(something) is going to (do something)

There's a slight difference between "going to do" and "will do" something. If you use "will" in this sentence...

Will you be able to make the deadline?

...the question has a different meaning. It's asking the person to make a sort of decision and a promise. If she answers "yes" it means that she's decided that she will be able to On the other hand, when you use "going to", you're making a prediction. So in the example above, the speaker is asking the listener if she thinks she will probably finish on time.

(someone) is able to (do something)

The phrase "be able to" means "can". When you are talking about things that someone can or can't do in the past or the future, it's better to use "be able to" than "can" or "could":

Were you able to find the I.D. you lost yesterday?

I'm sorry - I won't be able to make it to this week's meeting.

make a deadline

To "make a deadline" means to finish something by or before it is due.

People also use "meet a deadline" in the same way. When you use "make" it sounds like it was more difficult to finish on time. So you'd probably be more likely to see "make" in a sentence like this:

I just barely made the deadline.

And you'd see "meet" in a sentence like this:

Aaron's usually pretty good about meeting his deadlines.

the

In the sentence above, the speaker uses "the" because both people are thinking about the same deadline. You can imagine that they were probably already talking about the deadline or about the project. So when the speaker says "the deadline", the listener knows exactly which deadline it is.