As it gradually nears a launch date sometime in late January or early February, SpaceX’s new super-heavy launch vehicle (SHLV) Falcon Heavy has weathered a number of schedule delays in preparation for a historic and crucial moment – its first static fire/test ignition that’s currently scheduled for Tuesday, January 16, beginning at 4pm EST (2100 GMT).

Those focused on the gritty details of SpaceX’s prelaunch procedures will have immediately noted how different Falcon Heavy’s operations are when compared with SpaceX’s workhorse rocket and Heavy’s progenitor, Falcon 9. For a typical launch of Falcon 9, the rocket and payload will normally arrive at the given launch pad around a month or so before the anticipated launch date. Next, the satellite payload is encapsulated inside Falcon 9’s payload fairing, typically two or so weeks before launch. Pad facilities would be thoroughly examined after the previous launch to remedy any wear and tear and ensure that it is in good working order ahead of the next mission. Approximately a week before launch, Falcon 9’s first and second stages are mated together inside the pad’s integration facilities, the pad’s Transport/Erector/Launcher (TEL) is rolled into the integration facilities, and the Falcon 9 booster and second stage (sans payload) are mounted onto the TEL. Finally, the TEL and rocket are rolled out to the launch pad for a brief 3-5 second static fire around 5-7 days before launch. After testing is completed, the TEL is rolled back to the integration facilities, the payload fairing and payload are attached to the rocket, and the whole stack is once more rolled back to the pad, ready for launch.

For a used booster, this is the sum total of the prelaunch procedures it will go through at the pad, after recovery and refurbishment. For all new boosters, however, SpaceX currently conducts a thorough slate of tests for all Merlin 1D and MVac (2nd stage) rocket engines, as well as both the integrated first and second stages at its McGregor, Texas facilities. These tests last far longer than those conducted at the launch pad, and typically run for the full length of a launch in order to better simulate the stresses flight hardware will end up experiencing. In other words, new Falcon 9 hardware always has to make it through hundreds of seconds of live firing and post-test analysis before finally being shipped to SpaceX’s launch facilities, where it conducts the aforementioned brief static fire at the pad.

A whole new bird of prey

To put it simply, Falcon Heavy is a whole different animal when it comes to prelaunch testing. Due to the rocket’s sheer size and power in its fully integrated state, McGregor simply does not have the capability to conduct the same tests it does with Falcon 9. While two of the first Heavy’s three first stage boosters are modified flight-proven Falcon 9s (from Thaicom-8 and CRS-9), the center core required a far more extensive suite of changes from a normal Falcon 9 in order to survive the added stresses it would experience during a Falcon Heavy launch. Although the full-up vehicle could not be tested in Texas with a full-length firing, each of its three first stages and upper stage went through the same tests as a normal Falcon 9. Before that, both side core and center core structural test articles (STA) went through a large amount of mechanical stress testing to verify that Falcon Heavy’s re-engineered design would be able to easily survive the stresses of launch and then some. In short, months and months of work have gone into the hardware that both preceded and makes up the Falcon Heavy rocket currently vertical and weeks from launch at Kennedy Space Center.

However, SpaceX has learned the hard way that simulation and partial physical testing can only go so far, and cannot be completely trusted when it comes to flying new hardware, as evidenced by the both Falcon 1 and the company’s several first attempts at recovering a Falcon 9 booster (intact, at least…). Even the best and most brilliant engineers and technicians can only do so much without testing the real thing in real conditions, something that can often result in unintended failures – especially the case with new technologies. Falcon Heavy is indeed a new technology to some extent or at least incorporates numerous new technologies that SpaceX has little to no operational experience with. These and relatively untried aspects include the simultaneous ignition and operation of twenty seven already powerful Merlin 1D engines, new stresses on the center booster during launch, a unique non-explosive side booster separation mechanism, the also near-simultaneous recovery of three first stages, and a second stage tasked with placing an unusual payload in the highest orbit SpaceX has yet to attempt.

Hence Elon Musk’s aggressive expectation maintenance over the last year or so, in which he spared no punches while imparting upon several audiences the likelihood that Falcon Heavy’s first launch would fail entirely, and maybe even destroy the launch pad. In reality, SpaceX is clearly doing everything in their power to ensure that the massive rocket’s first launch is a total success.

What’s next for Falcon Heavy?

Recent delays to the vehicle’s first static fire test at SpaceX’s Launch Complex 39A are strong examples of this cautious approach. While fans and outsiders alike may be nipping at the bit for the vehicle’s long-awaited inaugural static fire and launch, SpaceX clearly is laser-focused on very thoroughly testing the vehicle and is exerting great caution. After the first static fire attempt was delayed, reportedly due to a buggy launch clamp, SpaceX had nevertheless completed its first (presumably successful) wet dress rehearsal (WDR), which saw the vehicle prepared for launch with a full load of propellant and other miscellaneous fluids. After a brief period back horizontal at the pad, likely to repair whatever fault initially caused the delay, Falcon Heavy has been vertical at the pad for the last several days. Intriguingly, albeit unsurprisingly, tank venting was reported early Sunday by local observers. This indicates that SpaceX conducted at least one additional wet dress rehearsal with Falcon Heavy, likely both contributing to an additional delay of the replacement static fire date (Monday) and solidifying confidence in the new test date, Tuesday, January 16.

Compared with the results of the first WDR (a three-day delay), the one day delay that followed Sunday’s rehearsal is great news for what is effectively a mature launch vehicle prototype. SpaceX’s confidence is clearly growing, and while all delays of the static fire will likely push back the launch date at least as much, Falcon Heavy will almost certainly find itself days away from its inaugural liftoff sometime in very late January or February 2018.

Follow along live as Teslarati’s launch photographer Tom Cross covers Falcon Heavy’s exciting series of events while they happen on our Instagram.