NASA is yet to make contact with its Mars Opportunity Rover ever since a massive storm started on the Red Planet in June.
Based on the longevity of a 2001 global storm, NASA scientists estimate it may be September before the haze has cleared enough for Opportunity to power up and call home, the US space agency said this week.
Scientists first observed a smaller-scale dust storm on May 30. By June 20, it had gone global.
For the Opportunity rover, that meant a sudden drop in visibility from a clear, sunny day to that of an overcast one.
Because Opportunity runs on solar energy, scientists had to suspend science activities to preserve the rover’s batteries.
NASA said no response has been received from the rover as of July 18.
Luckily, all that dust acts as an atmospheric insulator, keeping nighttime temperatures from dropping down to lower than what Opportunity can handle.
But the nearly 15-year-old rover is not out of the woods yet as it could take weeks, or even months, for the dust to start settling.
When the skies begin to clear, Opportunity’s solar panels may be covered by a fine film of dust. That could delay a recovery of the rover as it gathers energy to recharge its batteries. A gust of wind would help, but is not a requirement for a full recovery, NASA said.
While the Opportunity team waits in earnest to hear from the rover, scientists on other Mars missions have gotten a rare chance to study this storm.
The Mars Reconnaissance Orbiter (MRO), Mars Odyssey, and Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiters are all tailoring their observations of the Red Planet to study this global storm and learn more about Mars’ weather patterns.
Meanwhile, the Curiosity rover is studying the dust storm from the Martian surface, the US space agency added. (IANS)
With NASA launching a historic Parker Solar Probe deeper into the solar atmosphere than any mission before it, a moot question arises: Why won’t it melt?
Inside the solar atmosphere — a region known as the corona — the probe will provide observations of what drives the wide range of particles, energy and heat that course through the region.
The spacecraft will travel through material with temperatures greater than several million degrees Celsius while being bombarded with intense sunlight.
According to the US space agency, Parker Solar Probe has been designed to withstand the extreme conditions and temperature fluctuations for the mission.
“The key lies in its custom heat shield and an autonomous system that helps protect the mission from the Sun’s intense light emission, but does allow the coronal material to ‘touch’ the spacecraft,” NASA said in a statement.
While the Parker Solar Probe will travel through a space with temperatures of several million degrees, the surface of the heat shield that faces the Sun will only get heated to about 1,400 degree Celsius.
This is because “in space, the temperature can be thousands of degrees without providing significant heat to a given object or feeling hot. Since space is mostly empty, there are very few particles that can transfer energy to the spacecraft”.
The corona through which the Parker Solar Probe flies, for example, has an extremely high temperature but very low density.
The probe makes use of a heat shield known as the Thermal Protection System, or TPS, which is eight feet in diameter and 4.5 inches thick.
Those few inches of protection mean that just on the other side of the shield, the spacecraft body will sit at a comfortable 30 degrees Celsius.
The TPS was designed by the Johns Hopkins Applied Physics Laboratory, and was built at Carbon-Carbon Advanced Technologies, using a carbon composite foam sandwiched between two carbon plates.
This lightweight insulation will be accompanied by a finishing touch of white ceramic paint on the sun-facing plate, to reflect as much heat as possible.
“Tested to withstand up to 1,650 degrees Celsius, the TPS can handle any heat the Sun can send its way, keeping almost all instrumentation safe,” said NASA.
Another challenge came in the form of the electronic wiring — most cables would melt from exposure to heat radiation at such close proximity to the Sun.
To solve this problem, the team grew sapphire crystal tubes to suspend the wiring, and made the wires from the chemical element niobium.
Several other designs on the spacecraft keep Parker Solar Probe sheltered from the heat.
Without protection, the solar panels — which use energy from the very star being studied to power the spacecraft — can overheat.
At each approach to the Sun, the solar arrays retract behind the heat shield’s shadow, leaving only a small segment exposed to the Sun’s intense rays.
The solar arrays have a surprisingly simple cooling system: a heated tank that keeps the coolant from freezing during launch, two radiators that will keep the coolant from freezing, aluminium fins to maximise the cooling surface, and pumps to circulate the coolant.
The spacecraft, launched from Cape Canaveral Air Force Station in Florida on August 12, will transmit its first scientific observations in December. (IANS)