After multiple problems in the end of 2015 and with increasing probability of halting NASA participation in program on 2016, we have NASA final voice in discussion. InSight will start its mission in 2018 in first possible launch window.
InSight (Interior Exploration Using Seismic Investigations, Geodesy, and Heat Transport) was one of fundamental Mars research missions, example of well-organized and providing multiple benefits cooperation of USA and Europe in space. NASA (and Jet Propulsion Laboratory), CNES (French space agency) and DLR (German space agency) signed agreement for cooperation in creating Mars lander on February 2014. Lander was planned to be based on Phoenix Mars landing vehicle (which reached Mars surface on May 25, 2008 to search for traces of microbial life) combined with various devices for measuring seismic activity of Red Planet. NASA and JPL were set to be responsible for creating lander and part of scientific payload, CNES role was designing and manufacturing SEIS seismometer and DLR, in cooperation with German Aerospace Center, developed HP3 (Heat Flow and Physical Properties Package - device for monitoring flow of the heat from Mars core to surface). Mission launch was scheduled for March 2016 with Atlas V rocket. Unfortunately problems appeared during final tests and assembly of CNES seismometer. CNES engineers spotted leakage in November 2015. Even if leakage was extremely small, it made whole SEIS device out of order, because seismometer was designed to operate only in vacuum conditions. It appeared that CNES managed to fix leakage, but in December 2015 it was spotted again in another place of SEIS. This time it became clear that launch in March 2016 would be not possible. CNES confirmed in January that leakage would not be fixed in time which would let keep the mission schedule. Situation became hard due the necessity of covering costs of additional fixing SEIS by CNES and for NASA, which was forced to cover costs of cancelled launch and storing lander for next 26 months to next launch window on May 2018 (read more here). NASA started to consider even leaving whole program; luckily lack of sense launching InSight without SEIS and rather sad perspective of explaining in Congress reasons of cancelling such expensive program without any results, finally forced NASA to made only one proper decision. Insight is now scheduled for 2018 with (hopefully) fully operational SEIS. CNES, which recently confirmed that reason of leakage was discovered and problem was solved permanently, decided to participate in further costs of storing InSight lander (which were estimated for $150 million) in spite of lack previous declarations in agreement from 2014. Again it seems that science won over economy and Mars will became explored only with little delay.
On picture above: next time this parachute will open on Mars - testing of Insight lander parachute required for reducing speed before touch down.