SpaceX CRS-7

Summary

SpaceX CRS-7, also known as SpX-7,[1] was a private American Commercial Resupply Service mission to the International Space Station, contracted to NASA, which launched and failed on June 28, 2015. It disintegrated 139 seconds into the flight after launch from Cape Canaveral, just before the first stage was to separate from the second stage.[2] It was the ninth flight for SpaceX's uncrewed Dragon cargo spacecraft and the seventh SpaceX operational mission contracted to NASA under a Commercial Resupply Services contract. The vehicle launched on a Falcon 9 v1.1 launch vehicle. It was the nineteenth overall flight for the Falcon 9 and the fourteenth flight for the substantially upgraded Falcon 9 v1.1.

SpaceX CRS-7
Disintegration of the SpaceX CRS-7 launch vehicle approximately two minutes after liftoff as seen from a NASA tracking camera.
Mission typeISS resupply
OperatorNASA
Mission durationPlanned: 1 month
Final: 2 minutes, 19 seconds
Spacecraft properties
SpacecraftDragon C109
Spacecraft typeDragon CRS
ManufacturerSpaceX
Start of mission
Launch dateJune 28, 2015, 14:21:11 (2015-06-28UTC14:21:11) UTC
RocketFalcon 9 v1.1
Launch siteCape Canaveral SLC-40
ContractorSpaceX
End of mission
DisposalDestroyed on launch
DestroyedJune 28, 2015, 14:23:30 (2015-06-28UTC14:23:31) UTC
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Inclination51.6°

NASA SpX-7 mission patch  

Launch history edit

 
SpaceX CRS-7 prior to launch

In January 2015, the launch was tentatively scheduled by NASA for no earlier than June 13, 2015. This was adjusted to June 22, 2015, then moved forward to June 19, 2015, and adjusted again to June 26, 2015.[3] Subsequently, the launch had been rescheduled to June 28, 2015, at 14:21:11 UTC, from Cape Canaveral LC-40.[4] The launch was scheduled to be the third controlled-descent and landing test for the Falcon 9's first stage. It would have attempted to land on a new autonomous drone ship named Of Course I Still Love You – named after a ship in the novel The Player of Games by Iain M. Banks.[5] The spacecraft was planned to stay in orbit for five weeks before returning to Earth with approximately 1,400 pounds (640 kg) of supplies and waste.[5]

Launch failure edit

Video of disintegration and explosion of rocket

Performance was nominal until 139 seconds into launch when a cloud of white vapor appeared, followed by a rapid loss of pressure in the liquid oxygen tank of the Falcon 9's second stage. The booster continued on its trajectory until the vehicle completely broke up several seconds later. The Dragon CRS-7 capsule was ejected from the exploding launch vehicle and continued transmitting data until it impacted with the ocean. SpaceX officials stated that it could have been recovered if the parachutes had deployed, but the software in the capsule did not include any provisions for parachute deployment in this situation.[6] It is assumed that the capsule crumpled and broke up on impact. Subsequent investigation traced the accident to the failure of a strut that secured a high-pressure helium bottle inside the second stage's liquid-oxygen tank. With the helium pressurization system integrity breached, excess helium quickly flooded the liquid-oxygen tank, causing it to overpressurize and burst.[7] The report from SpaceX pointed out that the stainless-steel eye bolt was rated for a load of 10000 pounds, but failed at 2000 pounds.[8]

An independent investigation by NASA concluded that the most probable cause of the strut failure was a design error: instead of using a stainless-steel eye bolt made of aerospace-grade material, SpaceX chose an industrial-grade material without adequate screening and testing and overlooked the recommended safety margin.[9]

Payload edit

Primary payload edit

NASA contracted with SpaceX for the CRS-7 mission and set the primary payload, date/time of launch, and orbital parameters for the Dragon space capsule.

As of July 2013, the first International Docking Adapter, IDA-1, was scheduled for delivery to the International Space Station on CRS-7.[10] This adapter would have been attached to one of the Pressurized Mating Adapters (PMA-2 or PMA-3) and converted the APAS-95 docking interface to the newer NASA Docking System (NDS).[11][12] These adapters allow docking of the newer human-transport spacecraft of the Commercial Crew Program. Previous United States cargo missions after the retirement of the Space Shuttle were berthed, rather than docked, while docking is considered the safer and preferred method for spacecraft carrying humans. The subsequent Cargo Dragon missions CRS-9 and CRS-18 brought docking adapters IDA-2 and IDA-3, to PMA-2 and PMA-3 respectively. They have been in use since 2020.

