There’s concern that the European-Russian ExoMars 2020 mission could become ExoMars 2022.
The issue involves parachute testing and a series of snags encountering while trying to flight-qualify the descent system. The ExoMars team continues to troubleshoot the parachute design following an unsuccessful high-altitude drop test last week.
The coming ExoMars mission comprises a life-hunting rover named Rosalind Franklin and a surface science platform called Kazachok, which are scheduled to launch next summer and touch down on the Red Planet in March 2021.
If the mission misses the 2020 launch window, it would have to wait until at least 2022 for its next opportunity to lift off. (Launch windows for Mars missions open just once every 26 months.)
Several ExoMars parachute tests have been conducted at a Swedish Space Corporation site, European Space Agency (ESA) officials wrote in a statementyesterday (Aug. 12).
The first such test took place last year. It involved the largest main parachute, which is 115 feet (35 meters) wide — bigger than any chute that's ever flown on a Mars mission. A helicopter dropped the chute from an altitude of 0.7 miles (1.2 kilometers), and the parachute successfully deployed and inflated, ESA officials said.
But two subsequent tests did not go so well.
"On May 28 this year, the deployment sequence of all four parachutes was tested for the first time from a height of 29 km [18 miles] — released from a stratospheric helium balloon," ESA officials wrote in the statement. "While the deployment mechanisms activated correctly, and the overall sequence was completed, both main parachute canopies suffered damage."
The ExoMars team made some changes to the parachute system's design before the next high-altitude test on Aug. 5, which focused just on the 115-foot-wide chute. The results were similar to the previous trial: the initial steps were completed correctly, but the chute suffered canopy damage before inflation. The test module ended up descending only under the drag of a small pilot chute, ESA officials said.
"It is disappointing that the precautionary design adaptations introduced following the anomalies of the last test have not helped us to pass the second test successfully, but as always we remain focused and are working to understand and correct the flaw in order to launch next year," ESA ExoMars team leader Francois Spoto said in the statement.
The team plans to conduct another high-altitude test of the big main parachute before the end of 2019. The next qualification attempt of the second main parachute is then anticipated for early 2020.
Trying to understand the problem
There aren't many opportunities to conduct additional full-scale, high-altitude drop tests. So, ExoMars teams are also considering building more parachute test models and performing ground-based simulations to better understand the complicated, dynamic process of parachute extraction, ESA officials said.
ESA and NASA experts convene regularly to exchange ideas about space science and technology. In addition to those forums, Mars parachute specialists will convene at a workshop next month in an attempt to fix the issues.
Time running short
The coming ExoMars mission has a far more complex parachute decelerator system than those used for NASA's Mars missions.
Whether ExoMars is experiencing a parachute problem or other things associated with the parachute system is not clear.
And with time running short, ESA/NASA discussions can be muddled due to Technical Assistance Agreement (TAA) and International Traffic in Arms Regulations (ITAR) rules and regulations.
On the NASA side, the Mars Exploration Rover (MER) project — Spirit and Opportunity — went through similar nail-biting as parachute drop-testing at California's China Lake encountered problems. A chute redesign was needed, along with use of the National Full-Scale Aerodynamics Complex (NFAC) at NASA's Ames Research Center in Silicon Valley.
NASA’s mega-parachute for the Curiosity Mars rover mission underwent a total of six different tests between October 2007 and April 2009 within the NFAC. That parachute had 80 suspension lines, measured more than 165 feet (50 m) long, and opened to a diameter of nearly 51 feet (16 meters).
Spirit, Opportunity and Curiosity all landed safely on Mars. Curiosity touched down in August 2012, and Spirit and Opportunity landed a few weeks apart in January 2004.
The European-Russian ExoMars program consists of two phases. The first phase launched the Trace Gas Orbiter (TGO) and a landing demonstrator called Schiaparelli in March 2016. TGO reached Mars orbit safely, but Schiaparelli crashed during its landing attempt in October 2016 because of a data glitch.
