All joking aside, as a former NASA Space Shuttle engineer I'm very impressed by this private-enterprise venture into heavy-lift launch services. People have often speculated about how much cheaper launch services might be if they were in the private sector -- now we can find out. The preliminary signs are very good.
I read your IAmA where you had a reply to a message, now deleted, in which you must have been asked about aerial circumnavigation. You mentioned that you'd use a solar balloon, and that you merely would have to have a strategy for darkness.
I've spent a fair amount of time thinking about this, and it may interest you to know that:
Water vapor has both a lower molar density than air
The phase transition of water vapor gives more than enough energy to heat up more than the equivalent volume of air to displace the reduced volume of water vapor turning to liquid.
So, a possible strategy for darkness is to have a two bladdered balloon, one with water vapor + air, one with just air. Then, when the water vapor condenses, transfer the heat to air sourced from outside the balloon via a counterflow heat exchanger. Put that warmed air in the air bladder. You won't stay at precisely the same height, but you will retain volume and you can stay buoyant.
Many things work well when your thermal energy storage is positively buoyant.
Regards,
Come visit the next time you're free around Berkeley or Oakland.
That reminds me of a euphemism that I found delightful that I heard once while working for a space company... "achieving submerged geostationary orbit," I think it was.
Yes, I need to retract my prior comment about the engine "exploding" [1]; the failure mode was much more benign, and the surround engines were never under threat. However, the nozzle was very clearly ejected following the shut-down, so for all intents and purposes, it became an ex-engine. And the Falcon didn't flinch. Impressive.
Watching this private space stuff manifest is absolutely thrilling. I was tangentially involved in things way back in the early 90's, when the private space geeks were regarded as crackpots by the mainstream aerospace community, if indeed they were acknowledged at all. They certainly didn't have any money (aside from odd forays such as Andrew Beal's[2] and Gary Hudson's[3] abortive adventures), and often did come across as crackpots, but for the life of me it seemed like they had a valid point. To see those sort of folks finally succeed is just infinitely thrilling.
Just a heads up - I tried to send a message to you on your website (arachnoid.com) and got the following error:
Error: embedded tags.
Warning: eregi() [function.eregi]: REG_EMPTY in /home/arachn5/public_html/messages/processMessage.php on line 84
Please press the "back" button to correct your entry.
I don't have any HTML in my message, and I'd really like to send it :-) Do you have an email address I could use please?
I was curious about how reliable we should predict a Falcon 9 launch to be based on the stated design parameters (survives the loss of any 2 engines) and current launch data.
Good stuff OP, nice to see Bayesian getting more attention recently. However, after reading your blog post, I can't help get the feeling this is how a natural frequentist would approach the problem. This method is effectively relying on known, statistical record of past events to form the priors.
Often a more useful and appropriate construct in the Bayesian world, is the use of a belief network or Bayesian Network. This is a probabilistic directed acyclic graph (DAG) that encodes priors, often in the form of subjective beliefs (yes subjectivity can be useful), including specific domain knowledge.
Common example: Consider a naive Bayesian classifier (a specialized form of belief network) that identifies individual pieces of spam. Do we arrive at the spam score by entering the probability of past events into a simple model based of the Bayes theorem formula?
No, it's trained using the vast amount of domain knowledge and pattern recognition (through our experience and own estimation of what 'spam' is) encoded in our minds, that provide the priors. Thus, even though there is a large amount of subjectivity involved, the overall result can objectively be measured, within a given utility function. Incidentally, this is often what makes many hardcore empiricists 'nervous', and hence avoid belief networks altogether.
Coming back to the Falcon 9: A piece of prior information outside the scope of historic safety records, for example, one of the lead engineers having a nagging doubt about a particular technical risk based on some observed phenomenon, could have an impact on the real world probability of the next event being a failure. (Which is a pretty useful thing to know!)
