They had to evacuate the OPF due to a hydrazine leak yesterday. But they plan to continue to use hypergolics in Orion.

Just one more sign of business as usual at NASA.

Rand

No confirmation yet, but I am hearing, that due to performance shortfalls with the stick, that they are considering going back to CH4/O2.

Dennis

Do they want the MMH/NTO for RCS/ACS
or for main propulsion?

Ah, the good old days.

Used to be a bloody three ring circus at the slightest wiff of hyper. At the rumor of hyper. If I were to guess, someone removed a qd cap and there was a slight puff or a drop and it was Katie bar the door. (....oh darn...I just went to read the article.....)

KSC safety used to talk about hypers the way KOS talks about President Bush. I imagine that has not improved.

No one ever mentions the bajillion hours of perfectly safe hyper ops.

The major drawback to hypers is the prep time and training and support for operations. It is expensive I will agree.

But it is not irresponsible. It's just a way.

Somehow I cannot see KSC safety just a smilin' and saying "methane....sure, no problemo."

I had hot chicken wings, dirty rice, lima beans and cabbage for lunch, then ate at a Mexican restaurant last night for supper, I assure you, the methane program is still ongoing.

Rand: They did not cancel the methane program. NASA awarded 4 contracts early this year for "technology maturation" projects; two for RCS and two for upper stage main propulsion. The object is to raise the technology readiness level of LOX/CH4 in general, to flush out potential problems with the propellant combination in general, and to review the specific designs of the contractors. I can't speak at all for the other 3 contractors, and I can't say much more than this without having to go through the press release approval process, but the ATK-XCOR team is on the hook to start hot firing a 7500 lbf thrust LOX/CH4 pressure-fed engine next month.

Yep, recently GRC issued this Conceptual Design Study notification saying that LCH4 is under consideration for the Orion SM and the LSAM.

Just how much toxicity does methane have compared to hydrazine, anyway?

Compare the MSDS's. Methane isn't even listed as toxic, just flamable:

http://physchem.ox.ac.uk/msds/ME/methane.html

http://physchem.ox.ac.uk/MSDS/HY/hydrazine.html

http://ptcl.chem.ox.ac.uk/MSDS/NI/nitrogen_dioxide.html

Dan-

CH4 and LOX were baselined for the CEV. They were removed from the CEV. Unless Dennis' sources are correct, I'm willing to let Rand's 'cancelled' stand, even though there may be plans to 'someday' have methane/LOX propulsion on the CEV.

Phil: The differences in toxicity are huge. Hydrazine is a carcinogen, a mutagen, chronically toxic, acutely toxic, and can be absorbed through the skin. The maximum allowable concentration in air in the workplace is 0.1 parts per million, and kills 50% of rats in 4 hours breathing 570 ppm. That's 0.06% Quoting Henry Spencer, "the only good thing about hydrazine is that it's not radioactive".

Methane, on the other hand, can be inhaled short term at 100% concentration. Don't be smoking a cigarette though. Dairy cattle produce about 0.3 kg/day and some countries (e.g. New Zealand) have a significant fraction of their greenhouse gas production from cows. When we were running our 50 lbf LOX/LCH4 engine, we measured the spills in cow-days (never more than 10).

Could be worse, they could be using red fuming nitric acid, the way the Russkies still do.

Nitrogen tetroxide isn't much better than RFNA.

Just how much toxicity does methane have compared to hydrazine, anyway?

To add to the previous points on this question...

The background level of methane in the troposphere is greater than the regulatory limit on hydrazine in workplace air.

I don’t think much of methane as a propellant either because it isn’t easily storable for any length of time. It’s also a feed problem for RCS. MMH and NTO don’t have those problems.

Rocketdyne and Lockmart told NASA about a propellant that has all the advantages of methane and is storable and feedable (if that’s a word), but they have apparently ignored it so far. I suspect that someone at Marshall has their career invested in methane.

So, what is this propellant?

Anyone who had knowledge of what Rocketdyne or Lockmart submitted to NASA would probably be bound by a proprietary agreement. Sorry.

The point was that I and many others are often frustrated by NASAs NIH attitude and their tendency to keep all the money they can get their hands on to fund their own personal research projects. I view many NASA engineers/scientists (using the term loosely) as frustrated Ph.D.s that weren’t good enough for a faculty position at a research university.

Steve Chamberlin former CEO of Integrl Systems
referred to NASA as full of unemployed PhD's.
he may have used the wrong tense there.

two questions:

is the mystery fuel ethanol?

how toxic is nitric acid compared to RFNA or hydrazine?

Anecdotally, I recall a segment on a Discovery channel documentary talking about one of the countless test rockets from back in the '50's. After several pad explosions/failed launches one of the techs volunteered to do a last minute checkout of the rocket shortly before lift-off. He stuck his head into the rocket and used his sophisticated hydrazine detector to look for signs of leaks, his nose. As the guy relating the story on the show noted, OSHA would have had a field day with that one.

Hydrazine is a fuel. Nitric acid (and red fuming nitric acid) are oxidizers. You're asking for a comparison between apples and oranges, since you can't substitute one for the other. The oxidizer is a separate (and equally bad) issue.

is the mystery fuel ethanol?

No. It’s something that to my knowledge has never received much attention. Sorry to be so mysterious, but I really can’t say. Best left at that.

The heating value of a fuel is significantly reduced by the presence of oxygen. In general H good, C ok, O, bad. Don't buy oxygenated fuel, it’s a kilo joule rip off.

What's the feed problem with Methane? Thin pipes with cold fluid? Intuitively, that's the only thing that occurs to me.

Assuming it's correct, could the problem be solved using gaseous methane and GOX?

All this talk of methane and storability it is more storable then hydrogen proposed for the LSAM.
Though one over looked fuel for rcs/oms systems is propane it would give good isp,non corrosive,abosolutely nontoxic people cook with it, and is storable indefinetly.
Also propane is a liquid at sane tempertures and pressures so fuel plumbing would be a breeze.
personallyI think the best RCS fuel and oxidizer combo would be N2O,and propane with methane being the next best option.
Also they need to get away from the stick.
The direct launcher is a far better combination then the ares I and V combo.
Not only does the stick have marginal performance and can only be used to launch payloads that can make up the messing delta V so it cannot be used for iss parts or satilites.
This also means orion cannot do servicing mission for hubble or JWST if ares I is used.
It also is dymanicly unstable between mach 0 and 1.7 this could cause loss of a crew.
It almost seems they want orion to fail looking at ares I's short commings.