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They kave been talking about the Mars Polar Lander, the robotic spacecraft lander launched by NASA on a day like today in 1999.
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.
As part of the Mars Surveyor '98 mission, a lander was sought as a way to gather climate data from the ground in conjunction with an orbiter. NASA suspected that a large quantity of frozen water may exist under a thin layer of dust at the south pole. In planning the Mars Polar Lander, the potential water content in the Martian south pole was the strongest determining factor for choosing a landing location.
A CD-ROM containing the names of one million children from around the world was placed on board the spacecraft as part of the Send Your Name to Mars program designed to encourage interest in the space program among children.
The primary objectives of the mission were to:
-Land on the layered terrain in the south polar region of Mars;
-Search for evidence related to ancient climates and more recent periodic climate change;
-Give a picture of the current climate and seasonal change at high latitudes and, in particular, the exchange of water vapor between the atmosphere and ground;
-Search for near-surface ground ice in the polar regions, and analyze the soil for physically and chemically bound carbon dioxide and water; and
-Study surface morphology (forms and structures), geology, topography, and weather of the landing site.
More information: NASA
The spacecraft measured 3.6 meters wide and 1.06 meters tall with the legs and solar arrays fully deployed. The base was primarily constructed with an aluminum honeycomb deck, composite graphite-epoxy sheets forming the edge, and three aluminum legs. During landing, the legs were to deploy from stowed position with compression springs and absorb the force of the landing with crushable aluminum honeycomb inserts in each leg.
On the deck of the lander, a small thermal Faraday cage enclosure housed the computer, power distribution electronics and batteries, telecommunication electronics, and the capillary pump loop heat pipe (LHP) components, which maintained operable temperature. Each of these components included redundant units in the event that one may fail.
During the cruise stage, communications with the spacecraft were conducted over the X band using a medium-gain, horn-shaped antenna and redundant solid state power amplifiers. For contingency measures, a low-gain omni-directional antenna was also included.
The lander was originally intended to communicate data through the failed Mars Climate Orbiter via the UHF antenna. With the orbiter lost on September 23, 1999, the lander would still be able to communicate directly to the Deep Space Network through the Direct-To-Earth (DTE) link, an X band, steerable, medium-gain, parabolic antenna located on the deck.
Alternatively, Mars Global Surveyor could be used as a relay using the UHF antenna at multiple times each Martian day. However the Deep Space Network could only receive data from, and not send commands to, the lander using this method. The direct-to-Earth medium-gain antenna provided a 12.6-kbit/s return channel, and the UHF relay path provided a 128-kbit/s return channel. Communications with the spacecraft would be limited to one-hour events, constrained by heat-buildup that would occur in the amplifiers. The number of communication events would also be constrained by power limitations.
The cruise stage included two gallium arsenide solar arrays to power the radio system and maintain power to the batteries in the lander, which kept certain electronics warm.
After descending to the surface, the lander was to deploy two 3.6-meter-wide gallium arsenide solar arrays, located on either side of the spacecraft. Another two auxiliary solar arrays were located on the side to provide additional power for a total of an expected 200 watts and approximately eight to nine hours of operating time per day.
While the Sun would not have set below the horizon during the primary mission, too little light would have reached the solar arrays to remain warm enough for certain electronics to continue functioning. To avoid this problem, a 16-amp-hour nickel hydrogen battery was included to be recharged during the day and to power the heater for the thermal enclosure at night. This solution also was expected to limit the life of the lander. As the Martian days would grow colder in late summer, too little power would be supplied to the heater to avoid freezing, resulting in the battery also freezing and signaling the end of the operating life for the lander.
Mars Polar Lander was launched on January 3, 1999, at 20:21:10 UTC by the National Aeronautics and Space Administration from Space Launch Complex 17B at the Cape Canaveral Air Force Station in Florida, aboard a Delta II 7425-9.5 launch vehicle.
The complete burn sequence lasted for 47.7 minutes after a Thiokol Star 48B solid-fuel third stage booster placed the spacecraft into an 11-month, Mars transfer trajectory at a final velocity of 6.884 kilometers per second with respect to Mars. During cruise, the spacecraft was stowed inside an aeroshell capsule and a segment known as the cruise stage provided power and communications with Earth.
On December 3, 1999, at 14:39:00 UTC, the last telemetry from Mars Polar Lander was sent, just prior to cruise stage separation and the subsequent atmospheric entry. No further signals were received from the spacecraft. Attempts were made by Mars Global Surveyor to photograph the area in which the lander was believed to be. An object was visible and believed to be the lander. However, subsequent imaging performed by Mars Reconnaissance Orbiter resulted in the identified object being ruled out. Mars Polar Lander remains lost.
Despite the Mars Polar Lander's failure, Planum Australe, which served as the exploration target for the lander and the two Deep Space 2 probes, would in later years be explored by European Space Agency's MARSIS radar, which examined and analyzed the site from Mars' orbit.
More information: NASA
that allows you to dream big.
Peter Diamandis
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