In fact, this exact scenario happened in 2003 with the disastrous destruction of the Space Shuttle Columbia. [1] An engineer spotted something wrong on previous flights, but management failed to heed the warning[2]. This could quite possibly have been averted, if a risk mitigation model were in place to account for such evidence.
Looking forward, it's quite possible to imagine a future where this decision making has been outsourced to a sophisticated AI based off a Bayes net, with far more accurate real world modeling of risk and failure probabilities, outclassing the amount of evidence and a human or committee could possibly hope to compete with.
While I've nothing against frequentist approaches (albeit Bayesian naturally makes more intuitive sense to me), a minor drawback is the reliance on the past to predict the future. For example if you had safety records on 1 million previous flights, then one might be tempted to say, "well that's that then, we now know objectively the probability of failures in the future -- end of story". But, the 1 000 001 flight may have been designed to fly on a completely different type of technology, that will change significantly change the safety record of space flight going forward for the next "x" years. Thus using a Bayesian approach account for all relevant priors, it would in theory be possible to reflect a more accurate probability for the 1 000 001 flight, before it took place.
Lastly Bayes nets are not the best tool for every job, and do have drawbacks in certain situations. They are vulnerable to things like Bayesian poisoning or confirmation bias. A Bayesian approach is only as useful as the ongoing real world relevancy and accuracy of the priors. As the old adage goes, GIGO - garbage in, garbage out.
Horizontal axis is how many engines failed, and vertical axis is how many times that number of engines failed in the simulation.
The code that generated this is:
from scipy.stats import *
from pylab import *
failures = [binom(9,p).rvs() for p in beta(1,1,1e5) if binom(9,p).rvs() == 1]
hist(failures, bins=9, range=(0,9))
show()
The way this code works is it first picks a `p` from the prior. This `p` represents the failure probability for a single engine. Then we simulate the number of engines that fail when you have 9 of them, and filter out just the worlds where that number is equal to 1 as in the SpaceX launch. Or equivalently, we annihilate all the worlds that have a different observation than ours -- this is a central tenet in Bayesian statistics in contrast to frequentist statistics: we only base our inferences on the things that happened and not on things that hypothetically could have happened but didn't. In a slogan you could say "our fantasies are irrelevant". Then in the worlds that remain, where the same observation was made as in our world, we simulate the number of engines that fail on a new rocket launch and collect the results in a histogram.
So the posterior probability on the entire rocket failing for uniform prior is around 25%. Uniform prior means that you believe that all single engine failure probabilities are equally likely: you think it's equally likely that engines fail with 10% probability as with 63% probability. Tweak the first two parameters to beta to change your prior belief. If you've seen n engines fail in your life and k engines succeed, then setting the first parameter to n+1 and the second to k+1 is a reasonable choice (so the current setting corresponds to not having seen any rocket launches prior to this one). For example if you've seen 2 engines fail and 99 engines succeed you use `beta(3,100,1e5)`: https://dl.dropbox.com/u/388822/rocketfailuredistr_for_optim... Hardly any probability mass left for entire rocket failure :)
To make comparisons, IIRC the failure ratio of the unmanned missions is 10-15% and in the manned missions is about 2%.
An important detail is what happens when 3 or more engines fail simultaneously. Can they transform the mission in a soft landing or the "payload" is totally doomed? (For example, the Apollo XIII mission was a failure, but no one died.)
One factor that I don't think has been answered, if this engine shutdown was going to be the 3rd and would cause a mission loss, could if have been persisted with.
It isn't clear whether it was on the way to complete engine failure or it was shut down to play it safe.
Two thoughts here.
1) You're working from an awfully small sample, especially for a component that is supposed to be of such a high reliability. Then again, look at the probabilistic assessment of Shuttle success vs. actual.
2) The Merlin 1C engine is only going to make a few more flights afaik. Starting some time in 2013 they'll be switching to Merlin 1D.
>"Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines."
Can anyone that knows something about the Falcon 9 design or rockets in general shed some light on this? That sentence makes it sound like the panels were purposefully jettisoned, which doesn't make sense to me. What do those panels do, what do they look like, and where are they?
