Is hypersonic airline travel possible in the 21st century or supersonic what nasa is working on can the sonic boom be reduced?

Is hypersonic airline travel possible in the 21st century or supersonic what nasa is working on can the sonic boom be reduced? - 1

It is possible, at least theoretically, to reduce the sonic boom by carefully shaping the airframe and the engine inlets. NASA is working on this concept and even now is testing a scale model in a supersonic wind tunnel, but it will be a few more years until it has an actual test aircraft sitting on the ramp.

Possible yes.
Commercially viable? Quite possibly no.

The fact is that a supersonic -- let alone a hypersonic -- aircraft would be horribly expensive to design and certify, and therefore horribly expensive to sell. The problem is that the design has to be done and be paid before the first passenger can board it, meaning that banks would have to finance it.
And banks would not finance it unless they are sure they can make a buck. Which they won't because the plane would be too expensive to sell in adequate number.
Imagine an aircraft designed to replace, say, the Boeing 787; i.e. Same range of about 7000 NM and capacity of ~300 passengers.
Knowing that Boeing had invested $32 billion before entry in service, that the plane sells between $225 to $305 million depending on the version, and that Boeing has sold about 1300 and delivered 625, how much would the supersonic of the same size cost, and how many would sell?

Here are a few more things to consider: Boeing on average sells less than 90 787 each year since the the aircraft entered service (and I'm not even counting the first 2 years, where there were more cancellations than actual orders), so ultimately, over the next 10 years, they should have sold about 3000 787 in total.

How many supersonic, able to fly at Mach 3 would that be?
How about 1000 plane maximum? And that is assuming that ALL 787 end up being replaced by the supersonic 787 equivalent. Why? Because the airplane that flies at Mach 3 makes 3 trips when the one that flies at Mach 0.85 does one, so you need only 1/3 as many airplane.
Selling less than 30 airplane of a model in a year is not considered adequate volume, and again, that is assuming that all 787 would be replaced.
Low volume means less aircraft to amortize the development cost, which drives the cost of the airplane up. And a higher cost means less sales, as the ticket would go up.
Tell me, if there was a supersonic option at 5 times the ticket price (a somewhat conservative estimate) how frequently would you fly supersonic as opposed to the (much) cheaper alternative? I think that you would fly once or twice in your life, for bragging rights, top.
And that stands for everyone else.

No passengers means no interest form the airline.
No airline interest means no support from banks.

There will not be supersonic flight until someone figures out how to make it 5 times cheaper.
And good luck with that bit.