Manned space flight is costly and dangerous. Moreover, the recent success of a series of unmanned space probes and satellites has demonstrated that a great deal of useful information can be gathered without the costs and risks associated with sending men and women into space. Therefore, we should invest our resources in unmanned space flights.
In a letter to the national aeronautics magazine, the author suggested the use of unmanned space flights is more feasible than manned ones. However, while the conclusion drawn by the author might hold water, it rests on two unfounded assumptions that, if not substantiated dramatically would weaken the persuasiveness of the argument.
Firstly, manned space flight might not be more expensive and dangerous, as manned flight usually contains manual assistance but this might not be the case in unmanned one where the manual control is replaced by the automatic, as there is no physical assistance available to it in reach, an automatic system is to be developed, which are harder to develop and likely costs more to develop, if this proves true the assertion of the author on conclusion will be hampered.
Lastly, as our technology is limited nowadays the recently sent unmanned probes or satellites may be sent near locations or near planets in which the validity of their success of them decreases, with an increase in distance the variability might increase resulting in more failures and increase of the cost.
In conclusion, the idea to invest in unmanned might not be feasible nowadays, However, as it stands now the argument relies on three unreliable assumptions made by the author.
Comments
e-rater score report
flaws:
No. of Words: 211 350
Minimum 250 words wanted
Attribute Value Ideal
Final score: 3.0 out of 6
Category: Satisfactory Excellent
No. of Grammatical Errors: 3 2
No. of Spelling Errors: 1 2
No. of Sentences: 5 15
No. of Words: 211 350
No. of Characters: 1057 1500
No. of Different Words: 117 200
Fourth Root of Number of Words: 3.811 4.7
Average Word Length: 5.009 4.6
Word Length SD: 2.785 2.4
No. of Words greater than 5 chars: 83 100
No. of Words greater than 6 chars: 61 80
No. of Words greater than 7 chars: 50 40
No. of Words greater than 8 chars: 27 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 42.2 21.0
Sentence Length SD: 21.009 7.5
Use of Discourse Markers (%): 0.8 0.12
Sentence-Text Coherence: 0.521 0.35
Sentence-Para Coherence: 0.891 0.50
Sentence-Sentence Coherence: 0.127 0.07
Number of Paragraphs: 4 5
Transition Words or Phrases used:
but, first, firstly, however, if, lastly, may, while, in conclusion
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 12.0 19.6327345309 61% => OK
Auxiliary verbs: 8.0 12.9520958084 62% => OK
Conjunction : 6.0 11.1786427146 54% => More conjunction wanted.
Relative clauses : 4.0 13.6137724551 29% => More relative clauses wanted.
Pronoun: 9.0 28.8173652695 31% => OK
Preposition: 29.0 55.5748502994 52% => More preposition wanted.
Nominalization: 6.0 16.3942115768 37% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1089.0 2260.96107784 48% => More number of characters wanted.
No of words: 211.0 441.139720559 48% => More content wanted.
Chars per words: 5.16113744076 5.12650576532 101% => OK
Fourth root words length: 3.81127787577 4.56307096286 84% => OK
Word Length SD: 2.8664641769 2.78398813304 103% => OK
Unique words: 122.0 204.123752495 60% => More unique words wanted.
Unique words percentage: 0.578199052133 0.468620217663 123% => OK
syllable_count: 344.7 705.55239521 49% => syllable counts are too short.
avg_syllables_per_word: 1.6 1.59920159681 100% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 1.0 4.96107784431 20% => OK
Article: 3.0 8.76447105788 34% => OK
Subordination: 7.0 2.70958083832 258% => Less adverbial clause wanted.
Conjunction: 0.0 1.67365269461 0% => OK
Preposition: 3.0 4.22255489022 71% => OK
Performance on sentences:
How many sentences: 5.0 19.7664670659 25% => Need more sentences. Double check the format of sentences, make sure there is a space between two sentences, or have enough periods. And also check the lengths of sentences, maybe they are too long.
Sentence length: 42.0 22.8473053892 184% => The Avg. Sentence Length is relatively long.
Sentence length SD: 119.697284848 57.8364921388 207% => The lengths of sentences changed so frequently.
Chars per sentence: 217.8 119.503703932 182% => OK
Words per sentence: 42.2 23.324526521 181% => OK
Discourse Markers: 13.4 5.70786347227 235% => Less transition words/phrases wanted.
Paragraphs: 4.0 5.15768463074 78% => More paragraphs wanted.
Language errors: 0.0 5.25449101796 0% => OK
Sentences with positive sentiment : 1.0 8.20758483034 12% => More positive sentences wanted.
Sentences with negative sentiment : 3.0 6.88822355289 44% => More negative sentences wanted.
Sentences with neutral sentiment: 1.0 4.67664670659 21% => More facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.220010948707 0.218282227539 101% => OK
Sentence topic coherence: 0.104869192377 0.0743258471296 141% => OK
Sentence topic coherence SD: 0.0694773535768 0.0701772020484 99% => OK
Paragraph topic coherence: 0.115617264048 0.128457276422 90% => OK
Paragraph topic coherence SD: 0.0494495929822 0.0628817314937 79% => OK
Essay readability:
automated_readability_index: 24.0 14.3799401198 167% => OK
flesch_reading_ease: 28.85 48.3550499002 60% => Flesch_reading_ease is low.
smog_index: 11.2 7.1628742515 156% => OK
flesch_kincaid_grade: 19.7 12.197005988 162% => OK
coleman_liau_index: 13.54 12.5979740519 107% => OK
dale_chall_readability_score: 10.36 8.32208582834 124% => OK
difficult_words: 62.0 98.500998004 63% => More difficult words wanted.
linsear_write_formula: 19.0 12.3882235529 153% => OK
gunning_fog: 18.8 11.1389221557 169% => OK
text_standard: 19.0 11.9071856287 160% => OK
What are above readability scores?
---------------------
Minimum 250 words wanted.
Rates: 33.33 out of 100
Scores by essay e-grader: 2.0 Out of 6
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.