SpaceX will attempt to resupply the International Space Station for the first time since its attempt last June which ended in an explosion shortly after launch. Let’s be clear, that was not SpaceX’s first attempt to resupply the ISS, but it’s first failure to do so.

SpaceX Has Massive Task With Launch Today

And SpaceX hopes to stick the “water” landing for the first time

In a few hours’ time (4:43 PM EDT), SpaceX plans to launch a Falcon 9 vehicle for Cape Canaveral, Florida in order to resupply the ISS, and then once again try to land it on a “drone ship” floating in the ocean. The ship gets the drone distinction because when rockets explode on the deck, it’s better that they are unmanned.

In December 2015, SpaceX showed that it could vertically land the booster rocket on land, a small target on rolling seas is a different animal and presently SpaceX is 0 for 4. That’s not to say that, like a baseball player, they simply struck out wildly. They got quite close twice, but failed in the last seconds. But as an engineer, founder and CEO, Elon Musk will continue to try and like most engineers, has a perverse love of failure and the corrections that come after experiencing one.

Let’s not be mistaken, the primary mission, following last June’s disaster, is to resupply the ISS. Landing the rocket on a drone-ship would simply be icing on the cake and a necessary part of SpaceX’s mission plan to reuse rockets to make space flight considerably cheaper.

Elon Musk tweeted that SpaceX believes they have a “good chance” of landing the rocket, but getting the 7,000 pounds of NASA resupply to the ISS is of paramount importance.

It would be easy to say that resupplying the ISS is easy, but June proved it isn’t.

Why continue with the water landings?

Quite simply, there are certain missions where the return of the bulk of the Falcon 9 is impossible on land due to fuel constraints, and Musk knows this and will keep trying. But, after failing NASA and being rewarded a number of contracts for future flight, it’s important to get NASA’s stuff out the way.

Those contracts will see SpaceX resupplying the ISS through 2024 and the company is planning a manned mission to the ISS next year.

Included in the cargo on the Dragon cargo capsule which will make its way to the ISS are a number of science experiments as well as the 3,000-pound Bigelow Expandable Activity Module, which is an inflatable habitat, the first in space, that will be fastened to the ISS in an experiment of its own to determine if you can inflate something in space and have it both function and be safe.

Present weather conditions look good for an on-schedule launch in just a couple of hours from the time of this writing. Tuesday saw a successful static fire test of the engines of the Falcon 9 and today’s weather looks nothing short of fantastic.

For those interested in watching either the launch or attempted landing, NASA will be providing a live stream here.

This is a seminal moment for the company. A successful resupply is a must, but a successful landing would be the stuff of legend and something you tell your kids about as Mars exploration needs Musk’s help. A colony, well, that’s all him.