Here’s a long article by Leonard David.
Category Archives: Space
Win Some, Lose Some
I was supporting Boeing during Phase A of the Jupiter Icy Moons Orbiter (JIMO) on technology risk issues, and indirectly supported their Phase B proposal. However, NASA just announced that they’re awarding the contract to Northrop Grumman. At least the program is moving forward.
Better luck next time, guys.
First-Hand Description
Xeni Jardin scored a ride on one of the inaugural Zero G Corporation flights.
She loved it.
(I’d recommend scrolling down to the bottom first, repeatedly clicking on the previous ones until you get to the beginning, in which she continually describes all the advice that she gets from people leading up to the flight. Then read it in proper sequence by hitting the “back” button for the next page.)
[Via TexasBestGrok]
Launch Regulation Legislation
…is coming down to the wire.
This is an important piece of legislation for the alt-space community, and no one is paying attention to it except us, so any calls that Senators on the Commerce Committee get will be noticed. So get on the horn, particularly if you have one in your state.
Another Myth Of The Old Space Age
Alan Boyle reports on the inaugural services of Zero Gravity Corporation, an entity that’s been attempting to offer weightless flights to the general public in the US for over a decade. It was held up by FAA regulations.
In full disclosure, I attempted to start a business like this about that long ago, but couldn’t raise the money to get started. We did offer service for a brief time in a much smaller aircraft, but never managed to expand beyond that, though we had plans to do exactly what Zero G has done, using cargo 727s that could be quickly converted on a daily basis using pallets. But had I known what travails Peter Diamandis and company would have to go through, I probably wouldn’t have even made the attempt, and I’m probably lucky that I didn’t have to go through it at all.
I want to take exception to a quote that Alan has in his piece, however:
Cosmic Log reader Ayanna Bryan provides a cautionary note:
“As someone who has gone on parabolic flight several times for research purposes, let me assure you that most people do indeed get sick. And it’s not just nausea. There are other forms of motion sickness that are very unpleasant and sometimes disturbing.
Some people remain sick for several hours after the two-hour flight. Unless medicated (which has its trade-offs: comfort in-flight for discomfort 6 hours later), the normal human vestibular system is easily affected by sharp changes in gravitational level. Some fliers still get sick after taking the Scopolamine/Dexedrine medication. Some people even ‘freak out,’ for lack of a better term, once they experience the effects of increased and then decreased gravity.
I hope fair warning is given to paying customers, and I hope the preflight training is good enough to meet Air Force standards. Otherwise someone could get seriously hurt.”
As someone who has done extensive research in this business, let me point out that this comment is completely spurious. Research flights have a specific goal in mind–research. Comfort of participants is a distant second to that goal. They don’t call NASA’s airplane the “Vomit Comet” for nothing, but there’s no reason to think that such unpleasant side effects can’t be avoided.
For one thing, people who don’t have to perform research can use much more effective anti-nauseants than scope-dex. For another, since the purpose of a NASA research flight is to get as much research in as possible, the plane basically flies, and gets in as many parabolas as possible, until it’s either low on fuel, or until everyone on board has green gills, and no more productive activity is possible. That won’t be the case on these flights, in which the goal is to provide an enjoyable and exciting customer experience. There will be far fewer parabolas, and they will be developed gradually, with low-gravity maneuvers preceding the weightless ones.
If Zero G makes a significant number of people sick, it will be because they’re doing something wrong, not because it’s an intrinsic feature (or in this case, bug…) of the experience. Sadly, this is just the type of misinformation that makes it so difficult to raise money for space tourism ventures.
[Monday morning update]
Clark Lindsey has similar thoughts, and provides a little tutorial on weightlessness, but it requires one bit of clarification.
The “zero g” effect produced by these flights, just like in orbit, is an apparent one. Earth’s gravitational pull doesn’t change and remains as strong as ever. (It decreases as 1/(distance squared) as you move away from the planet.)
Over the top of the parabola, both you and the plane are falling together. You are no longer being pressed against the floor of the plane, which is usually keeping you at a fixed distance from the earth via the lift of its wings. (In the valleys of the trajectory, the plane is having to decelerate and reverse you from the speed gained during the falling portion of the parabola. So you feel higher g force in that case.)
In orbit, the same principle applies except you and the vehicle are falling around the earth because your rocket produced enough horizontal speed to keep you from hitting the ground as you fall. That is, the curve of your falling trajectory matches the curve of the earth.
