SpaceX Falcon 9 historic landing thread (1st landing attempt & most recent missions)

[davdue]

The situation of astronauts sitting on top of large amounts of hydrazine and nitrogen tetroxide, which is a hypergolic combination, does not strike me as a very comfortable situation, especially in light of this latest accident.

This isn’t any different than the Apollo missions. The lunar module (LEM) used a hypergolic propellant as well. It was Aerozine 50 (fuel) and Nitrogen Tetroxide (oxidizer). We will see what the reason for this catastrophic anomaly is. Most likely it wasn’t because of the propellant being used. Time will tell.

 

[aerostadt]

This isn’t any different than the Apollo missions. The lunar module (LEM) used a hypergolic propellant as well. It was Aerozine 50 (fuel) and Nitrogen Tetroxide (oxidizer). We will see what the reason for this catastrophic anomaly is. Most likely it wasn’t because of the propellant being used. Time will tell.

However, the current amount is much larger than the Apollo capsule itself, because the motors are used for the abort mode. In addition it must be delivered at high pressure in order to have the high thrust needed for the abort mode. The Apollo capsule used a much smaller system for attitude control.

A better argument would be to look at the main engines used on the LEM, which needed large quantities of propellant and high thrust.

 

[dhkaiser]

SpaceX confirms its Crew Dragon capsule, built to carry humans, was destroyed during a test fire

https://www.cnn.com/2019/05/02/tech/spacex-crew-dragon-destroyed/index.html

 

[Nytrunner]

I'm really not sure what anyone expected otherwise. That was not a minor explosion or a negligible cloud of nto

 

[georgegassaway]

CRS-17 launch set for EARLY tomorrow morning, at 3:11 AM, EDT.

Yes, as in hours from now.

 

[georgegassaway]

"SpaceX Confirms Dragon Capsule Was Destroyed in Test 'Anomaly', Could Affect Crew Launches

A SpaceX Crew Dragon capsule was indeed destroyed during engine tests that went awry last month, a company representative said today (May 2).

On April 20, SpaceX conducted a series of tests on the vehicle — which last month flew a successful uncrewed demonstration mission to the International Space Station (ISS) — on a stand at Florida's Cape Canaveral Air Force Station.

Firings of the capsule's small maneuvering Draco thrusters went according to plan, but things went south when the SpaceX team got ready to engage the SuperDraco abort engines, which are designed to rocket Crew Dragon away from danger in the event of a launch emergency.

"We fired them [the Dracos] in two sets each for 5 seconds, and that went very well," Hans Koenigsmann, vice president of Build and Flight Reliability at SpaceX, told reporters today (May 2) during a press conference previewing the company's planned cargo launch to the ISS early tomorrow morning (May 3). "And then, just prior, before we wanted to fire the SuperDracos, there was an anomaly and the vehicle was destroyed."

More at: https://www.space.com/spacex-crew-d...UdxQW6ldLNt_SFEOYN2qtH5oY8a3MHvmaYVY2Mko0eKlM

Also, this Klyde Morris explos....uh, anom....uh, cartoon, by Wes Oleszewski (who used to run Dr. Zooch rocketry).

 

[davdue]

Good thing I wasn’t drinking anything when I read the cartoon. That is way too funny

 

[aerostadt]

It will be interesting to see how the recovery from this anomaly plays out. I would suspect that some technicians/engineers might have their careers on the line. I find it bothersome that hydrazine(compounds)/N2O4 is being used for the abort escape system for the first time on a manned system. Yes, I am aware of the advantage of the extra delta-v taking such a system all the way to orbit. On the other hand this hypergolic propellant has been used before on many other US manned vehicles for attitude control and major propulsion. On Apollo the LEM used this propellant combination for decent and ascent modes to the lunar surface. The Apollo CSM used the same propellant for its major propulsion. In all likelihood if the US returns to the moon in the future It will need this propulsion system, again.

 

[SpaceManMat]

It will be interesting to see how the recovery from this anomaly plays out. I would suspect that some technicians/engineers might have their careers on the line. I find it bothersome that hydrazine(compounds)/N2O4 is being used for the abort escape system for the first time on a manned system. Yes, I am aware of the advantage of the extra delta-v taking such a system all the way to orbit. On the other hand this hypergolic propellant has been used before on many other US manned vehicles for attitude control and major propulsion. On Apollo the LEM used this propellant combination for decent and ascent modes to the lunar surface. The Apollo CSM used the same propellant for its major propulsion. In all likelihood if the US returns to the moon in the future It will need this propulsion system, again.

