Photo from NASA/SpaceX of the business end of CRS-27. Dreaming about a return to the Moon
Mission Rundown: SpaceX Falcon 9 - CRS-27
Written: March 17, 2023
Glad you came Mr. Dragon
Dragon CRS-2 SpX-27 (CRS-27) is a Commercial Resupply Service mission that flew to the International Space Station (ISS). SpaceX was awarded this mission by NASA back in 2016 and launched it on its Falcon 9 rocket B1073-7 using Cargo Dragon, C209-3.
Three different vehicles from three different entities have the capability to carry cargo to the ISS. Northrup Grumman’s Cygnus spacecraft launched by NASA, ROSCOSMOS’s Soyuz Progress spacecraft, and SpaceX’s Cargo Dragon spacecraft, which is the only launch system with a cargo return capability.
The Falcon 9 rocket lifted off on March 14/15, 2023 at 20:30 EDT - 00:30:41 UTC from historic Launch Complex 39A, at the Kennedy Space Center in Florida.
CRS-27 was the 7th flight for SpaceX under NASA’s CRS Phase 2 contract and SpaceX’s 17th launch in 2023 compared to a total of 61 launches in 2022. On board are ~2,812 kg (~6,200 lb) of food, hardware, and scientific research.
Dragon C209-3 separated from the second stage of the Falcon 9 at ~T+12 min. After that, it performed a series of thruster firings to adjust its orbit and reach the ISS. The spacecraft arrived at ISS ~35 hours later, on March 16, at 07:30 EDT - 11:30 UTC.
Dragon autonomously docked to the ISS’ Harmony module’s forward-facing port. Upon Dragon’s arrival, the crew will proceed with unloading the cargo.
After boosting the second stage along with Cargo Dragon 2, C209-3 towards orbit, the first stage will perform a 20 second re-entry burn to slow the vehicle down in preparation for atmospheric reentry. The booster will then perform a 20-25 second landing burn aboard one of SpaceX’s autonomous spaceport drone ships.
B1073-7 will launch CRS-27 to the International Space Station on this voyage.
B1073-7 didn’t perform a static fire test prior to its March 14 east coast launch out of Cape Canaveral. SpaceX has omitted this safety precaution many times on low risk missions. It is not required to perform a static fire test in house missions like Starlink. Other SpaceX customers have willingly omitted the static fire test.
The Cargo Dragon mission
Dragon C209-3 autonomously docked to the ISS Harmony module after soft capture.
Soft capture is the first contact between the spacecraft and the space station. A “soft” capture ring hooks to its counterpart on the docking port and slowly retracts to bring in Dragon for hard capture. Just 10 minutes later a hard capture was confirmed after the 12 hooks secured the spacecraft to the space station.
After leak checks and pressurization of the vestibule (the small space between station and Dragon), the hatch to C209-3 was opened granting the crew access to the cargo inside.
Dragon C209-3 will spend 30 days at the ISS. Its mission will end in mid April. After that, the spacecraft will travel back to Earth and will splash down under parachutes off the coast of Florida, returning valuable research and cargo to Earth.
The CRS 2 contract employs SpaceX’s Dragon 2 spacecraft now on its 27th mission to the International Space Station , as the Dragon 1 spacecraft was retired at the end of the initial extended CRS 1 contract after 19 CRS missions plus the COTS 2+ visit to ISS. CRS-7 was destroyed mid-flight by a loose COPV in the second stage.
Dragon 2 has flown under its own power 19 times; nine crewed and ten uncrewed.
Dragon C209-3 can double as an extra space science laboratory where 4 experiments will share power, downlink data streams and data storage from Dragon C209-3 internal supply. One experiment will be moved from its current home on ISS to its new location on Dragon C209-3, where it will join 3 already installed experiments.
The redesign of Cargo Dragon Capsules will extend ISS ability to conduct experiments, and it seems ISS is due for an extension with an extra laboratory module some time soon.
Dragon research payloads
Arriving on board Cargo Dragon C209-3 are dozens of science experiments and technology demonstrations. The following list is only an excerpt of what has been ferried to the ISS.
The Cargo Dragon is loaded with several metric tons of experiments, CubeSats, essential supplies, and other cargo.
This includes more than 15 experiments sponsored by the ISS National Laboratory, including the final two experiments in the Tissue Chips in Space initiative.
