SpaceX is moving forward with its flight of Cargo Dragon mission CRS-17, with a first launch window at 3 May 2019 at 071133 UT – though due to the weather around Cape Canaveral, the flight is likely to be delayed to 4 May 2019 0648 UT, or failing that, possibly the week of 13 May. While little has changed from the Cargo Dragon perspective, the recent energetic deconstruction of the larger, newer Crew Dragon capsule has attracted additional attention to the routine cargo launch.
On 20 April 2019, “half a second” prior to a test fire of 8 of the 12 SuperDraco thrusters, a Crew Dragon capsule being tested at Cape Canaveral Air Force Station was destroyed in an apparent explosion. Nearly two weeks later, neither SpaceX or Air Force teams have even been to the test pad to pick up the pieces – the site is still being evaluated for any remaining risks, including any remaining pressurized gas, combustibles, and toxic materials.
To work in any area that may still be contaminated with monomethylhydrazine fuel, workers will need a full body positive pressure suit. Hydrazine is commonly used for orbital maneuvering systems because it is reasonably energetic and ignites on contact with dinitrogen tetroxide, simplifying flight hardware needs. However, it is also extremely toxic from an environmental and personnel safety perspective, and continues to be a major concern in environmental assessments at new spaceports.
For its part, the Cargo Dragon capsule flying for the CRS-17 mission remains fully flight-qualified and will deliver the usual mix of supplies and science payloads to the ISS, including an algae experiment from Julie González, Biology professor at Des Moines Area Community College.
