Beyond The New 911 Release
Porsche AG, the venerable automaker from Zufffenhausen, Germany, has big plans! Despite the global economic downturn, the little car company that could continues to churn out new models and new engineering. Panamera - Hitting showrooms now is the Panamera sedan with optional V8 and turbocharged V8 engines as well as 2 and 4-wheel drive. In 2010 the Panamera will receive gas and diesel V6 engine choices as the entry-level offering. In 2011, look for the Panamera Hybrid to debut. Cayenne - Porsche鈥檚 SUV will appear in all-new from the ground up form in 2010. Expect better performance than the current model and power from V6, V8 and turbocharged V8 engines. Beyond the new 911 release, I look for both a smaller SUV model below the Cayenne which will be based on the Audi Q5 but with more of a sporting character per the Porsche heritage. I also expect a coupe and convertible version of the Panamera sedan, possible reviving the 928 moniker and using the Panamera鈥檚 underpinnings.
The LightSail 2 consists of a small cubesat about the size of a loaf of bread that will catch a ride inside the PROX-1, a small satellite designed by students at the Georgia Institute of Technology. The PROX-1 spacecraft will be deployed during the Falcon Heavy鈥檚 third and final destination in orbit, which will occur about an hour after launch. After about a week, the satellites deposited in the third orbit will have drifted apart from one another and the PROX-1 spacecraft will deploy the LightSail 2 cubesat using a small spring. After some testing to make sure everything is working correctly, the cubesat will begin to unfurl its mylar sail, which is about the size of a boxing ring and thinner than a human hair. For at least a month, the LightSail 2 will use pressure from light particles, or photons, to lift itself into a higher orbit. Although photons don鈥檛 have mass, they do have momentum. When they strike the solar sail, this momentum gets transferred to the spacecraft.
As the spacecraft orbits the Earth, a small flywheel inside the spacecraft will turn the sail to capture these photons, similar to how a sailboat adjusts its jib to travel in a desired direction. Simulations show that the LightSail 2 should be able to raise its orbit by half a kilometer per day, but its designers say they will consider any measurable altitude increase to be a success. The amount of force the photons will apply to the solar sail is equal to about 9 micronewtons per square meter. To put this in perspective, that鈥檚 about equal to the weight of a housefly on your hand on Earth. If satellites can harness photon pressure for propulsion, it will make navigating the solar system with cubesats far cheaper and simpler by eliminating the need for satellite fuel. Looking to the future, solar sails also open up the possibility of interstellar travel.
As a spacecraft travels further from the sun, the solar flux, or density of photons, drops rapidly, so a spacecraft outfitted with a solar sail wouldn鈥檛 reach high enough speeds to make interstellar travel possible on human timescales. But if solar sails are propelled using a powerful array of lasers on Earth or the moon, a small spacecraft could feasibly make an interstellar journey. This is, in fact, the goal of Breakthrough Starshot, a plan bankrolled by a Russian billionaire that aims to send the first interstellar probe to Alpha Centauri, our closest stellar neighbor. The LightSail 2 is a small step toward developing the technology that would make that mission possible. The Planetary Society鈥檚 LightSail project has been nearly a decade in the making, but the idea predates the organization. In 1976, four years before he created the Planetary Society, Carl Sagan appeared on The Tonight Show and showed off a 鈥渃rude model鈥?of a NASA solar sail for Johnny Carson.
Sagan envisioned the sail being used to rendezvous with Halley's comet, and Carson envisioned it being stamped with a giant McDonald鈥檚 logo. For better or worse, neither of their visions materialized, but solar sailing remained an integral part of the Planetary Society鈥檚 identity thereafter. 鈥淭his thing grabbed my heart in the 1970s, and it鈥檚 still with me,鈥?says Bill Nye, science guy and CEO of the Planetary Society. After failing to secure funding from NASA to launch a solar sail, the Planetary Society decided to tackle the project on its own. In the late 鈥?0s it began work on its first version of a solar sail, Cosmos 1, which looked like a giant fan. In 2005 a Russian submarine launched Cosmos 1 into space, but the rocket鈥檚 first stage failed and destroyed the solar sail. The Planetary Society pressed on and a decade later launched the LightSail 1 into low Earth orbit. The first LightSail was more of a technology demonstration mission鈥攊t didn鈥檛 go high enough to surf on sunlight. In retrospect, this was probably for the best. The LightSail 1 mission was plagued with technical problems from the outset, including a faulty battery and problems with the radio communication.