Purposefully jettisonning panels is a way of preventing an explosion from damaging the rest of the ship. The rocket creates energy in a direction, but what if something prevents the energy from going in that direction? The energy, in the form of expanding gasses, has to go somewhere. If these panels didn't break away to give the energy somewhere to go, it could have forced into another rocket or into the ship's body, causing a much bigger problem.
They probably refer to breakaway panel fairings above the engine isolation armor. Space X has an armor "cup"around the dangerous parts of the engine, and put fittings on top of that for some reason; aero probably.
Their statement suggests these came off when pressures radically changed during engine cut off, which is plausible. It was at max aerodynamic pressure, and removing all the pressure the motor generates is a big swing. I find it more likely that the nozzle (bell) shattered, as it is more exposed to both aero and combustion pressures. Maybe both happened.
When a liquid engine fails energetically, it's usually going to be a failure in the chamber. Nozzle or throat burn-through or other failure may also happen. The turbo pump might also let go and shred some stuff nearby. Plumbing failures may also kill the engine, but not destroy much; there are plenty of valves to fix leakage before it gets bad.
Here you can see the armored tub around the chamber section of each engine. It is meant to contain any problems. Mostly these would be hot gas from holes burned in the chamber or throat, fuel or oxidizer from leaks in the plumbing, or shrapnel from the turbo pump coming apart. Note that the other major failure mode, excessive vibration, cannot be armored against, but that is more a design thing than a random failure.
Most to all of these failures are easily detected by various pressure and flow sensors, and usually before they become big problems. Turn off the propellant valves, and the engine rapidly becomes safe, though off. But the armor does keep the neighbors safe from any problems, presuming it holds.
I would guess it is good enough for most failures.
Here you can see pretty white fairings hiding everything but the nozzles. Note that they appear to be a bunch of different pieces. Probably that is because they are meant to break away individually if something goes wrong.
Those are what I think the statement refers to. I doubt they are actively jettisoned, but may certainly be designed to pop off in an over-pressure situation. One could probably compare vs the video to see if the pieces look like that, the nozzle, or other engine parts. The corner fairing might also have failed under some circumstances.
Having seen the video in slow mo a few times, I think their assessment is plausible. Probably they will be able to tell what happened by telemetry. I don't know if they are still trying to recover stages, but if they are, they might get their hands in some physical evidence. Whether we will ever see any of this data, though, I don't know. They've been reasonably open in the past.
"Falcon 9 did exactly what it was designed to do. Like the Saturn V (which experienced engine loss on two flights) and modern airliners, Falcon 9 is designed to handle an engine out situation and still complete its mission. No other rocket currently flying has this ability."
Chills down my spine as I read this. I try to write eloquently, but sometimes the fact should stand alone: "No other rocket currently flying has this ability."
This reminds me of a major feature Chrome had when launched - to withstand a crash of any of the opened tabs. I thought it's a funny feature to have... other browsers just preferred not to crash in the first place. Then I tried Chrome and realized it was a great feature for them, because Chrome kept crashing all the time (back then).
What I wanted to say by this is that while it's a great thing for Falcon 9 to have fail-over in its maiden flights (as we could see yesterday), I wouldn't worry too much about "other rockets" not having this. Soyuz rockets are a great example (100% success rate for manned flights to ISS and over 97% success rate for all Soyuz rockets (that's since 1966)[1]).
I saw the engine flame out and the panels come apart during the launch. I expected some comment on the launch radio because it was obviously not SOP (engines shouldn go out with debris), yet, due to good design, the entire launch remained nominal.
I am now getting hopeful that I'll be able to experience zero-G before I die. SpaceX team, you are my heroes. Keep up the great work!
The main mission (Dragon/ISS) wasn't affected, but a secondary payload (an ORBComm test satellite) was left in the Dragon's insertion orbit, and didn't get the scheduled secondary boost --- apparently because, after the delayed orbital insertion, the reboost would have gone too close to ISS, according to an ORBComm press release:
Am I the only one who got confused by the first sentence? "The Dragon spacecraft is on its way to the International Space Station this morning and is performing nominally...".
