Space Exploration megathread

[DaFace]

Since a number of cool things are happening in space exploration these days, we'll widen the scope of this thread a smidge. Conversation about all things space exploration are welcome, whether it be from NASA, SpaceX, ULA, Blue Origin, or anyone else. Chances are most of the discussion will still be about SpaceX since they love to make things public and fun, but nothing's off limits. I'll eventually get around to modifying the OP to include resources for other companies too, but in the meantime, feel free to post any cool stuff you run across.

Lists of Upcoming Missions

Spoiler!

General lists:
https://nextspaceflight.com/
http://spaceflightnow.com/launch-schedule/

SpaceX specific list:
https://spacexnow.com/upcoming.php

How to Watch a Live Launch

Spoiler!

SpaceX:
https://www.spacex.com/launches/

ULA:
https://www.youtube.com/user/UnitedLaunchAlliance

RocketLab:
https://www.youtube.com/user/RocketLabNZ

NASATV will also cover some launches (primarily ISS resupply missions):
https://www.youtube.com/user/NASAtelevision

Where to Learn More

Spoiler!

Some cool pics...

https://www.flickr.com/photos/spacex/
https://www.instagram.com/spacex/?hl=en

Twitter feed is usually interesing...

https://twitter.com/SpaceX
https://twitter.com/elonmusk

The SpaceX sub is a great source of info...

https://www.reddit.com/r/spacex
https://www.reddit.com/r/spacex/wiki/index

And for a more forum-style discussion board...

http://forum.nasaspaceflight.com/index.php#c17

And there are plenty of YouTube channels with great content...

• Joe Scott - Lost of "future" discussion. Some about rockets and space. Much that goes beyond.
• Scott Manley - Super smart dude (engineer) who reviews a lot of major events in space exploration.
• Frazer Cain (Universe Today) - Podcast-style videos that go in-depth into space topics.
• Tim Dodd (Everyday Astronaut) - A "random dude" who got really into space (particularly SpaceX). He's a great resource for simple explanations of this stuff, as well as live hosting launches.
• USLaunchReport - Lost of videos of the more mundane stuff (e.g., booster recovery operations). Not a ton of commentary.
• NASASpaceFlight - Live hosting of most launches including a ton of video of Starlink operations.

Glossary

Spoiler!

Space discussions tend to get a little bogged down in jargon, so here's a list of terms you might encounter. (Others, please let me know of others that should be added.)

• ASDS - Autonomous Spaceport Droneship - The "barges" that they sometimes land rockets on.
• Dragon - The cone-shaped capsule that sits at the top of the rocket for ISS-bound launches that holds the cargo (or, in the future, humans).
• F9 - Falcon 9, the name of the rocket itself.
• FH - Falcon Heavy, the three-booster version.
• GTO - Geosynchronous Transfer Orbit, a type of orbit that will eventually result in the satellite orbiting the earth as it turns so that it seems to be in the same spot from the ground (such as DirecTV or Dish satellites). These types of launches are particularly challenging because they require a lot of power to get them into the right orbit, leaving very little fuel left for landing.
• HIF - Horizontal Integration Facility - the building near the launch pad where they put all of the pieces of the rocket together before rolling it out to the pad.
• ISS - The International Space Station
• JRTI - Just Read The Instructions, the name of the "barge" that they land on for west-coast launches.
• LEO - Low Earth Orbit, a fairly low orbit shared by many satellites and ISS. These launches usually require less power to achieve the proper orbit, so the first stage can often be landed back on land rather than on a drone ship.
• LZ1 - Landing Zone 1, basically a big open slab of concrete at Cape Canaveral where the first stage will attempt to land (for some launches).
• NET - No Earlier Than, basically the date they're hoping to launch, but rocket launches have a tendency of getting delayed.
• OCISLY - Of Course I Still Love You, the name of the "barge" that they land on for east-coast launches.
• RTLS - Return to Landing Site, a mission where the first stage comes back and lands at LZ1.
• Starship - SpaceX's next-generation rocket (and spacecraft) that will hopefully one day take us to Mars. Starship is the "second stage" that will carry cargo or people, but also refers to the whole system. (It's confusing, but think of it like the Space Shuttle, which was both the shuttle itself and the entire launch system.)
• Super Heavy - The giant booster that will carry Starship to space.

