[AR] Re: arocket Digest V1 #30
- From: Douglas Messier <21stcenturycomm@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Wed, 9 Oct 2013 16:17:35 -0700
I'm a bit amused by how SpaceX handles its anomalies. Oh, the engine didn't
explode, it was pressure differential that caused the outer casing to fly
off. And it's a good test of the engine out capability, even though we're
going to re-arrange the engine layout in the upgraded version so if the
same thing happens on a future flight, say goodbye to the payload.
The seemingly nonchalance of having the upper stage not restart when you
need that to launch all the comsats in your manifest is also pretty
interesting. I think the explanation was something like, "no biggie, we've
restarted these engines on the ground, no gotta figure out why it didn't
work in a vacuum." Well, yeah....that's pretty much the trick, isn't it?
Designing the engine for restart in a vacuum. I realize it was a test
flight of an upgraded engine, but still....And we have to take his word
that it's not a major problem.
Musk has played the underdog role here so well to the point where people
are really rooting for him and excuse problems on the launch vehicle and
spacecraft that would have gotten others a lot more criticism. Stages
rolling, engines blowing apart, thruster pods not working, engines failing
to light, sensors getting confused by too much sunlight off JEMS. You never
know what's going to go wrong next. Imagine things like that going wrong on
ULA rockets or Japanese and European cargo ships and see if people would be
that forgiving.
I think these issues have been one of the reasons the military's attitude
toward SpaceX. They want cheaper launches, but with payloads that cost $1
billion or more, they can't afford any failures. It's better for them for
SpaceX to work out its bugs launching clothing and food to ISS (where a
failure won't cost that much or endanger the station) and satellites for
other entities that have insurance.
On Tue, Oct 8, 2013 at 10:12 PM, FreeLists Mailing List Manager <
ecartis@xxxxxxxxxxxxx> wrote:
> arocket Digest Tue, 08 Oct 2013 Volume: 01 Issue: 030
>
> In This Issue:
> [AR] Re: Falcon 9 flight today Apollo 13?
> [AR] venting (was Re: Re: Falcon 9 flight today)
> [AR] Re: Falcon 9 flight today
> [AR] Re: venting (was Re: Re: Falcon 9 flight today)
> [AR] Re: Falcon 9 flight today
> [AR] Re: Falcon 9 flight today
> [AR] Re: Falcon 9 flight today
> [AR] Funding for projects
> [AR] Re: Funding for projects
> [AR] Re: Funding for projects
>
> ----------------------------------------------------------------------
>
> Date: Tue, 8 Oct 2013 07:44:55 -0700 (PDT)
> From: Charles Pooley <ckpooley@xxxxxxxxxxxxx>
> Subject: [AR] Re: Falcon 9 flight today Apollo 13?
>
> If I recall correctly, the venting of the Apollo LOX tank rupture was seen
> by telescope by an amateur astronomer in Texas.
> In any case, the "snow flakes" would quickly evaporate, leaving a volume
> of gas going toward the Moon, or in orbit in the case of the F-9. Gas has
> a high frontal area per unit mass.
>
>
>
> ________________________________
> From: Chris Jones <clj@xxxxxxxxx>
> To: arocket@xxxxxxxxxxxxx
> Sent: Monday, October 7, 2013 6:37 PM
> Subject: [AR] Re: Falcon 9 flight today
>
>
> On 10/7/2013 8:16 PM, qbert@xxxxxxxxxxxxxxx wrote:
> > My question of the dangers of what ever was vented came up when I
> > looked through many other launch reports and found no info of venting
> > in these situations. The fact that it's not mentioned either means
> > other flights never vented and or it was a no issue item. In any case
> > this is the first such incident reported by persons on the ground
> > that I know of which leads one to believe that is not that common of
> > an event, at least in the past.
>
> Such events HAVE been reported and photographed in the past, and, as
> HenryS stated, it IS a common event (in fact, it is uncommon not to do it,
> and is a sign of a failure of the launcher or a failure to follow
> agreed-upon space debris mitigation techniques). Although venting is very
> common, seeing it depends on the observer being in darkness while the
> venting stage is in sunlight, so that situation is less common, but not
> unheard of (more correctly, not unseen).
