COTS - status

Oldfart1939 · 2019-11-09 21:19:25

An interjection from the website resident chemist here. Full personal protective equipment (PPE) is required for getting anywhere near NTO. Far worse than hydrazine, as it's an oxidizer, and forms Nitric acid on contact with water. Best answer is simply stay the Hell away from the crash until the brown cloud gets blown away. NTO will cause severe skin burns, and if breathed, destroys the lungs. Oh, yeah. If you wanna keep using your eyes--full eye protection. Best answer is either stay the hell away from it or use a robotic vehicle with onboard fire hoses to flush the works down with dilute sodium bicarbonate solution. Contact with NTO in any amount is a medical emergency. Definitely don't want to come in contact with MMH, either. Hydrazines are easily absorbed through the skin , and the fumes are also highly toxic. Still--not as bad an actor as NTO.

GW Johnson · 2019-11-10 12:14:03

Hi Oldfart1939:

What you said about NTO is exactly why I suggested staying in the pressure suit and walking well away from the landing site with an oxygen bottle. That was pretty much what the protective suits were for the missile crews working with Titan ICBM's in the silos. Those missiles used NTO and hydrazine as well.

Not being a real chemist myself, I tend to lump all the hydrazines together, and compare them all to handling anhydrous ammonia. That's not "right", but it works out to be a good rule-of-thumb, near as I can tell. The recommended emergency response for a hydrazine spill was to dilute it with copious water, same as for anhydrous ammonia.

NTO is just bad news, period. Takes a full suit and breathing gear, and best to wait for the brown cloud to dissipate, just as you say.

GW

Last edited by GW Johnson (2019-11-10 12:15:19)

Oldfart1939 · 2019-11-10 16:51:30

For anyone interested, there is a YouTube video by NASA, which presents the handling and hazard details of NTO and MMH. I used to have the link in my files, but it seems to have gone missing.

Disposal of hydrazine industrially was done by, as GW stated above, initially dilution with copious water. Before it can be run into the sewer system, it is treated with Sodium Hypochlorite solution: common household bleach.

Last edited by Oldfart1939 (2019-11-11 14:40:58)

RobertDyck · 2019-11-10 23:37:41

I'm going to continue to be shit disturber. I described the problem with the Apollo-Soyuz mission. The valve to re-pressurize the capsule from outside ambient air was automatically opened when the capsule encountered sufficient air pressure. If that same valve is opened on Starliner, NTO vapour could be drawn into the capsule. So even staying in the capsule wouldn't be safe. Boeing would have to ensure that valve remains shut for abort. Did they design the control system to do that?

GW Johnson · 2019-11-11 09:23:45

OK, if Boeing's Starliner, in an abort the service module crashes somewhere in the general vicinity, with a lot of NTO and hydrazine on board. The capsule comes down somewhere on its chutes. It has some NTO and hydrazine on board, for its attitude thrusters. You CANNOT get away from the exposure risk.

So, stay in the pressure suits you need for the ride up anyway. If you abort, leave the visors closed and the gloves sealed. The cabin vent valve either needs to be a manually-operated valve, or have a manual override, to stay closed until on the ground, then briefly opened to equalize pressure so the hatch can be opened. The crew is suited and breathing from self-contained oxygen, so even if NTO vapor enters, they are safe, just inconvenienced.

There needs to be an oxygen bottle for each crew person to breathe while suited up for protection. They should ideally shelter in place inside the capsule until rescued, but they can exit and walk away from the scene, if needed, to clear the cloud of vapors. It's NOT a trivial oxygen bottle! May have to shelter for a couple of hours, or walk for an hour.

If you consider Crew Dragon, it's still the same scenario, just different in the details of where the hazard is. In this case, the capsule itself has considerable NTO and hydrazine on board, to power the Draco attitude system, and the Super Draco abort system that also serves as on-orbit propulsion. Again, they should be riding up in pressure suits anyway.

If there is an abort, leaves visors closed and gloves sealed. Override the cabin pressure equalization valve to stay closed, until on the ground with Super Draco's off. Riding down on chutes, there is no mistaking when you are on the ground. Open the equalization valve briefly so the hatch can be opened. Crew is suited and breathing from self-contained oxygen, so if NTO vapor enters, they are safe, just inconvenienced.

Because of the higher quantities of NTO and hydrazine on board, it might not be best to shelter in place aboard the capsule until rescued. Although, those tanks are outside the cabin pressure shell. You could shelter in place if the pressure shell is still intact after landing. You'll know that, if the equalization valve operation is manual, because you can hear the air rush.

Either way, if need be, suited crew can walk away from the scene, as long as they each have non-trivial oxygen bottles from which to breathe, while suited for protection.

