Minimize ISS Utilization: SpaceX CRS-16

ISS Utilization: SpaceX CRS-16

SpaceX CRS-16 (SpX-16), is a Commercial Resupply Service mission to the International Space Station launched on 5 December 2018 aboard a Falcon 9 rocket. The mission was contracted by NASA and is flown by SpaceX. 1) 2)

ISSCRS16_Auto2

Figure 1: A SpaceX Dragon spacecraft launched to the ISS at 1:16 p.m. EST (18:16 GMT) Dec. 5, 2018, on a Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. The spacecraft, on its 16th mission for NASA under the agency's Commercial Resupply Services contract, carries more than 2540 kg of research equipment, cargo and supplies (image credit: NASA TV)

Experiments in forest observation, protein crystal growth and in-space fuel transfer demonstration are heading to the International Space Station following the launch Wednesday of SpaceX's 16th mission for NASA under the agency's Commercial Resupply Services contract.

The SpaceX Dragon spacecraft will bring approximately 300 kg of research and hardware facilities to the orbiting laboratory under the ISS U.S. National Laboratory flight allocation. There are more than 20 payloads included on this mission sponsored by the ISS National Lab. This mission represents the largest number of payloads ever delivered to the ISS National Lab during a single launch to the orbiting research platform. The payloads that are part of the ISS National Lab flight manifest represent a diverse group of research investigations intended to benefit life on Earth. 3)

In addition to bringing research to station, the Dragon's unpressurized trunk is carrying the RRM3 and the GEDI payloads.

RRM3 (Robotic Refueling Mission 3): NASA will lay the foundation for spacecraft life extension and long duration space exploration with the upcoming launch of Robotic Refueling Mission 3 (RRM3), a mission that will pioneer techniques for storing and replenishing cryogenic spacecraft fuel. The third phase of an ongoing technology demonstration, RRM3 will attach to the International Space Station and build on two previous missions — RRM and RRM2. These first two phases practiced the robotic tasks of removing caps and valves on spacecraft, leading up to the act of replenishing fuel, but stopped short of cryogenic fluid transfer. 4)

Cryogenic fluid can serve as a very potent fuel. As a propellant, it produces a high thrust or acceleration, allowing rockets to escape the gravitational force of planetary bodies. As a coolant, it keeps spacecraft operational and can prolong their lifespan by years.

Besides these uses, the ability to resupply cryogenic fuel in space could minimize the amount of fuel spacecraft are required to carry from Earth's surface, making it possible to travel farther into space for longer periods of time.

Liquid oxygen is another type of cryogenic fluid, used for astronaut life support systems. Having the ability to efficiently store and replenish this type of oxygen could facilitate astronauts' capacity to embark on long duration human exploration missions and live on other planets.

"Any time we get to extend our stay in space is valuable for discovery," said Beth Adams Fogle, RRM3 mission manager in NASA's Technology Demonstration Missions program office at Marshall Spaceflight Center in Huntsville, Alabama. "RRM3's ability to transfer and store cryogenic fluid could alter our current fuel constraints for human exploration."

NASA engineers built on lessons learned from RRM and RRM2 to design next-generation hardware. During RRM3 mission operations, the space station's Dextre robotic arm will carry out tasks using a suite of three primary tools.

The task sequence begins with the multi-function tool 2, which operates smaller specialized tools to prepare for the fluid transfer. Next, the cryogen servicing tool uses a hose to connect the tank filled with liquid methane to the empty tank. To monitor the process, the Visual Inspection Poseable Invertebrate Robot 2 (VIPIR2) utilizes a state-of-the-art robotic camera to make sure tools are properly positioned.

RRM3 is developed and operated by the Satellite Servicing Projects Division at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and managed by the Technology Demonstration Missions program within NASA's Space Technology Mission Directorate. On the ISS, RRM3 will be positioned at the ELC1 (ExPRESS Logistics Carrier 1). It has a projected two-year life on station, though NASA intends to accomplish RRM3's objectives within the first year. 5)

RRM3 primary objectives:

1) Perform cryogenic liquid methane transfer in micro-gravity

2) Maintain cryogen fluid mass for six months via zero boil-off

RRM3 secondary objectives:

1) Demonstrate and validate the Compact Thermal Imager - An instrument that utilizes available room on RRM3 to observe Earth to detect smoke and fires, as well as measure crop transevaporation.

2) Complete Machine Vision Tasks - In-space assessment of fiducials (decals) with unique patterns that enhance machine vision algorithms and aid in autonomous rendezvous and tool positioning.

ISSCRS16_Auto1

Figure 2: Photo of the RRM3 module (image credit: NASA)

Contained within the RRM3 module is a source tank, filled with liquid methane, and an empty receiver tank, along with various transfer lines. During RRM3 mission operations, the space station's Dextre robotic arm will carry out tasks to transfer liquid methane from the source tank to the receiver tank using a suite of three primary tools. The task sequence begins with the multi-function tool 2, which operates smaller specialized tools to prepare for the fluid transfer. Next, the cryogen servicing tool uses a hose to connect the tank filled with liquid methane to the empty tank. To monitor the process, the Visual Inspection Poseable Invertebrate Robot 2 (VIPIR2) utilizes a state-of-the-art robotic camera to make sure tools are properly positioned.

Storing cryogens in space can be difficult because their extremely low boiling points cause them to boil off over time. The boil off can lead to the formation of one or more large bubbles that increase the pressure in the tank. The bubbles don't rise to the top like they do on Earth, because of microgravity; if a large bubble settles at the opening to the transfer line, it could interrupt the flow of liquid.

