SpaceX CRS-7 explained

SpaceX CRS-7
Names List:SpX-7
Mission Type:ISS resupply
Operator:SpaceX
Spacecraft Type:Dragon 1
Manufacturer:SpaceX
Launch Date: UTC
Launch Rocket:Falcon 9 v1.1 (B1018)
Launch Site:Cape Canaveral, SLC-40
Launch Contractor:SpaceX
Disposal Type:Destroyed on launch
Destroyed: UTC
Orbit Reference:Geocentric
Orbit Regime:Low Earth
Orbit Inclination:51.6°
Insignia:SpaceX CRS-7 Patch.png
Insignia Caption:NASA SpX-7 mission patch
Programme:Commercial Resupply Services
Previous Mission:SpaceX CRS-6
Next Mission:OA-4
Programme2:Cargo Dragon
Previous Mission2:SpaceX CRS-6
Next Mission2:SpaceX CRS-8

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.

Launch history

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 1400lb of supplies and waste.

Launch failure

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, but failed at .[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

Primary payload

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.

, 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

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

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, / Pressure Sensor, NORS Tank, **3 PBA Assemblies, 2 MF Beds, 2 Urine Receptacles, Toilet Paper Packages, Sensor, Ammonia Cartridge Bag, PTU XFER Hose

2 Avionics Restart Cables

The mission would have transported more than 4000lb 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.

CRS-7 would have brought a pair of modified Microsoft HoloLenses to the International Space Station as part of Project Sidekick.[16] [17]

Planned post-launch flight test

See main article: SpaceX reusable launch system development program.

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.[18]

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.[19] [20]

See also

External links

Notes and References

  1. News: Pressurization Event in Second Stage Likely Cause of SpaceX CRS-7 Failure . Space Policy Online . Marcia S. . Smith . June 28, 2015 . April 22, 2016.
  2. News: Unmanned SpaceX rocket explodes after Florida launch . June 28, 2015 . BBC News . June 28, 2015.
  3. Web site: Worldwide Launch Schedule . SpaceflightNow . June 26, 2015.
  4. Web site: NASA Opens Media Accreditation for Next SpaceX Station Resupply Launch . May 20, 2015 . NASA . May 27, 2015.
  5. News: Speck . Emilee . SpaceX resupply launch, barge landing attempt set for Sunday . June 26, 2015 . . June 25, 2015 . June 26, 2015 . https://web.archive.org/web/20150626150606/http://www.orlandosentinel.com/news/space/go-for-launch/os-spacex-resupply-launch-barge-landing-sunday-20150625-story.html . dead .
  6. News: Saving Spaceship Dragon – Software to provide contingency chute deploy . . Chris . Bergin . July 27, 2015 . April 6, 2018.
  7. Web site: CRS-7 Investigation Update . July 20, 2015 . SpaceX . August 7, 2015.
  8. Web site: CRS-7 INVESTIGATION UPDATE . https://web.archive.org/web/20150721152601/https://www.spacex.com/news/2015/07/20/crs-7-investigation-update . dead . July 21, 2015 . SpaceX . July 20, 2015 . June 15, 2020.
  9. Web site: NASA Independent Review Team SpaceX CRS-7 Accident Investigation Report Public Summary . NASA . March 12, 2018 . March 23, 2018.
  10. Web site: Status of Human Exploration and Operations Mission Directorate (HEO) . NASA . March 19, 2014 . July 29, 2013.
  11. Web site: International Space Station Program Status . Hartman . Dan . July 23, 2012 . NASA . August 10, 2012.
  12. Web site: NDS Configuration and Requirements Changes since Nov 2010 . Lupo . Chris . June 14, 2010 . NASA . August 22, 2011 . dead . https://web.archive.org/web/20110814205532/http://dockingstandard.nasa.gov/Documents/Configuration-Changes-post-CDR-public-revA.pdf . August 14, 2011 . mdy-all.
  13. News: SpaceX failure adds another kink in station supply chain . Spaceflight Now . Stephen . Clark . June 29, 2015 . April 28, 2016.
  14. News: Astronaut Scott Kelly Reveals Real Story Behind Video of Him in Gorilla Suit Aboard Space Station . People Magazine. Diane . Herbst . January 17, 2022 . May 12, 2024.
  15. News: Britain's first official astronaut to enjoy fine dining on space mission . The Telegraph . Sarah . Knapton . June 21, 2015 . April 28, 2016.
  16. News: Alfano . Andrea . HoloLens Is Going To Space As Sidekick In A Joint Project By NASA And Microsoft . June 26, 2015 . Tech Times . June 25, 2015.
  17. News: Bass . Dina . NASA to Use HoloLens on Space Station . June 26, 2015 . Bloomberg . June 25, 2015.
  18. News: Gebhardt . Chris . Bergin . Chris . World launch markets look toward rocket reusability . June 26, 2015 . NASASpaceFlight.com . June 24, 2015.
  19. News: Bergin . Chris . SpaceX preparing for a busy season of missions and test milestones . April 4, 2015 . NASASpaceFlight.com . April 3, 2015.
  20. News: Graham . William . SpaceX Falcon 9 scrubs CRS-6 Dragon launch due to weather . June 26, 2015 . NASASpaceFlight.com . April 13, 2015.