>
> ------------------------------
>
> Date: Tue, 8 Oct 2013 11:58:30 -0400 (EDT)
> From: Henry Spencer <henry@xxxxxxxxxxxxxxx>
> Subject: [AR] venting (was Re: Re: Falcon 9 flight today)
>
> On Mon, 7 Oct 2013, Ben Brockert wrote:
> > The LOX would have contributed to the particle cloud with the RP-1.
> > Pulling vacuum on liquid nitrogen will create solid nitrogen... Same
> > is true for oxygen. The oxygen ice crystals wouldn't last long in
> > sunlight, but it wouldn't have gone straight to gas from the rocket.
>
> Some would go to gas while some went to solid -- it's the evaporation of
> part of it that chills the rest enough to freeze.
>
> The crystals wouldn't last long even when not in sunlight, because the
> nice warm Earth filling almost half the sky is, if anything, even more
> important to the thermal balance of something in LEO. The crystals would
> quickly warm to the point that they'd have a substantial vapor pressure,
> and then dwindle and disappear.
>
> The gas, whether formed directly or by sublimation of the crystals, will
> expand rapidly to very low density, and then decelerate by collisions with
> the surrounding atmosphere, quickly merging into it.
>
> Henry Spencer
>
> henry@xxxxxxxxxxxxxxx
> (
> hspencer@xxxxxxxxxxxxx)
> (
> regexpguy@xxxxxxxxx)
>
>
> ------------------------------
>
> Date: Tue, 8 Oct 2013 13:06:04 -0400 (EDT)
> From: Henry Spencer <henry@xxxxxxxxxxxxxxx>
> Subject: [AR] Re: Falcon 9 flight today
>
> On Mon, 7 Oct 2013 JMKrell@xxxxxxx wrote:
> > Henry notes that most of the venting is LOX. Ionizing radiation quickly
> > converts oxygen to monatomic radicals. Monatomic oxygen does etch the
> > surfaces of satellites as they pass through the cloud...
>
> Note, though, that there is plenty of atomic oxygen already present in
> LEO. And it will take time for solar UV to split up many of the oxygen
> molecules, time in which the cloud will be expanding rapidly. This isn't
> likely to be a significant hazard.
>
> > The pressurizing gas in the RP-1 tanks is vented, but little RP-1.
>
> The vapor pressure of RP-1 isn't large by Earth standards, but it's still
> substantial by vacuum standards. The RP-1 won't stay in the tank,
> although it may leave a bit of residue behind.
>
> > Venting tons of RP-1 would pose a coating hazard to satellite optics and
> > sensors.
>
> Again, this sort of thing would be an issue only if the satellite passed
> very close to the venting stage, very soon after the venting started.
> The density of the vapor/crystal cloud just isn't high enough to be
> an issue otherwise. People vent RP-1 stages in orbit all the time; I
> don't believe any satellite problem has ever been attributed to this.
>
> Henry Spencer
>
> henry@xxxxxxxxxxxxxxx
> (
> hspencer@xxxxxxxxxxxxx)
> (
> regexpguy@xxxxxxxxx)
>
>
> ------------------------------
>
> From: Henry Hallam <henry@xxxxxxxxxxxxxxxx>
> Date: Tue, 8 Oct 2013 11:47:37 -0700
> Subject: [AR] Re: venting (was Re: Re: Falcon 9 flight today)
>
> On Tue, Oct 8, 2013 at 8:58 AM, Henry Spencer <henry@xxxxxxxxxxxxxxx>
> wrote:
> > The crystals wouldn't last long even when not in sunlight, because the
> > nice warm Earth filling almost half the sky is, if anything, even more
> > important to the thermal balance of something in LEO.
>
> As a small aside, this makes passive thermal control of small
> satellites in LEO *really easy*.
>
> - other Henry
>
> ------------------------------
>
> From: JMKrell@xxxxxxx
> Date: Tue, 8 Oct 2013 16:06:50 -0400 (EDT)
> Subject: [AR] Re: Falcon 9 flight today
>
>
> In a message dated 10/8/2013 10:06:43 A.M. Pacific Daylight Time,
> henry@xxxxxxxxxxxxxxx writes:
>
> On Mon, 7 Oct 2013 JMKrell@xxxxxxx wrote:
> > Henry notes that most of the venting is LOX. Ionizing radiation quickly
> > converts oxygen to monatomic radicals. Monatomic oxygen does etch the
> > surfaces of satellites as they pass through the cloud...
