Screenshot from SpaceX/NASA of CRS-28 on Pad 39A. FYI - Falcon 9 stacks in this order. Capiche
Mission Rundown: SpaceX Falcon 9 - CRS-28
Written: June 4, 2023 – Edit: July 1 and November 3, 2023
Hauling gifts with Dragon
Dragon CRS-2 SpX-28 (CRS-28) is a Commercial Resupply Service mission that flew to the International Space Station (ISS). SpaceX was awarded this mission by NASA in 2016 and launched CRS-28 on a Falcon 9 using booster B1077-5 and Cargo Dragon, C208-4.
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 one of the three launch systems with a cargo return capability.
NGA on CRS-28 flight path from Pad 39A. Blue dot is ASOG waiting some 667 km downrange
The Falcon 9 rocket lifted off on June 5, 2023 at 11:47:02 EDT - 15:47:02 UTC from historic Launch Complex 39A, at the Kennedy Space Center in Florida.
CRS-28 was the 8th flight for SpaceX under NASA’s CRS Phase 2 contract and SpaceX’s 38th regular launch in 2023 compared to a total of 61 launches in 2022. On board are ~3,304 kg (~7,284 lb) of food, hardware, IROSA and scientific research.
Dragon C208-4 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 and docked at ISS some ~18 hours later, on June 6, at 05:54 EDT - 09:54 UTC.
Dragon autonomously docked to the ISS’ Harmony module’s Space-facing zenit port. Upon Dragon’s arrival, the crew will proceed with unloading the cargo.
After boosting the second stage along with Cargo Dragon 2, C208-4 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 – ASOG.
B1077-5 will launch CRS-28 to the International Space Station on this voyage:
B1077-5 didn’t perform a static fire test prior to its June 5 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 C208-4 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 C208-4 was opened granting the crew access to the cargo inside.
Dragon C208-4 will spend 21 days at the ISS. Its mission will end in late June. 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 28th 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 21 times; 10 crewed and 11 uncrewed.
Dragon C208-4 can double as an extra space science laboratory where 4 experiments will share power, downlink data streams and data storage from Dragon C208-4 internal supply. One experiment could be moved from its current home on ISS to its new location on Dragon C208-4, 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 C208-4 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.
Two more rollable solar arrays will be launched to the International Space Station on CRS-28. These solar arrays will provide over 20 kW of power each, which will result in a 30% increase in power production for the ISS. The pair of arrays will be installed by crew members of Expedition 69 over the course of multiple planned EVAs.
Each array has been built from a composite carbon fiber which allows it to be rigid when deployed, but curl-up like a tape measure when stowed. The rolling and lightweight components of the ROSAs enable them to be launched with more equipment than heavier, non-rolling solar arrays.
These two solar arrays follow four other solar arrays that were previously launched on CRS-22 and CRS-26. All four previously launched solar arrays have already been installed and been in service ever since.
CRS-28 will carry a total of six CubeSats. Five of them are Nanorack sponsored CubeSats from Canadian Universities, while the 6th and final CubeSat will be a US satellite called Moonlighter by The Aerospace Corporation. Moonlighter will be the world’s first and only hacking sandbox in space and can be described as a cyber security test bed to identify methods for preventing the hacking of satellite systems in space.
Moonlighter: a 3U hacking sandbox built by The Aerospace Corporation, USA
Ukpik-1: a Teaching tool for students built by Western University, Ontario, Canada
SC-ODIN: a 3U Orbital Dust Imaging Nanosat built by Concordia University, Quebec
Iris: a space weathering study of asteroids built by University of Manitoba, Canada
RADSAT-SK: a Radiation dosimeter sensor built by University of Saskatchewan
ESSENCE: a wide-angle camera for observing snow built by York University, Ontario
Flight Tech Demo of Docking/Undocking Cubesats Inside ISS, also known as CLINGERS is a technology demonstrator for rendezvous and docking procedures, also known as Rendezvous Proximity Operations (RPO – an abbreviation we can understand).
According to NASA, there is no consensus between satellite operators on a standard method of making docking connections. This demonstrator aims to test a low-mass and low-cost interface system for CubeSats. CLINGERS will investigate the flight dynamics of both nominal and off-nominal modes of contact using a full 6 degrees of freedom model (3 translation axes, 3 rotation axes).
In principle, any platform that has a CLINGERS device attached could use its own sensor data to achieve autonomous docking with any other CLINGERS device – even if the second device cannot navigate on its own.
Pristine Onuoha, a student at East Chapel Hill High School in Chapel Hill, NC, has won the national competition that determined what experiment will be sent to the ISS on this Genes in Space mission. Genes in Space-10 will aim to gather more data and better our understanding on the mechanism of telomere lengthening.
Telomeres are molecular structures at the end of our chromosomes that get shorter and shorter over time and as humans age. Genes in Space-10 will specifically test a mechanism of measuring the length of aforementioned telomeres. Research has shown that telomeres might lengthen in microgravity.
The experiment aims to explore the cause for this telomere lengthening and if it might be caused by proliferating stem cells. This could improve our understanding of aging and the effects of long-term space travel/missions on the human body.
Researchers are asking themselves if epigenetic changes in plants grown in microgravity can pass on those changes in the plant’s genetic code. Epigenetic changes are usually caused by environmental stresses including space flight. Those DNA changes are often added to DNA sequences rather than changes in already existing DNA.
Researchers Anna-Lisa Paul and Robert Ferl from the University of Florida are exploring if aforementioned epigenetic changes are being continued or if they stabilize in future generations of plants.
Seeds from Arabidopsis thaliana plants, thale cress, that were previously grown in the ISS’ Plant Habitat have been recovered from space and have been analyzed back on Earth.
They are being sent back up on the CRS-28 mission to be re-grown in the same Plant Habitat as their parent plants to see how epigenetic changes change in plants grown in microgravity. The experiment’s results could improve our understanding of how to grow multiple generations of plants to provide food during long duration space 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 C208-4 - Recovery Location LZ 1-7 available - LZ 7 is chosen
The opportunity for CRS-28 to return to Earth has been determined; it departed from ISS from airlock IDA-3, now known as the space facing ‘zenit’ airlock.
The CRS-28 Cargo Dragon spacecraft undocked from the International Space Station at 12:30 EDT - 16:30 UTC on June 29, 2023 to begin its journey home.
NASA’s SpaceX CRS-28 mission is targeting a splash down on Earth no earlier than 10:30 EDT - 14:30 UTC on June 30, 2023 near Jacksonville, 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.
Recovery ship Shannon will be heading to LZ-7 near Jacksonville to retrieve a wet toasty Dragon
CRS-28 will after the trunk is jettisoned have performed its deorbit burn at 09:55 EDT - 13:55 UTC and have closed the nose hatch cover. Then CRS-28 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-28 spacecraft.
Teams on the recovery ship Shannon, including two fast boats, will be securing CRS-28 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-28 mission, jettisoned on June 30, was in a 252 x 394 km x 51.3 deg orbit. It’s very, very slowly deorbiting by itself.
It deorbited 35 days later at 03:56 UTC August 4 after passing over Argentina into the South Atlantic Ocean. Source
The low apogee of 252 km in this orbit is a contributing factor in deorbiting the Dragon trunk section 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 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-28 will mark the 18th 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, Axiom 2, CRS-27 and now CRS-28. Inspiration4 was a free flying spacecraft doing its own private mission in space.
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 carries 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 the drone ship “A Shortfall Of Gravitas'' in the Atlantic Ocean for landing and recovery.
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