PUNCH LEOPS is complete. commissioning continues.
PUNCH deployment images show two of the spacecraft just after separation from the Falcon 9 launch vehicle, 11-Mar-2025
21-Mar-2025 – "Launch and Early Operations" (LEOPS) is a difficult time in a mission's life: when a spacecraft is deployed from the launch vehicle, there's a scramble to make sure it's in a safe operating state, to check out its subsystems, and to "normalize" operations. Typically specialist staff are available for all subsystems during all available ground passes, 24 hours around the clock. That level of effort isn't sustainable (or necessary) in the long term, so we refer to LEOPS as a separate mini-phase of the mission.
PUNCH launched on 11-March, just ten days ago. The top images show the separation events from the Falcon 9 that lofted five spacecraft (our four and the SPHEREx observatory) PUNCH's LEOPS lasted five days, and we stood down to single-shift operations early this week. We're continuing with commissioning the four spacecraft now.
A big part of commissioning is getting the PUNCH Hydros thrusters commissioned. PUNCH needs small amounts of trim thust to maintain the constellation geometry. Each spacecraft has a small tank of purified water (just 0.6 liters -- about the size of a British pint); and a system to electrolyze that water into fuel (hydrogen and oxygen gases). When it's time to give the spacecraft a nudge, we burn few hundred milligrams of fuel in a shot-glass-sized rocket engine, which takes just a couple of seconds. The system is great for safety and for integration, since water is fully inert and we only have tiny amounts of fuel on-hand at any given time. But it's also somewhat finicky, since it's basically a small chemical factory as well as a rocket engine (and all the parts have to work in zero gravity). Not very many Hydros systems have ever been flown in space, so we're acting as "test pilots" -- homing in on how best to operate the thruster to get reliable "kicks" out of it once we really need it.
We have a little bit of time to think about it: at the current drift rate imposed by the springs on our original release mechanism, the spacecraft will be in their final positions (120° apart in orbit) in just over 100 days after launch.
Our schedule gives us another three weeks to finish shaking-out the spacecraft themselves. Then we'll open the instrument doors and start calibrating the imaging systems, sometime around the second week of April. Meanwhile, the spacecraft continue to drift apart a little more each day.
This image (below) is an orbital ground track from the website N2YO.com, showing the four PUNCH spacecraft heading north over the Pacific ocean, trailed by SPHEREx. All five spacecraft launched together from Vandenberg Space Force Base, just northwest of Los Angeles, California. Their separation is entirely due to the "kick" from spring forces in their deployment mechanisms, acting over the last ten days. PUNCH will continue to spread out until we stop it with the WFIs exactly 120° apart in orbit, about 90 days from now.
