Exomars

Origin and history

ExoMars is a joint astrobiology program of the European Space Agency (ESA) and the Russian space agency Roscosmos, with a significant contribution from NASA in its earlier phases. The program's origins trace back to the early 2000s, following the successful ESA Mars Express mission, which demonstrated European capability in Martian exploration. Formal approval for the ExoMars program was granted by ESA member states in the mid-2000s, with the primary objective of searching for signs of past or present life on Mars. The initial collaboration with NASA faced budgetary and programmatic challenges, leading to a restructuring of the partnership in the early 2010s. Roscosmos subsequently became the primary partner, providing launch vehicles and key elements of the lander and surface platform. This revised cooperation framework solidified the program's two-mission architecture, with launches planned for the 2010s.

What it is for

The ExoMars program is designed to investigate the Martian environment and specifically address the question of whether life has ever existed on Mars. Its core scientific goal is the search for biosignatures, chemical or physical markers left by biological processes, within the Martian subsurface. This focus stems from the understanding that the surface is inhospitable due to radiation and oxidative processes, making the subsurface a more promising target for preserving organic material. The program employs a two-mission architecture: the first mission combined an orbiter to study atmospheric trace gases with a stationary lander to test entry, descent, and landing technologies. The second, and primary, mission is tasked with delivering a robust rover equipped with a drill capable of reaching two meters below the surface to retrieve samples for onboard analysis. This subsurface sampling capability is a first for Mars exploration and is central to the mission's unique astrobiological purpose.

Pros and cons

A primary advantage of the ExoMars program is its dedicated technological focus on accessing and analyzing the Martian subsurface, a niche not directly addressed by other contemporary rover missions. The program's international partnership structure allows for cost-sharing and the pooling of specialized expertise from Europe and Russia. However, a significant con is the program's history of delays, budget overruns, and partnership instability, which have postponed its core objectives and increased overall costs. The complexity of the landing system, particularly for the rover mission, introduces a high risk of failure, as demonstrated by the loss of the Schiaparelli lander during its descent in 2016. Entities regretting their involvement might include national space agencies whose contributions were scaled back during program restructuring, leaving them with diminished scientific return. A common mistake in public perception is viewing ExoMars as a direct, equivalent competitor to NASA's rovers, rather than understanding its specialized, complementary role in subsurface biosignature investigation.

Who it suits

The ExoMars program primarily suits the scientific community focused on planetary science and astrobiology, particularly researchers specializing in organic chemistry, geology, and atmospheric science. It is suited to the strategic interests of ESA and its member states, which seek to establish independent capabilities in deep-space exploration, complex entry-descent-landing systems, and rover operations on Mars. The program also suits Roscosmos's aim of maintaining a high-profile role in international deep-space exploration following a period of limited interplanetary missions. Industrial consortia across Europe and Russia with expertise in aerospace engineering, precision instrumentation, and robotic systems are suited to participate in its development and construction. The mission is less suited to stakeholders seeking quick, low-risk scientific returns, given its protracted development timeline and the inherent perils of landing on Mars. Ultimately, it suits a long-term, patient approach to space science that prioritizes a specific, high-value scientific question about life over more generalized surface exploration.