[unlurking]

Good read on ISS and atmosphere leaks...

https://ntrs.nasa.gov/citations/20110012997

Originally Posted by Trending of Overboard Leakage of ISS Cabin Atmosphere

ISS cabin is maintained at a nominal total pressure between 96.5 kPa (14.0 psia) and 102.7 kPa (14.9 psia) and is composed of oxygen, nitrogen, small amounts of CO2 and other trace gases. The nominal total pressure allows for a livable environment similar to the pressures seen on the ground. The free air volume of the cabin also plays an important role due to the buffer it provides over the range of the nominal pressures. The free air volume is defined as the volume of the ISS that the atmosphere can equalize into. Volume taken up by structure or pressure vessels is not included. The free air volume has increased over the life of ISS due to the additions of modules to the United States On-Orbit Segment (USOS) and Russian On-Orbit Segment (RSOS). The increased ISS volume has extended the response time to having to add nitrogen or air for a given leak rate as well as adding oxygen in support of metabolic needs. At the beginning of 2008 the free air volume of the ISS was 434 m3 (15,318 ft3). After the addition of multiple modules, the ISS free air volume was 899 m3 (31,741 ft3) by March 2011. Visiting vehicles other than Shuttle are included in the volumes numbers. There are nominally 4 visiting vehicles docked to the ISS with the typical complement of vehicles consisting of 2 Soyuz and 2 Progress. An evaluation of a theoretical leak rate of 1 lbm/day air illustrates the benefit of the additional volume to the ISS. At the beginning of 2008, a 0.45 kg/day (1 lbm/day) air would have taken 70 days to drop the ISS total pressure from 102.7 kPa (14.9 psia) to 96.5 kPa (14.0 psia). However by March 2011, a 0.45 kg/day (1 lbm/day) air leak rate would have taken 146 days to drop the ISS total pressure from 102.7 kPa (14.9 psia) to 96.5 kPa (14.0 psia).

Some take aways for a Mars mission seem to be that the larger the vehicle volume, the more amount of time to resolve a leak; and the more connection ports, the more opportunities for leaks. Since SS has a similar volume to the ISS, it's probably comparable on leakage mitigation timelines. Since it has significantly fewer ports, it should also have significantly less opportunity for leaks to develop in the first place. I imagine a Mars colony (at least an early colony) would likely be built with lots of modules and connection ports, but hopefully with each module being much larger than the modules on ISS.

[RINGLEADER]

Originally Posted by unlurking

Good read on ISS and atmosphere leaks...

https://ntrs.nasa.gov/citations/20110012997



Some take aways for a Mars mission seem to be that the larger the vehicle volume, the more amount of time to resolve a leak; and the more connection ports, the more opportunities for leaks. Since SS has a similar volume to the ISS, it's probably comparable on leakage mitigation timelines. Since it has significantly fewer ports, it should also have significantly less opportunity for leaks to develop in the first place. I imagine a Mars colony (at least an early colony) would likely be built with lots of modules and connection ports, but hopefully with each module being much larger than the modules on ISS.

I seem to remember seeing that the plan would be to leave Starships behind that could be used as long-term habitats but that may have just been some rumor or idea someone had. Makes sense though if you could retrofit the entire rocket to be living quarters.

Also saw a thing where the PSI on a plane is only 4-5 but that may not be the case on a planet with little atmosphere to begin with. Clearly pressurizing habitats is not my strong suit but I find it super interesting and hope Musk pulls it off.

[Donger]

Originally Posted by RINGLEADER

I seem to remember seeing that the plan would be to leave Starships behind that could be used as long-term habitats but that may have just been some rumor or idea someone had. Makes sense though if you could retrofit the entire rocket to be living quarters.

Also saw a thing where the PSI on a plane is only 4-5 but that may not be the case on a planet with little atmosphere to begin with. Clearly pressurizing habitats is not my strong suit but I find it super interesting and hope Musk pulls it off.

Commercial aircraft pressurize to about 10 to 12 psi. Just like Denver.

[unlurking]

Originally Posted by RINGLEADER

I seem to remember seeing that the plan would be to leave Starships behind that could be used as long-term habitats but that may have just been some rumor or idea someone had. Makes sense though if you could retrofit the entire rocket to be living quarters.

Also saw a thing where the PSI on a plane is only 4-5 but that may not be the case on a planet with little atmosphere to begin with. Clearly pressurizing habitats is not my strong suit but I find it super interesting and hope Musk pulls it off.

Yeah, all sorts of people throwing out ideas on how to use SS as habitats (including the empty tankage) on reddit. The most common hurdle seems to be trying to figure out how to go from vertical to horizontal so that the ship could be partially buried in order to protect against radiation as well as making it easier to live in. Unfortunately their not build to withstand that orientation and I doubt Musk intends to create a special version. I imagine the first few SS on Mars may double as temporary or emergency shelters, but they won't be used longer term.

NASA has been running an autonomous 3D printed habitat challenge for a few years now. Some absolutely beautiful designs as well as some already tested concepts.

https://www.nasa.gov/directorates/sp...Hab/index.html

Here is a quick video from the finale winner. They are apparently trying to use the tech to build homes in areas with minimal access for construction/materials here on Earth as well.



From a purely aesthetic perspective, this was my favorite entrant...

