Feeds

Herschel and Planck off to meet Lagrange

European twin 'scope launch tomorrow

Intelligent flash storage arrays

The European Space Agency's Herschel and Planck space telescopes look good to go tomorrow (Thursday 14 May) at 13:12 GMT from the ESA spaceport in French Guiana.

Herschel and Planck seen in the upper stage. Pic: ESASitting atop an Ariane 5 ECA (see graphic), the two vehicles are ultimately destined for "L2", the second Lagrangian point lying around 1.5m km from Earth "where all the gravitational forces acting between two objects cancel each other out and therefore can be used by spacecraft to 'hover'".

Once "hovering", Herschel will get down to the business of probing the cosmos with its infrared telescope capable of covering the entire spectrum from far-infrared to sub-millimetre wavelengths.

Planck, meanwhile, will be set to studying the Cosmic Microwave Background "with the highest accuracy ever achieved".

That's the plan, but there's the small matter of first getting the two spacecraft onto the right trajectory using a single lifter. Once off the launchpad, the Ariane 5 ditches its solid boosters after around two-and-a-half minutes. Upper stage separation and engine ignition are scheduled for around nine minutes, after which the upper stage accelerates to towards the 10 km/s at which it will offload its cargo.

First to go will be Herschel (seen in the pic nestled at the top of the upper stage), departing at around 26 minutes after launch. One-and-a-half minutes later, the support structure which supported Herschel and protected Planck will be jettisoned and the latter will follow shortly after, at just under 29 minutes into the mission.

ESA continues: "The launcher will set the satellites directly on the path to L2. This means that no injection manoeuvre will be necessary for Herschel; the satellite will be close to its orbit around L2 right from separation. One major manoeuvre is planned to fine-tune the orbit about 24 hours after launch.

"Planck will also be in orbit around L2 at separation, but since the amplitude of its orbit is half that of Herschel, engineers will execute manoeuvres to reduce its orbit to half that of the original. The first manoeuvre is planned about 30 hours after launch."

Ultimately, and assuming all goes according to plan, Herschel's final "quasi-halo orbit" will see it at an average distance of 800,000 km from L2. Planck will settle into a Lissajous orbit "with an amplitude of 400,000 km".

For those of you who've never adopted a Lissajous or quasi-halo orbit, the former is "the natural motion of a satellite around a collinear libration point in a two-body system" (more here). The latter, ESA helpfully explains, is "an orbit that resembles a halo orbit"*, but it's actually a variant of the Lissajous orbit. ®

Bootnote

*"Where the satellite follows a simple circular or elliptical path about the libration point."

Security for virtualized datacentres

More from The Register

next story
Boffins who stare at goats: I do believe they’re SHRINKING
Alpine chamois being squashed by global warming
Comet Siding Spring revealed as flying molehill
Hiding from this space pimple isn't going to do humanity's reputation any good
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
LONG ARM of the SAUR: Brachially gifted dino bone conundrum solved
Deinocheirus mirificus was a bit of a knuckle dragger
MARS NEEDS WOMEN, claims NASA pseudo 'naut: They eat less
'Some might find this idea offensive' boffin admits
No sail: NASA spikes Sunjammer
'Solar sail' demonstrator project binned
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
prev story

Whitepapers

Choosing cloud Backup services
Demystify how you can address your data protection needs in your small- to medium-sized business and select the best online backup service to meet your needs.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.