Detailed payload manifest edit

A full listing of the cargo aboard the failed mission included:[13]

  • Crew Supplies — 690 kilograms (1,520 lb)
  • Utilization — 573 kilograms (1,263 lb)
    • Canadian Space Agency: Vascular Echo Exercise Band
    • European Space Agency: Circadian Rhythms, KUBIK EBOXes, Interface Plate, EPO Peake, BioLab, Spheroids, EMCS RBLSS, Airway Mon., LiOH Cartridge
    • Japan Aerospace Exploration Agency: Atomization, Biological Rhythms, Multi-omics, Cell Mechanosensing 3, Plant Gravity Sensing 3, SAIBO L&M, Space Pup, Stem Cells, MSPR LM, Group Combustion Camera
    • US: 2 Polars, 6 DCBs and Ice Bricks, 1 MERLIN, FCF/HRF Resupply, HRP Resupply [Kits, MCT, Microbiome, Twin Studies], IMAX Camera, Meteor, Micro-9, MSG Resupply, NanoRacks Modules & 0.5 NRCSD #7, Universal Battery Charger, Veg-03, Microbial Observatory-1, Microchannel Diffusion Experiment, Wetlab RNA Smartcycler, SCK, Story Time, MELFI TDR Batteries
  • Computer Resources — 36 kilograms (79 lb)
    • Projector Screen, Sidekick, OCT Laptop & Power Supply, 32GB MicroSD Cards, Generic USB Cables, Power Modules and Card Readers, Preloaded T61p Hard Drives, CD Storage Container, Network Attached Storage Devices, XF305 Camcorders, RS-422 Adapter Cables
  • Vehicle Hardware — 462 kilograms (1,019 lb)
    • CHECS CMS: HRM Watches, Bench Lock Studs, Glenn Harness for Kelly, Kopra and Peake
    • CHECS EHS: CO2 Monitoring Assemblies, Filter Assemblies, CSA-CP/CDM Battery Assemblies, SIECE Cartridge Assemblies, Water Kit, Petri Dish Packets
    • CHECS HMS: IMAKs, Oral Med Packs
    • C&T: C2V2 Communications Unit (and HTV-5 Unit Data Converter)
    • ECLSS: 3 Pretreat Tanks, Filter Inserts, 9 KTOs, UPA FCPA, CDRS ASV, IMV Valve, Wring Collector, Water Sampling Kits, OGS ACTEX Filter, ARFTA Brine Filter Assemblies, O2/N2 Pressure Sensor, NORS O2 Tank, **3 PBA Assemblies, 2 MF Beds, 2 Urine Receptacles, Toilet Paper Packages, H
      2
      Sensor, Ammonia Cartridge Bag, PTU XFER Hose
    • EPS: 2 Avionics Restart Cables
    • Makita Drill, PWD Filter, N3 Bulkhead Connectors, Yellow/Red Adapters, IWIS Plates, 6.0 & 4.0 Waste Xfer Bags, BEAM Ground Straps, JEM Stowage Wire Kit
  • EVA Hardware — 167 kilograms (368 lb)
    • SEMU, REBA, EMU Ion Filters (4), Equipment Tethers, Gas Grap, EMU Mirrors, Crew Lock Bags, SEMU arms/legs
    • Lindgren/Yui ECOKs & CCAs, Lindgren LCVG
    • Kelly LCVG, Padalka EMU Gloves
  • Russian Cargo
    • Russian Segment Torque Wrench
  • Unpressurized Cargo — 526 kilograms (1,160 lb)

The mission would have transported more than 4,000 pounds (1,800 kg) of supplies and experiments to the International Space Station including the Meteor Composition Determination investigation which would have observed meteors entering the Earth's atmosphere by taking high resolution photos and videos. The Center for the Advancement of Science in Space had arranged for it to carry more than 30 student research projects to the station including experiments dealing with pollination in microgravity as well as an experiment to evaluate a sunlight blocking form of plastic.[5]

