SpaceX F9 / Dragon 2 : CRS2 SpX-21 - Mission Updates : Dec - Jan (2020/21)

[Nomadd]

 It seems more likely that the loaded Dragon weighs that much because they're going with the ASDS, not the other way around.

[gemmy0I]

Mass. Dragon 2 is a heavy capsule

Around 12.5 tons.

12.5 tonnes is for Crew Dragon, which includes quite a bit of unburned launch abort propellant. Do we know roughly how much a Cargo Dragon 2 clocks in at? I'm sure it has more cargo mass onboard (both pressurized and unpressurized) than what the crew + consumables + additional ECLSS hardware on the crew version weigh, but my hunch is the removal of the abort propellant more than makes up for that.

The Iridium launches were just under 11 tonnes (to polar LEO, which is slightly more challenging) and were on the borderline of RTLS vs. ASDS, so at 12.5 tonnes, Crew Dragon seems pretty close. It seems strange for Cargo Dragon 2 to be over the line despite shedding the abort propellant, which (IIRC) adds up to several tonnes.

I could be misremembering, but I think I heard somewhere that the thing about Crew Dragon requiring a more flattened trajectory is actually a myth (or at least, ended up being untrue in the end - it may have been a consideration earlier in the design process). IIRC people examined the trajectory after Demo-1 and Demo-2 and concluded that it wasn't that different from a Dragon 1 launch. I know Starliner definitely requires a more flattened trajectory than usual (hence the need for a two-engine Centaur, plus two SRBs), and that may have caused some confusion to spread regarding Dragon. Perhaps others with sourceable knowledge can confirm one way or the other.

[ZachS09]

Mass. Dragon 2 is a heavy capsule

Around 12.5 tons.

12.5 tonnes is for Crew Dragon, which includes quite a bit of unburned launch abort propellant. Do we know roughly how much a Cargo Dragon 2 clocks in at? I'm sure it has more cargo mass onboard (both pressurized and unpressurized) than what the crew + consumables + additional ECLSS hardware on the crew version weigh, but my hunch is the removal of the abort propellant more than makes up for that.

The Iridium launches were just under 11 tonnes (to polar LEO, which is slightly more challenging) and were on the borderline of RTLS vs. ASDS, so at 12.5 tonnes, Crew Dragon seems pretty close. It seems strange for Cargo Dragon 2 to be over the line despite shedding the abort propellant, which (IIRC) adds up to several tonnes.

I could be misremembering, but I think I heard somewhere that the thing about Crew Dragon requiring a more flattened trajectory is actually a myth (or at least, ended up being untrue in the end - it may have been a consideration earlier in the design process). IIRC people examined the trajectory after Demo-1 and Demo-2 and concluded that it wasn't that different from a Dragon 1 launch. I know Starliner definitely requires a more flattened trajectory than usual (hence the need for a two-engine Centaur, plus two SRBs), and that may have caused some confusion to spread regarding Dragon. Perhaps others with sourceable knowledge can confirm one way or the other.

The Iridium-NEXT missions weighed in at 9.6 tons.

[jacqmans]

The Nanoracks Bishop Airlock is packed in the Dragon spacecraft’s trunk on Oct. 12, 2020, inside SpaceX’s processing facility at NASA’s Kennedy Space Center in Florida for its ride to the International Space Station aboard the company’s 21st Commercial Resupply Services (CRS-21) mission. The first commercially funded airlock for the orbiting laboratory, it will provide payload hosting, robotics testing, satellite deployment, serve as an outside toolbox for station crew spacewalks, and more. CRS-21 is scheduled to launch on a SpaceX Falcon 9 from Kennedy’s Launch Complex 39A.

[Zed_Noir]

<snip>
The Iridium-NEXT missions weighed in at 9.6 tons.

Does that included the payload adapter hardware or just the satellites?

[ZachS09]

<snip>
The Iridium-NEXT missions weighed in at 9.6 tons.

Does that included the payload adapter hardware or just the satellites?

Includes the payload adapter, which weighed 1 ton.

[gongora]

NASA and SpaceX Target Dec. 2 for Next Resupply Launch

While SpaceX continues preparations for the launch of NASA’s SpaceX Crew-1 mission to the International Space Station as part of the Commercial Crew Program, the company also is getting ready for the agency’s next cargo resupply mission to the orbiting laboratory.

