SpaceX is all set to launch the secret Zuma mission tonight, Nov. 16, though watching it lift-off is not kept secret and available online.

SpaceX's Falcon 9 rocket with the Zuma payload lifts off tonight from Pad 39A at NASA's Kennedy Space Center in Cape Canaveral, Florida, and the launch window opens at 8 a.m. EST for two hours.

However, the SpaceX has kept the exact time for the launch and the nature of the Zuma mission secret. If SpaceX fails to launch it tonight, the next window will be opened on Friday night.

"SpaceX is targeting launch of the Zuma spacecraft from Launch Complex 39A (LC-39A) at NASA's Kennedy Space Center, Florida. The two-hour primary launch window opens at 8:00 p.m. EST on Thursday, November 16, or 1:00 UTC on Friday, November 17. A backup two-hour launch window opens at 8:00 p.m. EST on Friday, November 17, or 1:00 UTC on Saturday, November 18," said SpaceX on its website.

Watch the launch directly from SpaceX's live webcast here.

To be launched into a low-Earth orbit, the Zuma payload is a "restricted payload" and it represents "a cost-effective approach to space access for government missions," said a spokesman for the SpaceX.

SpaceX's Falcon 9 being used for the launch is a simple two-stage configuration that minimizes the number of separation events, with nine first-stage engines, and it can safely complete its mission even in the event of an engine shutdown, said a brief mission description.

The space company is planning to land the first stage of the Falcon 9 rocket used in tonight's launch at Landing Zone 1, a pad at the Cape Canaveral Air Force Station near the company's Pad 39A launch site, within 7 minutes and 51 seconds after liftoff.

The Zuma launch is the company's third classified flight in 2017 after the NROL-76 spy satellite for the National Reconnaissance Office in May and the launch of an uncrewed X-37B space plane on the OTV-5 mission for the U.S. Air Force in September.

Mission Timeline:

COUNTDOWN

Hour/Min/Sec Events

01:13:00 SpaceX Launch Director verifies go for propellant load -

01:10:00 RP-1 (rocket grade kerosene) loading underway -

00:35:00 LOX (liquid oxygen) loading underway -

00:07:00 Falcon 9 begins engine chill prior to launch -

00:01:00 Flight computer commanded to begin final prelaunch checks -

00:01:00 Propellant tank pressurization to flight pressure begins -

00:00:45 SpaceX Launch Director verifies go for launch -

00:00:03 Engine controller commands engine ignition sequence to start -

00:00:00 Falcon 9 liftoff

LAUNCH AND LANDING

Hour/Min/Sec Events

00:01:10 Max Q (moment of peak mechanical stress on the rocket)

00:02:16 1st stage main engine cutoff (MECO)

00:02:19 1st and 2nd stages separate

00:02:21 2nd stage engine starts

00:02:30 1st stage boostback burn begins

00:03:08 Fairing deployment

00:06:09 1st stage entry burn begins

00:07:51 1st stage landing.