SpaceX is about to launch the Crew Resupply Mission 28 (CRS-28) mission to the International Space Station (ISS) on June 4 at 12:12 PM EDT (16:12 UTC) from Launch Complex 39A (LC-39A) on the Kennedy Space Center in Florida. The window for this launch is instantaneous, with the forty fifth Space Wing currently predicting a 40% probability of acceptable weather conditions at liftoff, with the major concerns being thick clouds and precipitation.
CRS-28 will resupply the ISS with equipment and supplies needed by Station astronauts and hardware for the approaching months, in addition to science experiments developed by different agencies, firms, and organizations from around the globe. Moreover, tucked away in Dragon’s trunk are two latest iROSA solar panels for the Station.
CRS-28’s Experiments
As mentioned, along with CRS-28’s delivery of food and other hardware, a wide selection of scientific payloads and science experiments might be launched to the Station on this mission.
Thor, a European Space Agency science project, will observe thunderstorms in Earth’s atmosphere from ~250 kilometers above the surface. Thor’s goal is to measure the frequency and altitude of blue discharges produced by internal phenomena and structures inside thunderstorms.
CRS-28 can also be carrying the Genes in Space-10 experiment, which is a student-designed DNA experiment that the ISS National Laboratory supports. The Genes in Space experiments allow students in grades seven through 12 to design DNA experiments that may withstand the challenges of space exploration and answer questions like “Can we detect latest life forms?” and “Can living organisms help us colonize latest worlds?” These experiments are then launched to the ISS where they’re tested.
The primary Genes in Space experiment, launched in 2016, researched the impact of microgravity on the human body, specifically the immune system, which has been found to be weakened by microgravity. For Genes in Space-10, the goal is to research a technique that will be used to measure the length of DNA segments in space, which was proposed by 2022 winner Pristine Onuoha. Common Earth-based methods for measuring DNA segment lengths are already complex, and adding zero-gravity to the methods will only increase their complexity.
The NASA Plant Habitat — an experiment used to research plant growth in microgravity environments — will get some latest seeds when CRS-28 arrives on the Station. The habitat goals to confirm the variation of assorted plants to the environment of space and studies the particular ways plants learn to thrive in an environment with no gravity. Moreover, the experiment goals to find out if humans can pre-adapt plants for prolonged spaceflights.
Arabadopsis thaliana plants growing in PH-03. (Credit: NASA)
One other payload that may launch onboard CRS-28 is the Moonlighter 3U cubesat, which was built by The Aerospace Corporation. Moonlighter might be the primary hacking testbed in space, serving as a sandbox that may allow cyber security experts to perform tests and try and hack the cubesat’s software in space. The aim of the cubesat is to research tactics for stopping satellite software and hardware hacking, with in-space assets like satellites becoming increasingly essential to global infrastructures.
Along with Moonlighter, the Canadian Space Agency will deploy five cubesats designed by students from the ISS. One cubesat from York University, named Essence, will observe arctic ice for climatic research purposes by utilizing a camera with a fisheye lens. Essence can even carry a solar energetic proton detector to gather additional data from solar ejection events, that are transient periods of solar activity wherein the Sun emits radioactive protons into space. These solar ejection events can damage spacecraft, and understanding the ways by which these radioactive protons damage spacecraft will help future satellite designs to be more immune to solar ejections.
Lastly, NanoRacks’ IRIS will observe the weathering of geological samples under cosmic radiation and direct solar radiation exposure. This might help geologists further understand the strength of Earth’s surface and the forces that satellites endure when flying in space.
The Moonlighter 3U CubeSat. (Credit: The Aerospace Corporation)
iROSA Solar Arrays
The Station will get two latest ISS Roll Out Solar Arrays (iROSA) on CRS-28, that are expected to assist improve the Station’s overall power availability. The solar arrays are significantly smaller and lighter than the arrays first installed on the ISS during its initial construction, with iROSAs having the flexibility to be rolled up during launch. Following Cargo Dragon’s docking to the ISS, certainly one of the Station’s robotic arms will remove the arrays, which can then be installed during a spacewalk. Once installed, the arrays will roll out of their spool and fully deploy.
CRS-28 is an element of three missions to launch and deploy iROSAs on the ISS. Each of the launches requires two spacewalks to put in the arrays, with the primary set of arrays being launched in November 2022 and installed the next month. One spacewalk prepares the world for the installation, and the second spacewalk installs the iROSA to the Station. Each latest array produces greater than 20 kilowatts of electricity, bringing the performance of all six latest iROSA panels, when installed on the ISS, to 120 kilowatts.
Two iROSA panels. (Credit: Deployable Space Systems)
Falcon 9’s Countdown and Launch
Days before the launch of CRS-28, Falcon 9 rolled out to LC-39A horizontally and rotated to the vertical position once on the launch mount. The major a part of the countdown will start on the T-35 minute mark when fueling of Falcon 9 will begin. During fueling, Falcon 9 might be loaded with RP-1 kerosene and liquid oxygen (LOX).
Later within the countdown, at T-20 minutes, RP-1 loading on Falcon 9’s second stage might be complete and is signified by the enduring T-20 minute vent, which is attributable to the purging of Falcon 9’s fuel lines in preparation for LOX loading on the second stage. At T-1 minute, Falcon 9 will enter startup, which is when Falcon 9’s onboard computer takes over the countdown and manages the ultimate seconds of the countdown ahead of liftoff.
At T0, Falcon 9 will liftoff under the facility of the nine Merlin 1D engines on the primary stage. Following maximum aerodynamic pressure, or the period of ascent where aerodynamic loads are best on the vehicle, the primary stage engines will shut down, and the primary and second stages will separate. The Merlin vacuum-optimized engine on the second stage will proceed to loft Cargo Dragon into orbit.
CRS-28 will feature the updated shorter nozzle on the Merlin vacuum-optimized engine on the second stage, which helps reduce manufacturing time, thus improving launch cadence. Moreover, the shorter nozzle signifies that less metal must be used during manufacturing, which, in turn, reduces construction costs and increases the variety of Falcon second stages that will be created. This shorter nozzle has barely lower performance than its larger counterpart, which is compensated by this mission not needing increased performance from Falcon 9.
Correction! That is for CRS-28! https://t.co/DuGAv3PrJf
— Gav Cornwell (@SpaceOffshore) May 31, 2023
Following stage separation, B1077 will land on SpaceX’s autonomous spaceport droneship , which is stationed within the Atlantic Ocean. Following landing, the booster will officially change from B1077-5 to B1077-6 and start to organize for its next flight in a number of months. B1077 has supported Crew-5, a GPS mission, the Inmarsat mission, and one Starlink flight.
When CRS-28 arrives on the Station, the Soyuz MS-23 crew and the Crew-6 crew will conduct the aforementioned science experiments. The MS-23 crew consists of Oleg Kononenko, Nikolai Chub, and Loral O´Hara. The Crew-6 crew consists of Stephen Bowen, Warren Hoburg, Sultan Al Neyadi, and Andrey Fedyaev