SpaceX’s 21st resupply mission for NASA, its first under the second-generation Commercial Resupply Services (CRS-2) contract, will be the first resupply mission to use the upgraded version of the Dragon spacecraft. The flight will bring science and supplies to the newly expanded Expedition 64 crew beginning with liftoff on the SpaceX Falcon 9 rocket from Launch Complex 39A at NASA’s Kennedy Space Center in Florida.

NASA and SpaceX currently are targeting no earlier than 12:50 p.m. ET on Wednesday, Dec. 2, for the CRS-21 launch, pending Eastern Range acceptance and successful preparations and an on-time liftoff of Crew-1, also from Launch Complex 39A.

The science to be delivered on this mission includes a study aimed at better understanding heart disease to support development of treatments for patients on Earth, research into how microbes can be used for biomining on asteroids, and a tool being tested for quick and accurate blood analysis in microgravity. The first commercially owned and operated airlock on the space station, the Nanoracks Bishop Airlock, will arrive in the unpressurized trunk of the Dragon spacecraft. Bishop will provide a variety of capabilities to the orbiting laboratory, including CubeSat deployment and support of external payloads.

[cferreir]

I am curious about the IDA dance that will happen since there are only 2 currently. It seems like it will be

1. Crew-1 arrives Nov 2020
2. CRS2 Spx-21 arrives Dec 2020
3. CRS2 Spx-21 leaves ??
4. Crew-2 arrives March 2020
5. Crew-1 leaves April 2020

There seems to be no IDA available for Starliner until May 2020 at least.

Am I correct?

Carlos

[gongora]

SpX-21 will only be there a month.  Almost the entire first quarter would be available for OFT-2.

[cohberg]

1. Crew-1 arrives Nov 2020
2. CRS2 Spx-21 arrives Dec 2020
3. CRS2 Spx-21 leaves ??
4. Crew-2 arrives March 2020
5. Crew-1 leaves April 2020

There will also be the port relocation between 3-4. Resilience is going to move from Node 2 Fwd (IDA 2) to Node 2 Zenith (IDA 3). Starliner needs to dock at Node 2 Fwd (likely due to the software not being ready for the zenith port like DM2) + iss flight planning documents have the vehicles doing that normally as CRS missions always need to go to the Zenith port due to unpressurized cargo.

[Josh_from_Canada]

1. Crew-1 arrives Nov 2020
2. CRS2 Spx-21 arrives Dec 2020
3. CRS2 Spx-21 leaves ??
4. Crew-2 arrives March 2020
5. Crew-1 leaves April 2020

There will also be the port relocation between 3-4. Resilience is going to move from Node 2 Fwd (IDA 2) to Node 2 Zenith (IDA 3). Starliner needs to dock at Node 2 Fwd (likely due to the software not being ready for the zenith port like DM2) + iss flight planning documents have the vehicles doing that normally as CRS missions always need to go to the Zenith port.

This is due to the limitations of the Canada Arm as it would not be able to take cargo out of the trunk if Cargo Dragon is docked to PMA-2 thus PMA-3 will see only it's third docking, the first since STS-98 in February 2001. I'm not sure if Crew-1 will relocate from PMA-2 to PMA-3 following the Starliner test flight in anticipation for Crew-2. If Crew-2 ends up docking to PMA-3 then it would have to relocate to PMA-2 not that long into the mission for the CRS-22 mission in May.

[cferreir]

1. Crew-1 arrives Nov 2020
2. CRS2 Spx-21 arrives Dec 2020
3. CRS2 Spx-21 leaves ??
4. Crew-2 arrives March 2020
5. Crew-1 leaves April 2020

There will also be the port relocation between 3-4. Resilience is going to move from Node 2 Fwd (IDA 2) to Node 2 Zenith (IDA 3). Starliner needs to dock at Node 2 Fwd (likely due to the software not being ready for the zenith port like DM2) + iss flight planning documents have the vehicles doing that normally as CRS missions always need to go to the Zenith port due to unpressurized cargo.

Do all 4 astronauts have to be on board for the relocation? I am thinking that in an emergency they might have to abort to earth and they can't leave anyone stranded on the ISS.

[Jansen]

Yes, all four will have to be aboard in case of docking issues and they have to do an emergency return to earth.

