Updated on: February 4, 2018 / 8:00 PM EST / CBS News — Elon Musk (@elonmusk) December 2, 2017 With forecasters predicting an 80 percent chance of good weather, liftoff is targeted for 1:30 p.m. EST (GMT-5) Tuesday. The test flight has generated widespread interest in the space community and beyond, but Musk has gone out of his way to downplay expectations. "This is one of those things that's really difficult to test on the ground," Musk said last year. "There's a lot of risk associated with the Falcon Heavy, a real good chance that that vehicle does not make it to orbit. Want to make sure I set expectations accordingly. I hope it makes it far enough away from the pad that it does not cause pad damage, I would consider even that a win, to be honest. And uh, yeah. Major pucker factor, it really is." SpaceX has shaken up the commercial rocket industry, launching 48 Falcon 9 rockets since the booster's debut in 2010 -- 18 last year alone -- and perfecting techniques for recovering the booster's first stage so it can be refurbished and re-launched, part of Musk's long-range plan to lower costs through "rapid reusability." The business end of the Falcon Heavy, showing 27 Merlin engines at the bases of three core stages. Firing together, the engines will generate about 5 million pounds of thrust. SpaceX The company has suffered one in-flight failure and one on-the-pad explosion, but it has put together an impressive list of accomplishments for a startup without decades of experience. It has a $10 billion backlog of payloads awaiting launch holds, more than $4 billion in NASA contracts to deliver supplies to the International Space Station and, eventually, astronauts starting late this year or early next. Lee Solid, a retired rocket engineer who helped build the engines that powered the Saturn 5 and the space shuttle, visited SpaceX's processing hangar at the base of pad 39A last week with former shuttle commander Eileen Collins. "I was impressed with the whole vehicle and the people working it," he said in an interview Sunday. "If I had any question or negative thoughts about what Elon's doing, they went away. It was a very professional operation out there." The Heavy is made up of three side-by-side Falcon 9 core stages, each equipped with nine SpaceX Merlin engines burning RP-1 kerosene fuel and liquid oxygen. An upper stage atop the central core is equipped with a single Merlin engine generating 210,000 pounds of push. For its maiden flight, the Tesla Roadster will be mounted in a nose-cone fairing atop the second stage. At liftoff, with all 27 core stage engines firing in concert at about 92 percent of full power, the Heavy will generate 4.7 million pounds of thrust. That's more than twice the liftoff power of a United Launch Alliance Delta 4 Heavy and more than one-and-a-half times the power of a European Ariane 5. Flying for the first time, it's difficult to predict exactly how the Falcon Heavy will perform. As it consumes propellant, loses weight and accelerates, hard-to-model aerodynamic stresses will build up, producing extreme "loads" on the structure and localized heating. And then there's the issue of controlling ignition, startup and steady operation of 27 engines firing in close proximity. The vibration environment with 27 clustered engines is extremely difficult to model, one veteran engineer said, subjecting the rocket to significant stresses. The Soviet Union built the huge N1 moon rocket with 30 first stage engines, but the booster failed all four times it was launched.