Manned space flights should not be invested in.
The opinion presented here falls short of providing enough evidence for arriving at such strong conclusions made by the author. The following arguments should be considered and weighed for a proper and justified analysis.
For starters, the letter to the editor does not mention anything about the nature of the manned and unmanned missions. The manned missions and thre recent successful unmanned ones could have been for completely different purposes altogether. It is imprudent to judge them against each other and then claim that one comes out as the vanquishing economic winner over the other. The opinion presented would be stronger and more reliable if it were comparing a mission that had similar technological objectives.
The veracity in the claims also falter at the point that there are certain space missions that might require a human intervention necessarily. It is true that better robotic arms and rovers can beat a human's data collection abilities in space exploration missions but what if the mission aims to study about the human body in space among other things? Unmanned missions can not completely replace manned missions in today's context in which space agencies around the world are obsessed with finding out more about the human space flight in a long term goal to colonize the Moon or Mars. These missions are essential and it is not suprising that space agencies that are not even financially well backed, like India's ISRO, are also be seen to be following suit and are investing a huge amount of money in manned missions despite their constricted resources.
The argument also heavily relies on the fact that all unmanned missions are cheaper than manned ones. It is possible that there are some missions in whichreplacing a human in the mission would be much more expensive for the space agency along with overtones of heightened chances of failure. Evaluating this aspect is also important in gauging the presented opinion in a more informed and critical manner.
The argument does not expound well on the risks associated with manned spaceflights. Risks reduce further after every successful manned flight as the spacecraft advances on the "Technology Readiness Level" ladder. These reduced risks in newer missions should also be taken into consideration without jumping to conclusions. It is possible that development of new unmanned teachnology also faces significant amount of risk to human life during the developemnt period. However, we may discount this if enough evidence is presented that underscores the risk associated with these missions.
If the opinion is backed with evidence on the aforementioned points, the letter's conclusion would hold value.
Comments
Essay evaluation report
Attribute Value Ideal
Final score: 4.5 out of 6
Category: Good Excellent
No. of Grammatical Errors: 0 2
No. of Spelling Errors: 0 2
No. of Sentences: 19 15
No. of Words: 431 350
No. of Characters: 2235 1500
No. of Different Words: 233 200
Fourth Root of Number of Words: 4.556 4.7
Average Word Length: 5.186 4.6
Word Length SD: 2.68 2.4
No. of Words greater than 5 chars: 168 100
No. of Words greater than 6 chars: 128 80
No. of Words greater than 7 chars: 96 40
No. of Words greater than 8 chars: 54 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 22.684 21.0
Sentence Length SD: 8.856 7.5
Use of Discourse Markers (%): 0.632 0.12
Sentence-Text Coherence: 0.306 0.35
Sentence-Para Coherence: 0.579 0.50
Sentence-Sentence Coherence: 0.092 0.07
Number of Paragraphs: 6 5
Grammar and spelling errors:
Line 9, column 202, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'humans'' or 'human's'?
Suggestion: humans'; human's
...tter robotic arms and rovers can beat a humans data collection abilities in space expl...
^^^^^^
Line 21, column 74, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'letters'' or 'letter's'?
Suggestion: letters'; letter's
...dence on the aforementioned points, the letters conclusion would hold value.
^^^^^^^
Transition Words or Phrases used:
also, but, however, if, may, so, then, well, it is true
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 24.0 19.6327345309 122% => OK
Auxiliary verbs: 10.0 12.9520958084 77% => OK
Conjunction : 12.0 11.1786427146 107% => OK
Relative clauses : 12.0 13.6137724551 88% => OK
Pronoun: 25.0 28.8173652695 87% => OK
Preposition: 53.0 55.5748502994 95% => OK
Nominalization: 11.0 16.3942115768 67% => OK
Performance on vocabulary words:
No of characters: 2297.0 2260.96107784 102% => OK
No of words: 431.0 441.139720559 98% => OK
Chars per words: 5.32946635731 5.12650576532 104% => OK
Fourth root words length: 4.55637350225 4.56307096286 100% => OK
Word Length SD: 2.77914657136 2.78398813304 100% => OK
Unique words: 231.0 204.123752495 113% => OK
Unique words percentage: 0.53596287703 0.468620217663 114% => OK
syllable_count: 720.9 705.55239521 102% => OK
avg_syllables_per_word: 1.7 1.59920159681 106% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 7.0 4.96107784431 141% => OK
Article: 9.0 8.76447105788 103% => OK
Subordination: 1.0 2.70958083832 37% => OK
Conjunction: 0.0 1.67365269461 0% => OK
Preposition: 1.0 4.22255489022 24% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 19.0 19.7664670659 96% => OK
Sentence length: 22.0 22.8473053892 96% => OK
Sentence length SD: 47.6367836645 57.8364921388 82% => OK
Chars per sentence: 120.894736842 119.503703932 101% => OK
Words per sentence: 22.6842105263 23.324526521 97% => OK
Discourse Markers: 2.89473684211 5.70786347227 51% => More transition words/phrases wanted.
Paragraphs: 6.0 5.15768463074 116% => OK
Language errors: 2.0 5.25449101796 38% => OK
Sentences with positive sentiment : 9.0 8.20758483034 110% => OK
Sentences with negative sentiment : 8.0 6.88822355289 116% => OK
Sentences with neutral sentiment: 2.0 4.67664670659 43% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.22752012481 0.218282227539 104% => OK
Sentence topic coherence: 0.0645309911694 0.0743258471296 87% => OK
Sentence topic coherence SD: 0.0582125638293 0.0701772020484 83% => OK
Paragraph topic coherence: 0.0961727645671 0.128457276422 75% => OK
Paragraph topic coherence SD: 0.0649462517254 0.0628817314937 103% => OK
Essay readability:
automated_readability_index: 15.0 14.3799401198 104% => OK
flesch_reading_ease: 40.69 48.3550499002 84% => OK
smog_index: 8.8 7.1628742515 123% => OK
flesch_kincaid_grade: 13.1 12.197005988 107% => OK
coleman_liau_index: 13.93 12.5979740519 111% => OK
dale_chall_readability_score: 8.94 8.32208582834 107% => OK
difficult_words: 115.0 98.500998004 117% => OK
linsear_write_formula: 8.0 12.3882235529 65% => OK
gunning_fog: 10.8 11.1389221557 97% => OK
text_standard: 9.0 11.9071856287 76% => OK
What are above readability scores?
---------------------
Rates: 83.33 out of 100
Scores by essay e-grader: 5.0 Out of 6
---------------------
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.