First Contact! Mars Express’ first ‘conversation’ with Curiosity

As we reported yesterday, Mars Express had a busy Sunday evening, pointing first at NASA's Curiosity rover on the surface of Mars and then swinging around to do another relay pass with Opportunity. We received the data from both of these passes this morning over ESA's New Norcia ground station and, on first look, it seems that both relays were very successful.

First Laser-Zapped Rock on Mars

First Laser-Zapped Rock on Mars. This composite image, with magnified insets, depicts the first laser test by the Chemistry and Camera, or ChemCam, instrument aboard NASA's Curiosity Mars rover. The composite incorporates a Navigation Camera image taken prior to the test, with insets taken by the camera in ChemCam. The circular insert highlights the rock before the laser test. The square inset is further magnified and processed to show the difference between images taken before and after the laser interrogation of the rock. The test took place on Aug. 19, 2012. Credit: NASA/JPL-Caltech/LANL/CNES/IRAP

In ESA's MEX team, we're particularly excited to have had our first contact with Curiosity – proof that the amazing new rover from the United States can talk with our veteran European Mars orbiter!

At the start of the contact, Mars Express was over 3600 km from Curiosity's landing site in Gale Crater and closed in to only 1300 km by the end of the contact – streaking across the sky as seen from Curiosity.

During this overflight by Mars Express, it 'hailed' Curiosity in Gale Crater and the rover responded. The two spacecraft then autonomously established a link with each other and Curiosity flowed data back to Mars Express for nearly 15 minutes. This international chat between two spacecraft in deep space is proof of all our preparation, standardisation and cooperation work in action – so it's something both agencies can be proud of.

ESA's first 35-metre deep-space ground station is situated at New Norcia, 140 kilometres north of Perth in Australia. The 630 tonne antenna will be used to track Rosetta and Mars Express, the latter to be launched in 2003, as well as other missions in deep space. The ground station was officially opened on 5 March 2003 by the Premier of Western Australia, Hon Dr Geoff Gallop. Credits: ESA

ESA's first 35-metre deep-space ground station is situated at New Norcia, 140 kilometres north of Perth in Australia. The 630 tonne antenna will be used to track Rosetta and Mars Express, the latter to be launched in 2003, as well as other missions in deep space. The ground station was officially opened on 5 March 2003 by the Premier of Western Australia, Hon Dr Geoff Gallop.
Credits: ESA

The actual data that flowed back was made available to NASA earlier today, who will now retrieve and process the data.

Hopefully we'll have some info from them in the next couple of days about what exactly was contained within. We'll also receive (within Tuesday) the 'housekeeping' telemetry of Melacom – information on how our radio performed. This will allow us to double-check the performance of this first important contact with Curiosity.

The data was sent at a rate of only 8 kbps – 125 times slower than the 1-Mbit/second Internet connection you might have at home!

We wanted to take things easy to start with, though, and test the performance of the link. Nonetheless, we received 955 data packets from Curiosity, totalling 867 kilobytes of data.

This will be the first of several contacts with Curiosity in the future, as we better learn how to use and optimise this relay link between the two craft and the two space agencies. Watch this space for more details as we get them on this pass and the future contacts between Mars Express and Curiosity.

 

What time is it?

How we solve the problem of multiple time zones

If you saw our descent timeline article, you'll have noticed that we speak about different time zones (of course with acronyms!). If you've also been following the NASA coverage for MSL arrival at Mars, then you'll see it gets even more confusing. In case you're wondering what they all are, then we're here to try and explain!

World time zones

World time zones

First of all, we have to deal with different time zones here on Earth - something you've no doubt experienced if you've taken a long distance flight.

Here at ESA's operations centre, ESOC, in Germany, we use CEST – Central European Summer Time – the time zone most of Europe is on during the summer. Over at JPL in California, they are 9 hours behind, on PDT – Pacific Daylight Time – summer time for the west coast of the United States.

This can get really confusing when agencies like ESA and NASA work together on time-critical activities like MSL landing. At NASA, Curiosity will land on 5 August – but here in Europe it'll land on the 6th! So not only is the time of landing different, but it happens on a different day depending on where you are!

To solve these problems, the space industry (and many other organisations facing similar issues) use a standard time zone called UTC – Coordinated Universal Time.

This time zone was standardised in 1961 to allow our increasingly networked world to work better together. It represents GMT (Greenwich Mean Time), the zero reference for all time zones, but with no daylight savings time shift – so it never changes throughout the year.

At ESOC our short-hand for this time-zone is to put a letter 'Z' after the time, which is where UTC gets its nickname of "Zulu Time" (Z = Zulu in the phonetic alphabet).

So when Curiosity lands, Europe (CEST) will be 2 hours ahead of UTC and JPL (PDT) will be 7 hours behind. Thanks to UTC, though, we can coordinate and communicate pretty well together, allowing multiple agencies and nations around the world to work together on this important event.

 

Experience MSL Landing with ‘Eyes on the Solar System’ from JPL

Link

If you liked our animations of Mars Express tracking the landing of MSL then you can watch it live or preview it yourself with a great website from JPL called "Eyes on the Solar System" (http://eyes.jpl.nasa.gov/).

You can see all the different stages of the entry, descent and landing of Curiosity and control the camera and speed yourself to experience the landing in every way possible!