[gemmy0I]

Yes, all four will have to be aboard in case of docking issues and they have to do an emergency return to earth.

I wonder if this means they need to plan the schedule for docking port relocations based on landing zone weather suitability and have recovery craft in place at the notional splashdown site, as they would for a nominal return?

I would imagine that, in the event of problems with re-docking, they'd want to keep the crew and Dragon in free flight for a while (potentially several days, consumables permitting) pending hopes of a resolution of the docking issue so they can return to the station. That would give time for SpaceX and NASA to select a splashdown site and reentry window during that time and scramble recovery vessels in case they can't resolve the docking issues and actually have to return home (a scenario that they'd surely prefer to avoid if at all possible, seeing how it would abruptly cut short a long-duration ISS expedition and, especially with the Russians not doing seat exchanges right now, potentially leave the station without any USOS crew members). But that's just my speculation...I'd be curious if anyone knows what their actual procedures are for this.

[jacqmans]

November 17, 2020
MEDIA ADVISORY M20-128

NASA Highlights Science, New Airlock on Next Space Station Resupply Mission


NASA will host a media teleconference at 1 p.m. EST Friday, Nov. 20, to discuss science investigations and a new privately funded airlock launching on SpaceX’s 21st commercial cargo resupply mission for the agency to the International Space Station. It is SpaceX’s first launch on its second Commercial Resupply Services contract with NASA and the company will use the upgraded version of the cargo Dragon spacecraft.

Audio of the teleconference will stream live online at:

http://www.nasa.gov/live

SpaceX is targeting 12:50 p.m. Wednesday, Dec. 2, for the launch of the Dragon on a Falcon 9 rocket from Launch Complex 39A at NASA’s Kennedy Space Center in Florida.

To participate in the teleconference, media must contact Stephanie Schierholz at 202-358-4997 or [email protected] by 11 a.m. Friday, Nov. 20, for dial-in information.

David Brady, associate program scientist for the International Space Station Program at NASA’s Johnson Space Center in Houston, will provide an introduction to the research and technology aboard the Dragon spacecraft.

Also participating in the briefing are:

Charles Cockell, professor of astrobiology at the University of Edinburgh and principal investigator for the BioAsteroid experiment, and Rosa Santomartino, postdoctoral research associate. BioAsteroid aims to better understand how microbes interact with and change asteroids, information that could be used for future mining on asteroids.

Joseph Wu, professor and director of the Stanford Cardiovascular Institute and principal investigator, and Dilip Thomas, postdoctoral research fellow for Cardinal Heart, which studies the effects of microgravity on heart tissue using tissue chips, in an effort to develop therapies on Earth and countermeasures for future space exploration.

Benjamin Easter, deputy element scientist for exploration medical capability in the NASA Human Research Program, who will discuss HemoCue, a commercial off-the-shelf device that will be tested as a tool to provide autonomous blood analysis as an important step toward meeting the heath care needs of crew members on future missions, including for NASA’s Artemis program to the Moon.

Brock Howe, program manager for the Nanoracks Bishop Airlock, the first privately funded module to be delivered to the space station. The Bishop Airlock will support science experiments, satellite deployment, and spacewalks.
Dusan Sekulic, professor of mechanical engineering at the University of Kentucky and principal investigator, and Sinisa Mesarovic, professor of mechanical and materials engineering at Washington State University, for SUBSA-BRAINS. This experiment looks at how liquid metals behave in microgravity as a first step toward developing techniques that could be used for construction of human space habitats, as well as to repair damage from micrometeoroids or space debris.

Pinar Mesci, project scientist for Space Tango-Human Brain Organoids, an experiment that studies how microgravity affects small, living masses of cells as a way to understand the effects of spaceflight on the brain. This investigation could pave the way for additional exploration of changes to neurons during spaceflight, including studies of pharmacology, disease, aging, and more.
Cargo resupply from U.S. companies ensures a national capability to deliver critical science research to the space station, significantly increasing NASA's ability to conduct new investigations at the only laboratory in space. The upgraded Dragon spacecraft has double the capacity for powered lockers that preserve science and research samples during transport to or from Earth.

The cargo Dragon will be the second SpaceX spacecraft parked at the orbiting laboratory, following the arrival Nov. 16 of the Crew Dragon that carried four new Expedition 64 astronauts, who will support these and other investigations as part of their six-month science mission.

