When the Dragon spacecraft from 2012’s SpaceX 4 mission successfully berthed with the ISS‘s Harmony module, the cargo capsule’s place in space-faring history was cemented, marking the first time a privately owned spacecraft berthed with the space station, vindicating long-held hopes that the commercial space industry could develop the ability to conduct complex operations in Earth’s orbit. Now the SpaceX/CRS-11 mission (originally slated for launch Thursday, 1 June 2017, and rescheduled for 3 June 5:07 ET), is another milestone in private space flight, as the Dragon capsule destined for the ISS is the first ever to be reused.
Reusable rocketry is expected to bring down the cost of spaceflight by reducing the costs associated with the most expensive part of spaceflight, the launch. But the Dragon spacecraft’s second flight validates another component of commercially driven spaceflight: that of evolvable spaceflight architectures’ fundamental principle, that the chapter of one-and-done missions must be closed in order to further reduce the high outlays of space-faring missions and design mission-versatile craft configured for multi-mission duration.
The launcher is on Pad 39A at Kennedy Space Center in Florida, but weather forecasters suggest there is only a 60% chance the launch will go off as planned, due to weather systems in the area. Concerns include towering cumulus clouds that can produce lightning, which is considered too dangerous for rockets. Coverage of the launch will be live streamed by NASA TV beginning at 4:30 ET; the live stream is also embedded below.
The Dragon comprises two major components, the pressurized capsule and the trunk. The capsule contains 11 cubic meters of cargo (or, later, crew) space, which can carry as much as 3,000 kilograms of cargo. The capsule also contains thrusters and a guidance system, as well as the heat shield which protects the craft from atmospheric friction during reentry. The trunk, which has 14 cubic meters of volume, supports the pressurized section during the launch phase, and contains and employs the solar array. The trunk remains attached to the capsule while berthed, but is jettisoned before reentry. The pressurized section, which is designed with crew launch and reentry in mind, descends to the surface on three parachutes, where it is recovered by a flotilla of SpaceX boats. Return missions allow for around 3,000 kilograms worth of cargo to be returned safely to Earth — a much greater capability than other extant vehicles configured for reentry.
WATCH LIVE: NASA’S USTREAM OF THE SPACEX/CRS-11 LAUNCH SATURDAY, 3 JUNE 2017 BEGINNING @ 1630R (1630R/4:40ET)
The value added from a reusable spacecraft isn’t limited to the cost, however. Subsequent launches of the same craft give engineers a wealth of data about the survivability of the individual module, which is extremely valuable — particularly for crew-oriented craft like Dragon, according to David L. Cheuvront, a retired NASA engineer and risk-analysis expert.
“As their program evolved, I saw that [SpaceX] was doing a lot of the same things that our Next Generation Launch Technology program wanted to do but we were never allowed to, like having extra design margins on the structure, or having [greater] engine-out capabilities than we could have,” Cheuvront told The Downlink in an interview at last week’s International Space Development Conference in St. Louis. “The big one was taking basically taking a crew-configured vehicle and launching cargo with it several times. Instead of trying to do some dedicated tests on it, as few tests as you could convince yourself was reasonable — to gain the confidence to put a crew in it, or maybe just put a crew in it the first time — instead, they were kind of steadily working up to it, demonstrating it with cargo so that if you lost it, it wasn’t human life.”
Cheuvront, who has studied and advocated for architectural evolvability for years, added that, while crew-rated spacecraft would always require “some” dedicated tests to address changes, launching cargo could reduce the time and expense associated. And, unlike dedicated tests that could determine the viability of a spacecraft’s ability to conduct manned missions — a rigorous and expensive process — flying an evolvable craft such as Dragon could see the acquisition of much of that data pay for itself, and then some.
“[They] might be launching expensive cargo — hopefully not too expensive — but you could actually generate revenue while gaining test flight experience,” said Cheuvront.
The reused Dragon craft, which is currently on the pad, also holds a place in history: its first mission, CRS-4, flew in September of 2014. Its payload manifest included the first 3D printer ever tested in space. Additive manufacturing (or 3D printing) is widely expected to usher in a new era of commercial space activity, from producing products to be returned to and sold on Earth to building components necessary for lunar or Martian settlement, and perhaps even to build replacement parts for spacecraft.
Also of note, due to Thursday’s scrubbed mission, this will be the first time two commercial spacecraft pass each other in orbit, as the ISS will release the Orbital ATK Cygnus cargo spacecraft, currently berthed with ISS on 4 June. Dragon will be grappled by ISS flight engineer Peggy Whitson with the Canadarm2 on 5 June. The Cygnus module will remain in orbit for a week supporting the SAFFIRE-III experiment, which provides data on the danger of fire aboard spacecraft, before de-orbiting and burning up in the atmosphere.
Whitson will have been busy; there’s been a lot of activity around the space station over the last few days, with Expedition 51 leaving the space station for Kazakhstan yesterday, 2 June. Oleg Novitskiy of Roscosmos and Thomas Pesquet of ESA (European Space Agency) had been on the station since November; Pesquet has been a crowd favorite with regular tweets and lots of images and video uploaded to social media. Their Soyuz MS-03 landed safely around 10 a.m. Whitson, who arrived at the ISS with Expedition 51, stays on until September; she currently holds the record for the woman with the most time in space and the most EVAs.