The LEM abort motor was the ascent motor, so really dragon is not the first. I can’t see there’s any real additional risk in using the motors for an abort situation as opposed to a non-abort situation. The type of motor has been used for a long time on human rated craft, it’s really just a matter of getting to the bottom of what went wrong and fixing it.

 

[georgegassaway]

The CRS-17 launch was postponed because the ASDS ship lost power, so was unable to support the booster landing on it (it uses propeller thrusters to maintain an exact position at sea. The booster lands at a GPS coordinate, NOT sensing the ship, so the ship needs to hold itself to the coordinates the booster is programmed to land at).

This is very ironic since the booster was supposed to be RTLS and land at LZ-1, not needing to land at sea. But can't due to LZ-1 being off-limts due to the Dragon-2 "Explosionomaly" (recent info is nobody is allowed near the explosion site yet. I am suspecting they are worried about tanks still with hypergolics in them and have not solved a plan for safely handling them).

CRS-17 next attempt tomorrow May 4th at 2:48 AM Eastern.

"May the 4th be with it."

 

[aerostadt]

This is very ironic since the booster was supposed to be RTLS and land at LZ-1, not needing to land at sea. But can't due to LZ-1 being off-limts due to the Dragon-2 "Explosionomaly" (recent info is nobody is allowed near the explosion site yet. I am suspecting they are worried about tanks still with hypergolics in them and have not solved a plan for safely handling them).

There could also be a cautious mindset to preserve as much evidence as possible, sort of like a forensic study, and peel back the evidence layer by layer without bias or tampering.

 

[RocketGeekInFL]

The abort engines for Starliner are also using Hyperbolic fuels. These mixtures have been used for decades on many manned spacecrafts, this is just a new mentality for an abort system.

 

[Nytrunner]

The abort engines for Starliner are also using Hyperbolic fuels

Are you sure? I could've sworn it was going to go back to Parabolic propellant

 

[aerostadt]

The abort engines for Starliner are also using Hyperbolic fuels. These mixtures have been used for decades on many manned spacecrafts, this is just a new mentality for an abort system.

Thanks, for the update. It looks like the two commercial manned capsules (SpaceX and Boeing) are using the hypergolic propellants for abort. The NASA Orion capsule is using the old solid rocket methodology for abort.

 

[RocketGeekInFL]

There are a few reasons they are moving to hypergolic for the abort systems. One is that thrust can be attenuated which means once they dock at the space station the motors could be used to move the station in much the same way the Space Shuttles hypergolic positioning system was used. Another is reuse, ejecting an escape tower makes the cost go up and refuel reflight take longer. The windows would have to be covered if there was a tower more than likely due to the sheer weight of the capulses in comparison to the past.

 

[RocketGeekInFL]

Thanks, for the update. It looks like the two commercial manned capsules (SpaceX and Boeing) are using the hypergolic propellants for abort. The NASA Orion capsule is using the old solid rocket methodology for abort.

I believe Orion is in addition to using legacy solid fuel motors pointed down also using another solid rocket motor at the top of the stack for attitude control that will be computer aided. There is a great video somewhere of this tech. If I find it I will post it.

 

[boatgeek]

Are you sure? I could've sworn it was going to go back to Parabolic propellant

Parabolic didn't have enough power, so they had to go to Cubic.

 

[georgegassaway]

There could also be a cautious mindset to preserve as much evidence as possible, sort of like a forensic study, and peel back the evidence layer by layer without bias or tampering.

Yes, that was the initial info. But it's been nearly 2 weeks, and reportedly NOBODY has approached any of the debris yet. That's an awful long time not to inspect anything at all. Therefore it is seeming like the area is too unsafe (likely related to the Hypergolics, some may remain inside of some tanks), but curiously there are HazMat suits rated for working with Hypergolics. So it may be more than just potential exposure to fumes. It may be concern of fire or explosion from disturbing any of the tanks that might remain. Which if true, the first attempts would likely involve robotics of some sort. I would expect if nothing else, they might fly (or have flown) a $1000-2000 Quadcopter to get some close up video of the scene (possibly then land it into a pond or a set-up open tank of water or kiddie pool to deal with concerns it might be contaminated. This is why I say $1000-2000 rather than a more expensive one, a one-shot disposable recon vehicle). Or, an R/C model tank with a boom mounted to raise a camera a few feet up, the camera capable of motion for remote aiming rather than being fixed to wherever the tank points.

