Tala Yasinpoor
TPO 50 Writing
Practice mode Back Continue
Integrated Writing
00:05
Scientists are considering the possibility of sending humans to Mars in the coming decades. Although there have been successful manned missions to the Moon in the 1960s and 1970s, Mars is 150 times further away from Earth than the Moon is. Thus the project of sending humans to Mars would require solving an array of problems the Moon missions did not have to face.
One problem is that a round-trip to Mars and back is likely to take at least two years. The trip to the Moon lasted only a few days, and it was easy to bring enough supplies of food, water, and oxygen; but the cargo capacity of space vehicles is too limited to put on board the food, water, and oxygen required by a crew for a period of two years. Without those essentials, though, a Mars mission is impossible.
A second problem is that astronauts on the Mars mission would be in the zero-gravity environment of space for many months at a time. Spending a long time in the zero-gravity environment has negative effects on the human body, such as decreased muscle mass and lower bone density. Over the course of a two-year mission, the effects would be so severe, they would make it impossible for humans to make the trip without experiencing grave medical problems.
Finally, astronauts on a mission to Mars would be exposed to dangerous levels of space radiation, much of which comes in the form of charged particles emitted by the Sun. Earth's magnetic field, which normally protects us from dangerous solar radiation, would not be able to protect a spaceship traveling in interplanetary space. Constructing a shield that would protect the whole spaceship from space radiation is at present impossible because it would add too much weight to the ship.
The reading passage presents some problems with the manned Mars trip indicating
that such an effort would be impossible. Nevertheless, the lecturer finds the
putative reasons stated by the reading passage fallacious and debunks them one by
one by providing some solutions.
First of all, the writer contends that the long distance between Earth and Mars
would cause a problem for supplying food, water and oxygen due to the fact that
the limited space of space vehicles makes it impossible to carry such amount of
supplies. Conversely, the lecturer brings up the idea that by the hydroponics
method this problem can be addressed. This is a technique by which not only is it
possible to cultivate plants in a little space to produce food, absorb carbon dioxide
and release oxygen, but also it can provide astronauts with water supplies by
recycling waste water. By this technique, water, oxygen and food supply would not
be a problem anymore.
Secondly, the reading passage holds the view that the zero-gravity environment
would have detrimental effects on the muscle mass and bone density of astronauts
in the long run. By contrast, the speaker accentuates the fact that some astronauts
have already spent some months in space stations with zero-gravity condition, and
the harmful effects of it can be avoided just by several techniques including regular
exercise and taking vitamin and calcium pills. Thus, the zero-gravity condition
would not be an obstacle to manned travel to Mars, if astronauts use these
methods.
Finally, yet importantly, the passage alleges that in the absence of the magnetic
field of Earth, astronauts would be exposed to dangerous levels of space radiation,
which is inevitable considering the weight of possible protections. Contrary to this,
the professor disproves this issue regarding the fact that astronauts would not be in
the exposure of dangerous radiation all the time. It will happen occasionally, so
they can build a small protection of light weight, monitor the radiations, and
survive under the small shield when it is needed.
No. of Words: 334 250
Write the essay in 20 minutes.
Attribute Value Ideal
Final score: 24 in 30
Category: Good Excellent
No. of Grammatical Errors: 0 2
No. of Spelling Errors: 0 2
No. of Sentences: 12 12
No. of Words: 334 250
No. of Characters: 1699 1200
No. of Different Words: 175 150
Fourth Root of Number of Words: 4.275 4.2
Average Word Length: 5.087 4.6
Word Length SD: 2.67 2.4
No. of Words greater than 5 chars: 128 80
No. of Words greater than 6 chars: 102 60
No. of Words greater than 7 chars: 65 40
No. of Words greater than 8 chars: 45 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 27.833 21.0
Sentence Length SD: 9.948 7.5
Use of Discourse Markers (%): 0.75 0.12
Sentence-Text Coherence: 0.366 0.35
Sentence-Para Coherence: 0.62 0.50
Sentence-Sentence Coherence: 0.093 0.07
Number of Paragraphs: 4 4