PARIS — The European and Russian space agencies on May 2 said their joint ExoMars 2018 mission carrying a rover and an experiment-filled landing platform to Mars would not be ready in time and would be delayed to July 2020.
The delay, which ESA and Roscosmos officials had warned of since March, will add undetermined new costs to the program. ESA is expected to present to its governments a revised ExoMars scenario in June, including the financial impact of the delay, with governments likely to make a final decision during a December meeting of ESA government space ministers.
The ExoMars 2016 mission launched in March featured a Russian Proton rocket carrying a mainly European-built payload of a trace-gas-analyzer orbiter and communications relay; and an entry, descent and landing package built to prove decent and landing techniques. It is expected to survive only a few days.
For ExoMars 2018, now renamed ExoMars 2020, the European and Russian contributions are more evenly divided.
ESA provides a 300-kilogram rover vehicle, under construction in Stevenage, England, by Airbus Defence and Space. On April 29, ESA astronaut Tim Peake, a British national, operated the vehicle from the international space station.
Among other tasks, the rover will drill up to 2 meters beneath the Mars surface, where scientists believe any evidence of past or present life on Mars is more likely to be found than on the planet’s surface.
An 828-kilogram surface platform with a dozen-odd experiments, mainly Russian but with European contributions, will be deployed at the landing site and, for one Earth year, observe the climate, atmosphere, subsurface water and radiation environment.
The surface platform and rover will be transported to Mars aboard a Russian-built descent module to which ESA is contributing.
Rolf de Groot, head of ESA’s robotic exploration coordination office, said multiple pieces of equipment and experiment hardware — of both European and Russian origin —
would have had difficulty making the 2018 launch date. In an interview, de Groot discussed the reasons for the decision, and the consequences.
Could you have preserved the 2018 date by removing the late-arriving hardware?
No. There were too many different parts of the mission that had severe problems with the 2018 schedule. If you have a mission where it’s only one instrument or one component that is creating the problem, you can talk about de-scoping. But here we would have had to de-scope 50 percent of the mission. So it was not possible.
Did you assess whether launching in late 2018 or even 2019, then storing the package in orbit, would keep costs down?
We looked at launch windows later in 2018 and also early in 2019. For some of them we would have arrived even later than the 2020 date we have now agreed to. But they would add significantly more requirements to the spacecraft because of radiation and other issues.
We will try to finish the development as soon as possible, and then begin storage on Earth before completing the testing later on, in the period leading up to the 2020 launch. Storage on Earth is less risky than storage in space.
The ExoMars 2016 Trace Gas Orbiter, with a telecommunications relay for the ExoMars 2020 mission, was launched in March. If you’d known then that the companion mission would be late, would you have delayed the launch?
Definitely not: The lifespan for TGO is long enough to be around for the 2020 mission. It would have added costs to the mission itself. Now we can do the nominal science mission of TGO before starting to support the rover mission. For the people running the TGO instruments, this is not such bad news.
TGO is designed for a nominal five years, but look at Mars Express, still going 13 years after launch. We are very confident that the two-year delay will not change the ability of the TGO to support the second mission.
Two years’ delay means additional costs. What are they?
A: We are trying to minimize them by building the spacecraft as quickly as possible so as not to stretch all the [program development elements] over two years and two months, which would mean maximum extra costs. The subcontractors are pretty much on schedule, so what we plan to do – pending a new, integrated and finalized schedule – is try to build all the models we have to build. Then during the storage period we would no longer have very big teams working for the mission. That will decrease the cost as much as possible.
Do you have a cost estimate?
We are negotiating with the prime contractors on what will be a reasonable price. We were still negotiating the full development contracts for the 2018 mission. We were very close to finalizing this and now this adds a little bit of complexity. That’s why we are trying not to mention any numbers here, because it will not help our negotiations with Airbus Defence and Space, which is responsible for the rover, and with Thales Alenia Space Italia, which is overall program prime contractor.
I had thought the rover instruments were on schedule.
A: There are several that — well, let’s say they are not unhappy to have a bit more time.
Do you have a clear sense of the state of the Roscosmos contributions?
They too recognized that they would have severe difficulties meeting the 2018 launch date. European and Russian industry and the payload developers are all in the same boat here. So the decision was supported on all sides. We obviously have more transparency on what European industry is doing but we count on Roscosmos to have transparency on what their industry is doing.
This mission is very important for both agencies’ exploration programs. The responsible thing to do now is to make a good mission and a good schedule for 2020.
Does this have anything to do with Roscosmos budget cuts?
No, it has nothing to do with that. They are having severe budget cuts compared to last year, but this is not impacting ExoMars. ExoMars is still a high priority for them.