MXJ: Model-Centric, Safety-Critical Java for

Exploration

Matthias AnlauffKestrel Institute, Palo Alto, CA

ma@kestrel.edu

Project Goals

• Java for flight and ground software in exploration missions

• Java-centric software development environment

• Formal representation of requirements

• Generation of certifiable mission-critical Java

Background

• The MXJ project has been proposed and accepted by NASA as one of 70 proposals out of 3750 entries (11/04)

• MXJ will be part of the NASA Exploration Systems Mission Directorate (ESMD) Vision for Space Exploration

• MXJ: Java-based, high-assurance development environment suitable for Exploration applications

MXJ Team

Matthias Anlauff, Principal Investigator, Kestrel

Institute (KI)

Bill Bush, co-Investigator, Sun Microsystems (Sun)

Klaus Havelund, co-Investigator, Kestrel Technology

(KT)

Doug Wells, SC Java Standardization, The Open Group

Meyer/Clark/Schoppers, Domain Modeling, NASA/JPL

John Anton, Project Manager, KI & KT

Model-centric approach

Problem DescriptionDomain-Specific

Language(s)

Problem DescriptionDomain-Specific

Language(s)

Problem DescriptionDomain-Specific Language

High-level Model(s)JSL (Java Spec Language)

Operational ModelJSL

Translation

Composition & Refinement

Source/Byte CodeSCJ VM

Generator

AtmosphereModel

PlanetaryModel

Nav.,G&C Model

Land on Mars Surface at Position x,y

Precision Landing Models in JSL

Component Operation Control Models

Precision landing SCJ code

Mars Lander

Byte Code Compiler

Concrete Platform

Approach Overview

MXJ – Model-centric Architecture

High-assurance Java code

• High-assurance must be enforced on all levels implementation language VM must be

precisely defined and analyzable

• Exploration applications require real-time language constructs

• Java-based implementation language

Safety-Critical Java

Summary

• MXJ aims at enabling Java to be used in safety-critical Exploration applications

• High-assurance model approach using refinement and composition techniques

• Safety-Critical Java will be the main target VM