SpaceX's seventh resupply mission to the International Space Station, CRS-7, is scheduled to launch tomorrow, June 28, from Cape Canaveral. The launch is exciting for two main reasons. For space travel fans, the highlight will be the third attempt at landing the Falcon 9 main stage on a barge in the middle of the ocean. For tech geeks, you'll be excited to learn that the cargo capsule will deliver two Microsoft HoloLens headsets to the astronauts aboard the ISS.

HoloLens is being sent to the ISS as part of Project Sidekick. HoloLens gives the user an augmented view of reality by overlaying digital imagery on whatever you happen to be looking at. Microsoft has demonstrated HoloLens' gaming capabilities (Minecraft!) but so far the messaging has been mostly about telepresence, remote assistance, and new UI and UX paradigms.

Project Sidekick will allow NASA to "provide virtual aid" to astronauts aboard the ISS when they need it. "This new capability could reduce crew training requirements and increase the efficiency at which astronauts can work in space," reads the press release. NASA also mentions that offloading training and expertise "could also empower future explorers requiring greater autonomy on the journey to Mars."

When an astronaut equips HoloLens, there will be two modes of operation to choose from: Remote Expert Mode, which lets mission control see what the astronaut sees and draw annotations on the holographic display; and Procedure Mode, which provides "animated holographic illustrations" on top of the object that the astronaut is interacting with, to help with whatever task they're trying to complete.

SpaceX CRS-7 is set to launch at 14:21 UTC tomorrow, June 28 (that's 15:21 BST or 10:21 EDT). After breaking away from the second stage, the Falcon 9 main stage will attempt to land on a platform off the coast of Florida. Elon Musk has previously said the chances of a successful landing are about "50/50." The previous attempt at landing on a barge, back in April, was, er, rather explosive.