NASA - Kepler Mission

NASA - Kepler


If by chance you're planning on testing out a teleportation device at around 10.49 pm Eastern Standard Time, Friday March 6th, take care not to plot your co-ordinates anywhere near Pad 17-B, Launch Complex 17 at Cape Canaveral Air Force Station, otherwise you might well find your evening's experimentation coming to an untimely end beneath the Kepler Mission spacecraft, as it is thrust skywards by the power of its Delta II rocket. Here are some details of what would be singeing your eyebrows...

• Stage I: RP-1 and liquid oxygen tanks that feed the Rocketdyne RS-27 main engine for the ascent.
• Solid rocket booster motors: Used to increase thrust during the initial two minutes of flight. The medium-capacity Delta II has nine motors total (six fire on the ground, three in flight); the other models use only three or four.
• Stage II: Fuel and oxidizer tanks feeding a restartable, hypergolic Aerojetlow Earth orbit. This propellant mixture is highly corrosive and once loaded the launch must occur within approximately 37 days or the stage will have to be refurbished or replaced.^[4] This stage also contains the vehicle's "brains", a combined inertial platform and guidance system that controls all flight events. AJ10-118K engine that fires one or more times to insert the vehicle-spacecraft stack into
• Stage III: Optional ATK-Thiokol solid rocket motor (some Delta II vehicles are two-stage only, and generally used for Earth-orbit missions) provides the majority of the velocity change needed to leave Earth orbit and inject the spacecraft on a trajectory to Mars or other target beyond Earth orbit. It is connected to the spacecraft until it is done firing, and then separates. This stage is spin-stabilized and has no active guidance control; it depends on the second stage for proper orientation prior to Stage II/III separation. It also includes a yo-yo de-spin mechanism to slow the spin before spacecraft release, as many spacecraft cannot handle the high spin rates needed for stability of this stage.
• Payload fairing: Thin metal or composite payload fairing (aka "nose cone") to protect the spacecraft during the ascent through Earth's atmosphere.

i.e. the rocket is big, emits a great deal of heat, and generally makes a lot of noise - another reason for staying well away from the launch site is that this is a night launch, and to get a panoramic view of the illuminated sky, it's probably best to be a good mile or more away.

It is hoped that once clear of Earth's atmosphere, the craft will, as we see from this report at Physics World...

... enter in a “trailing orbit” that will fall behind Earth by roughly 18 million km each year. From here, it will stare at the same part of the sky in hopes of catching any star that "blinks" as a planet passes in front.

In fact, Kepler will keep up this multi-million mile stare for at least 3 years and 6 months, with the sole aim of detecting other Earth-sized planets whose orbits lie within the habitable zones of distant stars, i.e. where temperatures on those planets allow for the existence of liquid water, thought by many to be a prerequisite for life.

Although I'm not sure whether Kepler's imaging equipment will also be able to detect moons around those planets - if our own solar system is anything to go by, moons (such as Jovian Europa), would also seem to be a good target to investigate - Kepler's onboard telescope is nevertheless well equipped for the job in hand. As we see...

The Kepler telescope is specially designed to detect the periodic dimming of stars that planets cause as they pass by. Some star systems are oriented in such a way that their planets cross in front of their stars, as seen from our Earthly point of view. As the planets pass by, they cause their stars' light to slightly dim, or wink.

The telescope can detect even the faintest of these winks, registering changes in brightness of only 20 parts per million. To achieve this resolution, Kepler will use the largest camera ever launched into space, a 95-megapixel array of charged couple devices, known as CCDs.

"If Kepler were to look down at a small town on Earth at night from space, it would be able to detect the dimming of a porch light as somebody passed in front," said James Fanson, Kepler project manager at NASA's Jet Propulsion Laboratory in Pasadena, California.

By staring at one large patch of sky for the duration of its lifetime, Kepler will be able to watch planets periodically transit their stars over multiple cycles. This will allow astronomers to confirm the presence of planets. Earth-size planets in habitable zones would theoretically take about a year to complete one orbit, so Kepler will monitor those stars for at least three years to confirm the planets' presence. Ground-based telescopes and NASA's Hubble and Spitzer space telescopes will perform follow-up studies on the larger planets.

The mission is named for Johannes Kepler (1571-1630), credited with discovering the laws of planetary motion, it's primary stages will be covered on NASA TV, and the BBC has a piece called 'Is There Anybody Out There?', which is described thus...

What is the chance that alien life exists? Nasa's latest mission - the Kepler Space Telescope due to launch on Friday night to survey the heavens for Earth-like planets - could take us a step closer to an answer. Kathryn Westcott asks four experts whether mankind prefers the idea of being alone and unique or whether we long for cosmic cousins.

Whilst over at Centauri Dreams, the post entitled 'Kepler, SETI and Ancient Probes' is worth a read, while this link should enable you link to other articles covering the same and related topics.

Launch is due in about 1 hour and 11 minutes as I write this, so there's just time to wish NASA and everyone involved the very best of luck with what should be a revelatory project that many will hope will be of benefit to ourselves of the present, as well as our descendants, far into their future.

Update: NASA's Kepler Mission Rockets to Space in Search of Other Earths

Kepler Mission: Frequently Asked Questions

image :: Johannes Kepler