Therefore, a critical part of RRM3 will be storing 42 liters of liquid methane for six months with zero boil off, demonstrating methods to more efficiently use cryogens. By using cryocoolers and advanced multilayer insulation to balance temperatures, fluid loss will be dramatically lowered, eliminating the need for oversized tanks and extra propellant.

GEDI (Global Ecosystem Dynamics Investigation lidar): The GEDI instrument is described in a separate file called "ISS: GEDI" on the eoPortal.

In addition to GEDI and RRM3, the following CubeSats will be flown:

• UNITE (Undergraduate Nano Ionospheric Temperature Explorer), a 3U CubeSat (4 kg) of the University of Southern Indiana. The objective is to measure plasma in the lower ionosphere, a relatively unexplored region of space.

• TechEdSat-8 (Technical and Educational Satellite 8), a 6U CubeSat developed jointly by SJSU (San Jose State University) and the University of Idaho with oversight from the NASA Ames Research Center.

• CATSat-1 (Cooperative Astrophysics & Technology Satellite-1) of JHU/APL (Johns Hopkins University /Applied Physics Laboratory). Use of two CubeSats to support a government-furnished equipment communications experiment.

• Delphini-1, a 1U CubeSat demonstration mission of Aarhus University, Denmark.

A small satellite deployment mechanism, called SlingShot, will ride up in Dragon and then be installed in a Northrop Grumman Cygnus spacecraft prior to its departure from the space station. SlingShot can accommodate as many as 18 CubeSats of any format. After the Cygnus cargo ship departs from station, the spacecraft navigates to an altitude of ~500 km to deploy the satellites.

The SpaceX CRS-16 will arrive at the station on 8 December. Expedition 57 Commander Alexander Gerst of ESA and Flight Engineer Serena Aunon-Chancellor of NASA will use the space station's robotic arm to capture Dragon when it arrives. NASA astronaut Anne McClain will monitor telemetry during the spacecraft's approach.

Dragon is scheduled to depart the station in January 2019 and return to Earth with more than 1800 kg of research, hardware and crew supplies. About five hours after Dragon leaves the space station, it will conduct its deorbit burn, which lasts up to 10 minutes. It takes about 30 minutes for Dragon to reenter the Earth's atmosphere and splash down in the Pacific Ocean off the coast of Baja California.

 

Dragon at the ISS

• Three days after its launch from Florida, the SpaceX Dragon cargo spacecraft was installed on the Earth-facing side of the International Space Station's Harmony module at 10:36 a.m. EST on 8 December. 6)

- While the International Space Station was traveling about 400 km over the Pacific Ocean north of Papua New Guinea, Expedition 57 Commander Alexander Gerst of ESA (European Space Agency) and Flight Engineer Serena Auñón-Chancellor, captured the Dragon spacecraft at 7:21 a.m. EST using the space station's Canadarm2 robotic arm.

- Ground controllers will now send commands to begin the robotic installation of the spacecraft on bottom of the station's Harmony module.

Among the research it will bring to station, science investigations and technology demonstrations aboard Dragon include:

- GEDI (Global Ecosystem Dynamics Investigation). The instrument will be mounted on the Japanese Experiment Module's Exposed Facility and provide the first high-resolution observations of forest vertical structure at a global scale.

- RRM3 (Robotic Refueling Mission-3) will demonstrate the first transfer and long-term storage of liquid methane, a cryogenic fluid, in microgravity. The ability to replenish and store cryogenic fluids, which can function as a fuel or coolant, will help enable long duration journeys to destinations, such as the Moon and Mars.

ISSCRS16_Auto0

Figure 3: On 8 December 2018, six spaceships are attached at the space station including the U.S. resupply ships Northrop Grumman Cygnus and the SpaceX Dragon-16; as well as Russia's Progress 70 and 71 resupply ships and the Soyuz MS-09 and MS-10 crew ships all from Roscosmos (image credit: NASA)


1) "NASA Sends New Research, Hardware to Space Station on SpaceX Mission," NASA Press Release 18-111, 5 December 2018, URL: https://www.nasa.gov/press-release/nasa-sends-new-research-hardware-to-space-station-on-spacex-mission

2) "SpaceX Launches Again, Transporting Supplies and Experiments Including Crystals and Dental Glue to the ISS," Satnews Daily, 6 December 2018, URL: http://www.satnews.com/story.php?number=1005465878

3) "More than 20 U.S. National Laboratory Payloads Part of SpaceX's 16th Mission to Space Station," ISS CASIS, 27 November 2018, URL: https://www.iss-casis.org/press-releases/more-than-20-u-s-national-laboratory-payloads-part-of-spacexs-16th-mission-to-space-station/

4) "NASA to Launch New Refueling Mission, Helping Spacecraft Live Longer and Journey Farther," NASA, 20 November 2018, URL: https://www.nasa.gov/feature/goddard/2018/nasa-to-launch-new-refueling-mission-helping-spacecraft-live-longer-and-journey-farther

5) "Robotic Refueling Mission RMM3," NASA, URL: https://sspd.gsfc.nasa.gov/RRM3.html

6) Mark Garcia, "Dragon attached to Station, returns to Earth in January," 8 December 2018, NASA space Station, URL: https://blogs.nasa.gov/spacestation/
 


The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (herb.kramer@gmx.net).