SpaceX is now aiming to launch a reusable Falcon 9 booster on its third flight, a first for the company, no earlier than Monday (Dec. 3) to allow time for additional checks. 

The Falcon 9 rocket, the first of SpaceX’s upgraded “Block 5” series, was slated to launch Sunday, but will now lift off from California’s Vandenberg Air Force Base Monday at 1:32 p.m. EST (1832 GMT; 10:32 a.m. PST). The mission has been delayed since mid-November over booster checks and bad weather at the launch site.

“Standing down from tomorrow’s launch attempt of Spaceflight SSO-A: SmallSat Express to conduct additional inspections of the second stage,” SpaceX representatives said in a Twitter update Sunday. “Working toward a backup launch opportunity on December 3.” [The Evolution of SpaceX’s Rockets in Pictures]

SpaceX’s upcoming launch is a milestone of sorts for the company in a few different ways.

First, there’s the resuability aspect. So far, SpaceX’s Falcon 9 first stages have made at most two flights before being retired. But the first stage of the Falcon 9 rocket launching Monday is making its third flight to space after launching the Bangabandhu-1 communications satellitefor the government of Bangladesh in May and the Merah Putih satellitefor PT Telkom Indonesia in August. That May launch marked the first of a Block 5 Falcon 9, an upgraded version of SpaceX’s workhorse booster designed for at least 10 flights, if not more, as part of the company’s reusability program to drive down the cost of spaceflight. As on its two previous flights, the Falcon 9 first stage is expected to return to Earth. It will land on SpaceX’s drone ship “Just Read the Instructions” in the Pacific Ocean.

There’s also the number of SpaceX launches this year. SpaceX closed out 2017 with 18 launches, a record at the time and a significant step up from its previous record of eight flights. Monday’s launch will mark SpaceX’s 19th launch of 2018, setting a new record that the company will then break on Tuesday (Dec. 4) when it launches a Dragon cargo ship to the International Space Station for NASA from Cape Canaveral, Florida. More SpaceX launches are scheduled for this month, so expect that record to be just over 20 by the end of the year.

And finally, there’s the payload. The Falcon 9 launch will be dedicated rideshare mission for the company Spaceflight, which is sending up 64 different small satellites on this flight. So there’s literally a lot (of satellites) riding on this mission for SpaceX and its customer. 

You can watch SpaceX launch its milestone Block 5 Falcon 9 mission live on Monday. SpaceX will webcast the launch live here, and you can see it on Space.com here, courtesy of the company. The webcast will begin about 15 minutes before liftoff at 1:17 p.m. EST (1817 GMT; 10:17 a.m. PST).

Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik. Follow us  and FacebookOriginally published on Space.com