Is everything fine now, or is it not? "Nominally" in this sense to me means that something is amiss, but reading the rest of the article seems to imply that everything is on track.
Wikipedia has a better explanation than I or others' comments, so far, could provide: http://en.wikipedia.org/wiki/Real_versus_nominal_value, and it 's "secondary" meaning is not, at all, limited to aerospace linguistics.
The engine failed prior to MECO-1 (where the first two scheduled shutdowns occur) so there were still 8 lit engines. There's no capability to restart the engines that have been shut down.
It's amazing that this could have worked as a Dragon 7. One engine failed and they still could have made it with one other engine malfunctioning. Bearing in mind the cost of the launches for SpaceX are forecasted to be significantly lower than old shuttles, this is all the more impressive.
There was a misshap though, since the Orbcomm satellite wasn't nearly put on the right orbit. I have no idea whether the onboard propulsion of the satellite will be enough to get into the desired orbit, but if they do manage it, it will be a testament to the quality and interest of fault-tolerant space operations.
I have to admit that I'm impressed at how well the system they build compensated for the mechanical failure. It looks like they have some good people building things.
One aspect that's worth consideration is the private/corporate aspects of spaceflight. When there were failures in Apollo and the shuttle, the public had a right to know everything that happened since we'd paid for everything. SpaceX has been super cool about disclosure here, but how long can we count on that? At some point, there's too much money at stake for them to maintain full transparency.
What's more important than disclosure to the public after something has gone wrong, is disclosure to the customers (e.g. NASA) and future astronauts ahead of time if something has been identified as a potential problem before launch. The Space Shuttle Challenger disaster occurred because managers failed to acknowledge the warnings of engineers, who recommended postponing the launch due to cold weather which could prevent some O-rings from functioning properly. Having the ability to acknowledge and correct problems ahead of time, even if it means a launch delay and potentially some lost profits, will ultimately pave the path for a sustainable private space industry.
But I think that SpaceX understands that NASA is funded by the public and it will be easier to get the support of NASA if they have the support of the public. I would suspect that for this reason they will continue a decent amount of public disclosure.
I saw the launch live and I saw the debris ejecting about 90 seconds in. What I found particularly amazing was that SpaceX either didn't know it, didn't want to confirm it or just realised that their design worked because all I heard after that was my favourite aerospace term "Situation nominal".
[+] [-] lutusp|13 years ago|reply
No, it just became a "Falcon 8" while enroute.
All joking aside, as a former NASA Space Shuttle engineer I'm very impressed by this private-enterprise venture into heavy-lift launch services. People have often speculated about how much cheaper launch services might be if they were in the private sector -- now we can find out. The preliminary signs are very good.
[+] [-] DaniFong|13 years ago|reply
I read your IAmA where you had a reply to a message, now deleted, in which you must have been asked about aerial circumnavigation. You mentioned that you'd use a solar balloon, and that you merely would have to have a strategy for darkness.
I've spent a fair amount of time thinking about this, and it may interest you to know that:
Water vapor has both a lower molar density than air The phase transition of water vapor gives more than enough energy to heat up more than the equivalent volume of air to displace the reduced volume of water vapor turning to liquid.
So, a possible strategy for darkness is to have a two bladdered balloon, one with water vapor + air, one with just air. Then, when the water vapor condenses, transfer the heat to air sourced from outside the balloon via a counterflow heat exchanger. Put that warmed air in the air bladder. You won't stay at precisely the same height, but you will retain volume and you can stay buoyant.
Many things work well when your thermal energy storage is positively buoyant.
Regards,
Come visit the next time you're free around Berkeley or Oakland.
[+] [-] kmfrk|13 years ago|reply
[+] [-] majormajor|13 years ago|reply
[+] [-] toomuchtodo|13 years ago|reply
DUDE, give them a break.....
read next line
Oh. OH! I have no business commenting on this subject.