The JAXA astrobiology experiment is also flying on CRS-27. Tanpopo-5 will study how various microbes, sporophytes, amino acids, peptides, and nucleotide precursors fare during exposure to the space environment.
Experiments involving engineered heart tissues, 3D-printed RF circuits, the MAPT-I radiation detector, photonic integrated circuits, biotherapeutic compounds crystallization, foam, emulsions structure, and other areas of study will be flown on CRS-27.
Another notable payload on this flight is a ball clamp monopod – manufactured by students – that can simplify filming in space. However, this is not the only payload on CRS-27 that students have been involved in.
Experiments from Canadian and German universities are also onboard. Four Canadian CubeSats – Ex-Alta 2, AuroraSat, YukonSat, and NEUDOSE – are flying on Dragon, along with the University of Stuttgart’s FARGO ferrofluid experiment.
The ELaNa (Educational Launch of Nanosatellites) 50 mission will fly a pair of CubeSats aboard CRS-27. ARKSAT-1, developed by the University of Arkansas, is a 1U CubeSat that is equipped with an LED light. This light will be activated, and a spectrometer on the ground will conduct orbit-to-ground atmospheric measurements by tracking the light.
ARKSAT-1 will also attempt to deorbit itself at the end of its mission with a Solid State Inflation Balloon (SSIB). Inflating the SSIB will increase the atmospheric drag on the satellite, causing it to deorbit sooner than it otherwise would. If this technology works, it can be used to deorbit CubeSats at the end of their useful lives, preventing additional “space junk” from cluttering low Earth orbit.
Another 1U CubeSat that is part of ELaNa 50 is LightCube, a cooperative effort between Arizona State University, CETYS Universidad in Mexico, and Vega Space Systems. Like ARKSAT-1, LightCube will have a powerful light as its main payload. In this case, LightCube is equipped with a flashbulb that can be controlled by amateur radio operators.
The operators can activate a flash that will make the satellite as bright as the International Space Station for a brief period of time. The developers of LightCube hope to inspire its users to learn about satellites and space concepts, through the users being able to issue a command and see a tangible result in the night sky.
In addition, the US Space Force is flying the STP-H9 external payload on this mission with eight experiments on board. STP-H9 will be mounted on the Japanese Kibo module’s Exposed Facility as an external payload, and its experiments will test out technologies that could be used on future USSF missions.
All these research experiments can range from NASA-funded experiments to private companies and universities. If you’d like to learn more, reach out or explore NASA’s website and the ISS National Lab.
Where to land the Dragon?
Seven hazard areas for Dragon C209-3 - Recovery Location LZ 1-7 available - LZ 4 is chosen
The opportunity for CRS-27 to return to Earth has been determined; it departed from ISS and was docked to IDA-2 now known as the forward facing airlock.
The CRS-27 Cargo Dragon spacecraft was scheduled to undock from the International Space Station at 11:05 EDT - 15:05 UTC on April 15, 2023 to begin the journey home.
NASA’s SpaceX CRS-27 mission now is targeting a splash down on Earth no earlier than 16:58 EDT - 20:58 UTC on April 15, 2023 near Tampa, Florida.
The Cargo Dragon spacecraft will aim for a splashdown at one of seven targeted landing zones in the Atlantic Ocean or Gulf of Mexico off the coast of Florida.
The recovery ship Shannon was loitering around LZ-4 near Tampa before going back with CRS-27
CRS-27 will after the trunk is jettisoned perform its deorbit burn at 16:03 EDT - 20:03 UTC and close the nose hatch cover. Then CRS-27 will reorient itself with its heat shield forward and enter the Earth's atmosphere.
Four minutes before splashdown, the drogue parachutes will deploy at about 18,000 feet in altitude while the Cargo Dragon is moving approximately 350 miles per hour, and less than a minute later, the main parachutes deploy at about 6,000 feet in altitude while the spacecraft is moving approximately 119 miles per hour.
For normal crew rescue and recovery operations, the NASA and SpaceX teams select two primary splashdown locations from the seven possible locations about two weeks prior to return, with additional decision milestones taking place prior to crew boarding the spacecraft, during free flight, and before the Cargo Dragon performs a deorbit burn.
NASA and SpaceX coordinate with the U.S. Coast Guard to establish a 10-nautical-mile safety zone around the expected splashdown location to ensure safety for the public and for those involved in the recovery operations, as well as the cargo aboard the returning CRS-27 spacecraft.
