SpaceX CRS-21, also known as SpX-21, was a Commercial Resupply Service mission to the

International Space Station The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...

which launched on 6 December 2020. The mission was contracted by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

and was flown by

SpaceX Space Exploration Technologies Corp., commonly referred to as SpaceX, is an America, American space technology company headquartered at the SpaceX Starbase, Starbase development site in Starbase, Texas. Since its founding in 2002, the compa ...

using a Cargo Dragon 2. This was the first flight for SpaceX under NASA's CRS Phase 2 contract awarded in January 2016. This was also the first Cargo Dragon of the new Dragon 2 variant, as well as the first Cargo Dragon flight that was docked at the same time as a Crew Dragon spacecraft (

SpaceX Crew-1 SpaceX Crew-1 (was also known as USCV-1 or simply Crew-1) was the first operational crewed flight of a SpaceX Dragon 2, Crew Dragon spacecraft and the maiden flight of the Crew Dragon Resilience, Crew Dragon ''Resilience'' spacecraft. It was ...

). This mission used Booster B1058.4, becoming the first NASA mission to reuse a booster previously used on a non-NASA mission. This was also first time SpaceX launched a NASA payload on a booster with more than one previous flight.

Cargo Dragon

SpaceX plans to reuse the Cargo Dragons up to five times. It was launched without seats, cockpit controls, the life support system required to sustain astronauts in space and SuperDraco abort engines.

Dragon 2 Dragon 2 is a class of partially reusable spacecraft developed, manufactured, and operated by the American space company SpaceX for flights to the International Space Station (ISS) and private spaceflight missions. The spacecraft, which cons ...

improves on

Dragon 1 SpaceX Dragon 1 is a class of fourteen partially reusable cargo spacecraft developed by SpaceX, an American private space transportation company. The spacecraft flew 23 missions between 2010 and 2020. Dragon was launched into orbit by the co ...

in several ways, including lessened refurbishment time, leading to shorter periods between flights. While CRS-21 was for a standard 30 days mission, the most recent Flight Planning Integration Panel (FPIP) document indicates that beginning with CRS-23, SpaceX cargo missions will begin to stretch out to 60 days and beyond. Sarah Walker, director of Dragon mission management at SpaceX, said "the new Cargo Dragon can stay at the space station for up to 75 days, more than twice as long as the first-generation Dragon spacecraft". With this mission, this was the first time that two Dragon capsules were docked at the ISS at the same time. Beginning with the CRS-21 mission, the new Dragon Cargo capsules splash down under parachutes off the coast of Florida in either the

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

or the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

. This NASA preference was added to CRS-2 awards.

Mission

Expedition 64 - Status with the new NanoRacks Bishop airlock

Timeline

T+00:00: Liftoff
T+01:18: Maximum aerodynamic pressure
T+02:30: First stage main engine cutoff (MECO)
T+02:34: Stage separation
T+02:41: Second stage engine start
T+06:37: First stage entry burn begins
T+08:38: Second stage engine cutoff (SECO)
T+08:38: First stage landing on drone ship
T+11:49: Dragon separation
T+12:35: Dragon nose cone open sequence begins

Return

Dragon undocked from the ISS on 12 January 2021 at 14:05 UTC. SpaceX recovery teams were on standby for the parachute-assisted splashdown on 14 January 2021 at 01:26 UTC in the

, west of

Tampa, Florida Tampa ( ) is a city on the Gulf Coast of the United States, Gulf Coast of the U.S. state of Florida. Tampa's borders include the north shore of Tampa Bay and the east shore of Old Tampa Bay. Tampa is the largest city in the Tampa Bay area and t ...

. Dragon returned to

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

with of cargo, according to

Payload

NASA contracted for the CRS-21 mission from SpaceX and therefore determines the primary payload, date of launch, and

orbital parameters Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are considered in two-body systems using a Kepler orbit. There are many different ways to mathematically describe the same o ...

for the Cargo Dragon. The CRS-21 mission carries of cargo to ISS. * Science investigations: * Vehicle hardware: * Crew supplies: * Spacewalk equipment: * Computer resources: * Russian hardware: * External payload (Nanoracks Bishop Airlock): KSC-20200929-PH GEB02 0028

Nanoracks Bishop Airlock The Nanoracks Bishop Airlock is a Commercial use of space, commercially funded airlock module launched to the International Space Station on SpaceX CRS-21 on 6 December 2020. It was berthed to the Tranquility (ISS module), ''Tranquility'' modul ...

, formerly known as Bishop Airlock Module, is a payload airlock attached to the ''Tranquility'' module of the ISS, commercially developed and operated by

Nanoracks Nanoracks LLC is an American private in-space services company which builds space hardware and in-space repurposing tools. The company also facilitates experiments and launches of CubeSats to Low Earth Orbit. Nanoracks's main office is in H ...

. The Bishop Airlock provides five times the satellite deployment volume previously available, when the Japanese Kibō airlock served that role alone. Nanoracks is the prime contractor, with

Thales Alenia Space Thales Alenia Space () is a joint venture between the French technology corporation Thales Group (67%) and Italian defense conglomerate Leonardo (company), Leonardo (33%). The company is headquartered in Cannes, France. It provides space-based ...

manufacturing the pressurized shell and

Boeing The Boeing Company, or simply Boeing (), is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, and missiles worldwide. The company also provides leasing and product support s ...

providing the berthing mechanism. It is the second commercial module of the ISS, after the

Bigelow Expandable Activity Module The Bigelow Expandable Activity Module (BEAM) is an experimental inflatable space habitat, expandable International Space Station#Pressurised modules, space station module developed by Bigelow Aerospace, under contract to NASA, for testing as a ...

