[UPDATED] Mars Express chats with Curiosity: Practice makes perfect

UPDATE 16 June: MEX Deputy Spacecraft Operations Manager James Godfrey just emailed to report that yesterday's MSL overflight seems to have gone rather well! "We have received good telemetry from the MEX Melacom radio and we are now in the process of analysing the data to extract the signal from MSL."


Today, Mars Express established a communication link with NASA's Curiosity rover (MSL) on the surface of Mars to conduct an important test prior to the arrival of ESA's ExoMars Trace Gas Orbiter (TGO), carrying the the ExoMars Entry, Descent and Landing Demonstrator Module (EDM), Schiaparelli, in October.

Curiosity selfie Credit: NASA/JPL-Caltech/MSSS

Curiosity selfie Credit: NASA/JPL-Caltech/MSSS

The test saw Curiosity serve as a stand-in (rove-in?) for Schiaparelli on the surface, transmitting a signal to MEX similar to how Schiaparelli will transmit during landing on 19 October. From orbit above, MEX had its lander communication system (Melacom) – with recently updated software – configured as it will be in October, and the orbiter tested receiving signals from below.

Here's the timeline of how today's test went, as programmed; all commands were uploaded in advance and the sequence was executed automatically on board (times in UTC).

  1. 2016-06-15 06:22:53.000 - MEX begins to slew to point the radio antenna towards MSL's position on the surface
  2. 2016-06-15 06:40:00.000 - Melacom Switches on
  3. 2016-06-15 06:55:00.000 - MSL starts transmitting its beacon
  4. 2016-06-15 06:55:00.000 - After a 15-minute warm-up, Melacom starts recording the signal from MSL
  5. 2016-06-15 07:05:00.000 - Melacom is powered down and the first part of the recording is complete
  6. 2016-06-15 07:10:00.000 - After a 15-minute wait, Melacom is powered back up
  7. 2016-06-15 07:14:00.000 - No waiting this time; 4 minutes allowed for start up as Melacom starts its second recording
  8. 2016-06-15 07:23:00.000 - MSL stops transmitting
  9. 2016-06-15 07:23:00.000 - Melacom is powered down and the second recording is complete
  10. 2016-06-15 07:23:10.000 - Test complete; MEX now begins to slew back to Earth; data will be dumped in a few hours
Melacom

A photo of the Melacom UHF communications package carried on Mars Express.

Note: Data were still arriving as we posted this, so no analysis to report yet:

Here's a brief description of the actual Schiaparelli arrival activity that this test was meant to exercise (see also: A little help from friends):

On 19 October, about 80 minutes before landing, expected at 14:48 GMT (16:48 CEST), Schiaparelli will wake up and a few minutes later begin transmitting a beacon signal (Schiaparelli will have se4parated from the ExoMars/TGO orbiter on 16 October).

Mars Express will already have pointed Melacom’s small antenna to the spot above the planet where Schiaparelli will appear, and will begin recording the beacon signal, ‘slewing’ – rotating – continuously so as to keep its antenna pointed to follow the module’s descent trajectory.

ExoMars 2016 Schiaparelli descent sequence Credit: ESA/ATG medialab

ExoMars 2016 Schiaparelli descent sequence Credit: ESA/ATG medialab

“Recording will continue through touch-down and the first approximately fifteen minutes of surface operation, after which Schiaparelli will be programmed to switch off and Mars Express will stop recording,” says Mars Express Spacecraft Operations Engineer Simon Wood.

The Schiaparelli signal data will be saved on board Mars Express in two segments; the first, larger, segment will record signals from wake up of the module until about 20 minutes before it reaches the Martian atmosphere, while the second, smaller, segment will record the descent through the atmosphere, touch down and the first 15 minutes of surface operations.

“Then, Mars Express will re-orient its main antenna toward Earth and download the second, smaller segment of recorded data, which should contain the first in-situ confirmation from Mars of Schiaparelli’s arrival and landing,” says Simon.