Teams on the recovery ship Megan, including two fast boats, will be securing CRS-27 Cargo Dragon and ensuring the spacecraft is safe for the recovery effort. As the fast boat teams complete their work, the recovery ship will move into position to hoist the Cargo Dragon onto the main deck of the ship.
Once on the main deck, the important and time-sensitive research samples will be taken out of the spacecraft before a helicopter ride back to Cape Canaveral.
The discarded Dragon trunk from the CRS-27 mission, jettisoned on April 15, was in a 210 x 394 km x 51.3 deg orbit. It deorbited 12 days later at 08:50 UTC April 27 over Arizona and New Mexico. Source
A low apogee of 210 km in this orbit must have been the contributing factor in deorbiting the Dragon trunk section so fast. It is after all a BIG barrel or dustbin, so maybe it should be rebuilt as a space debris hunter gatherer collecting space junk.
The Cargo Dragon 2
Dragon capsule C208 during processing at SpaceX HQ in Hawthorne prior to CRS-21
Cargo Dragon 2 is essentially a Crew Dragon, without an abort system, so it has all of the upgrades from Crew Dragon. Most importantly, Dragon 2 is designed to be reused up to 5 times, with a turnaround time of under 6 months, which is significantly lower than Dragon One; Dragon One’s fastest turnaround time was 418 days, with most turnaround times being significantly longer.
Dragon 1 was unable to dock with the International Space Station. Meaning that Dragon 1 would hold a position away from the ISS. In this position the Canadarm would capture the spacecraft, and attaching it to the ISS. This is called berthing.
CRS-27 will mark the 16th autonomous docking to the ISS that SpaceX has completed: DM-1, DM-2, Crew-1, CRS-21, Crew-2, CRS-22, CRS-23, Crew-3, CRS-24, Axiom 1, Crew-4, CRS-25, Crew-5, CRS-26, Crew-6 and now CRS-27. Inspiration4 was a free spacecraft.
In this G. DE CHIARA drawing of DM-2 there are measurement sticks inserted by Me; the side section has been split to separate the capsule and the trunk. Haven’t found a Cargo Dragon.
Cargo Dragon 2’s trunk is also different from Dragon 1 and Crew Dragon 2, that has its solar panels integrated onto its trunk, while Dragon 1 had a deployable solar array from its trunk. However, Crew Dragon 2 is equipped with 4 fins, which are used for aerodynamic control during ascent. Cargo Dragon 2’s trunk only has 2 fins with solar cells.
Externally, Cargo Dragon 2 differs from its crewed counterpart, lacking windows and the SuperDragon abort system. The differences between Crew Dragon and Cargo Dragon are derived from the fact that Cargo Dragon is not required to have launch escape capability. Crew Dragon is fitted with eight SpaceX-developed SuperDraco engines, located in four, twin engine clusters around the outside of the capsule, which are there to pull the capsule and its crew to safety away from a Falcon 9 in the event of a catastrophic failure during fueling or launch as seen in the inflight abort mission.
Since Cargo Dragon does not carry crew, the spacecraft does not have to carry those systems; therefore the SuperDracos have been removed from the Cargo Dragon capsule giving a mass reduction that allows for additional cargo to be carried to ISS.
Cargo Dragon 2 also lacks most of the life support and onboard control systems present on Crew Dragon that are needed for humans. Instead, it carries minimal support systems to ensure conditions are kept acceptable for hatch opening on the Station and ISS Crew ingress to the vehicle.
Cargo Dragon 2 is also significantly more massive, with a dry mass of ~12,000 kg. With this mass increase Dragon 2 is able to carry ~50% more science to the ISS than Dragon 1. Because of this, missions can stay docked to the ISS for up to 3 months, rather than the one month that CRS-21 stayed docked.
Dragon 2’s nose cone is also significantly different as it opens instead of being jettisoned on ascent. It is protecting the docking mechanism.
At a press conference after Crew-1, Gwynne Shotwell said SpaceX is expecting to have a fleet of 8 dragons: 5 Crew Dragons and 3 Cargo Dragons. This will allow SpaceX to conduct up to 25 crewed missions and 15 resupply missions.
Unlike prior cargo resupply missions, the new Cargo Dragon 2 carried too much mass to permit a Return To Launch Site (RTLS) landing of the Falcon 9 first stage. Instead, the first stage — like Crew Dragon, from which Cargo Dragon is now derived — made use of a new drone ship “A Shortfall Of Gravitas'' in the Atlantic for landing and recovery.
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