The Mars 2001 program is one of a series of planetary missions to Mars being planned in the next 10 years. It consists of two vehicles, an orbiter that will study the atmosphere and a lander that will take soil samples. The project is a joint effort between NASA, JPL, and Lockheed-Martin.

My group here at NASA Ames, the Reacting Flow Environments Branch, has the responsibility of computing the thermal environments the vehicles will experience when it enters the Martian atmosphere. In space there are no gas molecules (or not very many) so the spacecraft just sails along, but in an atmosphere the gas particles hit the spacecraft and cause the surface to heat up. My job was to use a computer program to compute exactly how hot the surfaces of the vehicles will get.

Since the project managers work in Pasedena, CA and Denver, CO, I spend a lot of the time in the beginning in teleconferences and sending email. I receive a surface geometry data file from JPL and a trajectory file from Lockheed-Martin. With this input data, I am able to begin my calculations.

One of the interesting features of the Martian atmosphere is that it is dusty. The Mars 2001 vehicles are supposed to enter the Martian atmosphere during a period when a dust storm is likely to be occurring. We develop a computer program to determine how much of the vehicle heatshield will be eroded due to impact with the atmospheric dust. The heatshield material is manufactured by Lockheed-Martin and there is a limit to how thick it can be made. If there is a lot of erosion due to dust, the heatshield might not be thick enough to protect the vehicle. It turns out there isn't that much erosion, so everyone is happy.

One cool thing about the orbiter is that it will use aerocapture to slow itself down when it reaches Mars. Aerocapture means the vehicle will use the friction caused by the atmosphere to slow down to the point where it can orbit the planet. This is to be the first use of aerocapture in a planetary mission.

Then last month something bad happened. Lockheed-Martin experienced a budget cut in the Mars 2001 program and the mission had to be re-structured. The orbiter mission was cancelled and the lander vehicle is still being re-worked as I write this. We are all disappointed because we have done a lot of work on the orbiter and we wanted to see if the aerocapture concept worked. This kind of program re-structuring happens a lot which is why people you see on TV are all very happy when their mission actually flies.