[+] [-] nkoren|13 years ago|reply
Watching this private space stuff manifest is absolutely thrilling. I was tangentially involved in things way back in the early 90's, when the private space geeks were regarded as crackpots by the mainstream aerospace community, if indeed they were acknowledged at all. They certainly didn't have any money (aside from odd forays such as Andrew Beal's[2] and Gary Hudson's[3] abortive adventures), and often did come across as crackpots, but for the life of me it seemed like they had a valid point. To see those sort of folks finally succeed is just infinitely thrilling.
[1] http://news.ycombinator.com/item?id=4625221
[2] http://en.wikipedia.org/wiki/Beal_Aerospace
[3] http://en.wikipedia.org/wiki/Rotary_Rocket
[+] [-] wamatt|13 years ago|reply
The fact that an engine failed, should be viewed as a success, as it allowed for the validation of the fault tolerant design.
It's not that one should never have failures, what matters is how they mitigate and adapt, in order to complete the mission.
[+] [-] pasbesoin|13 years ago|reply
[+] [-] davedx|13 years ago|reply
Just a heads up - I tried to send a message to you on your website (arachnoid.com) and got the following error:
Error: embedded tags.
Warning: eregi() [function.eregi]: REG_EMPTY in /home/arachn5/public_html/messages/processMessage.php on line 84 Please press the "back" button to correct your entry.
I don't have any HTML in my message, and I'd really like to send it :-) Do you have an email address I could use please?
[+] [-] btilly|13 years ago|reply
I found that under a simple Bayesian model, the estimated probability of catastrophic failure during the next launch is 3.6%. See http://bentilly.blogspot.com/2012/10/how-reliable-will-falco... for details.
Update: I made a careless calculation error. Change 3.6% to 2%. Oops.
[+] [-] wamatt|13 years ago|reply
Often a more useful and appropriate construct in the Bayesian world, is the use of a belief network or Bayesian Network. This is a probabilistic directed acyclic graph (DAG) that encodes priors, often in the form of subjective beliefs (yes subjectivity can be useful), including specific domain knowledge.
Common example: Consider a naive Bayesian classifier (a specialized form of belief network) that identifies individual pieces of spam. Do we arrive at the spam score by entering the probability of past events into a simple model based of the Bayes theorem formula?
No, it's trained using the vast amount of domain knowledge and pattern recognition (through our experience and own estimation of what 'spam' is) encoded in our minds, that provide the priors. Thus, even though there is a large amount of subjectivity involved, the overall result can objectively be measured, within a given utility function. Incidentally, this is often what makes many hardcore empiricists 'nervous', and hence avoid belief networks altogether.
Coming back to the Falcon 9: A piece of prior information outside the scope of historic safety records, for example, one of the lead engineers having a nagging doubt about a particular technical risk based on some observed phenomenon, could have an impact on the real world probability of the next event being a failure. (Which is a pretty useful thing to know!)
In fact, this exact scenario happened in 2003 with the disastrous destruction of the Space Shuttle Columbia. [1] An engineer spotted something wrong on previous flights, but management failed to heed the warning[2]. This could quite possibly have been averted, if a risk mitigation model were in place to account for such evidence.
Looking forward, it's quite possible to imagine a future where this decision making has been outsourced to a sophisticated AI based off a Bayes net, with far more accurate real world modeling of risk and failure probabilities, outclassing the amount of evidence and a human or committee could possibly hope to compete with.
While I've nothing against frequentist approaches (albeit Bayesian naturally makes more intuitive sense to me), a minor drawback is the reliance on the past to predict the future. For example if you had safety records on 1 million previous flights, then one might be tempted to say, "well that's that then, we now know objectively the probability of failures in the future -- end of story". But, the 1 000 001 flight may have been designed to fly on a completely different type of technology, that will change significantly change the safety record of space flight going forward for the next "x" years. Thus using a Bayesian approach account for all relevant priors, it would in theory be possible to reflect a more accurate probability for the 1 000 001 flight, before it took place.
