by Chris Tobias

It’s hard to believe that the SpaceX Dragon capsule will be heading out to the black for the 20th time this coming week.

It doesn’t seem all that long ago that we experienced the excitement of that first commercial resupply mission to the International Space Station in October of 2012, almost one month to the day after Take Back the Sky was founded to convince Elon Musk and SpaceX to name the crewed version of the Dragon capsule after Joss Whedon’s fictional transport ship Serenity from the TV series Firefly.

image courtesy Wikipedia

Now, a little less than seven years later, the Dragon is about to make its 20th flight and its 18th operational delivery flight to the ISS, with liftoff scheduled NET Sunday, July 21 at 7:32 PM EST (23:32 UTC) from Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station.

As with the previous resupply missions, this one will deliver supplies, equipment and science investigations (a.k.a. experiments) to the ISS.  Astronauts aboard the station will also be able to send completed experiments and equipment that is no longer needed or in need of repair back to Earth when the capsule makes its return trip.

Even though these Dragon resupply missions will soon number three dozen, they should not be taken for granted or regarded as routine.  Each one is a unique opportunity for NASA, the ESA, Roscosmos, JAXA and other space agencies of the world to do some pretty mind-blowing science.  According to officials at Johnson Space Center, this particular mission will carry equipment and science investigations that will allow astronauts to test the ability to print human tissues and study the process of biomining in microgravity, as well as develop innovative bone healing therapies.  Goodyear Tire will also test the limits of silica fillers in microgravity in an attempt to improve the manufacture and performance of its tires (putting a real emphasis on the “commercial” in Commercial Space).  Other investigations will study how bacterial life adapts to long-term space travel, which might yield data that could lead to new therapies for diseases like Parkinson’s and Multiple Sclerosis. 

Over 40 of the experiments delivered on this mission were developed by students and educators.  Many of these will utilize “MixStix,” tiny mixture enclosure tubes that use clamps to keep fluids or solids (such as chemicals or biological materials) separate until they are released in space, allowing the contents to mix.

The Dragon will also deliver a new docking adapter that will add another docking port for future US Commercial Crew vehicles (Crew Dragon, Starliner, Dream Chaser, etc.).  This International Docking Adapter, designated IDA-3, will help convert the older shuttle-era Androgynous Peripheral Attach System-95 (APAS-95) docking systems on the ISS’s Pressurized Mating Adapter-2 and 3 (PMA-2 and PMA-3) docking ports into the newer International Docking System Standard (IDSS) style.  IDA-3 is identical to the first International Docking Adapters, IDA-1, which was destroyed when the Falcon 9 that was carrying the Dragon of CRS-7 experienced an in-flight anomaly and was lost, and IDA-2, which has already been installed on the ISS.  (IDA-2 was the docking port for Crew Dragon on her DM-1 mission.)  IDA-3, which was constructed mainly from spare parts, will be extracted from the Dragon by Canadarm2 and and permanently installed by astronauts during an EVA (“spacewalk”) next month.

The Falcon 9 booster core for this mission also carried the last Dragon into orbit for the CRS-17 mission and was recovered aboard SpaceX’s drone ship Of Course I Still Love You.  After it takes this Dragon out to the black, it will return to Landing Zone 1 (LZ-1) at Cape Canaveral.

If you’d like to watch this launch, SpaceX’s usual webcast should go live approximately 20 minutes before liftoff at spacex.com and on the company’s YouTube channel.

Peace, love and rockets…