SpaceX is expected to launch 143 satellites into space on a single Falcon 9 rocket on Sunday after having to postpone its launch day of Saturday at Cape Canaveral Space Force Station in Florida due to bad weather.

The decision to postpone came just six minutes before blast off, Space.com reported.

“Weather is looking a little dicey for our current liftoff time,” SpaceX production supervisor Andy Tran said about seven minutes before the rocket was scheduled to blast off, citing electrical fields.

Due to unfavorable weather, we are standing down from today’s launch; the team will continue with the countdown until T-30 seconds for data collection. Another launch attempt is available tomorrow, January 24 with a 22-minute window opening at 10:00 a.m. EST

— SpaceX (@SpaceX) January 23, 2021

Space.com reported that less than a minute later, the SpaceX team made the call to postpone the launch attempt entirely, not waiting for the clock to run out.

Electrical fields are a risk to rocket launches because they can prompt lightning formation during liftoff.

The Transporter-1 launch will be SpaceX’s first dedicated rideshare mission, carrying 133 assorted small satellites and 10 of the company’s Starlink internet satellites. When it launches, the mission will hold the record for most satellites deployed from a single rocket, Tran said.

The launch will be the fifth flight for the Falcon 9 first-stage booster. Its previous flights, all in 2020, include the company’s first-ever crewed launch, called Demo-2, in May 2020, which sent two NASA astronauts to the International Space Station for a two-month stay.

The booster also launched a military communications satellite for South Korea, a Cargo Dragon resupply ship to the station for NASA and a separate Starlink mission.