Crew Dragon arrives at Cape; Space Station schedule to drive DM-1 launch date

by Chris Gebhardt

SpaceX’s first Crew Dragon that will fly the uncrewed Demonstration Mission -1 (DM-1) as part of NASA’s Commercial Crew Program has arrived at Cape Canaveral Air Force Station, Florida, for final launch processing.  With an internal work-to launch readiness date of 31 August 2018, it is now likely that the International Space Station’s crew rotation and Visiting Vehicle schedule over the next few months will be the primary driver for the flight’s eventual launch from the Florida Spaceport.

Crew Dragon gets ready for DM-1:

The arrival of the Crew Dragon for DM-1 marks an important and major milestone in SpaceX’s preparations for what looks to be the first flight of NASA’s Commercial Crew Program.

Moreover, it is a critical step in returning the ability to launch astronauts to the International Space Station on a craft other than the venerable and extremely reliable Russian Soyuz crew vehicle.

The ability to launch astronauts to the Station on more than one spacecraft was lost on 20 July 2011 with the landing of Space Shuttle Atlantis and the retirement of NASA’s Shuttle fleet.

With that retirement, the Russian Soyuz became the sole vehicle capable of launching NASA, ESA, CSA, and JAXA astronauts to the USOS (United States Operating Segment) – of which Canada, Japan, and the European Space Agency are a part – section of the Station.

Thankfully, the Soyuz has suffered no incidents in that time, as such an event would have eliminated the world’s ability to reach its international orbital laboratory.

Nonetheless, this gap in U.S. human launch capability is not the only period in the Station’s lifetime that the Soyuz has been the sole human ride to the lab.

Following the 2003 loss of Shuttle Columbia and the STS-107 crew, the Soyuz took up solo crew transportation duty to the Station until the Shuttle fleet returned to flight (STS-114) and began ferrying crewmembers to the outpost again (STS-121) in 2005 and 2006, respectively.

Now, the U.S. is on the cusp of being able to launch humans into space again – and with final preparations now underway at the launch site for SpaceX’s Crew Dragon DM-1 mission, the commencement of Commercial Crew Program launches is tangible.

Having completed assembly at SpaceX headquarters in Hawthorne, California, the Crew Dragon that will fly the DM-1 mission was taken to NASA’s Plum Brook Station facility in Ohio – part of NASA’s Glenn Research Center – for vacuum chamber and acoustic testing.

Based on the craft’s arrival at Cape Canaveral Air Force Station, Florida, on Thursday, it appears that all went well with those tests – with no major issues that would impede the continuation of processing and delivery to the launch site discovered during the critical tests that ensured the Crew Dragon could properly function in the vacuum, thermal, and acoustic conditions it will experience during launch and while in Low Earth Orbit.

With the first Crew Dragon now safely at the Cape, the next major visual milestone will be the delivery of the Falcon 9 Block 5 booster that will launch the mission.

That Falcon 9 core is B1051 as confirmed by NASA documentation and public NASA conversations over the last several months.

First Block 5 on the McGregor Test Stand on Monday – via Gary Blair for NSF/L2

Based on core sightings/observations and launch campaigns, it is believed that core B1051 is finishing up construction in Hawthorne now and will ship to McGregor, Texas, for acceptance firing in the coming weeks.

With cores B1047 and B1048 getting ready for their July roles in the Telstar 19V and Iridium NEXT-7 launches, respectively, core B1049 was the last core spotted at the McGregor test facility.  This likely indicates – as cores generally come off the assembly line and head for Texas in numerical order, that core B1050 will be next out of Hawthorne and on the test stand at McGregor soon.

Core B1051 was selected as the booster for the DM-1 flight several months ago, and its processing schedule was aligned with a work-to launch readiness date of NET (No Earlier Than) 31 August 2018.

Of note, at a press briefing prior to the launch of SpaceX’s CRS-15 Dragon resupply mission to the International Space Station in late-June, International Space Station Program Manager Kirk Shireman and SpaceX’s Dragon Mission Manager, Jessica Jensen, both stated and reiterated that SpaceX’s work-to date for the DM-1 flight was 31 August.

However, Mr. Shireman made an interesting point during that briefing: that NASA was now looking at the Visiting Vehicle and crew rotation schedules aboard the International Space Station to see exactly when the upcoming demonstration flight could fit into the Station’s overall schedule.

Crew Dragon heads uphill on the Falcon 9 – via Nathan Koga for NSF/L2

To this end, it appears possible that SpaceX could in fact be internally ready to launch the DM-1 mission by or very close to its internal work-to date of 31 August but end up having to delay the flight because the International Space Station itself is not capable of receiving the Crew Dragon due to the current Visiting Vehicle schedule in September and October.

Most prominently on the U.S. side of the Station is the scheduled 10 September launch of the Japan Aerospace eXploration Agency’s (JAXA’s) HTV-7 uncrewed resupply vehicle.  

The HTV is berthed via Canadarm2 to Node-2 “Harmony’s” nadir (Earth-facing) port.  Just feet away from where the HTV will be berthed to Station is the location of the DM-1 Dragon docking port – Pressurized Mating Adaptor-2 (PMA-2) on the Forward end of Node-2 “Harmony”.  

HTV-7 is scheduled to remain at Station for 59 days based on the most-recent NASA documentation.  

The main potential complication between HTV-7 and DM-1 is the amount of crew time dedicated to berthed resupply vehicles like HTV – periods that take up a great deal of the U.S. segment crews’ time as they unload the craft, perform time-critical experiments, and reload the craft ahead of its departure.

Canadarm2 reaches and grabs the arriving HTV-7 resupply vehicle in December 2016. (Credit: NASA)

This is a complication to the uncrewed DM-1 Dragon flight because SpaceX has stated that the DM-1 vehicle will bring up some supplies to the International Space Station, thus requiring Station crew time to unload the craft and fill it back up with any materials that require a ride back to Earth in a capsule that can safely reenter Earth’s atmosphere, splash down in the ocean, and be recovered.

Complicating crew-time matters more is the upcoming Soyuz crew rotation period in early- to mid-October, during which the Station’s crew complement will be temporarily reduced to three people from six – further limiting the remaining crews’ ability to work with HTV-7 and support the DM-1 mission in that timeframe.

Looking beyond HTV-7’s departure and the October crew rotation, the next Progress resupply vehicle from Roscosmos is currently slated to launch on 31 October (UTC), followed on NET 17 November by the 10th mission of Northrop Grumman’s Cygnus resupply spacecraft.  SpaceX’s own CRS-16 resupply mission is then set to follow NET 29 November.

There is also a planned November Soyuz crew rotation for the International Space Station – during which the Station’s crew will again be temporarily reduced to three people from six.

In short, these are complications.  But they are not, in and of themselves, complete impediments to launching the SpaceX DM-1 flight in September or October.

A Crew Dragon approaches the International Space Station for docking with PMA-2 on the forward end of Node-2 Harmony. (Credit: Nathan Koga for NSF/L2)

Potentially threading the 14-day DM-1 uncrewed flight of Dragon to the Station between all of these events could be somewhat tricky.

But as ISS Program Manager Kirk Shireman stated, this is what is currently being discussed between the ISS Program, Commercial Crew Program, and SpaceX as all three programs work to determine an exact target launch date for the DM-1 mission.

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