(BEAM), which was attached to the ISS in April 2016 and is expected to stay at the ISS until at least 2028. The Bishop Airlock began construction in 2015, and was berthed to ''Tranquility'' on 19 December 2020 by the

Canadarm2 The Mobile Servicing System (MSS) is a robotic system on board the International Space Station (ISS). Launched to the ISS in 2001, it plays a key role in station assembly and maintenance; it moves equipment and supplies around the station, suppo ...

Experiments

BioAsteroid is an experiment designed to test the infrastructure and tools needed for asteroid, lunar, and Martian rock biomining. It will use microorganisms (the

bacterium Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the ...

S. desiccabilis and the

fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

P. simplicissimum) to extract

metals A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. These properties are all associated with having electrons available at the Fermi level, as against no ...

from L-

chondrite A chondrite is a stony (non-metallic) meteorite that has not been modified by either melting or planetary differentiation, differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar Syste ...

, testing the possibility to use this technique to obtain resources that will allow long-term and long-distance human space exploration and extraterrestrial settlements. Hemocue is a test of the system for white blood cell testing on the Moon and Mars. The systems were developed under Earth's gravity, and still need to be tested in zero-g's. The Brain Organoid experiment is a continuation of the first Brain Organoid experiment. Its goal is to validate the first round of experiments and to continue the research recorded during those first tests. The program studies the early developed human brain, its movements in microgravity, and can help address and create better models of neurodegenerative disorders. Cardinal Heart is a continuation of a previous experiment. This experiment will study cardiomyocytes in human heart tissue and its reaction to a zero-g environment. NASA Astronaut Kate Rubins was present for the experiment on station a few years ago, and she said that, paraphrased, few things on station make her gasp, but this is one thing that does. Subsa-Brains studies the effects of micrometeorites and space junk and the damage they can cause, as well as the process to repair the tissue, called brazing, and if it still works in a zero-gravity environment. Three-Dimensional Microbial Monitoring (3DMM) is a project that aims to construct a three-dimensional map of bacteria and metabolites that are present at various locations throughout the ISS, and determine how the spaceflight environment affects the various species identified. Monoclonal Crystal Research in Microgravity (MCRM) is a protein crystallization experiment by the American pharmaceutical company

Bristol Myers Squibb The Bristol-Myers Squibb Company, Trade name, doing business as Bristol Myers Squibb (BMS), is an American multinational pharmaceutical company. Headquartered in Princeton, New Jersey, BMS is one of the world's largest pharmaceutical companies ...

. NASA astronauts will study the crystallization of

monoclonal antibodies A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a Lineage (evolution), cell lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell. Mon ...

in space, with the aim of improving drug formulation and delivery for patients on Earth. Monoclonal antibodies are lab-created proteins designed to interact with specific targets, called

antigen In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...

s. Monoclonal antibodies are used in the treatment of numerous diseases, including cancer. Rodent Research-23 will study the effects of spaceflight on the eyes, specifically on the structure and function of the arteries, veins, and lymphatic vessels that are needed to maintain vision. Student Spaceflight Experiments Program: The

Student Spaceflight Experiments Program The Student Spaceflight Experiments Program (SSEP) provides an opportunity for student groups from upper elementary school through university to design and fly microgravity experiments in low Earth orbit (LEO). SSEP is a program of the National ...

(SSEP) has 27 experiments manifested as part of Mission 14A. The CRS-21 pressurized capsule carries a variety of other research including studies on how space conditions affect the interaction between microbes and minerals.

Returning hardware

Beginning with the CRS-2 contract, NASA reports major hardware (failed or expended hardware for diagnostic assessment, refurbishment, repair, or no longer needed) returning from the International Space Station. The CRS-21 mission returned of cargo to Earth. This cargo included: Treadmill Data Avionics Unit: Failed avionics unit that supports the treadmill, a critical item returning to the ground following the on-orbit replacement with a working spare. Carbon Dioxide Removal Assembly (CDRA) Air Selector Valve: Critical degraded valve returning for repair and refurbishment to support the carbon dioxide removal capability on-orbit. Nitrogen Oxygen Recharge System (NORS) Tank: Depressurized tank capable of flying oxygen or nitrogen, and will be utilized for future on-orbit demand in 2021. Rodent Research Habitats and Transporters: Live rodents from the Rodent Research-23 mission, along with used habitats and transporters that support future research missions and analysis. Minus Eighty Laboratory Freezer for ISS (MELFI) Electronics Unit: Failed cold stowage item requiring ground repair to enable future cold stowage missions. Thermal Amine Bulk Water Save Valve: Failed valve that supports efficient usage of the Thermal Amine system returning to ground for repair. The returned valve is intended to help inform robustness of a similar valve design on the

Orion spacecraft Orion (Orion Multi-Purpose Crew Vehicle or Orion MPCV) is a partially reusable crewed spacecraft used in NASA's Artemis program. The spacecraft consists of a Crew Module (CM) space capsule designed by Lockheed Martin that is paired with a Eu ...

Gallery

References

External links

NASA

SpaceX official page for the Dragon spacecraft

Nanoracks Bishop Airlock

GNSS Remote Sensing aboard the ISS
{{Orbital launches in 2020 SpaceX Dragon 2 Spacecraft launched in 2020 Spacecraft which reentered in 2021 SpaceX payloads contracted by NASA Supply vehicles for the International Space Station 2020 in the United States