Mars Exploration Rover Machine Using Java Technology Presented by k.Pranusha k.Ishwarya

We will present how we used Java client applications, J2EE, and Web Services to build the Collaborative Information Portal (CIP) for NASA’s current Mars Exploration Rovers mission. Java Provides Many Tools, But … … software integration is still a major challenge! Overview

Mission Overview

Mars Exploration Rovers Mission  NASA’s twin robot geologists, the Mars Exploration Rovers, will launch toward Mars in search of answers about the history of water on Mars.  Launch: May - Jun, 2003  Landing: Jan - Feb, 2004  Duration: 90+ days  Mission Center: Jet Propulsion Laboratory, Pasadena, CA

Stages of the Mission Launch Entry

Stages of the Mission DescentLanding

Stages of the Mission Surface Operations

Surface Operations Process  Rover is solar-powered, so must operate during daylight hours  Mission will run on Mars time (Martian “sol” is 40 minutes longer than Earth day)  Daily process for mission personnel: Receive downlink from Rover Process and analyze results Plan tomorrow’s activities Construct rover command sequence Send uplink of command sequence to Rover

Collaborative Information Portal (CIP)  Architecture overview

CIP Application Goals  Provide a central place to access mission information  Provide a Mars time clock  Navigate, search, and view mission data, plans, reports and schedules from various perspectives  Provide notification of new events  Provide automated updates of various mission data and documents based on subscription  Provide mission broadcast messages  Flexibility as mission requirements change

CIP Components  Client Java Application  Server Middleware (Web Services and Enterprise JavaBeans)  Backend Database (Oracle) Loader (Java Application) Monitor (Java Application)

Client Design Goals  Demand driven operation  Support common scientific user platforms (Sun, PC, Mac)  Leverage current technologies  Thick client  Quick, painless deployment  User customizable  High usability

Client Design Web Service Client Stub Service Mgr Service Mgr Service Mgr Service Mgr Service Mgr Service Mgr Service Mgr Service Mgr Web Service Client Stub CIP Client CIPSERVERCIPSERVER CIPSERVERCIPSERVER

Middleware Goals  Reliable  Scalable  Maintainable  Secure  Platform and language independent  Support hundreds of users  Adheres to standards  Off-the-shelf software

Middleware Architecture FIREWALLFIREWALL FIREWALLFIREWALL HTTPS Web Services expose the remote methods of the Service Provider EJBs. J2EE Application Server SOAP Processor Service Provider Remote Stateless Session EJB Web Service Client Stub SOAP Processor Service Provider Remote Stateless Session EJB Web Service Client Stub HTTPS HTTPS encrypts the transmissions and gets them through the firewall. Application Java Application C++ HTTPS

Real Time Specification for JAVA (RTSJ) Real-Time application development requires: An API set and semantics which allow developers to correctly reason about and control the temporal behavior of application. RTSJ/Java RTS Provides: An API set, semantic JVM enhancements, and JVM-to-OS layer modifications which allow java developers to correctly reason about and control the temporal behavior of java applications.

The Java 3D specification The Java enables creation of 3D graphics application and internet based 3D applets. Rover Hardware:  Due to the limits of mass on the Rover, the hardware needs to be versatile.  The Rover also carries several cameras not only for photography and positioning but also in surface navigation and descent. Rover Software:  The software that drives the mission is known as Science Activity Planner(SAP)  SAP uses additional Java tools, including Java Expression Parser(JEP), Java Compiler Compiler (JCC)

Summary  The Collaborative Information Portal is a key component of the Mars Exploration Rovers mission.  The client applications are highly graphical and interactive. Most are written in JAVA.  We have two rovers on mars each exploring the red planet. These are working efficiently since January 2004 using JAVA technology.  SUN is also working to implement JAVA in physical systems like Rovers and power plants  Now the JAVA has helped us get to mars, who knows what “JAVA Everywhere” will mean the in the future?

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