SpaceX CEO Elon Musk took one more poke at rival tycoon Jeff Bezos’ space startup, Blue Origin, on Monday in the midst of a fight more than a $2.9 billion agreement to assemble a lunar lander for NASA.

The New York Times revealed Monday Blue Origin had filed a protest with the Government Accountability Office to challenge NASA’s decision to award the exclusive agreement to SpaceX.

Blue Origin CEO Bob Smith disclosed to The Times NASA had failed in its evaluation of the proposals submitted by his organization, SpaceX, and a third bidder, Dynetics.

On Twitter, Musk reacted to the report about Blue Origin’s challenge by poking a not at all subtle fun at the male anatomy, saying: “Can’t get it up (to orbit) lol.”

The joke insinuated the way that Blue Origin has not yet accomplished an effective orbital spaceflight with its rockets.

Blue Origin didn’t react to a solicitation for input on this story.

Blue Origin recently launched its suborbital New Shepherd rocket system with a crash-test dummy dubbed “Mannequin Skywalker,” however has lagged overall in its space race contrasted with Musk’s SpaceX.

The feud between Musk and Bezos started over 15 years prior when a discussion about reusable rockets allegedly went south. From that point forward, the two executives have fought habitually over their adversary plans for colonizing space and infrequently their different organizations, Tesla and Amazon.