Published December 15, 1999
NASA’s polar lander and two miniature probes, carrying ten experiments, are dead on arrival at Mars. These research vessels, launched January 3, 1999 slammed into Martian soil December 3, 1999, after a 470 million-mile journey. No signal has been received from these three spacecraft.
The Deep Space 2 probes’ tiny data-gathering laboratories, riding piggyback on the Mars Polar Lander, were the space agency’s first integrated and miniaturized space flight systems. Microinstruments aboard were to collect and analyze soil samples for water content. Data transmitted from it’s 5 inch UHF antenna was to be relayed to the Mars Global Surveyor Spacecraft, already orbiting and mapping the red planet.
The Mars Polar Lander itself has not been heard from either. The onboard radar altimeter was to control the pulsing action of a dozen rocket thrusters. Hazardous obstructions encountered at touchdown were known to be unavoidable. “At the scale of the 3.5 foot tall, 12-foot wide lander, even something the size of a table could represent an obstacle,” says Project Scientist Richard Zurek.
Communications was attempted using a 151-foot antenna at Stanford University. Engineers sent commands to the spacecraft that would aim its antenna in every possible direction so to be heard by mission controllers on Earth.
Project manager Sarah Gavit expects the probes’ two lighium-thionyl chloride batteries, after four days on Mars, are no longer charged. The Polar Lander’s unexpected silence is a mystery.
The mission was intended to be a demonstration of subsurface ice detection and a test of new devices in preparation for future missions. A NASA spokesperson acknowledged on December 7th, 1999 that they are less than hopeful for communicating with the spacecraft. Project manager Richard Cook of JPL said, “We’re certainly disappointed but extremely determined to recover from this and go on.”
Fly-overs by the Mars Global Surveyor, in orbit since 1997, will photograph the landing site in search for the Mars Polar Lander and its probes.
Deep Space 2 probes carried first-of-a-kind instruments designed for hostile space conditions. They were also the first spacecraft to use only an aeroshell to soften the descent and landing, dispensing with a parachute and rockets. They were, therefore, lighter and less expensive, but insufficiently durable to survive the impact and/or operate in the extremely low temperatures.
The probes were each 11 inches high, 14 inches diameter, and about the weight of a lap-top computer. The costs for development was $29.2M, not including the launch and tracking. Review boards within NASA and JPL are examining the cause of this mishap, the most recent failure of a Mars mission.
Just two months earlier, the Mars Climate Orbiter was loss in deep space due to suspected navigational errors, a very devastating setback to the program. On September 24, 1999, the search for that spacecraft was abandoned. It’s out there, somewhere.
Wide-ranging managerial and technical actions are presently underway at NASA’s Jet Propulsion Lab, a division of the California Institute of Technology in Pasadena, including their industrial partner, Lockheed Martin Astronautics, Denver.
The failure board identified eight contributing factors that led to the loss of the Climate Orbiter. These involved such things as teams not following mission objectives, inconsistent communications/training, and lack of critical verifications for navigation software in computer models.
The peer review found that one team used English units (e.g., inches, feet and pounds) while another team used metric units for propulsion and course calculations.
Contributing factors for the loss of Mars Climate Orbiter:
The orientation and direction of the spacecraft was not communicated to the operational navigation team. The final optional engine firing, which would have raised the spacecraft’s path before arrival, was considered but not actuated. A double-check of interconnected mission aspects was inadequate. An inexperienced multi-missions team accepted the first-time handover of a Mars-bound spacecraft from the group that constructed and launched it who were insufficiently trained to report anomalies while immersed in technical details. And an understaffed and overworked mission navigation team was not peer-reviewed.
With the failures of two missions and four spacecraft in a few months, NASA has its hands full. The schedule toward the eventual manned mission to Mars will be understandably postponed.
[Trivia: NASA calls one Martian day a sol, or 24 hours 37 minutes, 23 seconds. An Earth literal day is 23 hours, 56 minutes, 4 seconds.]