The space station is a convergence of science, technology, and human innovation that demonstrates new technologies and enables research not possible on Earth. NASA recently celebrated 20 years of continuous human presence aboard the orbiting laboratory, which has hosted 242 people and a variety of international and commercial spacecraft. The space station remains the springboard to NASA's next great leap in exploration, including future human missions to the Moon and eventually to Mars.

For launch countdown coverage, NASA's launch blog, and more information about the mission, visit:

https://www.nasa.gov/spacex

[FutureSpaceTourist]

[Danderman]

Question for the experts: does the Bishop Airlock take up the entire trunk, or is it smaller than the trunk space?

I figure that Bishop’s length is determined by the available space at the end of Node 3, not the trunk size of Dragon. It would be a minor miracle if the space at the end of Node 3 were the same length as the Dragon trunk.

[vaporcobra]

Question for the experts: does the Bishop Airlock take up the entire trunk, or is it smaller than the trunk space?

I figure that Bishop’s length is determined by the available space at the end of Node 3, not the trunk size of Dragon. It would be a minor miracle if the space at the end of Node 3 were the same length as the Dragon trunk.

A dozen or so posts up:

Next-Generation Airlock Prepped for SpaceX CRS-21 Launch

The first commercially funded airlock for the International Space Station is ready for its journey to space. On Saturday, Oct. 10, teams moved the Nanoracks Bishop Airlock to SpaceX’s processing facility at NASA’s Kennedy Space Center in Florida. Two days later, it was packed in the Dragon spacecraft’s trunk for its ride to the orbiting laboratory.

The airlock will provide payload hosting, robotics testing, and satellite deployment, and also will serve as an outside toolbox for crew members conducting spacewalks.

The Bishop Airlock is launching on SpaceX’s 21st commercial resupply services (CRS-21) mission to the space station. This will be the first flight of SpaceX’s upgraded cargo version of Dragon, which can carry more science payloads to and from the space station.

The pressurized capsule will carry a variety of research including studies on the effects of microgravity on cardiovascular cells, how space conditions affect the interaction between microbes and minerals, and a technology demonstration of a blood analysis tool in space. CRS-21 is scheduled to launch aboard a Falcon 9 rocket from Kennedy’s Launch Complex 39A. Teams are targeting late November or early December for liftoff.

Author James Cawley   Posted on October 16, 2020

https://blogs.nasa.gov/kennedy/2020/10/16/next-generation-airlock-prepped-for-spacex-crs-21-launch/

[Jansen]

Question for the experts: does the Bishop Airlock take up the entire trunk, or is it smaller than the trunk space?

I figure that Bishop’s length is determined by the available space at the end of Node 3, not the trunk size of Dragon. It would be a minor miracle if the space at the end of Node 3 were the same length as the Dragon trunk.

Bishop Airlock:
Length   6.706 metres (22.00 ft)
Height   1.507 metres (4 ft 11.3 in)
Diameter   2.014 metres (6 ft 7.3 in)

Volume ~24.12 m³

Dragon 2 trunk:
37 m³ / 1300 ft³

Seems like there is plenty of room

[CJ]

Question for the experts: does the Bishop Airlock take up the entire trunk, or is it smaller than the trunk space?

I figure that Bishop’s length is determined by the available space at the end of Node 3, not the trunk size of Dragon. It would be a minor miracle if the space at the end of Node 3 were the same length as the Dragon trunk.

Bishop Airlock:
Length   6.706 metres (22.00 ft)
Height   1.507 metres (4 ft 11.3 in)
Diameter   2.014 metres (6 ft 7.3 in)

Volume ~24.12 m³

Dragon 2 trunk:
37 m³ / 1300 ft³

Seems like there is plenty of room

I have to quibble with the number cited for length. I can't find a source for it other than Wikipedia, and I strongly suspect that Wikipedia has it wrong.

Nanoracks, the manufacturer, shows Bishop to be less in length than diameter.
https://nanoracks.com/bishop-airlock/
 
Edit to add: per the photos of the airlock on the nanoracks page linked above, either Nanoracks employees pictured in the shots with the airlock are in excess of 6 meters (22feet) tall, or Wikipedia is wrong on the length of the airlock. My guess is that Wikipidia used the length in feet and called them meters.