>
> Note, though, that there is plenty of atomic oxygen already present in
> LEO. And it will take time for solar UV to split up many of the oxygen
> molecules, time in which the cloud will be expanding rapidly. This isn't
> likely to be a significant hazard.
> As I stated monatomic oxygen is a nuisance and not an issue.
>
>
>
>
> > The pressurizing gas in the RP-1 tanks is vented, but little RP-1.
>
> The vapor pressure of RP-1 isn't large by Earth standards, but it's still
> substantial by vacuum standards. The RP-1 won't stay in the tank,
> although it may leave a bit of residue behind.
>
> Henry, I agree with 99.9% of what you post, but on this I must go with my
> empirical data. Some RP-1 is expelled during the venting of the RP-1 tank.
> The rest quickly gels and solidifies within the tank. Frozen fluids under
> high vacuum transfer mainly between hot and cold junctions, complicating
> venting with a thermal gradient function together with the molecular
> pressure
> function. Most of the RP-1 remains a solid until the vehicle reenters the
> atmosphere. This is one reason why it has never been an issue. Are there
> any
> molecular flow studies of vent lines?
>
>
>
> > Venting tons of RP-1 would pose a coating hazard to satellite optics and
> > sensors.
>
> Again, this sort of thing would be an issue only if the satellite passed
> very close to the venting stage, very soon after the venting started.
> The density of the vapor/crystal cloud just isn't high enough to be
> an issue otherwise. People vent RP-1 stages in orbit all the time; I
> don't believe any satellite problem has ever been attributed to this.
>
>
> Henry Spencer
> henry@xxxxxxxxxxxxxxx
> (hspencer@xxxxxxxxxxxxx)
> (regexpguy@xxxxxxxxx)
>
>
>
>
>
> ------------------------------
>
> Date: Tue, 8 Oct 2013 19:00:21 -0400 (EDT)
> From: Henry Spencer <henry@xxxxxxxxxxxxxxx>
> Subject: [AR] Re: Falcon 9 flight today
>
> On Tue, 8 Oct 2013 JMKrell@xxxxxxx wrote:
> > > The vapor pressure of RP-1 isn't large by Earth standards, but it's
> > > still substantial by vacuum standards. The RP-1 won't stay in the
> > > tank, although it may leave a bit of residue behind.
> >
> > Henry, I agree with 99.9% of what you post, but on this I must go with
> > my empirical data. Some RP-1 is expelled during the venting of the RP-1
> > tank. The rest quickly gels and solidifies within the tank. Frozen
> > fluids under high vacuum transfer mainly between hot and cold
> > junctions... Most of the RP-1 remains a solid until the vehicle reenters
> > the atmosphere.
>
> Is that empirical data published? If so, references please! I have
> trouble believing that the solid would be stable in vacuum for any length
> of time, unless the thermal situation was very unusual.
>
> Henry Spencer
>
> henry@xxxxxxxxxxxxxxx
> (
> hspencer@xxxxxxxxxxxxx)
> (
> regexpguy@xxxxxxxxx)
>
>
> ------------------------------
>
> Date: Tue, 8 Oct 2013 17:34:14 -0700
> Subject: [AR] Re: Falcon 9 flight today
> From: Keith Henson <hkeithhenson@xxxxxxxxx>
>
> The vapor pressure of RP-1 at 50 deg F is given as 0.031 psia.
>
> That's not high, but open to space, the stuff is going to evaporate
> unless, as Henry says, it's awful cold.
>
>
>
> On Tue, Oct 8, 2013 at 4:00 PM, Henry Spencer <henry@xxxxxxxxxxxxxxx>
> wrote:
> > On Tue, 8 Oct 2013 JMKrell@xxxxxxx wrote:
> >> > The vapor pressure of RP-1 isn't large by Earth standards, but it's
> >> > still substantial by vacuum standards. The RP-1 won't stay in the
> >> > tank, although it may leave a bit of residue behind.
