"MARS PATHFINDER STATUS"

MARS PATHFINDER STATUS

In Mars Pathfinder Flight System assembly, test and launch operations (ATLO), we have completed integration of our flight "electronics box", vibrated it and spun it in a centrifuge chamber to test for launch and landing loads.

This "electronics box" is the "guts" of our three-in-one spacecraft which cruises to Mars, enters the Mars atmosphere, descends and lands, and opens up to conduct surface operations. It contains our flight computer, power conditioning and pyrotechnic firing circuits, instrument electronics, and radio.

We are currently testing it with flight software in flight-ground system tests which simulate the launch, cruise, entry/descent/landing, and surface operations mission phases. Here, we are installing its "brains". The flight system electronics will have a distinct personality after we finish this test phase in December.

Next in ATLO, we will proceed into stacking and nesting of the flight system for the string of space environmental tests planned before shipping to the launch site in August 1996.

In parallel with ATLO, we are drop testing elements of the entry/descent/landing system in various locations, qualifying its design for space use:

Airbag drop tests in simulated Mars atmospheric pressure on a slope of rocks in the NASA Lewis Plum Brook 70-foot test chamber in Sandusky, OH
Multi-body drop tests at a test range in Boise, ID, with a flight-like parachute, lander backshell, bridle and lander
Flight-like cruise stage/lander backshell/bridle/lander separation tests at the China Lake Naval Research Test Facility in the Mojave desert outside of Los Angeles, where we fire live pyrotechnic devices
Flight-like rocket drop tests, again at China Lake
In addition, we are conducting airbag retraction and lander uprighting tests here at JPL in Pasadena.
We are scheduled to complete the majority of our entry/descent/landing space qualifying tests in January 1996, 10 months before launch on December 2, 1996, and in time for our next NASA Formal Status Review planned for the end of January 1996.

It is evident by the nature of our test program above, that landing on the surface of a planet takes much more space qualification testing before launch--almost three times the standard set of spacecraft testing needed for launch and routine deep space flight. This is due to the additional environments associated with entry/descent/landing and surface operations mission phases.

Mars Pathfinder Lander and Rover Models on display at JPL open house.

Launch preparations are heating up as we have recently visited our launch site at the Eastern Test Range (ETR) in Cape Canaveral, FL. We conducted technical interchange meetings with launch support personnel there and with range safety at Patrick Air Force Base in the same area. We have decided on locations for our Project Office and Flight System Test Complex at ETR in support of launch.

Finally, we have made arrangements for practice of the launch countdown in the Mission Control Center at the launch time of 2:00 a.m. Eastern Standard Time, at least three times before the actual event. In these exercises, "Green Cards" are inserted each of which represents a problem situation which we could face in the real countdown. This is done to train us to deal with nonstandard conditions.

--Tony Spear