Zachary NorcrossProfessor Guy CortesiICEN 140 Introduction toEngineering Design30th January2018AnEvaluation of a Trip to MarsSpacetravel is a long-held dream by many on Earth. Being able to travel to otherplanets requires an enormous amount of work and resources to complete, but tosend humans to another planet requires even more. Many factors also affect ourability to make this mission a success, such as launch vehicle, food reserves,launch time, fuel reserves, return flight, and more. These parameters make the projectof conducting such a mission a difficult one.
Firstly,is the transportation time. This time will ultimately affect every otherparameter because all resources have a limited lifespan before rotting orexpiring. According to Makuch, and Davies, “a trip to Mars at the mostfavorable launch option takes about six months with current chemical rockettechnology” (Makuch et al.
). This journey is only one way as well, so it wouldtake roughly a year to complete the entire journey. This time estimate does notinclude the time you may need to stay on Mars to wait for the orbits to matchup. Mars and Earth both have orbits and in six months they can be in radicallydifferent positions than they were therefore we must use mathematical formulasto find when the planets will be in the correct positions so that we may launchand arrive in the correct position at the correct time.
This will of course add time to the journey byforcing the astronauts to stay on Mars until such time that they may launch. Nowthat the timeframe is analyzed we must look at the design of the ship.Thereis also the question of design parameters of the spacecraft. Due to theduration of the flight and the distance it would be traveling it poses aninteresting question: how do we design a space craft that can store all thenecessary amenities needed for the mission such as food and fuel, but also hasa proper amount of weight so that it may take off and land on both Earth and Mars?Both these planets have different atmospheres and forces of gravity.
Accordingto NASA Mars’s gravity is “0.375 that of Earth” (NASA), which is significantlyless. The change in gravity effectseverything from the astronaut’s health, to the needed lift to launch for thereturn mission. As well as the amount of breaking done by entering theatmosphere that would help slow the craft down. Preferably we would design aship that can effectively manage the weight so that it will be able to takeoff,and land on both planets as well as hold the fuel needed. The ship would alsoneed to be able to withstand radiation levels from space.
This is an essentialdesign parameter to keep the astronauts healthy a similar design to the Marsrovers may be suitable. With the parameters discussed we must evaluate theresources required.Overa year in space is difficult enough; it becomes even harder when consideringthe amount of resources needed. Most importantly is food. To keep the food fromrotting it must be frozen. The only types of food that should be brought are onesthat would be able to last more than a year (because it will take more than ayear for a full trip). The food will also have to cover the range of essentialfood groups to keep the astronauts healthy. According to the United StatesDepartment of Agriculture the five food groups are “fruits, vegetables, grains,proteins, and dairy” along with the recommended amount of each per day (Chang).
An alternative to this is one the US military employs. Meals Ready to Eat (MRE’s),according to the US Army, “…provide an average of 1,250 calories …. andone-third of the military recommended daily allowance of vitamins and minerals”(Military, US). These MRE’swould take up less space and according to the US Army “… have a minimum shelflife of three and a half years at 80 degrees F” (Military, US).
This allows for the food to last morethan long enough for the entire trip. This may also help with storage as MRE’scome in small packages that can be easily stored in a container (see figure 1).Food is essential to keeping these astronauts healthy but the change in gravityand environment will require extensive exercise to minimize biological effectsof space travel. Foodgoes hand in hand with exercise, to keep the astronauts well fed and physicallyhealthy, but exercise becomesespecially important when traveling in space or on another planet. In a studydone by Fitts et al. they found that “… prolonged weightlessness producedsubstantial loss of fibre mass, force, and power …” (Fitts et al). This studyonly studied a flight that was “~180 days” (Fitts et al).
