A Saturday pre-launch press conference for Sunday’s liftoff of the Deep Space Climate Observatory or DSCOVR spacecraft, revealed new details regarding SpaceX’s second attempt to land a Falcon 9 first stage on its seagoing platform. One fact seems clear, this attempt will be more difficult than the last. It may be also be a harbinger of things to come.

Unlike the recent CRS-5 launch in which the Falcon 9 boosted a Dragon spacecraft to low Earth orbit, Sunday’s flight will see a very different ascent profile, one which is much steeper. And even though at 570 kilograms, DSCOVR is a fraction of the weight of the heavily laden Dragon capsule, the necessity of hurling it to a solar orbit nearly a million miles from Earth, a task which will demand even more of the second stage, means that it will re-enter the atmosphere much more dynamically, and without the fuel margin for three separate burns. Instead it will make just two burns, depending on the hypersonic grid fins to adjust its trajectory and target the Autonomous Spaceport Drone Ship (ASDS) waiting nearly 400 miles down range.

Consequently, according to SpaceX Vice President of Mission Assurance Hans Koenigsmann, even though his company has now doubled the capacity of the booster’s hydraulic fluid reservoir, as well as made several other undisclosed tweaks to the landing plan, the odds for success on this attempt will still be roughly 50-50. Left unstated is the thought that if this were another LEO launch, the odds would be greatly improved over the last landing attempt. But that is not the case, and as Koenigsmann strove to point out, stage recovery, no matter how compelling is still a secondary objective.

Given the challenges of the DSCOVR launch, that point is worth underscoring. For all it has accomplished thus far, this is still SpaceX’s first launch to deep space, although it should be pointed out that on the SES-8 flight, the company’s first mainstream comsat mission, the Falcon 9 boosted its payload to a geostationary transfer orbit with an apogee or high point, which saw it travel nearly a quarter of the way to the Moon. The reason for the odd jaunt was to take advantage of a highly elliptical orbit to lessen the fuel penalty required to move a spacecraft from the the 28.5 degree inclination of Cape Canaveral to a final position some 23,000 miles above the Equator. In simple terms, like much work done against the force of gravity, it is easier to perform if you are starting from a higher point.

This time however, SpaceX is aiming for a target a very long distance away, and how well it hits that target will have a great deal of influence over the spacecraft’s ultimate lifespan. If SpaceX misses, mission controllers will have to use more of DSCOVR’s limited supply of on-board fuel to make course corrections, and then more still to maintain a stable orbit. Acknowledging the challenge, Koenigsmann observed that the DSCOVR preparations had required more trajectory analysis than normal.

If that extra work pays off, then the company will have started to earn its deep space credentials, moving closer to gaining for the Falcon 9 a coveted designation as a NASA approved booster for more expensive and higher risk missions which are currently entrusted to the Atlas V.

Much will depend on the second stage, which will ignite for an initial five minute burn to reach a preliminary orbit at approximately 185 km, and an inclination of 25 degrees. Following a 22 minute coast, the Falcon second stage’s Merlin 1-D Vacuum engine will re-ignite for a second burn which will send it out of Earth orbit. After the payload separates, the second stage will alter its trajectory slightly, and then undergo venting in order to prevent any possible debris inducing explosion.

As for the Air Force, which is paying for the DSCOVR launch under the Orbital/Suborbital -3 program, based on responses to questions posed during the press conference, it appears that even a flawless performance may have negligible impact on SpaceX’s very public struggle to become a certified vendor under the more stringent Evolved Expendable Launch Vehicle program. Part of the reason is that SpaceX elected to submit data to the Air Force from its first three Falcon 9 V1.1 launches (this is the 9th) in an effort to speed up the certification process, although based on continued Air Force foot dragging, that strategy does not appear to have had the intended effect. The other reason is that the Air Force, being rather segmented, has apparently not seen the need to co-ordinate between the EELV program office and the entirely separate office which is handling this launch. Speaking for the Air Force today, Col. Jason Cothern, Space Demonstration Division Chief a Kirtland Air Force Base in Albuquerque said “Unfortunately, neither I nor my office have been involved in EELV certification.”

As with any SpaceX launch however, even if there is no defined upside for EELV certification, there is most certainly a potential downside, and thus the pressure to keep pace with rival ULA’s impressive launch record remains unrelenting.

For all that, attention will invariably focus on the landing attempt, and for good reason. Every time a Falcon 9 takes off equipped with a set of legs and an ASDS patiently waiting at sea, is another chance to make history of the sort which will be remembered long after the actual mission payload is forgotten. The DSCOVR launch is something more however.

Last week, SpaceX set off something of a media frenzy with the release of a video depicting a Falcon Heavy returning all three stages to powered landing on dry land. In some ways, the excitement generated was a little perplexing. After all, it was animated video, not real footage, and for anyone who has been paying close attention in recent years, it merely provided a visual interpretation of plans which Elon Musk has been discussing quite some time. In fact graphic representations of Falcon Heavy on the company website have depicted all three cores with legs since early 2013.

Still, the excitement, and the widespread reporting was remarkable.

Consider this then. In many ways the DSCOVR launch and the subsequent landing effort is a real life version of the hardest segment of that event, with the Falcon 9 V 1.1 serving as a stand in for the Falcon Heavy center core. Although it is not returning to land as depicted in the video, there are a number of future scenarios involving heavy payloads on deep space trajectories, where the core stage will either have to be expended, or recovered via ASDS such as Just Read the Instructions fairly far out to sea. By comparison, the twin booster flyback and landing depicted in the video, taking place both lower and slower, and much closer to shore, is likely to prove the easier task.

DSCOVR is, forgive the expression, not going to deep space as much as it is going to Innerspace, towards the Sun, but it is still headed well outside of the Earth-Moon system. In terms of performance, and in comparison to its previous flights, this Falcon 9 could just as easily be headed towards Mars.

Which is where SpaceX is headed.

So whether the landing works or not, take some measure of satisfaction that what is on tap is not just another space launch, but a partial demonstration, a test flight if you will, of the key segment of a reusable heavy lift booster which is capable of throwing 30,000 lbs to the Red Planet.