Today, SpaceX is set to launch another one of its Falcon 9 rockets from Florida, sending cargo and supplies to the International Space Station for NASA. It’s an otherwise routine launch that will include one of SpaceX’s signature rocket landing attempts afterward. But it wouldn’t be a SpaceX mission if the company didn’t try something completely new: this launch will be the first time that SpaceX reuses one of its Dragon cargo capsules — one that’s already flown to the station and then landed back on Earth.
The Dragon that’s going up on this flight was the same one used for SpaceX’s fourth cargo resupply mission to the station in September 2014. After a nearly month-long stay at the ISS, the Dragon landed with the help of parachutes in the Pacific Ocean. SpaceX then inspected the vehicle and refurbished it to make sure it was ready to fly again. A few components have been swapped out, but the overall structure and the thrusters from the original vehicle are the same, according to Hans Koenigsmann, vice president of flight reliability at SpaceX. One notable upgrade, however, was the addition of a new heat shield, plus the replacement of few outside components that came in contact with sea water when the Dragon splashed down in the ocean.
If all goes well, Dragon will join a small group of vehicles that have orbited the Earth multiple times — the most notable of which was NASA’s Space Shuttle. And it will be the first time a private company has sent a vehicle into orbit a second time. Eventually, SpaceX expects to re-fly most, if not all, of its Dragon cargo capsules. Such a move could likely result in substantial cost savings. The company hopes that by reusing the cargo vehicles, it can focus on making the next version of the Dragon, according to a Space News report from last year. That upgraded spacecraft will soon carry people to the International Space Station.
SpaceX seems to be making the shift into reusing its flight hardware more frequently now. The company has successfully landed 10 of its Falcon 9 rockets since 2015, and one of these used boosters flew again for the first time in March — an important proof-of-concept in SpaceX’s pursuit of reusability. Now the company plans to use another previously flown booster during its next satellite mission in a couple of weeks, and CEO Elon Musk said that up to six used Falcon 9s could fly by the end of the year. Meanwhile, the company is also making moves to save the rocket fairings (the nose cones) that surround the payloads at the top of the rocket, which easily cost millions of dollars. On that same historic March flight, SpaceX successfully landed parts of the nose cone via parachutes, the first step toward reusing them in the future.
On Saturday, SpaceX will also try to land the Falcon 9 after launch, the company’s 15th landing attempt. This time the target is the company’s landing pad, called Landing Zone 1, at Cape Canaveral, Florida. So far, SpaceX has attempted most of its landings on one of the company’s two autonomous drone ships in the ocean, but whenever the company has tried to land on land, it’s only seen success. All four of SpaceX’s previous landings at Landing Zone 1 have been perfect touchdowns.
But of course, the primary mission is not to land the rocket but to get nearly 6,000 pounds of supplies and science experiments to the ISS. Ironically, some of the most interesting experiments are riding up inside the Dragon’s unpressurized trunk, the expendable part of the spacecraft that provides support during launch and contains the vehicle’s solar panels. One such experiment is the NICER, an instrument that will eventually be mounted to the outside of the ISS to search for neutron stars. Another part of the trunk’s manifest includes the Roll Out Solar Array, or ROSA, a new type of solar panel technology that launches wound-up, and then rolls open in space. Meanwhile, fruit flies are headed up inside the Dragon to study how the heart responds to microgravity.
Whenever this flight does get off the ground, it’ll mark the 100th launch from NASA’s historic pad at LC-39A, which was used to launch the first astronauts to the Moon. The pad is now being leased by SpaceX to support flights of the Falcon 9 and the company’s future Falcon Heavy rocket. Saturday’s launch is currently slated for 5:07PM ET, and SpaceX has an instantaneous launch window this time — so it either has to launch right on schedule or move to another date. Originally, the launch was supposed to happen on Thursday at 5:55PM ET, but lightning in the Cape Canaveral area forced SpaceX to postpone the mission until Saturday. Weather isn’t looking too great for this weekend either. Right now, there’s a 60 percent chance that conditions will be favorable.
NASA’s coverage of the launch is set to begin at 4:30PM ET on Saturday, so check back then to watch the mission live.
Update June 1st, 5:35PM ET: This post was updated to include the scrub and new launch time.