The space race between the world's two richest men has gone into hyperdrive after Tesla chief Elon Musk took a swipe at Jeff Bezos' attempt to challenge a major NASA contract.
The two billionaires, who have been trying to launch long-range orbital rockets, were competing for a coveted contract from the government to build a spaceship to deliver astronauts to the moon as early as 2024.
Musk won. Bezos was not happy.
Bezos' Blue Origin has filed a protest with the Government Accountability Office (GAO), accusing the National Aeronautics and Space Administration (NASA) of moving the goalposts for contract bidders at the last minute.
Musk, who also leads SpaceX, fired back with a tweet that said: "Can't get it up (to orbit) lol."
He did not elaborate on the tweet, but pasted a screenshot of a 2019 report about Bezos unveiling Blue Origin's moon lander on the same Twitter thread.
Blue Origin has fallen far behind SpaceX and United Launch Alliance (ULA) on orbital transportation, losing out on billions of dollars' worth of US national security launch contracts that begin in 2022. ULA is a joint venture of Boeing Co and Lockheed Martin Corp.
These rocket startups mainly aim to send satellites for clients into orbit at an affordable price and reuse parts of rockets to keep costs in check.
Earlier this month, NASA awarded SpaceX the lunar contract over Blue Origin and defense contractor Dynetics. The sought-after project aims to put humans back on the moon for the first time since 1972.