$US 963,723 per day for an answer to a non-problem

The?Ice, Cloud and land Elevation Satellite-2, or ICESat-2, is NASA’s most technologically advanced ice-monitoring spacecraft to date.? It was launched on the weekend on the last of the Delta II rockets.? It is scheduled to operate for three years and cost?$US 1.056 billion, or $963k/day.

Space.com reports on this pretty impressive piece of kit (as you would expect for that moolah) Quote.

Capable of measuring changes in ice thickness, forest growth and cloud height down to 0.02 inches (0.4 millimeters) every year ? the thickness of a No. 2 pencil, according to NASA ? ICESat-2 offers scientists an unprecedented view of Earth’s changing systems, especially at its poles. End of quote.

0.4 mm resolution?? Really?? Seemingly not. The official NASA specifications say 0.4cm/year on an ice sheet or?0.25 m/year for an outlet glacier,?surface elevation change rates for dynamic ice features to an accuracy of better than or equal to 0.4 m/year along 1-km track segments or?ice-sheet elevation change to 10 cm. Quote.

“Watching and understanding how it [ice] is changing helps us understand why it?s changing,” said Waleed Abdalati, a geographer at the University of Colorado in Boulder and a concept designer of ICESat-2. In turn, the information will sharpen environmental-prediction models and help scientists better forecast rising sea levels and climate shifts because of melting ice. End of quote.

An interesting unspoken assumption by this concept designer is that there will be melting ice and sea level rise.? Surely they have not spent a billion bucks with a predetermined outcome in mind? Quote.

ICESat-2 was manufactured by Northrop Grumman Innovation Systems in Dulles, Virginia, and constructed at NASA Goddard Space Center in Washington, D.C. At 12.5 feet (3.81 meters) tall and with a base measuring 8.2 feet by 6.2 feet (2.5 by 1.9 m ? about the size of a small camper trailer), ICESat-2 is one of the largest satellites built at Goddard, according to Donya Douglas-Bradshaw, instrument manager at Goddard.

After 10 years and multiple re-scheduled launch dates, the satellite [was launched] aboard a Delta II rocket on Sept. 15, 2018, from the Vandenberg Air Force Base in California.

ICESat-2 will set off with four primary objectives:

  • Measure changing mass on ice sheets and glaciers from around the world.
  • Measure how much ice melt from Greenland and Antarctica contributes to rising sea levels. Ice melt in Antarctica, for example, has accelerated over the past five years. “We know that there’s going to be some sea level rise,” said Peter Neff, a glaciologist at the University of Washington in Seattle, but scientists don’t know how much or how soon.
  • Estimate the thickness of sea ice in the Arctic and monitor any changes. Scientists know how much sea ice area in the Arctic has changed since 1980. But satellites like ICESat-2 help determine changes in sea ice thickness. A decrease in sea ice thickness could exacerbate ocean warming by allowing more light to reach the ocean’s surface and increase water temperature.
  • Measure forest height to calculate the amount of carbon stored in plants. Plants stash carbon as food and use it to grow. That stored carbon can’t contribute to warming the climate or acidifying oceans. […] End of quote.

Most of the cost of this beast went into the laser altimeter system, ATLAS. The techno-nerds? will find the details on the NASA site and elsewhere fascinating but in short: Quote.

ATLAS fires a single green (532 nanometers) laser beam into a diffractor that breaks the beam into six rays, coupled as three pairs. At Earth’s surface, these lasers form a line. Each laser in a pair sits 90 meters apart, and each pair of lasers lies 3.3 kilometers from one another.

This design allows ICESat-2 to calculate the slope of a surface, which, if not accounted for, could appear as changes in elevation.?[…]

ATLAS shoots 10,000 laser pulses every second, with each pulse containing about 300 trillion photons. Only about a dozen photons return to the satellite, where they bounce off a 0.8 metre reflective beryllium mirror into a sensor. The sensor stops the “stopwatch” and measures the photons’ travel time to within 1-billionth of a second. This timing is matched with the satellite’s location ? determined by an onboard GPS system and a Star Tracker that observes nearby constellations to figure the spacecraft’s orientation ? and determines what object on Earth was measured.

“To put this in perspective, in the half-second it takes a person to blink, ICESat-2 will collect 5,000 elevation measurements in each of its six beams,” said Tom Wagner, ICESat-2’s program scientist at NASA headquarters in Washington, D.C. And each of those measurements is 71 centimetres apart.

Moving in an orbit that goes from pole to pole, ICESat-2 traverses 1,387 different orbital paths every 91 days. Consequently, the spacecraft will provide data for every season of the year.

At launch, the satellite was scheduled to operate for three years, but much of its 1,580 kilograms is fuel that, if desired, can extend ICESat-2’s mission to seven years. End of quote.

Excellent, that brings the cost down to just $US 413,000 per day.

As we know, the climate changes over geological time periods, thousand and thousands of years.? However, in just three short years’ of measurements this amazingly accurate device will provide an answer that is somehow relevant to something.

It will show that in the three years the earth got a little less ice (or more likely, a little more ice) and this will prove that the earth got a little more or a little less ice or possibly but unlikely, no change in the ice.? Since there are only two probable outcomes, more ice or less ice, was it worth a billion bucks?