Lastly Bayes nets are not the best tool for every job, and do have drawbacks in certain situations. They are vulnerable to things like Bayesian poisoning or confirmation bias. A Bayesian approach is only as useful as the ongoing real world relevancy and accuracy of the priors. As the old adage goes, GIGO - garbage in, garbage out.
[1] http://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster
[2] http://www.guardian.co.uk/science/2003/jun/22/spaceexplorati...
[+] [-] jules|13 years ago|reply
Horizontal axis is how many engines failed, and vertical axis is how many times that number of engines failed in the simulation.
The code that generated this is:
The way this code works is it first picks a `p` from the prior. This `p` represents the failure probability for a single engine. Then we simulate the number of engines that fail when you have 9 of them, and filter out just the worlds where that number is equal to 1 as in the SpaceX launch. Or equivalently, we annihilate all the worlds that have a different observation than ours -- this is a central tenet in Bayesian statistics in contrast to frequentist statistics: we only base our inferences on the things that happened and not on things that hypothetically could have happened but didn't. In a slogan you could say "our fantasies are irrelevant". Then in the worlds that remain, where the same observation was made as in our world, we simulate the number of engines that fail on a new rocket launch and collect the results in a histogram.So the posterior probability on the entire rocket failing for uniform prior is around 25%. Uniform prior means that you believe that all single engine failure probabilities are equally likely: you think it's equally likely that engines fail with 10% probability as with 63% probability. Tweak the first two parameters to beta to change your prior belief. If you've seen n engines fail in your life and k engines succeed, then setting the first parameter to n+1 and the second to k+1 is a reasonable choice (so the current setting corresponds to not having seen any rocket launches prior to this one). For example if you've seen 2 engines fail and 99 engines succeed you use `beta(3,100,1e5)`: https://dl.dropbox.com/u/388822/rocketfailuredistr_for_optim... Hardly any probability mass left for entire rocket failure :)
[+] [-] gus_massa|13 years ago|reply
An important detail is what happens when 3 or more engines fail simultaneously. Can they transform the mission in a soft landing or the "payload" is totally doomed? (For example, the Apollo XIII mission was a failure, but no one died.)
[+] [-] robryan|13 years ago|reply
It isn't clear whether it was on the way to complete engine failure or it was shut down to play it safe.
[+] [-] ghostfish|13 years ago|reply
[+] [-] uvdiv|13 years ago|reply
https://gist.github.com/3855660
And the probability of any rocket engine failing, per launch, is 1 in 3!
[+] [-] hyperbovine|13 years ago|reply
[+] [-] throwaway54-762|13 years ago|reply
[+] [-] ghostfish|13 years ago|reply
Can anyone that knows something about the Falcon 9 design or rockets in general shed some light on this? That sentence makes it sound like the panels were purposefully jettisoned, which doesn't make sense to me. What do those panels do, what do they look like, and where are they?
[+] [-] stephengillie|13 years ago|reply
[+] [-] jccooper|13 years ago|reply
Their statement suggests these came off when pressures radically changed during engine cut off, which is plausible. It was at max aerodynamic pressure, and removing all the pressure the motor generates is a big swing. I find it more likely that the nozzle (bell) shattered, as it is more exposed to both aero and combustion pressures. Maybe both happened.
A visual guide:
1) naked engine: http://farm3.static.flickr.com/2355/2230438397_487afd40a2.jp...
When a liquid engine fails energetically, it's usually going to be a failure in the chamber. Nozzle or throat burn-through or other failure may also happen. The turbo pump might also let go and shred some stuff nearby. Plumbing failures may also kill the engine, but not destroy much; there are plenty of valves to fix leakage before it gets bad.
