SpaceX's Falcon Heavy - most powerful still operational rocket, 'too small' says Boeing

• Boeing and NASA are working on the Space Launch System which will be used to take humans into deep space 
• SLS will be bigger and have more carrying capacity than the Falcon Heavy
• It is still under construction and the first-gen SLS will not be much bigger than the SpaceX flagship
• SpaceX's now under construction BFR will be both reusable and eclipse even the Saturn V in terms of lifting capacity 

Boeing is working with NASA to build the Space Launch System (SLS) - a rocket class which is expected to one day carry humans and cargo into deep space. If completed, it will become the most powerful rocket system ever built. In a promotional website set up by the aerospace giant, they also threw some serious shade at Elon Musk's SpaceX, calling it "too small" for deep space exploration.

"The Falcon Heavy launch turned heads in February, but SpaceX's rocket is a smaller type of rocket that can't meet NASA's deep-space needs," reads the Boeing site. "Once the Boeing-built SLS is operational, it will be the most powerful rocket ever built." According to a report by ARS Technica, the company is making such claims based on what NASA's head of human spaceflight- Bill Gerstenmaier said in March. He reportedly mentioned that the SLS will have certain "unique capabilities" that the Falcon Heavy does not really have as yet.

Having said that, Gerstenmaier was also not able to explain why exactly NASA needed the SLS because it is yet to build anything that can actually take advantage of said "unique capabilities", notes ARS.

Another issue with the SLS claims, notes the report, is that Boeing actually speaks of the SLS as though it will be ready in the near future when in reality, the booster stage is at least two years away from being capable of flight. The rocket that is two years away will not even come close to the "most powerful rocket" tag. That comes much later, if ever, the report points out.

As of now, the "most powerful rocket" ever built is still Saturn V used by NASA in the Apollo missions that took man to the Moon. They were powerful enough to carry 118 metric tons to low Earth orbit (LEO). The first config of the SLS will be able to lift 70 tons to LEO, which is a bit more than the Falcon Heavy's 64 tons.

Higher configurations of the SLS, making it capable of lifting 105 tons will only happen in the mid-2020s and will cost NASA several billion dollars. The 130-ton variant- the "most powerful rocket ever" does not even have a timetable, notes the report.

Meanwhile, Elon Musk is busy building his BFR- which he says will take humans to Mars and carry 150 tons of cargo with them. His timetable is 2022 BFR takes 150 tons of cargo to Mars, 2024, the first crew arrives at the red planet, ready to colonize it. Also, the BFR is touted to be completely reusable.