An amazing mission from day 1 and they half ass the recovery. Skylab recoveries were much more professional from the videos I have seen.
Apparently an NO2 gas leak?
ETA: Its NTO…leak, not good.
NTO. Trioxide?
They just corrected it, the announcers were saying NO2.
How are they “half-assing” the recovery? Remember this is a test flight. Looks like SpaceX might have something to fix before the next mission. They’re still a bit ahead of schedule.
edit: and it may not be a “leak” per se, possibly just wafting out of one of the thrusters. they said it’s 2x exposure limits so it’s not like it’s spewing…
Nitrogen tetroxide, a hypergolic rocket propellant component. -Wikipedia.
yep. ignites on contact with another component (like hydrazine) but unfortunately pretty damn toxic.
it’s worth noting the Shuttle orbiter used hypergolics for its control thrusters, and actually did “spew” it out after landing.
If it were a real leak, we’d have seen a deck full of dead crew. It’s good that they’re being careful, but as you say it’s probably just residual fumes.
Twice normal, or twice the limit?
Twice the limit, but that limit is very small.
Six parts per billion, the man just said.
I didn’t catch the second gas they are measuring, but I wonder if it is the other hypergolic?
still, it’s really, really nasty stuff. you should see the protective equipment they use when they fuel a device, they look like bomb suits.
MMH, monomethylhydrazine. Also nasty stuff.
They just checked that no leakage is going inside.
Commercial flight, and no “sensitive national security issue” involved, and it is still a test.
Next time they will need to coordinate with the Coast Guard to send some assets to shoo away the looky-loos.
They began telling the recovery task force to stand away, after Apollo 8 actually crossed overhead of the carrier and splashed down less than 3 miles away. So they have been able to be precise for a long time.
With Dragon being well tested for stability in the water, it’s safer to stay aboard until they are secured.
When the shuttles landed they would also go around with the sniffers to test for the thruster hypergolics. On the last Apollo capsule splashdown a step in the sequence was taken out of order and hypergolics were still exhausting at the same time as the ambient equalization valves opened – everyone got gassed quite nastily. Also in the old capsules the reentry vessel had only minimal internal fuel, most of it being carried in service modules or retropacks that would be dumped before reentry.
Fun fact the last US splashdown, Apollo Soyuz also had propellant leak , which caused the crew the nearly die and spend 3 weeks in hospital in Honolulu.
(As far as I know, they aren’t totally clear on what caused it).
During which it was discovered that both Stafford and Slayton had pre-existing conditions which should have disqualified them from spaceflight.
ETA: damn, ninjad by @JRDelirious. Though as far as I know, its speculation as to the cause, since it was a craft about to be retired, they did’t do much testing.
As for the illnesses, I think Gene Cernan once suggested (he was on the support crew for some unfathomable reason) that NASA knew about the conditions and looked the other way until theu were “discovered”, since they wanted the first phase to go out on a high note.
Deke Slayton was grounded for an irregular heart rhythm. He ran the astronaut program. When finally cleared to fly the Apollo Soyuz mission, a NASA doctor want to stop his flight if the heart acted up, and the flight director muttered something about firing the physician.
Hatch open!
Apparently not really a leak, something was not happening in the expected time/order so the crew actuated a process manually where the automation whould have sealed off the thruster fuel system first. Exposures of 300 ppm!!!
And I would not put it past them to have tried their damn best to find a way to justify that Deke was “back to flying status” before it was too late.
Just a quick note about “hypergolics” in case anyone is unfamiliar/confused:
All spacecraft need propellant, and Dragon is no different–it needs propellant for its maneuvering thrusters.
Hypergolic propellants ignite immediately upon mixing. This is in contrast with, for example, the kerosene/liquid oxygen used by the Falcon 9 rocket. The latter has to use special chemicals (hypergolics, in fact) to ignite, but this is a complicated process. For maneuvering thrusters, simplicity and reliability are crucial. The thrusters are only a bit more complicated than two pressurized propellant tanks and some valves that let it flow into a chamber.
The NTO/MMH (nitrogen tetroxide/monomethylhydrazine) are also “storable”. This basically just means they stay liquid over a wide temperature range, and specifically aren’t cryogenic like liquid oxygen. So they can stay in orbit for a very long time without evaporating, freezing, or otherwise degrading.
Unfortunately, hypergolic propellants tend to be ludicrously toxic. They also have lower performance than hydrocarbon propellants, but these are reasonable sacrifices to make.
The recently passed Dr Berry, who was also responsible for DQing Jim Lovell from astro selection for medical reasons, diagnosing Pete Conrad as “unsuitable for long-duration space missions”, bumping Ken Mattingly from Apollo 13.
He nearly got Gene Cernan removed from command of Apollo 17, when he injured his leg and had a simultaneous prostate massage.
Cernan stayed on by avoiding him as much as possible and getting another surgeon to do regular prostate and leg massages.
Deke was diagnosed with a lung lesion post-Apollo Soyuz and I believe Stafford had early CAD.
Nitrogen really, really does not like being part of other molecules, and the more nitrogen atoms you force into weird arrangements, the unhappier it gets. Derek Lowe quipped that his “Things I Won’t Work With” series could also be called “Things Which Suddenly Turn Back Into Elemental Nitrogen.”
They are used in some ICBMs, like the Titan II, SS-18 and the Sarmat. They also were used in some SLBMs by the Soviet Navy since they decided sending problematic crewmen to Siberia was getting boring.