CRS-7 would have brought a pair of modified Microsoft HoloLenses to the International Space Station as part of Project Sidekick.[15][16]

Planned post-launch flight test edit

 
The Of Course I Still Love You floating landing platform prior to the launch

After the second stage separation, SpaceX planned to conduct a flight test and attempt to return the Falcon 9's nearly empty first stage through the atmosphere and land it on autonomous spaceport drone ship Of Course I Still Love You.[5][17]

This would have been SpaceX's third attempt to land the booster on a floating platform after earlier tests in January 2015 and April 2015 were not successful. The boosters were fitted with a variety of technologies to facilitate the flight test, including grid fins and landing legs to facilitate the post-mission test.[17][18][19]

See also edit

References edit

  1. ^ Smith, Marcia S. (June 28, 2015). "Pressurization Event in Second Stage Likely Cause of SpaceX CRS-7 Failure". Space Policy Online. Retrieved April 22, 2016.
  2. ^ "Unmanned SpaceX rocket explodes after Florida launch". BBC News. June 28, 2015. Retrieved June 28, 2015.
  3. ^ "Worldwide Launch Schedule". SpaceflightNow. Retrieved June 26, 2015.
  4. ^ "NASA Opens Media Accreditation for Next SpaceX Station Resupply Launch". NASA. May 20, 2015. Retrieved May 27, 2015.
  5. ^ a b c d Speck, Emilee (June 25, 2015). "SpaceX resupply launch, barge landing attempt set for Sunday". Orlando Sentinel. Archived from the original on June 26, 2015. Retrieved June 26, 2015.
  6. ^ Bergin, Chris (July 27, 2015). "Saving Spaceship Dragon – Software to provide contingency chute deploy". NASASpaceFlight.com. Retrieved April 6, 2018.
  7. ^ "CRS-7 Investigation Update". SpaceX. July 20, 2015. Retrieved August 7, 2015.
  8. ^ "CRS-7 INVESTIGATION UPDATE". SpaceX. July 20, 2015. Archived from the original on July 21, 2015. Retrieved June 15, 2020.
  9. ^ "NASA Independent Review Team SpaceX CRS-7 Accident Investigation Report Public Summary" (PDF). NASA. March 12, 2018. Retrieved March 23, 2018.
  10. ^ "Status of Human Exploration and Operations Mission Directorate (HEO)" (PDF). NASA. July 29, 2013. Retrieved March 19, 2014.
  11. ^ Hartman, Dan (July 23, 2012). "International Space Station Program Status" (PDF). NASA. Retrieved August 10, 2012.
  12. ^ Lupo, Chris (June 14, 2010). "NDS Configuration and Requirements Changes since Nov 2010" (PDF). NASA. Archived from the original (PDF) on August 14, 2011. Retrieved August 22, 2011.
  13. ^ Clark, Stephen (June 29, 2015). "SpaceX failure adds another kink in station supply chain". Spaceflight Now. Retrieved April 28, 2016.
  14. ^ Knapton, Sarah (June 21, 2015). "Britain's first official astronaut to enjoy fine dining on space mission". The Telegraph. Retrieved April 28, 2016.
  15. ^ Alfano, Andrea (June 25, 2015). "HoloLens Is Going To Space As Sidekick In A Joint Project By NASA And Microsoft". Tech Times. Retrieved June 26, 2015.
  16. ^ Bass, Dina (June 25, 2015). "NASA to Use HoloLens on Space Station". Bloomberg. Retrieved June 26, 2015.
  17. ^ a b Gebhardt, Chris; Bergin, Chris (June 24, 2015). "World launch markets look toward rocket reusability". NASASpaceFlight.com. Retrieved June 26, 2015.
  18. ^ Bergin, Chris (April 3, 2015). "SpaceX preparing for a busy season of missions and test milestones". NASASpaceFlight.com. Retrieved April 4, 2015.
  19. ^ Graham, William (April 13, 2015). "SpaceX Falcon 9 scrubs CRS-6 Dragon launch due to weather". NASASpaceFlight.com. Retrieved June 26, 2015.

External links edit

  • Mission Overview, NASA, 2 pages, pdf, June 24, 2015.
  • Press Kit, NASA, 27 pages, pdf, June 26, 2015.