This last sentence is true only for a circular orbit–it’s not true in general. For suborbit, or elliptical (or hyperbolic trajectories), there’s no relationship between the trajectory and the earth’s curvature. But this is not required for free fall.
Essentially, what you feel when you feel “gravity” is the force of some other object (such as your chair if sitting, or the floor if standing or walking) supporting your weight against it. In a free-fall trajectory, the airplane is basically “flying around you,” following the path that you would take if you’d simply been launched from a cannon (in vacuum), so it never contacts you and can thus not give you any feeling of weight by supporting you against the force.
One more subtle point. What we call a parabola in so-called parabolic flight isn’t a true parabola, mathematically, precisely because of the curvature of the earth. If we were using a flat earth model, in which gravity were a constant, (as Galileo assumed when he first started doing calculations for his pioneering work in ballistics), then it would be a parabola. In reality, it’s a small section of a non-circular ellipse (that is, a suborbit would be an orbit with an extremely low perigee, if the earth didn’t get in the way). However, over the distances involved in subsonic aircraft, flat earth is a reasonable approximation, and the difference between the trajectory and a true parabola are inconsequential, and probably unmeasurable.
[Update at noon eastern]
Here’s a space.com article that describes the (overly onerous, in my opinion) FAA approval process for the flights.
Incidentally, I don’t buy the notion that Zero G can really patent the idea of using cargo airplanes during the day for this that fly at night–it seems almost as silly to me as Amazon’s single-click system. I doubt if that would stand up in court very long.
Whether it does or not, though it looks like the real barrier to entry to this is the FAA certification process (though now that there’s a precedent for the Special Type Certificate it may be easier for a competitor to come in than it was for Zero G, should the market prove robust enough to support one). Space enthusiast Peter Diamandis should welcome this, even if Zero G investor and executive Peter Diamandis doesn’t…
The New Saudi Arabia?
Mark Whittington asks if that’s what the moon will be in the twenty-first century. He also misspells Gerard O’Neill’s name in the process…
I assume that he means in the energy-production aspect, not the exporting-murderous-nutballs-with-a-misogynistic-fascist-ideology aspect.
Maybe, but we’re a long way from it, both in terms of the cost of getting there, and in developing the technologies to make it happen. I think that it’s a race between using space for energy, and developing radical new technologies on earth that will make that unnecessary, and I don’t have my money on either one right now.
A New Human Launcher?
Jeff Foust has an overview at The Space Review today about a new concept that many (including many in the astronaut office) are pushing as a CEV delivery vehicle–an SRB-based design, with a new J-2 powered upper stage. This is what many are calling a “single-stick” vehicle, as opposed to the EELVs with their strap-on boosters.
I actually agree that such a system could be built, and could have a (marginal) cost of a hundred million per flight (though it’s not clear what the actual cost per flight would be, including amortization of the development costs). However, the issues aren’t quite as simple as the proponents make out.
A major drawback of using an EELV to launch the CEV is that neither the Atlas 5 nor the Delta 4 are
The Path Not Taken
The post title is the title of my (long) essay on space policy, that’s finally appeared on line in this quarter’s issue of The New Atlantis. It’s a survey of the myths of the old space age, and will probably form the basis for a book on which I’m working, between hurricanes, still moving into the new house, and trying to make a living.
And no, before anyone asks, I don’t in fact know why it’s right justified, and ragged left. Go ask the folks at The New Atlantis.
[Update a few minutes later]
The ragged left problem seems to be the use of non-standard HTML. It looks OK in Explorer–it’s only weird in Mozilla.
[Update on Thursday morning]
The justification problem has been fixed by the good folks at The New Atlantis (a publication that I highly endorse, and recommend that folks get a dead-tree subscription to, so you can get it early and often).
Call The Senate Commerce Committee This Week
If you care about the future of commercial human spaceflight. Clark Lindsey explains why.
Nature’s Judgment?
Paul Dietz points out (in comments) that if Frances hits the cape as a Cat 4 or greater, none of the major facilities are designed to take it. If the VAB, OPF and LC-39 are significantly damaged, it could mean that the Shuttle will retire even sooner than the current plan (i.e., it will never fly again). It would be a strange end to the current trajectory of our four-plus-decade manned space program, but it might be an opportunity for a clean start, since there won’t be an opportunity for a rear-guard action to save the Shuttle (and it may even finally put to rest notions of Shuttle derivatives, though that’s probably asking too much).
[Update a few minutes later]
As Paul mentions, he found the info at the new and improved NASA Watch, now with an infinite percent more permalinks.