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.
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.
SpaceX is targeting June 5 for the next flight of its massive Starship rocket, the company said Friday.
The highly anticipated test flight— the fourth in a program to bring Starship to operational readiness and make progress toward its eventual reuse—will seek to demonstrate the ability of the Super Heavy first stage to make a soft landing in the Gulf of Mexico and for the Starship upper stage to make a controlled reentry through Earth's atmosphere before it falls into the Indian Ocean.
This mission will carry no payloads as SpaceX seeks additional flight data about the performance of the complex Starship vehicle. It is simultaneously the largest and most powerful rocket ever built and the first launch system ever intended to be fully and rapidly reusable.
As part of its announcement of the flight date, SpaceX provided some information about its learnings from the most recent flight test, Flight 3, which launched on March 14, 2024.
Dissecting Flight 3
During that flight, SpaceX also attempted a soft landing of the Super Heavy first stage. After its separation from the Starship upper stage, as intended, 13 of Super Heavy's 33 Raptor engines successfully relit to make a controlled flight through the lower atmosphere. During this boostback burn, however, six of these engines shut down early. Later in the descent, as the rocket neared the sea surface, the rocket was supposed to use the same 13 engines to make a final landing burn.
"The six engines that shut down early in the boostback burn were disabled from attempting the landing burn startup, leaving seven engines commanded to start up with two successfully reaching mainstage ignition," the company said in its recap of the flight. "The booster had lower than expected landing burn thrust when contact was lost at approximately 462 meters in altitude over the Gulf of Mexico and just under seven minutes into the mission."
The cause of this failure was traced to blockage in a filter where liquid oxygen flows into the Raptor engines. Notably, a similar problem occurred during the second test flight of Starship in November 2023. SpaceX says it implemented "hardware changes" to address this blockage issue for the third test flight. Now, the company said, "Super Heavy boosters for Flight 4 and beyond will get additional hardware inside oxygen tanks to further improve propellant filtration capabilities." It will be interesting to see whether the company's engineers have successfully addressed this issue.
As for the Starship upper stage, the vehicle began losing the ability to control its attitude during its coast phase in space. This was found to be due to clogged valves used by reaction control thrusters on the upper stage. The company's update notes that "SpaceX has since added additional roll control thrusters on upcoming Starships." But it is not clear that they will be available for Flight 4. Indeed, the fact that SpaceX is not attempting an in-flight relight of Raptor engines on the Starship upper stage suggests these new roll control thrusters are not yet in place.
Ultimately this lack of attitude control during Flight 3 resulted in a non-nominal reentry to Earth's atmosphere. SpaceX was able to maintain contact with the vehicle down to 65 km in altitude before telemetry was lost due to excess heating.
Back to the basics
On Flight 3, SpaceX achieved some important milestones, including the opening of the Starship payload bay door in space and a small propellant transfer demonstration. Due to the loss of attitude control, however, a planned Raptor rocket engine re-light test was not conducted. This is an important test, as Raptor ignition is needed to perform a controlled reentry—essentially to ensure that Starship returns to a remote section of ocean rather than land.
For the next flight, SpaceX is focused on solving the technical issues observed on Flight 3: the filter blockages observed during Super Heavy's boostback and landing burns, Starship's attitude control during its coast phase, and managing reentry of that vehicle from orbital velocity.
Once these issues are resolved, the company can proceed to more advanced tests, including landing the Super Heavy booster back at the South Texas launch site, deployment of Starlink satellites, and additional tests of propellant transfer essential for NASA's Artemis Program to land humans on the Moon. [Reply]
Starship and Super Heavy loaded with more than 10 million pounds of propellant in a rehearsal ahead of Flight 4. Launch is targeted as early as June 5, pending regulatory approval pic.twitter.com/lss0brCZgN
The Boeing Crew Flight Test mission is the first flight of Boeing's Starliner spacecraft with humans onboard. The crew is composed of Commander Barry "Butch" Wilmore and Sunita "Suni" Williams. This is the second attempt to launch the mission.
Launch on June 1st at 12:25:40PM EDT (16:25:40 UTC)
Mission: Atlas V launch with Starliner Calypso to the International Space Station
Launch location: Space Launch Complex 41, Cape Canaveral Space Force Station, Earth.
Target orbit: Low Earth Orbit; 72.91-by-181.53 kilometers 51.62 degree inclination
Booster: AV-085
Configuration: N22 - No fairing, 2 solid rocket motors, and 2 RL10 engines on the Centaur upper stage. "Body Guard"
Capsule: Spacecraft 3 (Calypso); 1623d 3h 26min 44s turnaround
Capsule history: OFT-1
Rocket trajectory: Northeast hugging the east coast of the United States
Mission Commander: Butch Wilmore - 3rd spaceflight
Mission Pilot: Sunita Williams - 3rd spaceflight
Stats:
· ULA's 161st launch overall and its 3rd launch of the year
· Atlas V's 100th launch, 3rd launch in N22 configuration
· ULA's 75th launch from SLC-41, 83rd launch of Atlas V from SLC-41
· 3rd orbital flight of a Starliner spacecraft and 1st human spaceflight by Boeing
· This mission will bring up to 2 the total of people sent by Boeing to orbit
Sounds like today's issue was with a card in the ground support equipment. It's crazy that they've now had separate launches scrubbed for the service module, rocket, and GSE. [Reply]
