Elon Musk's SpaceX defended its progress developing a Moon lander in a blog post Thursday, following NASA's decision to reopen the program to other companies.

On Oct. 30, SpaceX posted an update about its Starship moon-landing plans, which includes a reference to a possible "simplified mission architecture and concept of operations" for NASA's Artemis 3.

SpaceX said it has pitched NASA a "simplified mission" to put astronauts back on the moon following criticisms over delays by Sean Duffy, the space agency's acting administrator.

Former Real World cast member and current Transportation Secretary / acting NASA administrator Sean Duffy recently said SpaceX was “behind” on its contract for Artemis III and proposed reopening it. (Elon Musk responded with a predictable slew of insults.

Elon Musk's SpaceX (SPACE) and Jeff Bezos' Blue Origin (BORGN) have submitted plans to NASA for ramping up efforts to take astronauts to the moon, the agency told CNBC. NASA "has received and is evaluating plans from both SpaceX and Blue Origin for acceleration of HLS [Human Landing System] production,

The company announced Thursday that its ongoing test campaign and infrastructure expansion have positioned Starship to support lunar missions and, eventually, crewed flights to Mars.