The trip to Mars isconsiderably longer. This training program also consisted of three categories: cycling,treadmill, and resistance training (Fitts et al.). These appear to be a goodstep towards the required exercise but Fitts et al. states later that “theexercise counter measures employed were incapable of providing the highintensity needed to protect fibre and muscle mass” (Fitts et al). This means amore intense workout regimen must be employed that involves more resistancetraining to put more strain on the muscles. Not only must it be more intense,but it must also target almost every major muscle group so that the astronautsstay physically fit.
This does not account for loss of bone density. Continuedweightlessness influences bone usage since humans do not have the same force ofgravity acting on them in space or on Mars as previously discussed making themweigh less. A journal entry from White and Averner found that after acollection of space flights ranging from 4.5 months to 14.5 months that “theextent of bone loss for individual astronauts or cosmonauts is considerable,varying from 0% to up to 20%” (White et al.). A solution to this would be toenforce a strict training regimen that features more resistance based exercisesusing machines that isolate each muscle group to help minimize the effects ofaltered gravity. Now that health has been discussed we may look at wastemanagement and fuel for the return trip.
The ship will produce a large amount of waste from theastronauts and the used fuel. Carbon dioxide waste is simple enough to handle.An air filtration system like the Apollo missions had will need to be employedhowever the question rises about physical waste. This waste must be disposed ofin some way to prevent it from accumulating.
A solution would be to store thewaste in containers and then leave those containers on MarsNZH1 after arriving. While this is apossibility it is not ideal as it pollutes the planet being travelled too. Adifferent solution would be to empty the waste into the vacuum of space. Thisis also not ideal as we would have to pollute space to do this, making future launches unsafe. An ideal scenario would be a hybrid of storageand recycling. If we could store whatever cannot be recycled and recycle therest it would assist in cutting down on the amount of waste and would give areusable cause to the other part of waste.
This is an idea also put forward byHoffman “Self-sufficiency undoubtedly requires highly advanced life supportsystems in which most of the waste product from human activity is recovered andreused”. (Hoffman, Kaplan, 2-15) This shows the need for advanced systems tohelp manage all systems of living including waste management. As far asspecific methods and technologies Drysdale et al. Suggest that “physicochemicalregeneration is most cost effective. However, bioregeneration is likely to beof use for producing salad crops” (Drysdale et al.). These two techniques couldbe used to help recycle waste and supply food and water. The two optionsproposed are either storing the waste or recycling it.
The other neededrecourse is energy. What will power the craft to and from Mars. Space travel requires a good amountof fuel to be successful. A trip to Mars and back would require even more thanthe usual trips that we perform when sending out rovers.
One of the biggestchanging factors is the return trip. We would have to send the ship with enoughfuel for both the trip to Mars and the return trip. This can be difficult dueto storage and weight concerns as that much fuel will weigh the ship down andmay not have enough room to be stored. As discussed previously the techniquesused in life support by Drysdale et al. may be of use as they may be able tohelp create fuel. Another solution may be to send a rover like canister to Marsthat would contain more fuel for the return trip.
In conclusion space travel to Mars is clearly a verydaunting task. The sheer distance from Earth poses many challenges that theMoon did not have. Food would have to be either prepackaged or made usinghighly advanced technology. The astronauts would have to stay on Mars for atime until they could launch when Earth was at the proper location in orbit sothat they arrive back on Earth. The ship itself would have to handle a largeamount of weight and withstand prolonged radiation from space.
The astronautswould also need to have a very strict diet and workout to minimize healtheffects of low gravity. Waste would have to be either recycled or stored untilit could be disposed of. Or a hybrid of recycling and storing waste that can’tbe recycled. The return trip would need fuel that would be either sent on arover like capsule or created through highly advanced technologies.
As shownthe likelihood of a trip to Mars and back is a difficult engineering question.Many areas require large sums of money to develop the parts or technologiesneeded. As noted by Koelle when referring to ships for travel “They are too smalland too expensive for this job” (Koelle, 1) but as we as a species continue to develop more technologyengineers will keep innovating so that we will be able to visit Mars andreturn. NZH1