> >>
> >> Henry, I agree with 99.9% of what you post, but on this I must go with
> >> my empirical data. Some RP-1 is expelled during the venting of the RP-1
> >> tank. The rest quickly gels and solidifies within the tank. Frozen
> >> fluids under high vacuum transfer mainly between hot and cold
> >> junctions... Most of the RP-1 remains a solid until the vehicle reenters
> >> the atmosphere.
> >
> > Is that empirical data published? If so, references please! I have
> > trouble believing that the solid would be stable in vacuum for any length
> > of time, unless the thermal situation was very unusual.
> >
> > Henry Spencer
> >
> henry@xxxxxxxxxxxxxxx
> > (
> hspencer@xxxxxxxxxxxxx)
> > (
> regexpguy@xxxxxxxxx)
> >
> >
>
> ------------------------------
>
> Date: Tue, 08 Oct 2013 19:38:31 -0700
> From: Aidan Sojourner <aidan@xxxxxxxxxxxx>
> Subject: [AR] Funding for projects
>
> How do you guys get funding for your projects? My team has a wonderful
> design that will probably never see the light of day due to lack of
> funds. We are expecting upwards of $7.5k for the project, something that
> none of us can manage.
>
> We have thought about kickstarter, but I personally don't see the
> appeal. Why would someone donate $100 for ANOTHER PERSON to go do
> something? It's a donation, sure, but what does the donator get out of
> it? For Video Games/Movies/other content, the donate gets the content.
> This is why Kickstarter is successful in this category. What exactly
> does the donator get in our case, save for a magnificent view of earth
> from onboard our project? I would never pay $10, let alone $100 for
> that, and I don't know anyone else who would.
>
> Another option is a capital investment from a single source. How would
> you convince someone to give you $7.5k to send a sounding rocket to
> 200,000 feet? The same with kickstarter, what exactly would they get out
> of it? CSXT got a lot of funding from the GoFast energy drink company.
> How did Ky manage to swing this? Was it simply because it was a large,
> historic event? The recent "Aeropac 100k" project in 2012 got funding
> from Google, I believe since Google wanted to do a commerical based on
> the project. In both of these examples, the donator got their name
> heard. (google has not yet, although I hear they are going to release
> the commerical sometime this fall) Everyone in the rocketry community
> heard of the "GoFast Rocket", and the google commercial will likely
> bring more revenue in sales than they spent.
>
> </wall of text>
> Maybe I seem negative. What have you guys tried/thought about? I am open
> to any suggestions, and I would love to get this project started.
>
> ------------------------------
>
> Date: Tue, 8 Oct 2013 23:45:16 -0400
> Subject: [AR] Re: Funding for projects
> From: Thomas McNeill <thomas.mcneill@xxxxxxxxx>
>
> Aidan,
>
> Is this a university club project? There are plenty of options there.
> When I was at UCF our SEDS club managed to get good funding from local
> companies and the university. If it is on your own I have to say $7.5k
> isn't much. I could swing that on a part time job or some freelance work.
> It might delay my projects some but I would have the money. It you were
> needing $75k or $750k then it is a bigger problem.
>
> Thomas
>
>
>
>
> On Tue, Oct 8, 2013 at 10:38 PM, Aidan Sojourner <aidan@xxxxxxxxxxxx>
> wrote:
>
> > How do you guys get funding for your projects? My team has a wonderful
> > design that will probably never see the light of day due to lack of
> funds.
> > We are expecting upwards of $7.5k for the project, something that none of
> > us can manage.
> >
> > We have thought about kickstarter, but I personally don't see the appeal.
> > Why would someone donate $100 for ANOTHER PERSON to go do something?
> It's a
> > donation, sure, but what does the donator get out of it? For Video
> > Games/Movies/other content, the donate gets the content. This is why
> > Kickstarter is successful in this category. What exactly does the donator
> > get in our case, save for a magnificent view of earth from onboard our
> > project? I would never pay $10, let alone $100 for that, and I don't know
> > anyone else who would.
> >
> > Another option is a capital investment from a single source. How would
> you
> > convince someone to give you $7.5k to send a sounding rocket to 200,000
> > feet? The same with kickstarter, what exactly would they get out of it?