Rosalind Franklin and Kazachok represent the second phase of ExoMars. Europe built the rover, while Russia is supplying the Kazachok lander.
NASA plans to launch a life-hunting rover to the Red Planet next summer as well. The Mars 2020 rover is based heavily off Curiosity and will employ the latter's descent system, which depended on parachutes and a rocket-powered sky crane.
ALL INSTRUMENTS ONBOARD ROSALIND FRANKLIN ROVER
The full suite of scientific instruments, including cameras that will give us our eyes on Mars, the drill that will retrieve pristine soil samples from below the surface, and the onboard laboratory that will seek out signs of life are all installed on the ExoMars rover.
The rover, named after the pioneering scientist Rosalind Franklin, is part of the ESA-Roscosmos ExoMars programme, and is nearing completion at Airbus Defence and Space, Stevenage, UK. The rover is now seen with its recently added PanCam, which sits on top of a mast that rises 2 m above the ground. PanCam will be fundamental in the day-to-day scientific operations of the rover to assist with scientific decisions on where to drive and drill.
Determining whether life ever existed on the Red Planet, or still does today, is at the heart of the ExoMars programme. While spacecraft exploring Mars in the last decades have shown that the surface is dry and barren, billions of years ago it was much more reminiscent of Earth, with water flowing in rivers and lakes, perhaps seas. If life ever began in this very early period, scientists think that the best chances to find evidence for it is to look underground, in ancient regions of Mars that were once influenced by water.
The Rosalind Franklin rover will land in what scientists think might have been an ancient ocean, close to the boundary where channels from the southern highlands of Mars connect to the smooth northern lowlands. After the initially wet era in the planet’s early history, lavas from volcanic eruptions covered large areas of Mars, some resisting erosion until today. This means that the landing site’s underlying materials may only have been exposed recently, initially protecting them from space radiation and later making them accessible to the rover and its analytical tools.
PanCam, with its stereo and high-resolution cameras will provide detailed views of geologically interesting features in visible and near-infrared wavelengths, and together with measurements made by the spectrometers, will tell us what the rocks are made of and if they were influenced by water in the past. In select locations the drill will retrieve samples from up to 2 m below the surface, delivering them to the onboard science laboratoryfor detailed analysis to sniff out signs of biological signatures.
A camera on the bottom of the drill unit will provide close-up images of the soil that is churned out by the drilling action. When the drill is in ‘stowed’ position the camera will be able to image the area in front of the rover. The close-up imager, or Clupi recently underwent final calibration tests at ESA’s technical facility in the Netherlands, before being shipped to Stevenage to be attached to the drill unit.
In addition to the cameras, spectrometers, drill and analytical lab, the rover also has sub-surface sounding radar and neutron detector.
“Our rover has really taken shape,” says Jorge Vago, ESA’s ExoMars rover project scientist. “We have an incredibly powerful scientific payload to explore the surface and subsurface of Mars on our quest to find biosignatures.”
With the scientific suite of instruments onboard, the rover is sealed up in a dedicated cleanroom. Once final checks have been completed, the rover will be transported from the UK to Toulouse, France. There it will undergo environmental testing to confirm it is ready for the conditions on Mars. Once complete it will move on to Cannes, France for final integration with the lander platform, named Kazachok, and with the descent module and carrier module that will transport the mission from Earth to Mars.
The mission is foreseen for launch in just under a year from now (the launch window is 26 July–13 August 2020) on a Russian Proton-M launcher, arriving at Mars in March 2021.
Notes to editors
The ExoMars programme is a joint endeavour between ESA and Roscosmos. In addition to the 2020 mission, it also includes the Trace Gas Orbiter (TGO) launched in 2016. The TGO is already both delivering important scientific results of its own and relaying data from NASA’s Curiosity Mars rover and Insight lander. It will also relay the data from the 2020 mission once it arrives at Mars.