I see a real need for careful precautions appropriate to the toxin dangers faced. I do NOT see this as a "killer" issue. All that is needed is to think through the scenario and provide the items and procedures required. The abort scenario will always preclude riding up in shirt sleeves. But that would be stupid anyway, because of accidental depressurization risks.

Manually-operated controls for things like cabin equalization valves may be very superior to any sort of automatic things, under such circumstances. Simpler is just more versatile for wildly-different scenarios.

I know that approach is not popular with younger folks who want computer-controlled everything, but it has served humanity very well in the past.

GW

Last edited by GW Johnson (2019-11-11 09:24:14)

SpaceNut · 2019-11-11 10:32:04

Good comments on "Risk Mitigation" from NTO, Hydrazine for abort and return home by staying in the presurized space suits.

This would also want to be the case for even a unit altered for mars use thou I do not think these will be the ships for mars. They may be left on orbit to rendevous with for the return trip home as in the ERV concepts.

elderflower · 2019-11-12 10:36:59

You may need pressure equalisation operable from outside as well, in case rescuers need to get the people, if they are unconscious, out of the vehicle. Otherwise the rescuers may not be able to open the hatch due to the pressure difference.

SpaceNut · 2019-11-12 19:26:23

One wonders now why Nasa was insistant to having an ocean landing for humans....

So on mars we have not the issue so long as we do not have contact with the space suits and then bring it into the habitat. So its going to need a bath once we land so as to not have an un-needed risk.

Oldfart1939 · 2019-11-12 20:37:14

Here is the YouTube presentation from NASA. titled "Toxic Propellant Hazards."

https://www.youtube.com/watch?v=Zha9DyS-PPA

Oldfart1939 · 2019-11-13 22:15:34

Here's a link to Nuclear Propulsion in Space:

https://www.youtube.com/watch?v=eDNX65d-FBY

tahanson43206 · 2019-11-14 07:36:42

For Oldfart1939 re #210

Thanks for the link to that film in particular, and to the entire archive in general.

I followed it for a few minutes, confirming that it is worth returning later for a full viewing.

That was an optimistic time!

(th)

SpaceNut · 2019-11-14 17:45:44

What I see is a whole lot of heel dragging by all parties as the status of manned flights to ISS has not changed any

SpaceNut · 2019-11-16 18:54:25

A successful test for Space x but how many more will be needed before there is confidence for men to ride in the Dragon.

http://www.spacedaily.com/reports/Space … t_999.html

http://www.spacedaily.com/reports/Space … s_999.html

Oldfart1939 · 2019-11-17 15:17:39

Only party NOT doing the heel-drag routine is Elon. NASA seems stuck in granny gear, moving forward on this program. Even after the OIG stating the possibility of not having American astronauts on the ISS in 2020. Somebody needs a red hot poker up the wazoo to get things rolling.

SpaceNut · 2019-11-19 21:29:12

Nasa paid for a bit more pork than what they were authorized to do so.... Audit criticizes Nasa Payments to Boeing in Human Spaceflight Program

SpaceNut · 2019-11-21 20:11:23

Boeing Starliner Crew spacecraft heads to pre-launch processing

Boeing's uncrewed flight test, which is targeted for Dec. 17, will provide valuable data on the end-to-end performance of the rocket, spacecraft and ground systems, as well as, in-orbit and landing operations.

Boeing Starliner to cost $90 Million per seat for flights on the CST-100 Starliner, a spacecraft currently being constructed by Boeing to transport people to the International Space Station (ISS).

NASA's Inspector General (IG) also stated that the estimated average cost per seat for flights on SpaceX's Dragon capsule, which is contracted under NASA's Commercial Resupply Services program to also deliver people to the ISS, is approximately $55 million.

Send up 1 of each, average them and we are near the current Russian cost per seat on the Soyuz....

GW Johnson · 2019-11-22 15:56:42

I'm not sure who or what to believe, but I did see a news report that Crew Dragon will be cheaper per purchased seat than Soyuz, while Starliner will be more expensive.

I am sure that cost per seat estimates are mostly BS until both vehicles have been flying for a while.

GW

SpaceNut · 2019-11-22 19:13:36

Since both do not have a human rate staging to go with the capsule its still a crap shoot to whether its going up or up in smoke....

GW Johnson · 2019-11-23 11:00:20

Well, it gets down to how important this thing is to do. John Glenn went up on top of an Atlas that had yet to be successfully "man-rated". In fact, the meaning of "man-rated" had not even been established then.

Somehow or another, General Dynamics (the maker of early Atlas boosters) got their act together between the earlier test flights and Glenn's flight. Which is why Scott Carpenter, Wally Schirra, and Gordon Cooper were able to ride the Atlas to orbit without getting blown up.