[DaFace]

29 Raptor engines and 4 grid fins have been installed on Super Heavy ahead of first orbital flight pic.twitter.com/XHkCZ9VYK4

— SpaceX (@SpaceX) August 3, 2021

I almost think this frantic pace is just Elon trying to light a fire under the FAA's ass. Seems crazy that they could possibly be ready to launch it soon.

[RINGLEADER]

Originally Posted by Donger

Commercial aircraft pressurize to about 10 to 12 psi. Just like Denver.

The thing I pulled up said 4-5 — but at cruising altitudes if 30K to 40K feet.

Damn you Internet.

[unlurking]

Originally Posted by DaFace

29 Raptor engines and 4 grid fins have been installed on Super Heavy ahead of first orbital flight pic.twitter.com/XHkCZ9VYK4

— SpaceX (@SpaceX) August 3, 2021

I almost think this frantic pace is just Elon trying to light a fire under the FAA's ass. Seems crazy that they could possibly be ready to launch it soon.

They also did this right before the press event when they showed off SN1. I'm kind of hoping we get another one of those next week. Been a long time since Elon spoke about current plans/vision with more characters than Twitter. I imagine the FAA would factor heavily into the talk and questions.


Also looking forward to Dodd's recent interview/tour to drop. Not a fan of his live events, but love his interviews and ELI5 videos.

[Donger]

Originally Posted by DaFace

29 Raptor engines and 4 grid fins have been installed on Super Heavy ahead of first orbital flight pic.twitter.com/XHkCZ9VYK4

— SpaceX (@SpaceX) August 3, 2021

I almost think this frantic pace is just Elon trying to light a fire under the FAA's ass. Seems crazy that they could possibly be ready to launch it soon.

Are they saying that Super Heavy is going to orbit without a Starship attached?

Surely they'll do a few hop tests of just Super Heavy first.

[Donger]

Originally Posted by RINGLEADER

The thing I pulled up said 4-5 — but at cruising altitudes if 30K to 40K feet.

Damn you Internet.

I'm not sure what you pulled up, but commerical aircraft aren't pressurized at 4 to 5 psi at any altitude. The passengers wouldn't like it much... That's what it's like at the summit of Everest.

[unlurking]

Originally Posted by Donger

Are they saying that Super Heavy is going to orbit without a Starship attached?

Surely they'll do a few hop tests of just Super Heavy first.

Nope, it will have SN20 on top. SH won't actually go to orbit, just SS.
A lot of people hoping for a launch date of September 6th due to the meme-generation of fans (unofficial flight # 69420).

[Donger]

Originally Posted by unlurking

Nope, it will have SN20 on top. SH won't actually go to orbit, just SS.
A lot of people hoping for a launch date of September 6th due to the meme-generation of fans (unofficial flight # 69420).

Oh wow. That seems... ambitious.

[unlurking]

Yeah. I'd love to see it, but I'm guessing October or November at best due to FAA NEPA process. Apparently a 30 day window for public comment is required and that hasn't started yet.

[Donger]

Originally Posted by unlurking

Yeah. I'd love to see it, but I'm guessing October or November at best due to FAA NEPA process. Apparently a 30 day window for public comment is required and that hasn't started yet.

If I remember the filed FAA flight plan, they have SH landing off the coast of Texas. Are they planning a water landing, or do they have something out there large enough for it to land on? The existing droneships are too small, no?

[unlurking]

Originally Posted by Donger

If I remember the filed FAA flight plan, they have SH landing off the coast of Texas. Are they planning a water landing, or do they have something out there large enough for it to land on? The existing droneships are too small, no?

Not yet, Phobos and Deimos are still in port getting "rebuilt". As I understand it, they plan to simulate an RTLS soft landing over water. SS is supposed to be completing almost 1 orbit and also attempt a soft landing over water north of Hawaii. I imagine NASA will have it's chase planes out for some excellent footage. I'm sure SpaceX will have some drones too.

Link to an Eric Berger article with comments about the FAA process...
https://arstechnica.com/science/2021...et-last-night/

Originally Posted by Berger

For months, SpaceX has been working with the FAA on an environmental assessment. After a "draft" of this assessment is published, there will be a minimum of a 30-day period for public comments. This will be followed by other steps, including a determination by the FAA on whether SpaceX's proposed environmental mitigations will be enough, or if more work is required. More information about this process is available on the FAA's website.

[Donger]

Originally Posted by unlurking

Not yet, Phobos and Deimos are still in port getting "rebuilt". As I understand it, they plan to simulate an RTLS soft landing over water. SS is supposed to be completing almost 1 orbit and also attempt a soft landing over water north of Hawaii. I imagine NASA will have it's chase planes out for some excellent footage. I'm sure SpaceX will have some drones too.

Link to an Eric Berger article with comments about the FAA process...
https://arstechnica.com/science/2021...et-last-night/

Right, I knew about Starship body surfing off Hawaii, but not SH. Thanks.