Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Crucial moments on the way to Mars

03.12.2003


Mars Express, ESA’s first probe to Mars, still has some challenges to face.



The spacecraft has successfully come through its first power test after the gigantic solar flare on 28 October.

Since 17 November the on-board software has been ’frozen’ after several updates and the spacecraft is now quietly proceeding to its destination. The next major task, starting on 19 December, will be to safely release the Beagle 2 lander.


Separation

To deliver Beagle 2 where planned, Mars Express has been put on a collision course with Mars, since Beagle 2 does not have a propulsion system of its own and must therefore be aimed precisely at its destination.

Intense activity will begin six days before the arrival at Mars on 25 December with the release of Beagle 2. The orbiter will follow Beagle 2 for a while until, three days before arrival at Mars, ground controllers must make it change trajectory to avoid crashing onto the planet.

This will be the first time that an orbiter delivers a lander without its own propulsion onto a planet and attempts orbit insertion immediately afterwards.

Orbit insertion

The spacecraft speed will be reduced from about 11 kilometres per second to 9 kilometres per second. At that speed, the planet’s gravitational field will be enough to ‘capture’ Mars Express and put it into Martian orbit.

Several manoeuvres will follow to set the spacecraft into its final operational orbit. This orbit is a highly elliptical polar orbit, taking Mars Express as close as 260 kilometres from the Martian surface, and out to more than 11 000 kilometres away at its furthest from the planet.

This is another crucial moment, as it is the first time after the launch that the orbiter’s propulsion system comes into action. On top of this, the deployment of the radar booms will take place – one of the most critical instrument activities.

Landing

The landing itself is another very complicated and challenging operation. Beagle 2 will enter the Martian atmosphere at 20 000 kilometres per hour, but friction with the thin atmosphere will slow it down. Once its speed has decreased to about 1600 kilometres per hour, two parachutes will be deployed in sequence.

Finally, large, gas-filled bags will inflate to protect the lander as it bounces on the surface. Once Beagle 2 comes to a halt, the bags are ejected and the lander can open up and start operating.

Any one of these operations could go wrong. An incorrect alignment of the lander could mean it burns up in the atmosphere. The parachutes could fail to deploy, plunging Beagle 2 into the surface at great speed. The balloons could become detached, or get punctured, again possibly causing Beagle 2 to crash.

If the lander does not land on the planned spot, then this is less serious. The landing area is not one ‘spot’ but a large ‘ellipsis’, 300 kilometres long and 100 kilometres wide.

It has been calculated taking into account the density of the Martian atmosphere, the winds and many other factors. So the risk of missing the landing site is very small. If the winds are stronger than calculated, for instance, they may ‘push’ Beagle 2 a little further away, but still within the selected area.

Top-class science

On the orbiter, if one or more of the instruments fail, then the mission could still carry on. All seven instruments on board are designed to work independently. So even some instruments fail, it would still be possible to perform top-class science.

Past missions to Mars have been lost due to a variety of problems, ranging from trivial errors in calculations to system problems. Errors can always happen, but all aspects of the Mars Express mission have been tested as much as possible to be confident that there will be no errors due to trivial mistakes. Mars Express has been developed in a record-breaking time, but there have been no compromises in testing.

Irina Bruckner | ESA
Further information:
http://www.esa.int/export/SPECIALS/Mars_Express/SEM5Z0UZJND_0.html

More articles from Physics and Astronomy:

nachricht Water without windows: Capturing water vapor inside an electron microscope
13.12.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

nachricht Columbia engineers create artificial graphene in a nanofabricated semiconductor structure
13.12.2017 | Columbia University School of Engineering and Applied Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>