With a little more than a year to go before U.S. astronauts launch aboard a U.S.-built spacecraft, and from U.S. soil, for the first time since the end of the Space Shuttle era, NASA has ordered its second Post-Certification Mission (PCM) from SpaceX. The Hawthorne, Calif.-based launch services company—which received a $2.6 billion slice of NASA’s Commercial Crew transportation Capability (CCtCap) “pie” in September 2014—has now been awarded the maximum number of “guaranteed” missions for its Crew Dragon spacecraft, with the possibility that up to four others may follow. Alongside Boeing, whose CST-100 Starliner vehicle will share the Commercial Crew workload of delivering crews to the International Space Station (ISS), it is expected that the first flights of the new spacecraft may occur as soon as the fall of 2017. The announcement comes as the station’s incumbent Expedition 48 crew prepares for a critical EVA on 18 August to install the International Docking Adapter (IDA)-2 onto the Harmony node.
“The order of a second crew-rotation mission from SpaceX, paired with the two ordered from Boeing, will help ensure reliable access to the station on American spacecraft and rockets,” said Kathy Lueders, manager of NASA’s Commercial Crew Program (CCP). “These systems will ensure reliable U.S. crew rotation services to the station and will serve as a lifeboat for the space station for up to seven months.” By handing over its crew transportation responsibilities to the ISS to commercial providers, it is expected that NASA can focus upon bringing the Space Launch System (SLS) booster to operational status—with a maiden voyage targeted for the fall of 2018—as part of efforts to stage the first piloted missions beyond low-Earth orbit since the twilight of the Apollo Program.
Almost two years have now passed since NASA announced the winners of the coveted CCtCap contract, with Boeing awarded $4.2 billion and SpaceX some $2.6 billion. In May 2015, Boeing became the first of the companies to receive a PCM order, followed by a second in December. Receipt of this second mission came only weeks after the November 2015 announcement of SpaceX’s first PCM. With Friday’s award of a second SpaceX mission, it remains to be seen which of the Commercial Crew partners will make the historic first flight. NASA noted only that both Boeing and SpaceX “have started planning for, building and testing the necessary hardware and assets to carry out the first flight tests and ultimately missions for the agency.” Under the terms of the CCtCap contract, which totals $6.8 billion, they will fly at least two—and perhaps up to six—missions apiece.
Friday’s award came about following SpaceX’s successful completion of internal development milestones and internal design reviews for its Crew Dragon spacecraft, which is closely modeled upon the unpiloted Dragon cargo ship, as well as the Upgraded Falcon 9 launch vehicle and its associated ground systems. “We’re making great progress with Crew Dragon, with qualification of our docking adapter and initial acceptance testing of the pressure vessel qualification unit completed,” said SpaceX President and Chief Operating Officer (COO) Gwynne Shotwell. “We appreciate the trust NASA has placed in SpaceX with the order of another crew mission and look forward to flying astronauts from American soil next year.”
At present, SpaceX is in the process of fabricating four Crew Dragon vehicles, of which two will be utilized for qualification tests and the others for flights in 2017. Although exact target dates remain in flux, Novosti Kosmonavtiki has indicated that a 26-day unpiloted Crew Dragon mission will launch on 12 May, followed by a 22-day piloted mission, which is scheduled to fly on 24 August. They will travel to the ISS and dock at Pressurized Mating Adapter (PMA)-2 at the forward end of the Harmony node. Unused since the departure of Atlantis on STS-135 in July 2011, PMA-2 will shortly be readied for its Commercial Crew role when International Docking Adapter (IDA)-2 is installed at its tip. The 1,150-pound (520-kg) IDA-2, which recently arrived aboard SpaceX’s CRS-9 Dragon, will be attached to PMA-2 in a joint EVA/robotics operation involving Expedition 48 astronauts Jeff Williams and Kate Rubins on 18 August.
That operation will be the subject of a NASA briefing at 12 noon EDT on Monday, 15 August. Current plans call for IDA-2 to be robotically detached from the unpressurized “trunk” of the CRS-9 Dragon spacecraft—via the 57.7-foot-long (17.6-meter) Canadarm2 robotic arm and its Dextre “hand”—about 48 hours prior to the EVA. At the controls of the “Big Arm” will be Robotics Officer (ROBO) David Gruntz. He will position IDA-2 between 10 inches (25 cm) and 2 feet (60 cm) from PMA-2, whereupon Williams and Rubins will perform their 6.5-hour EVA-36 to maneuver the adapter into position and close external connectors and internal switches and drive hook-motors.
For the EVA, Williams—who has three prior EVAs and around 19 hours of spacewalking time under his belt—will serve as “EV1,” clad in Extravehicular Mobility Unit (EMU) #3003, whilst first-timer Rubins (“EV2”) will wear EMU #3008. Interestingly, Williams will become America’s oldest spacewalker when he ventures into vacuum at the age of 58 years and 213 days. In doing so, he will eclipse Hubble Space Telescope (HST) repairman Story Musgrave by about 100 days, but will fall shy of the accomplishment of Russian cosmonaut Pavel Vinogradov, who made an EVA aged 59 years and 262 days during Expedition 35 in April 2013. In readiness for their upcoming EVA, Williams and Rubins have worked to prepare their suits and the station’s Quest airlock, as well as reviewing timelines and detailed procedures. Last week, EMU #3003 was resized for Williams and #3008 was resized for Rubins, as the Expedition 48 crew also worked to gather suit components to be returned to Earth and replaced a frayed Thermal Micrometeoroid Garment on one of the EVA Helmet Interchangeable Portable Lights (EHIP).
The installation of IDA-2 will be critical for the SpaceX and Boeing Commercial Crew flights to go ahead. According to Novosti Kosmonavtiki, SpaceX’s first piloted test flight of its Crew Dragon will deliver astronauts Doug Hurley and Sunita Williams to the station in August 2017, after which Boeing’s maiden CST-100 Starliner will fly unpiloted in December 2017 and later carry astronauts Eric Boe and Bob Behnken in February 2018. Satisfactory completion of these critical flights will allow both Commercial Crew partners to press ahead with their dedicated PCM missions, which can transport up to four astronauts and cosmonauts and around 220 pounds (100 kg) of pressurized cargo, remaining at the station for up to 210 days. It remains to be seen whether the first dedicated flight—designated “U.S. Crew Vehicle” (USCV)-1—will be undertaken by Boeing or SpaceX.