Space Planes and Supersonic Biplanes
1. Virgin Galactic
The heavy hitter in commercial suborbital flight right now is definitely Virgin Galactic. Its White Knight Two carrier aircraft and Space Ship Two passenger spacecraft are currently undergoing flight testing. WK2 has undergone 78 flight tests, and SS2 has done 16 glide tests. The rocket engine is being test-fired on the ground (with the most recent firing lasting the full duration that SS2 would need to make it to orbit), and Virgin plans for a fully integrated flight of SS2 later this year, which should reach 110km at Mach 3.5.
Looking farther ahead, Virgin Galactic's Vice President of Special Projects William Pomerantz said that it's "actively exploring" both point to point suborbital transportation (sweet!) and flights to low Earth orbit. As far as we know, this makes Virgin the first company to talk about point to point flights: you shouldn't go expecting a suborbital commuter flight yet, but it's exciting to think about taking a rocket plane into space to travel across the world.
2. XCOR Aerospace
XCOR's Lynx rocketplane is undergoing hardware integration, which means that they're sticking a bunch of operational bits together to make the final spacecraft. XCOR COO Andrew Nelson promised that a prototype would be "off the ground toward the end of this year," and since Lynx is self-powered, that suggests a flight with the engines lit up and everything (although probably not to space).
XCOR also announced their first passengers and payload: researchers from SWRI (sponsors of the NSRC conference) along with some science experiments including a bio-harness for astronauts, something about asteroid regolith, and a small telescope. This highlights one of the other major markets for suborbital spaceflight besides tourism: it's possible to get some series science done in a few minutes of high-quality microgravity, and since it's not something we can replicate on Earth, suborbital flights are the going to be the cheapest way to make it happen.
3. Blue Origin
Bretton Alexander, the director of business development and strategy over at Blue Origin, made it clear that the recent loss of its test vehicle was unfortunate, but that it "always expected to lose it during flight testing." The rest of the panel very deliberately backed Alexander up on this, saying that they all expected to lose test vehicles at one point or another and that it was just part of the process. Still, potential space tourists should certainly be aware of the risks: getting into space does generally involve sitting on top of a barely controlled explosion, and while it's probably one of those things that'll end up being safer than driving a car, we imagine that strapping yourself into a rocket is probably one of the most nerve-wracking things that a human can do.
Blue Origin is currently building its next vehicle, which will have a capsule on top that separates from the propulsion module in flight. The module will come to a powered landing, while the capsule coasts up to space (spending 3-5 minutes in microgravity) before using parachutes to land. Long term, this will be an orbital (not just suborbital) launch system, but nobody is talking about selling tickets for an orbit or two quite yet.
4. Masten Space Science Systems
Masten is focusing primarily (let's just go ahead and say exclusively, at least for now) on cargo flights as opposed to passengers. Just over a week ago, their Xaero rocket (which is functionally complete) made a short-hop test flight, and CEO Joel Scotkin says that Masten is ready to start FAA testing, gradually increasing fuel tank size and target altitude, with flights to five or six kilometers happening in the "very near future.
To hit 20 kilometers, they'll need a bigger rocket, and parts are currently on order for what will be called "Xaero20." 100km+ suborbital flights should happen within a few quarters, and Masten has been secretly working on a suborbital lunar lander demonstration vehicle called Xeus, which you can see in the picture above. Xeus won't be going to the Moon, but it will be proving a testbed for the technologies that will one day take private industry to the lunar surface, asteroids, and beyond.
5. Armadillo Aerospace
Armadillo has been working on a rocket called Stig B (after The Stig from Top Gear), which should be complete in under 70 days. Stig B is tall and skinny, and a "six pack" of them will likely be used to launch payloads (including people). Neil Milburn, a VP at Armadillo, said that they hope to make a first flight in May of this year, but that they're still working on a few different options for re-entry, including a supersonically-deployed balloon to slow down followed by steerable parachutes to make a landing somewhere near the launchpad.
Long term, Armadillo will be partnering with Space Adventures to develop a crewed vehicle codenamed "Hyperion." It may look something like the concept in the picture above, and it'll make vertical takeoffs and landings, taking two passengers into space. Hyperion will only seat two people, meaning that no pilots will be on board: it'll be under autonomous control the whole time, making for a "personal and intimate" experience. Yeah, use your imagination on that one.
When an airplane is in flight, it's continuously pushing a series waves of air out of the way in front of it, the same way that a boat moving through water is pushing out a bow wave. These waves of air travel at the speed of sound, and as long as the airplane is going slower than that, the waves can get out of the way of each other and people on the ground will just hear a regular airplane noise when the plane passes overhead.
Sonic booms happen when an aircraft starts going fast enough that the waves of air (pressure, really) that it's producing can't outrun the aircraft anymore, and they all stack up on each other, forming a single shockwave of sound at the front of the plane which can be decidedly unpleasant for anyone on the ground who gets smacked with it. And then they get smacked again by another, trailing shockwave, formed by the negative pressure at the rear of the aircraft. This is where that distinctive "double boom" comes from.
Misora (the honorific name for "sky" in Japanese) is a conceptual design for an entirely new sort of supersonic aircraft, from the Institute of Fluid Science at Tohoku University. As you can see, it's a biplane, a type of aircraft that went out of style back in the 1930s since two wings create tons of drag, generally making high speeds difficult. If you're clever, though, you can arrange those two wings to reflect shock waves back at each other, taking the positive pressure shockwave and the negative pressure shockwave and zeroing them both out. Without shockwaves, you get supersonic airspeeds with no booms at all.
As far as getting to supersonic speeds with two wings, a group from MIT and Stanford has come up with a design that uses smooth inner-wing surfaces combined with bumpy wing edges to reduce drag so much that it should be possible to develop a supersonic biplane that can travel at Mach 5 while simultaneously using half as much fuel as a conventional supersonic aircraft. Mach 5, for the record, is nearly 4,000 mph, which is fast enough to make the hop from LA to New York, or New York to London, in under an hour.
Labels: access to space