1999 жылғы Марсқа сәтті қонбаған роботтық зонд

Failed 1999 robotic Mars lander

The Mars Polar Lander, also known as the Mars Surveyor '98 Lander, was a 290 kilogram robotic spacecraft lander launched by NASA on January 3, 1999, to study the soil and climate of Planum Australe, a region near the south pole on Mars. It formed part of the Mars Surveyor '98 mission. On December 3, 1999, however, after the descent phase was expected to be complete, the lander failed to reestablish communication with Earth. A post mortem analysis determined the most likely cause of the mishap was premature termination of the engine firing prior to the lander touching the surface, causing it to strike the planet at a high velocity. The total cost of the Mars Polar Lander was US$165 million. Spacecraft development cost US$110 million, launch was estimated at US$45 million, and mission operations at US$10 million.

While traveling to Mars, the cruise stage was three axis stabilized with four hydrazine monopropellant reaction engine modules, each including a 22 newton trajectory correction maneuver thruster for propulsion and a 4 newton reaction control system thruster for attitude control (orientation). Orientation of the spacecraft was performed using redundant Sun sensors, star trackers, and inertial measurement units. Surface Stereo Imager (SSI) Using a pair of charge coupled devices (CCD), the stereo panoramic camera was mounted to a one meter tall mast and would aid in the thermal evolved gas analyzer in determining areas of interest for the robotic arm. In addition, the camera would be used to estimate the column density of atmospheric dust, the optical depth of aerosols, and slant column abundances of water vapor using narrow band imaging of the Sun. Light Detection and Ranging (LIDAR) The laser sounding instrument was intended to detect and characterize aerosols in the atmosphere up to three kilometers above the lander. The instrument operated in two modes: active mode, using an included laser diode, and acoustic mode, using the Sun as the light source for the sensor. In active mode, the laser sounder was to emit 100 nanosecond pulses at a wavelength of 0.88 micrometer into the atmosphere, and then record the duration of time to detect the light scattered by aerosols. The duration of time required for the light to return could then be used to determine the abundance of ice, dust and other aerosols in the region. In acoustic mode, the instrument measures the brightness of the sky as lit by the Sun and records the scattering of light as it passes to the sensor. Robotic Arm (RA) Located on the front of the lander, the robotic arm was a meter long aluminum tube with an elbow joint and an articulated scoop attached to the end. The scoop was intended to be used to dig into the soil in the direct vicinity of the lander. The soil could then be analyzed in the scoop with the robotic arm camera or transferred into the thermal evolved gas analyzer. The microphone was built using off the shelf parts including a Sensory, Inc. RSC 164 integrated circuit typically used in speech recognition devices.

Timeline of observations Date Event 1999 01 03 Spacecraft launched at 20:21:10 UTC 1999 12 03 Begin atmospheric entry and landing Time Event 1999 12 03 14:39:00 14:42:00 17:34:00 18:49:00 19:21:00 19:26:00 20:00:00 20:03:00 20:05:00 20:10:00 20:11:00 20:12:00 20:13:00 20:13:00 20:13:00 20:14 20:14:00 20:14:00 20:14 20:14:00 20:14:00 20:15:00 20:15:00 20:20:00 20:20:00 20:39:00 21:24:00 21:45:00 22:10:00 1999 12 04 02:50:00 03:25:00 04:25:00 06:25:00 1999 12 03 Failure to regain communication after landing Time Event 1999 12 03 20:39:00 22:04:00 1999 12 04 04:08:00 1999 12 05 04:30:00 18:50:00 1999 12 06 06:10:00 1999 12 07 08:20:00 1999 12 08 2000 01 17 Mission declared a loss. No further attempts to contact.