The data will be received via ESA’s Cebreros deep-space ground station, in Spain, by the Mars Express flight control team at ESOC, ESA’s mission control centre in Darmstadt, Germany, and then passed on to the ExoMars mission controllers.

Even more friends

Mars Express won’t be the only ‘set of ears’ listening in to Schiaparelli’s descent that day.

At Mars, NASA’s Mars Reconnaissance Orbiter (MRO) will monitor signals from Schiaparelli, but only after its landing, due to MRO’s orbital geometry.

MRO - Mars Reconnaissance Orbiter

Credit: NASA/JPL-Caltech

The TGO orbiter, while conducting its own critical orbit entry manoeuvre, will also record Schiaparelli’s descent and landing, but this data can only be downloaded some hours after it has completed orbit entry.

In the following days, Mars Express and MRO – as well as the other NASA Mars orbiters, Odyssey and MAVEN – will each serve as data-relay platforms, overflying Schiaparelli’s landing site in Meridiani Planum once or twice per day, picking up data transmitted from the lander during its nominal two- to four-day surface science mission, and relaying these to Earth.

Mars Express will also support the Schiaparelli mission through remote sensing measurements over the landing site during several weeks prior to the event.

 

Testing cooperation: ESA’s Mars Express transmits commands to NASA rover

This update sent in earlier today by ESA's Simon Wood, one of the engineers working on the Mars Express mission operations team at ESOC.

Today, ESA's Mars Express orbiter will send telecommands to NASA's Curiosity rover on the surface of Mars.

This self-portrait of NASA's Curiosity Mars rover shows the vehicle at the "Mojave" site, where its drill collected the mission's second taste of Mount Sharp. Credit: NASA/JPL-Caltech/MSSS

This self-portrait of NASA's Curiosity Mars rover shows the vehicle at the "Mojave" site, where its drill collected the mission's second taste of Mount Sharp. The scene combines dozens of images taken during January 2015 by the Mars Hand Lens Imager (MAHLI) camera at the end of the rover's robotic arm. The pale "Pahrump Hills" outcrop surrounds the rover, and the upper portion of Mount Sharp is visible on the horizon. Darker ground at upper right and lower left holds ripples of wind-blown sand and dust. Full image and caption via NASA web. Credit: NASA/JPL-Caltech/MSSS

The transmission is part of a routine quarterly test of the communications link between MEX and Curiosity – NASA's Mars Science Laboratory (MSL). Aside from its prime science mission, Mars Express is able to provide contingency communications with MSL (or with any NASA rovers) in case of any problems with the normal data relay links.

This particular test consists of MEX hailing MSL – sending a specific signal requesting MSL to listen – then transmitting commands (provided by the MSL team at NASA/JPL) to the rover and then recording data transmitted back.

Background sequence of activities

  • MEX mission planning system schedules pointing of MEX's UHF (ultra high-frequency) antenna at MSL - end-December 2104
  • MSL team provides command file (i.e. the telecommands to be transmitted) to the MEX flight control team at ESOC - last week of February 2015
  • MEX flight control team uploads the commanding 'products' (files to be executed on board MEX) on 27 February; these were generated on 24 February
Mars Express orbiting the Red Planet - artist's impression Credit: ESA/Alex Lutkus

Mars Express orbiting the Red Planet - artist's impression Credit: ESA/Alex Lutkus

Operations timeline today

All times UTC

14:29 MEX will slew from Earth pointing to pointing its UHF antenna at MSL on the surface
14:41 MEX UHF antenna switches on – takes 15 mins to warm up
14:56 Overflight begins with MEX hailing MSL; overflight lasts 9 mins
15:05 MEX begins to slew back toward Earth pointing

Data received from MSL will be transmitted back to Earth by MEX at around 16:30 UTC via ESA's deep-space ESTRACK station in Malargüe, Argentina.

Later, NASA's deep-space network teams will extract the data from the MEX packet archive and pass this on the the MSL team for analysis.

Best regards from the MEX control team at ESOC!

– Simon

Mars in a Minute: What happens when the Sun blocks our signal?

