Friday , December 4 2020

Insight: Before Mars landing, and nail-biting 'six and a half minutes of terror'



TAMPA: A spacecraft that cost almost
a billion dollars is on course to make
a perilous
landing Monday on
Mars, if it can survive
a high-speed approach and the scorching heat of entering Red Planet's atmosphere,
a NASA's process has nicknamed "six and
a half minutes of terror. "

"There is very little room for things to go wrong," said Rob Grover, head of the entry, descent and
landing team at NASA's Jet Propulsion Laboratory in Pasadena, California.

If successful, the entry, descent and
landing of the
Mars InSight – designed to be the first mission to listen to the interior of another planet and reveal how rocky planets formed – will add another success to NASA's record when it comes to sending spacecraft to
Mars.

So far, the United States is the only nation to have made it there, and only NASA's unmanned Curiosity robotic rover is still working around the surface.

But if it fails, it will certainly not be the first.

Of 43 other international attempts to send orbiters, probes, landers or rovers to
Mars, 25 have not made it. Either they crashed into the surface, missed their planned orbit, or disappeared after launch.

There will be no live streaming of videos
Mars Insight's approach on Monday, and signals will be transmitted back to Earth on an eight-minute delay.

Nor can mission managers intervene if anything goes awry. The whole
landing the sequence is all pre-programmed into the on-board flight computer.

Here's what to expect:

– At 11:40 am Pacific Time (1940 GMT), the spacecraft separates from the cruise stage that carried it to
Mars.
A minutes later, the spacecraft makes
a turn to atmospheric entry.

– At 1947 GMT, the spacecraft is hurtling through space at
a speed of 12,300 miles per hour (19,800 kilometers per hour) as it begins to enter
Mars'atmosphere.

– Two minutes later, friction with the atmosphere raises the heat shield to its peak of 2,700 Fahrenheit (1,500 degrees Celsius). This intense heat could cause temporary dropouts in radio signals.

– At 1951 GMT, the parachutes deploy. Fifteen seconds later, the heat shield separates from the spacecraft. Ten seconds on, the lander's three legs deploy to get ready for touchdown.

– At 1952 GMT,
a radar activates to sense the distance to the ground.

– At 1953 GMT, the first radar signal is expected, followed by 20 seconds later by the spacecraft's separation from the back shell and parachute. Then, the descent engines, known as retrorockets, start to fire. InSight's speed is slowly increasing, from 17 mph to
a constant five mph (27 kph to eight kph) for its soft
landing.

– Touchdown is expected at 1954 GMT.

– The first "beep" from the X-band radio's spacecraft – indicating whether InSight survived the
landing – is scheduled for 2001 GMT.

– The first image from the surface of
Mars is expected at 2004 GMT. However, this image may not arrive until Tuesday.

– The orbital pattern of the
Mars Odyssey Spacecraft, flying overhead, means NASA will not know until 0135 GMT on Tuesday if the InSight's solar arrays have deployed or not. This step is crucial because the quake-sensor is powered by Sun for its one-year mission.


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