Even today, we have to look with jaundiced eye about what we really mean by "man-rated". How much of that makes technical sense, and how much is just bureaucratic nonsense (the crap government procurement generates in spades)?

I'm not at all sure that question has been properly answered yet. Even today, after nearly 6 decades.

GW

Last edited by GW Johnson (2019-11-23 11:02:27)

Oldfart1939 · 2019-11-23 23:32:20

Were Columbia and Challenger "man rated?" Apollo 1?

GW Johnson · 2019-11-24 11:35:46

Depends upon what you mean by "man-rated". The only true way is to fly massive quantities and look at the actual failure rates. NASA cannot, and has never been able to, afford that. All else more-or-less borders on wishful thinking.

There was never any attempt to claim "man-rating" for the Apollo-Saturns. Those were experimental from the word "go". Saturn 5 flew twice unmanned before the first manned flight, which (astoundingly-enough) was the Apollo 8 flight around the moon. Both of the unmanned test flights had problems, one serious enough to almost cause a loss.

With the shuttle, NASA developed a set of criteria to improve the flight reliability, in the face of all the multitude of failure modes. Then they failed to observe their own rules, which cost 2 crews their lives. Bluntly put, but true.

GW

Oldfart1939 · 2019-11-25 00:19:01

GW-
I knew you would understand my post, and were perceptive enough to spell it out for others here.

kbd512 · 2019-11-25 00:58:22

Oldfart1939 and GW,

I view man-rating as a series of best practices to try to minimize failure rates. It's certainly nothing like a guarantee. If you subsequently fail to observe your own best practices, well... we've already seen the results of that and they're not pretty. It seems to me like best practices could be implemented in a more practical and thus affordable way, but I'm not a rocket scientist and don't even play one on TV. There are undoubtedly countless things that I've never even thought of.

What I would like to see us do is to pick a vehicle, such as Falcon 9 or Falcon Heavy, and fly it once per week so that we can see what breaks and what works so well that we don't need to spend any more time fussing with it, to no practical effect. What I expect to learn is what we need to do to have a launch process that's so repeatable that we can't screw it up, provided that the process is followed. Then and only then will we truly know what we have mastered.

I guess this is an attempt to move our current launch procedures, which seem to be unique / one-off science experiments, to flight procedures that have answers for everything that we know about. In commercial aviation, we have procedures for everything that we know about. In order to truly commercialize access to space, we need something approximating the procedures we use for flying an airliner half way around the world. As part of that procedural testing, schedule-based, rather than condition-based turnarounds need to be demonstrated. Unless the booster is simply not flightworthy to continue operation, that sort of capability is what must be clearly demonstrated. The edges of the flight envelope also need to be real world tested, even if we destroy some vehicles to accomplish that.

SpaceNut · 2019-11-25 09:32:42

The Human rating for a space suit is simular to what is submarine safe in that they are designed to protect the asset and hopefully save the humans using it. Its where we come to a military specification standard for each and every part used to control quality.
Best practices come back to standard materials acceptability as earlier indicated by break it and test procedures until its does not break.

https://en.wikipedia.org/wiki/Human-rat … tification

PROGRAM STANDARDS Office of Manned Space Flight - NASA
https://ntrs.nasa.gov/archive/nasa/casi … 011555.pdf

NASA RELIABILITY PREFERRED PRACTICES FOR DESIGN & TEST
www.klabs.org/DEI/References/design_guidelines/nasa_reliability_preferred_practices.htm

SpaceNut · 2019-12-04 21:52:04

Boeing's 1st Starliner Spacecraft Test Launch Delayed to Dec. 19

New Mars Forums

Announcement

#201 2019-11-09 21:19:25

Re: COTS - status

#202 2019-11-10 12:14:03

Re: COTS - status

#203 2019-11-10 16:51:30

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#204 2019-11-10 23:37:41

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#205 2019-11-11 09:23:45

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#206 2019-11-11 10:32:04

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#207 2019-11-12 10:36:59

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#208 2019-11-12 19:26:23

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#209 2019-11-12 20:37:14

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#210 2019-11-13 22:15:34

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#211 2019-11-14 07:36:42

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#212 2019-11-14 17:45:44

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#213 2019-11-16 18:54:25

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#214 2019-11-17 15:17:39

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#215 2019-11-19 21:29:12

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#216 2019-11-21 20:11:23

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#218 2019-11-22 19:13:36

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#219 2019-11-23 11:00:20

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#220 2019-11-23 23:32:20

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#221 2019-11-24 11:35:46

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#222 2019-11-25 00:19:01

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#223 2019-11-25 00:58:22

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#224 2019-11-25 09:32:42

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#225 2019-12-04 21:52:04

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