Well, not 'our' signal  – this is in fact a NASA video referring to what happens when their Curiosity rover's signal gets blocked. But precisely the same thing happens with ESA's Mars Express, which happens regularly (see previous reports in ESA web here).

But we love this nifty JPL video that illustrates the situation in a fun and humours way – and wanted to make sure you saw it, too!

Fostering Curiosity: Mars Express relays first science data

The data are finally here!

You'll recall our blog posting early in October (see Mars Express to relay first science data from Mars Curiosity) when we got word that Mars Express would, for the first time, relay actual science data from NASA's Curiosity. Now, after a bit of a wait, we've got the the images transferred by Mars Express plus some nice context images showing the rocky target, thanks to Roger Wiens, PI on ChemCam, and several of the colleagues at NASA.

Colour image of Rockenest3, about as big as a shoebox Credit: NASA/JPL-Caltech/Malin Space Science Systems

Colour image of Rockenest3, about as big as a shoebox Credit: NASA/JPL-Caltech/Malin Space Science Systems

There's a full report in ESA web today (see Fostering Curiosity: Mars Express relays rocky images to NASA), which is well worth a quick read.

To summarise, MEX relayed a set of two close-up images of target 'Rocknest3' acquired by the the Remote Micro-Imager (RMI) on the ChemCam on 4 October 2012 (Sol 57). ChemCam is more than only a 'cam(era)'; it actually comprises two units – the RMI plus the Laser-Induced Breakdown Spectrometer (LIBS). (See the ChemCam instrument page here). LIBS works by firing a laser at targets and analysing the chemical composition of the vaporised material. Is that cool, or what?

Our web report (and this blog post!) includes the two close-up RMI images plus two more: an RMI mosaic (combination of several images) showing the LIBS targets on Rocknest3, as well as a wider angle view of Rocknest3, acquired separately by Curiosity's MastCam.

Without further ado – voilà! The images relayed by MEX:

ChemCam image of Rocknest3 relayed by Mars Express Credit: NASA/JPL-Caltech/LANL/CNES/IRAP

ChemCam image of Rocknest3 relayed by Mars Express Credit: NASA/JPL-Caltech/LANL/CNES/IRAP

ChemCam image of Rocknest3 relayed by Mars Express Credit: NASA/JPL-Caltech/LANL/CNES/IRAP

ChemCam image of Rocknest3 relayed by Mars Express Credit: NASA/JPL-Caltech/LANL/CNES/IRAP

These two images were taken on sol 57 (4 October 2012) of target Rocknest3 using the ChemCam Remote Micro-Imager (RMI) on the NASA Curiosity rover at a distance of 3.7 m. The images were downlinked to Earth using ESA’s Mars Express orbiting spacecraft. The first image above was taken before a series of five ChemCam Laser-Induced Breakdown Spectrometer (LIBS) observations and the second image was taken after. The first image is centred on the fifth LIBS observation point. Rocknest is the name of the area where Curiosity stopped for a month to perform its first mobile laboratory analyses on soil scooped from a small sand dune. Rocknest3 was a convenient nearby target of which ChemCam made more than 30 observations overall consisting of 1500 laser shots; it was also interrogated by the arm-mounted Alpha Particle X-ray Spectrometer (APXS)  instrument. Credits: NASA/JPL–Caltech/LANL/CNES/IRAP

The two processed RMI images were sent to us here at ESOC by Roger Wiens, ChemCam PI (principal investigator) at the Los Alamos National Laboratory, New Mexico, USA. Thanks, Roger, for the images and caption above!

The RMI mosaic image – showing the LIBs targets on Rocknest3 – was produced by Stéphane Le Mouélic, a research engineer at France's Université de Nantes and one of the collaborators on ChemCam (access the team bios here).

Mosaic: ChemCam laser targets on Rocknest3 Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGN/CNRS

Mosaic: ChemCam laser targets on Rocknest3 Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGN/CNRS

Stéphane is also co-investigator on the Visible and Infrared Mineralogical Mapping Spectrometer (OMEGA) on Mars Express.