> > CSXT got a lot of funding from the GoFast energy drink company. How did
> Ky
> > manage to swing this? Was it simply because it was a large, historic
> event?
> > The recent "Aeropac 100k" project in 2012 got funding from Google, I
> > believe since Google wanted to do a commerical based on the project. In
> > both of these examples, the donator got their name heard. (google has not
> > yet, although I hear they are going to release the commerical sometime
> this
> > fall) Everyone in the rocketry community heard of the "GoFast Rocket",
> and
> > the google commercial will likely bring more revenue in sales than they
> > spent.
> >
> > </wall of text>
> > Maybe I seem negative. What have you guys tried/thought about? I am open
> > to any suggestions, and I would love to get this project started.
> >
> >
>
>
>
> ------------------------------
>
> Date: Tue, 08 Oct 2013 22:01:35 -0700
> From: Aidan Sojourner <aidan@xxxxxxxxxxxx>
> Subject: [AR] Re: Funding for projects
>
> Sorry, I forgot to mention-
> We are all students with either a retail job, or no job. My current
> "life savings" is about $1k. $7.5k is a lot for us, but not really a lot
> for someone who has a college degree and makes more than $10 an hour.
> I forgot option 3: Beg parents for money. Say it's for "education"(I
> guess it is, in a sense).
>
> Thanks,
> Aidan
>
> On 8/10/13 8:45 PM, Thomas McNeill wrote:
> > Aidan,
> >
> > Is this a university club project? There are plenty of options
> > there. When I was at UCF our SEDS club managed to get good funding
> > from local companies and the university. If it is on your own I have
> > to say $7.5k isn't much. I could swing that on a part time job or
> > some freelance work. It might delay my projects some but I would have
> > the money. It you were needing $75k or $750k then it is a bigger
> problem.
> >
> > Thomas
> >
> >
> >
> >
> > On Tue, Oct 8, 2013 at 10:38 PM, Aidan Sojourner <aidan@xxxxxxxxxxxx
> > <mailto:aidan@xxxxxxxxxxxx>> wrote:
> >
> > How do you guys get funding for your projects? My team has a
> > wonderful design that will probably never see the light of day due
> > to lack of funds. We are expecting upwards of $7.5k for the
> > project, something that none of us can manage.
> >
> > We have thought about kickstarter, but I personally don't see the
> > appeal. Why would someone donate $100 for ANOTHER PERSON to go do
> > something? It's a donation, sure, but what does the donator get
> > out of it? For Video Games/Movies/other content, the donate gets
> > the content. This is why Kickstarter is successful in this
> > category. What exactly does the donator get in our case, save for
> > a magnificent view of earth from onboard our project? I would
> > never pay $10, let alone $100 for that, and I don't know anyone
> > else who would.
> >
> > Another option is a capital investment from a single source. How
> > would you convince someone to give you $7.5k to send a sounding
> > rocket to 200,000 feet? The same with kickstarter, what exactly
> > would they get out of it? CSXT got a lot of funding from the
> > GoFast energy drink company. How did Ky manage to swing this? Was
> > it simply because it was a large, historic event? The recent
> > "Aeropac 100k" project in 2012 got funding from Google, I believe
> > since Google wanted to do a commerical based on the project. In
> > both of these examples, the donator got their name heard. (google
> > has not yet, although I hear they are going to release the
> > commerical sometime this fall) Everyone in the rocketry community
> > heard of the "GoFast Rocket", and the google commercial will
> > likely bring more revenue in sales than they spent.
> >
> > </wall of text>
> > Maybe I seem negative. What have you guys tried/thought about? I
> > am open to any suggestions, and I would love to get this project
> > started.
> >
> >
>
>
>
>
> ------------------------------
>
> End of arocket Digest V1 #30
> ****************************
>
>
--
Douglas Messier
Mojave, CA
Email: 21stCenturyComm@xxxxxxxxx
Phone: (310) 739-0952
Linkedin: www.linkedin.com/in/douglasmessier
Facebook: http://profile.to/douglasmessier/
Blog: www.parabolicarc.com
Twitter: @spacecom
Other related posts:
