In April 2026, NASA approved the cost and schedule baselines for the ROSA project with the cost set at $396 million and a launch readiness date of December 2028. The project also set a baseline for the delivery of the lander engines in August 2026. In addition, NASA approved the project to enter the system assembly, integration and test, and launch phase at the same time. Officials said this approval was originally scheduled for June 2025 but was postponed because the project was proposed for cancelation in the Fiscal Year 2026 President’s Budget Request.
The project is making progress on the instrument and lander engines. NASA delivered the mass spectrometer to ESA in June 2025, and it is currently undergoing integration and testing. The next critical delivery is the lander engines. The project faced a schedule risk related to potential late deliveries of these engines because of production delays or technical issues. The ROSA project worked with the Mars Sample Return project, which manages the contract for the engines, to accelerate the deliveries. NASA expects to deliver all four engines on time.
ROSA’s top risk is the delay in receiving nuclear launch authorization, which is needed because the rover’s heaters contain nuclear material. NASA could not start the authorization process until the project selected a launch vehicle. The selection was delayed by 3 months because of the government shutdown. Project officials said that NASA is working on the authorization schedule with the Department of Energy to mitigate this risk.
