts of fuel, as the manned missions would have to be particularly concerned with leaving themselves enough gas to get home with.  However most future plans to visit Mars include a supplementary supply of fuel provided by previously flown unmanned flights to orbit.

The possibility of sending two manned flights to Mars in coalition with each other poses another interesting question.  Is the potential for success increased in a mission involving more men and machine, or is the potential for failure merely doubled from what it would have been before?  Perhaps both bare truth of one form or another, but regardless, the fact remains that more research needs to be made.  The prosperity of all past robotic missions to Mars can only be attributed to the failed ventures in their own past, such as Challenger and the recent Mars Observer.  Both the increased robotic activity around Mars and the expansion of our own technology here on the moon would serve as great drawing boards to further consider different alternatives to taking man farther than he’s ever gone before.

Though the human hand craves to reach forth into the unknown and beyond, we must first grasp that hand, take it apart chromosome by chromosome, and ameliorate its every aspect.  For before we strive to travel infinitely far, we must further understand the infinitely small.  This leads us to better improve upon ourselves, which fuels the infinite cycle in which we are more inclined to reach our goals faster, create more superior innovations, and further improve upon everything else imaginable.  The truth remains that while the technology may forever build upon itself, the growing error exists in its creator himself. And while the journey to Mars poses a real risk that may be insurmountable at the time, it’s a risk that man attacks with endless effort and a passion for glory.

Sources:

1)      http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Kepler.html

2)    http://nssdc.gsfc.nasa.gov/nmc/tmp/1992-063A.html

3)    http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980419b.html

Last Updated: 09/07/01