The MastCam image was processed courtesy of Mike Malin of Malin Space Science Systems (as far as we've heard at ESOC, all these images will also go into the NASA/JPL website).

In a mail sent in earlier, Stéphane wrote:

I can just tell you that several of us in the ChemCam team are also involved in the Mars Express mission, and, as such, this successful communication of data between the two spacecraft also takes a sentimental value. Mars Express has provided a wealth of information and has paved the way for a new generation of explorers such as Curiosity. Making the two spacecraft work together is not only scientifically and technologically interesting, but also representative of how the collaboration of agencies is advancing science.

The Deputy PI for ChemCam is also French; Sylvestre Maurice is based in Toulouse, at France's Institut de recherche en Astrophysique et Planétologie (IRAP). Along with PI Roger Wiens, he was responsible for the design, construction, testing and delivery of the LIBS instrument on ChemCam ("ChemCam is the greatest of all instruments, the 'Jedi light-saber' of the MSL mission!").

Sylvestre wrote:

To me, the cooperation between ESA and NASA extends even further: the RMI camera is a spare of a series of cameras on ESA's Rosetta mission, scheduled to arrive at the comet 67P/Churyumov-Gerasimenko in 2014. ESA-NASA and MSL-Rosetta – a spirit of collaboration!

Finally, we also heard from Brigitte Gondet, who is also a collaborator on both ChemCam and Mars Express at Institut d'Astrophysique Spatiale (IAS):

The quality of the images provided by the RMI camera (the head was developed at France's IAS and optics developed at IRAP) is outstanding. The context information for the LIBS analyses has proved essential for the scientific interpretation of the data. This combination of imaging and analysis has demonstrated its potential for future missions.

ESA–NASA cooperation at Mars is a continuing success, and, in this case, there is also tremendous involvement of the co-PIs and collaborators on the ChemCam science team from France!

Notes:

IAS - Institut d’Astrophysique Spatiale

IRAP - The Research Institute in Astrophysics and Planetology - opened in 2011. IRAP is a new mixed research unit of the CNRS (National Centre for Scientific Research) and University Paul Sabatier, Toulouse.

Mars rover gets instructions daily from NASA via a network of antennae

Nice article today in WaPo:

Brian van der Brug/AP - Activity lead Bobak Ferdowsi

Brian van der Brug/AP - Activity lead Bobak Ferdowsi, who cuts his hair differently for each mission, works inside the Spaceflight Operations Facility for NASA's Mars Science Laboratory Curiosity rover at Jet Propulsion Laboratory (JPL) in Pasadena, Calif. on Sunday, Aug. 5, 2012.

To get its messages to Earth, Curiosity first sends information to a pair of orbiters, Odyssey and Reconnaissance, that were sent in 2001 and 2005, respectively, to analyze Mars from a distance and are constantly circling the planet. (The Mars Express orbiter, operated by the European Space Agency, is also available if necessary.) The antennae on the orbiters are more than 1,300 times as powerful as the antenna on Curiosity. The rover waits for the orbiters to pass overhead to ship its messages, usually around 3 p.m. and again at 3 a.m.

Access full text via Washington Post

 

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.

 

Mars Express rocking and rolling with NASA’s Curiosity & Opportunity

On 19 August, Sunday evening (European time), Mars Express will start its first data relay with NASA's Mars Curiosity rover in style by fitting in not just our first pass with Curiosity but also by 'rolling away' afterwards to talk with NASA's veteran Mars rover, Opportunity.

Still Life with Rover This full-resolution self-portrait shows the deck of NASA's Curiosity rover from the rover's Navigation camera. The back of the rover can be seen at the top left of the image, and two of the rover's right side wheels can be seen on the left. The undulating rim of Gale Crater forms the lighter color strip in the background. Bits of gravel, about 0.4 inches (1 centimeter) in size, are visible on the deck of the rover. Credit: NASA

Still Life with Rover This full-resolution self-portrait shows the deck of NASA's Curiosity rover from the rover's Navigation camera. The back of the rover can be seen at the top left of the image, and two of the rover's right side wheels can be seen on the left. The undulating rim of Gale Crater forms the lighter color strip in the background. Bits of gravel, about 0.4 inches (1 centimeter) in size, are visible on the deck of the rover. Credit: NASA

This will be the first time in the history of the Mars Express mission where this double lander contact has been attempted within a single orbit of the spacecraft (1 orbit around Mars for Mars Express lasts around 7 hours).

