July 18, 2018

InSight mission to Mars, CNES’s SEIS seismometer is in good shape

On 16 July at 15:45 UTC, the SEIS seismometer was powered up on its nominal channel for the first time in space since the launch of InSight on 5 May to test its health during the cruise phase of the mission. All data received from SEIS are as expected, confirming that the instrument on its way to Mars is in perfect working order.

SEIS had not been switched on again since final checks on the launch pad at Vandenberg Air Force Base (VAFB) on 25 and 26 April, ten days before InSight’s launch. The short test on Monday, lasting just 10 minutes, involved starting up the instrument and then collecting data from the seismic sensors and numerous temperature sensors.

All data generated were then relayed back to Earth via the 34-metre Deep Space Network (DSN) antenna in Canberra, Australia, and conveyed via NASA’s ground infrastructures to the SeIS on Mars Operations Centre (SISMOC) at CNES in Toulouse. Analysis of the data by engineers at CNES, the IPGP global physics institute in Paris, NASA’s Jet Propulsion Laboratory (JPL) and the instrument’s UK and Swiss partners found no anomalies.

Two of the three short-period sensors supplied by the United Kingdom—the horizontal sensors capable of operating in zero-gravity conditions—sent back an excellent signal, while the signal from the third, a vertical sensor designed to operate in Martian gravity, was logically saturated. The data from the very-broad band sensors (VBB) for which France has responsibility were also very good, with power consumption matching the levels that engineers are looking for. The VBB sensors also sent back a saturated signal, as they are designed to operate in Martian gravity like the vertical sensor.

The next operations on SEIS during the cruise phase are scheduled for 19 July and 16 August, when the instrument will again be switched on. Data from the two horizontal sensors will be used to conduct initial calibrations.

InSight is now about 18½ million kilometres from Earth. Mars is currently in opposition and on 30 July it will be only 57.6 million kilometres from Earth, almost as close as the record closest distance during the historic opposition of 2003. The lander is 132 days away from setting down on Elysium Planitia on 26 November.

Pascale Bresson          Press Officer    Tel: +33 (0)1 44 76 75 39    pascale.bresson@cnes.fr
Raphaël Sart                Press Officer     Tel: +33 (0)1 44 76 74 51    raphael.sart@cnes.fr
Sébastien Martignac    Press Officer    Tel. +33 (0)1 44 76 78 35    sebastien.martignac@cnes.fr