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.
This is an interesting altitude-control scheme. When I think about this problem, I consider a method that involves a flexible helium container (in the simplest form, a helium balloon) and a control system that involves pumping helium out of the balloon into a high-pressure tank to descend, and releasing it from the tank to the balloon to rise. It's a variation on the submarine buoyancy method, which also requires power to run pumps.
The advantage is that the method doesn't just throw away the helium, it recycles it, but the recycling activity require a lot of power. And it's way complicated compared to your method.
Some key parts: "Lutus designed electronics for the NASA Space Shuttle and created a mathematical model of the solar system that was used by the Jet Propulsion Laboratory during the Viking Mars mission" and then "... he started writing computer programs on his first personal computer, an Apple II. In the 80s, he would eventually program Apple Writer,"
I also recommend his book about sailing around the world "Confessions of a Long-Distance Sailor"!
My all-time favorite sailing book quote, from a book titled "Never Again", about a sail in the terrifying "South 40s" near Antarctica: "After the mast blew off, the boat become much more stable." :)
Why 'f * ing'? (Sorry, I'm italian... of course I know the meaning of the word, but I would like to know why do you use it for Paul Lutus, TIA)
I'm not the OP, but in some circles the four-letter expletive is used to emphasize the importance or intensity of something. E.g. "William [freaking] Shatner" means the original, unique, William Shatner, not some other William Shatner. "So [freaking] good!" means extremely good.
Hey I think I met this guy. I was in Houston for a NASA internship, he had a telescope set up in front of a Barnes & Noble, and he was introducing random passers by to a view of Jupiter (or Saturn) in the telescope.
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.
I always thought "controlled flight into terrain" was a good euphemism for "pilot error leading to crash". If you don't think about it, "controlled flight into terrain" almost sounds good: It's controlled! It's flight! Terrain is involved!
It really means "The plane crashed because of pilot error, not because the pilot lost control due to a mechanical fault or extreme weather."
> I always thought "controlled flight into terrain" was a good euphemism for "pilot error leading to crash".
Usually, but not always. The "controlled flight" part means the airplane wasn't either broken or outside its normal control envelope. The implication is that the crash resulted from something other than an inability to control the airplane. The usual assumption at that point is pilot error, but there are other possibilities -- malfunctioning navaids, bad charts, bad instructions from the ground such as incorrect headings or altimeter settings.
Once an airliner pilot asked for clearance into La Guardia in NYC involving a path that led across the downtown area after dark. He was given a flight level in meters but understood his assigned altitude to be in feet. He was flying between the buildings when the ATC and pilot sorted out their unit-of-measurement difficulties. The only reason ATC knew something was wrong was because the aircraft had an altitude-reporting transponder, or we might have had a 9/11 level catastrophe much earlier.
On that topic, in 1945 a B-25 flew into the Empire State Building in fog, something most people have long since forgotten:
To summarize, the aircraft model with which the crew were most familiar had a pitot heat switch that was activated by an upward movement (the ergonomic standard direction), but this aircraft required a downward movement (or the reverse, I forget which it was, but they were reversed). This meant they went through the checkist and set all the controls, but this control was set wrong through no fault of the pilots (more the fault of the manufacturer). Result: no pitot heat in winter conditions.
Next, during the after dark flight, the pitot tube froze solid in icing conditions, after which the airspeed indication became an altitude indication, at a time when the aircraft was in a climb. This made the pilots think they were overspeeding the aircraft, and they responded by pulling back on the controls. The stick shaker worked as it should have (warning of a speed approaching a stall), But the pilots interpreted this as ... get this ... mach buffet. The pitot system kept delivering seemingly higher and higher airspeeds as they climbed and (in reality) approached stall speed.
The aircraft finally stalled fully, deeply, and unrecoverably. For those who don't know this, you must not ever stall an airliner, because they are perfectly balanced front to back, to save fuel, but the side effect is if the aircraft is stalled, it cannot be recovered and will flat-spin right into the ground.
Small private planes will typically nose down in a stall, often recovering right away for an inexperienced pilot, but airliners have different priorities, one of which is economical operation. An economical airplane cannot afford to have a constant air pressure on the top of the elevator control surfaces, so this is designed out. But in trade, you must not ever stall the aircraft or you will lose it.
In the final analysis, multiple factors were involved (as usual), but the fact that the pitot heater switch had an activation direction opposite the ergonomic standard, all by itself could have prevented the crash.
It's my favorite story about the value of adopting consistent ergonomic standards -- to increase a quantity or activate something, controls should move up, or to the right, or clockwise. To deactivate or decrease a quantity, the reverse. How hard is that?
For those reading this who aren't pilots: pilots aren't ghouls, we like reading accident reports because every report teaches us something that we might use to save ourselves and/or our passengers if we encounter the same conditions.
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?
> Do you have an email address I could use please?
Yes, But for obvious reasons I don't want to post it in this forum.
Please post a plain-text message to my message board and I will reply. Then you can embed links and tags in your reply if you want. That way neither of us needs to post our e-mail addresses in a public forum.
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.