As the spacecraft approaches the planet it will turn away from Earth and 'roll' over the top of Curiosity's new home in Gale Crater, keeping the Melacom antennas pointed directly at the new rover.

After this contact, Mars Express will turn back to Earth briefly and then spin away again, performing the same 'Spot Pointing' manoeuvre for Opportunity as Mars Express flies over its location in Endeavour Crater. This double relay will be an exciting test of the capabilities of Mars Express, both in relay terms and in pointing, and to not only prove our communication capability with the new (and fantastic!) Curiosity rover but also to continue our commitment to its predecessor – the venerable Opportunity rover.

A Digital Opportunity Rover on Mars Credit: Mars Exploration Rover Mission, Cornell, JPL, NASA Rover Model: D. Maas - Synthetic Image: Z. Gorjian, K. Kuramura, M. Stetson, E. De Jong.

A Digital Opportunity Rover on Mars Credit: Mars Exploration Rover Mission, Cornell, JPL, NASA Rover Model: D. Maas - Synthetic Image: Z. Gorjian, K. Kuramura, M. Stetson, E. De Jong. Via http://apod.nasa.gov/apod/ap051214.html

The past weeks have seen intense cooperation between NASA and ESA to coordinate and plan these activities, which are intended as demonstrations of the relay capabilities of Mars Express. The overflight of Opportunity will be part of a long-standing activity to periodically check the ability of Mars Express to relay data from Opportunity, if ever needed.

Many of these overflights were done leading up to the landing of Curiosity to cement the technical ability of the two agencies to work together on planning routine relay operations. The overflight of Curiosity will be the first time that Mars Express and Curiosity have actually 'talked' to each other.

During the landing of Curiosity, Mars Express only listened in and recording the radio signal of Curiosity, but Sunday evening, 19 August, the two spacecraft will actually have a 'conversation' and for the first time Mars Express will receive and decode actual data from the lander.

We're confident in the ability of the two spacecraft to be able to communicate for several reasons – the main one being that both implement an international standard called Proximity-1 [this is mentioned in our earlier Melacom post - Ed].

This standard was designed to make sure that even though the spacecraft come from different manufacturers and different agencies, the way they talk to each other is still the same – it can be thought of like an 'agreed common language'.

On top of this, is our extensive experience relaying data for Phoenix, Spirit and Opportunity and the fact that a team from QinetiQ (who built our Melacom radio) travelled to JPL to test a copy of it with a copy of the Curiosity radio. However, any new activity in space is challenging and we stand ready at ESOC to investigate, analyse and improve – optimising our ability to support the Curiosity mission for NASA.

All of this will allow Mars Express to make a call to Curiosity in Gale Crater and between the spacecraft agree autonomously to exchange data. Curiosity will send back data that will be decoded by Mars Express and stored ready for forwarding to Earth; then we'll quickly reset and prepare a very similar activity for Opportunity in Endeavour Crater.

Next, on Monday morning, Mars Express will send the data to ESA's 35m New Norcia (Australia) ground station and then from there it will make its way to ESOC and on to the control room at JPL.

The data's journey will be long (Gale Crater/Endeavour Crater -> Mars Express -> New Norcia, Australia -> ESOC, Germany -> JPL, USA) but we'll make sure it arrives safe and sound – proving the ability of Mars Express to support communications with both Curiosity and Opportunity whenever needed.

We'll post more details when we know the results of the test and can hopefully announce on Monday that Mars Express has been 'qualified' as a really-long-distance relay for Curiosity – expanding the network of spacecraft and cooperation at Mars in spectacular style!