 

[georgegassaway]

So, second try to launch CRS-17 in a few hours, 2:48 AM Eastern.

 

[PhysicsGuy]

I captured this photo (from my driveway) of the CRS 17 launch earlier this morning. You can clearly see the first stage burn out and second stage ignition. The stage separation provided quite a light show tonight (I almost thought something had exploded). This was just over a 5 minute exposure on my iPhone using the Slow Shutter Cam app. We also had a nice view of the re-entry and landing burns but didn't capture them with the camera.

I'm not sure, but I think the long greenish line to the right of center is a meteor that we caught purely by coincidence. Turns out the Eta Aquariid meteor shower also peaks this weekend and we may have caught one just by luck. It appeared in the photo just a few seconds after liftoff. Anybody else observe the launch?

--MARK

 

[georgegassaway]

PhysicsGuy, NICE shot!

A really good launch of CRS-17. An unexpected infrared camera view of the booster descending before the landing burn, and then the landing burn (Pretty sure that was a NASA or CCAFS camera, not SpaceX). OCISLY was only about 12 miles offshore (also allowed them to go back to port Friday to swap out the bad generator. If that problem had happened for a normal landing hundreds of miles out at sea, it would have taken many days to come in and go back). Nice that the onboard camera was providing video as OCISLY came into view and landed on it.

Great Launch and landing long exposure/multi exposure photo by Mike Killian: His post describing how he shot it is here:
https://www.facebook.com/MikeKillia...491563205369/2174447906009719/?type=3&theater

Streak in the middle is the re-entry burn. Lower right very short streak is the landing burn.

.

 

[RocketGeekInFL]

 

[Event Horizon]

Speaking of the hypergolic propellants that have been mentioned here, how do they compare with c stof and t stof? I'm not a chemist...thanks for helping

 

[Peartree]

I saw this post on Twitter this afternoon and I'm wondering if this has anything to do with the SpaceX "anomoly" and leftover un-safed hypergolics:

45th Space Wing‏Verified account @45thSpaceWin

SpaceX personnel, under supervision of the 45th SW Safety office, will perform venting if weather permits for several tanks on Cape Canaveral AFS on May 8, 2019. The venting may create an orange cloud however public safety will not be affected.

 

[georgegassaway]

I saw this post on Twitter this afternoon and I'm wondering if this has anything to do with the SpaceX "anomoly" and leftover un-safed hypergolics:

Yes, absolutely. This is why SpaceX has not begun a physical examination of Dragon-2's explosion. The area is too dangerous with what are expected to be several tanks with Hypergolic fuels inside. So they need to vent them.

BTW - I have invented a few new words and phrase:

Explosionomaly

Detonationomaly

Kaboomomaly

Truthanomaly (obfuscation of the truth, or outright avoiding the truth, or plain a** lying).

Crash and Burnomaly -> In honor of the CRS-5 Kamikaze crash into the ASDS, which obliterated the booster, which Elon Musk described as a "Hard Landing". There was no video (at first), to which Elon Musk said it was too dark for video. Days later a video miraculous appeared, showing the high-speed diagonal out of control crash, not a "hard landing". See "Truthomaly".

 

[pyrobob]

An interesting article https://www.wired.com/story/the-obsessive-tumultuous-lives-of-spacex-rocket-chasers/

 

[georgegassaway]

Next launch is NET May 15th. Launching SpaceX's own "Starlink" WiFi satellites, a space-based internet communications system. This is a developmental flight with prototype satellites, to test them out before moving on to a final production version. https://en.wikipedia.org/wiki/Starlink_(satellite_constellation)

Launch is NET Wednesday* May 15th, at 10:30 PM, EDT. It will be after sunset, but MAYBE it will fly into sunlight to light up the exhaust plume by the time of staging (Likely too late for that, though). Booster will land at sea, on OCISLY.

Article on the satellites here:
https://www.teslarati.com/spacex-st...kwOd5AN0CQsoDJKQEOMkCm5WKuM7bYG-5-YcgAU8rJhXM

It will carry SIXTY satellites.

That is one tightly sardine-packed payload shroud!

The satellite altitude is lower than ISS and they will decay from orbit in a few years.

* - originally typed "Monday" for some silly reason and edited it on seeing the post below. Knew it was Wednesday.

 

[dhkaiser]

The 15th is Wednesday

 

[Nytrunner]

will carry SIXTY satellites.

Wooo! more spacejunk!

 

[RocketGeekInFL]

It will all be in a decaying orbit. Won't be up there long.