Yes, the slingshot orbit strategy is not a new, brilliant idea.
No one claimed it was, perhaps that's why a "junior astrophysicist was able to come up with the notion.
As for "repeated success' of NASA, not only is that not true,
Read the list for yourselves, you'll learn like I did, that there have in fact been many more success' than failures.
http://www.spacelaunchreport.com/logsum.html
The science is "befuddled" because Mars gravity is less than Earth's and nothing indicated this (looked like they were in Arizona). And they had so much equipment on Mars they must have spent twenty years stocking up.
Also, you don't blow up part of your spacecraft when you have to travel for eighteen months before you get back to Earth(they did this to rendezvous with Matt Damon "orbitng" around Mars. Jessica Chastain said that they could "worry about damage later".).
And Matt Damon got so scrawny (body double or video tricks) at the end that it would be near impossible for him to do all the hard work he had to when he trekked out to 'boot up' the Mars prober and whatever so he could blast off planet, assuming he had enough nourishment not to get rickets or something.
And no way the "junior" NASA astrophysicists or whatever he was comes up with the only viable plan to make it to Matt in time while all the senior scientists are hard put to think up anything---and the idea was the same tired "loop around the planet' to get a boost of acceleration they've used in dozens if not hundreds of space stories. And of course, NASAish astronauts "mutinying" to save Matt (forgetting about their own spouses and kids) and blocking NASA control's ability to send commands to the space rocket? Hard to believe.
Lastly, Matt Damon's advice to the newbie astronauts:
"Just solve one problem at a time and you'll make it through" is B.S. Outer Space is deadly and with limited resources there is only so much you can do. Damon in the movie is pretty much an atheist (although he does use a cross for firewood) but while
"failure is not an option" often it is a sad eventuality.
Yes, Very good indeed, All this proves that not all the public is mislead by the fictional story "The Martian" when it comes to science.