2) un faired: http://www.spacenews.com/images/Falcon9engines_SpaceX02.jpg
Here you can see the armored tub around the chamber section of each engine. It is meant to contain any problems. Mostly these would be hot gas from holes burned in the chamber or throat, fuel or oxidizer from leaks in the plumbing, or shrapnel from the turbo pump coming apart. Note that the other major failure mode, excessive vibration, cannot be armored against, but that is more a design thing than a random failure.
Most to all of these failures are easily detected by various pressure and flow sensors, and usually before they become big problems. Turn off the propellant valves, and the engine rapidly becomes safe, though off. But the armor does keep the neighbors safe from any problems, presuming it holds. I would guess it is good enough for most failures.
3) faired vehicle: http://www.brendans-island.com/blogsource/20101015ff/falcon-...
Here you can see pretty white fairings hiding everything but the nozzles. Note that they appear to be a bunch of different pieces. Probably that is because they are meant to break away individually if something goes wrong.
Those are what I think the statement refers to. I doubt they are actively jettisoned, but may certainly be designed to pop off in an over-pressure situation. One could probably compare vs the video to see if the pieces look like that, the nozzle, or other engine parts. The corner fairing might also have failed under some circumstances.
Having seen the video in slow mo a few times, I think their assessment is plausible. Probably they will be able to tell what happened by telemetry. I don't know if they are still trying to recover stages, but if they are, they might get their hands in some physical evidence. Whether we will ever see any of this data, though, I don't know. They've been reasonably open in the past.
[+] [-] eupharis|13 years ago|reply
Chills down my spine as I read this. I try to write eloquently, but sometimes the fact should stand alone: "No other rocket currently flying has this ability."
[+] [-] rplnt|13 years ago|reply
What I wanted to say by this is that while it's a great thing for Falcon 9 to have fail-over in its maiden flights (as we could see yesterday), I wouldn't worry too much about "other rockets" not having this. Soyuz rockets are a great example (100% success rate for manned flights to ISS and over 97% success rate for all Soyuz rockets (that's since 1966)[1]).
1. my numbers are only from wiki: http://en.wikipedia.org/wiki/R-7_(rocket_family) and http://en.wikipedia.org/wiki/List_of_Russian_manned_space_mi...
[+] [-] SoftwareMaven|13 years ago|reply
I am now getting hopeful that I'll be able to experience zero-G before I die. SpaceX team, you are my heroes. Keep up the great work!
[+] [-] rst|13 years ago|reply
www.orbcomm.com/Collateral/Documents/English-US/ORBCOMM%20Launches%20Prototype%20OG2%20Satellite%20FINAL.pdf
[+] [-] jakkals|13 years ago|reply
Is everything fine now, or is it not? "Nominally" in this sense to me means that something is amiss, but reading the rest of the article seems to imply that everything is on track.
[+] [-] frabcus|13 years ago|reply
"Aerospace & Engineering. According to plan or design: a nominal flight check."
http://www.thefreedictionary.com/nominally
[+] [-] thezilch|13 years ago|reply
[+] [-] CUViper|13 years ago|reply
[+] [-] molecule|13 years ago|reply
[+] [-] HodCarrier|13 years ago|reply
[+] [-] VSerge|13 years ago|reply
[+] [-] bravesirrobin|13 years ago|reply
One aspect that's worth consideration is the private/corporate aspects of spaceflight. When there were failures in Apollo and the shuttle, the public had a right to know everything that happened since we'd paid for everything. SpaceX has been super cool about disclosure here, but how long can we count on that? At some point, there's too much money at stake for them to maintain full transparency.
[+] [-] wprice|13 years ago|reply
But I think that SpaceX understands that NASA is funded by the public and it will be easier to get the support of NASA if they have the support of the public. I would suspect that for this reason they will continue a decent amount of public disclosure.
[+] [-] confluence|13 years ago|reply
[+] [-] maaku|13 years ago|reply
[+] [-] dhughes|13 years ago|reply
[+] [-] knodi|13 years ago|reply
[+] [-] rorrr|13 years ago|reply
[+] [-] biot|13 years ago|reply