If all goes to plan, Nasa will later put a small space station into the same orbit as a precursor to returning astronauts to the moon under the US space agency's Artemis programme.
The cost of Artemis is stunning - some US$93 billion over 13 years.
Rocket Lab's Capstone launch will cost Nasa just $14 million, however, as the Kiwi-American company again seeks to showcase its high-tech but low-cost smarts.
This launch is crucial for Rocket Lab because previous Photon has been used as a "space bus" that places micro-satellites into correct low-earth orbit. This will be the first time a Photon has headed to another celestial body.
It also marks an increasingly close relationship between Rocket Lab and Nasa.
Rocket Lab has a number of projects in the pipeline, including a contract (for an as-yet-undisclosed sum) to design and built two Photon spacecraft that will go into orbit around Mars in 2024, after being carried to the red planet by a Nasa-provided rocket. The mission's aim is to shed light on how Mars lost its once-habitable atmosphere.
Rocket Lab also recently won a contract to make a radiation-hardened solar panel array for Nasa's Glide spacecraft, due to launch in 2025.
Glide (an acronym for Global Lyman-alpha Imagers of the Dynamic Exosphere) will survey the exosphere, the little-understood outermost layer of Earth's atmosphere).
Rocket Lab did not put a value on the Glide contract, but it's part of an ongoing push to diversify its revenue from rocket launches to a lot of business in "space systems" too. And it was possible because Rocket Lab bought SolAero, a New Mexico maker of solar components, for US$80m ($125m) last December - the fourth of a series of purchases of North American space system makers.
And Rocket Lab's new Launch Complex 2 in Virginia - soon to see its first launch - sits inside Nasa's Wallops Flight Facility.
The Capstone launch comes after a month of mixed fortunes for Rocket Lab's rivals.
The Elon Musk-owned SpaceX managed two Falcon 9 launches within 15 hours (a rapid-fire capability Rocket Lab hopes to match with its recently opened second launchpad at Mahia), while a failed launch by Astra destroyed two Nasa satellites.
Rocket Lab shares, which reverse-listed at US10.00 last August and shot to US18.69 the following month, were recently trading at US$4.10.
While the Kiwi-American firm recently reported that its forward-bookings had fattened to US$550 million, and that it had won major funding from both the US military ($34m) and the state of Virginia ($69m) in support of its new, much larger Neuron rocket, due for its first launch in 2024, its stock has been caught up in the general Tech Wreck 2.0 downdraft.