ESA's Tigers on prowl for solar corona's secrets

December 11, 2009,
An external coronagraph is due to fly on the formation flying mission Proba-3, revealing normally unseen sections of the solar corona

( -- Bring together a small group of highly motivated researchers, grant them full access to laboratory and production facilities, remove all administrative distractions, and let them work intensively for four to six months. That's what 'StarTiger' is all about!

It is a different approach to conducting research and development that aims to demonstrate the feasibility of a new and promising technology within a very short time scale.
Within this initiative, ESA is running a six-month crash effort to design an instrument to operate between a pair of satellites flying in formation. One will cast a precisely-controlled shadow across the other to produce a perpetual , revealing parts of the Sun’s corona usually hidden in sunlight.

ESA's latest StarTiger project is to create a complete working model of such a ‘giant external coronagraph’. The effort began on 15 September, with a core team of seven multidisciplinary experts from France, Belgium, Greece and Italy based at the Laboratoire d’Astrophysique de Marseille (LAM) in France, plus a 20-strong support team. Project hardware is being designed and manufactured, with testing due to begin early next year.

“StarTiger is an initiative within the Agency’s Basic Technology Research Programme (TRP), aimed at facilitating breakthrough innovation,” said Peter de Maagt, the project's manager. “It is innovative not just in terms of technology but also by changing the way research and development is done.”

Eike Kircher, Head of ESA’s TRP, added: “Researchers work together face-to-face, participating in a very dynamic design flow on a rapid turn-around basis. They also work against the clock, because at the end of the process they produce a complete instrument from scratch.”

Closing in on the Sun’s corona

The Sun is a million times brighter than the faint corona around it. The best way of seeing the corona is during a solar eclipse, when the Moon perfectly covers the solar disc. Eclipses are rare however, and last only a few minutes.

Such brief glimpses have left scientists with unanswered questions, including how the corona comes to have a temperature millions of degrees higher than the Sun’s surface, and how ‘coronal loops’ are connected to solar flares and coronal mass ejections.

“Sun-observing satellites such as ESA’s SOHO incorporate internal Sun-shading ‘occulters’ for coronal monitoring,” commented Dominic Doyle of ESA’s Optics Laboratory. “But stray light can spill over the occulter’s edge into the instrument, a phenomenon called ‘diffraction’. So SOHO, for example, can observe only the corona from two solar radii distant from the Sun’s centre, missing the crucial inner zone close to the Sun’s surface.”

StarTiger is developing a method of flying an occulter on a separate spacecraft to minimise diffraction and bring more of the corona into view. The occulter would fly 150 metres away from the observing spacecraft, the two vehicles remaining lined up with the and each other to an accuracy of just a few millimetres.

Instrument taking shape

The StarTiger team is using a large LAM cleanroom to construct and test a scale-model ‘breadboard’ of the coronagraph - which will be capable of spectroscopy as well as high-resolution imaging. Photosensors around the coronagraph’s entrance will monitor the occulter’s shadow, while an LED array on the occulter will let the observing spacecraft track it.

“The demonstrator is being fully developed before our six months is up,” said Sebastian Vives of LAM, leading the StarTiger team. “Such an approach requires a strong commitment from everyone involved, but all of us are very motivated and excited about this project.”

This StarTiger should pave the way for the actual flight of a two-spacecraft coronagraph on ESA’s next-decade Proba-3 mission. The systems and techniques it delivers could also have other formation flying uses.

StarTiger stands for ‘Space Technology Advancements by Resourceful, Targeted and Innovative Groups of Experts and Researchers’.

The initial StarTiger in 2002 resulted in the development of a compact colour terahertz imager. The spin-off ThruVision company went on to market the technology commercially for applications such as airport security. A short-term StarTiger also contributed to the Herschel mission, pinpointing reasons for telescope performance anomalies during cryogenic testing.

Provided by European Space Agency (news : web)

Explore further: ESA's SOHO will lead a fleet of solar observatories

Related Stories

ESA's SOHO will lead a fleet of solar observatories

May 24, 2006

New funding, to extend the mission of ESA's venerable solar watchdog SOHO, will ensure it plays a leading part in the fleet of solar spacecraft scheduled to be launched over the next few years.

Proba-3: ESA’s first step towards formation flying

August 8, 2006

Proba-3 is the third in ESA’s series of missions for validating developments in space systems while carrying an ‘added value’ user payload which can directly benefit from the innovations under test. Proba-3 will demonstrate ...

The Spooky Sun

October 31, 2006

Just in time for Halloween, astronomers have taken a haunting new portrait of the sun. In this color-coded image from the Hinode spacecraft (formerly Solar-B), the sun glows eerily orange as though celebrating with earthly ...

History's Greatest Comet Hunter Approaches Major Milestone

July 6, 2005

The Solar and Heliospheric Observatory (SOHO) spacecraft is expected to discover its 1,000TH comet this summer. The SOHO spacecraft is a joint effort between NASA and the European Space Agency. It has accounted for approximately ...

The Sun's X-file under the Spotlight

September 3, 2004

One of the Sun's greatest mysteries is about to be unravelled by UK solar astrophysicists hosting a major international workshop at the University of St Andrews from September 6-9th 2004. For years scientists have been baffled ...

Recommended for you

Three 'super-Earths' orbiting a cool dwarf star discovered

January 23, 2018

Using NASA's prolonged Kepler mission, known as K2, astronomers have found three new "super-Earth" exoplanets. The newly detected alien worlds orbit the cool dwarf star designated LP415-17. The finding is reported January ...

Dust storms linked to gas escape from Martian atmosphere

January 23, 2018

Some Mars experts are eager and optimistic for a dust storm this year to grow so grand it darkens skies around the entire Red Planet. This type of phenomenon in the environment of modern Mars could be examined as never before ...

Scientist proposes new definition of a planet

January 23, 2018

Pluto hogs the spotlight in the continuing scientific debate over what is and what is not a planet, but a less conspicuous argument rages on about the planetary status of massive objects outside our solar system. The dispute ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (2) Dec 11, 2009
Thank you, ESA, for trying this different approach to research.

The recent scandal over manipulation of climate data will hopefully be a wake-up call for funding agencies to be more careful about telling researchers what the agency wants discovered.

With kind regards,
Oliver K. Manuel

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.