Sunday, 10 December, 2017

NASA Nails Test on Voyager Spacecraft, 13 Billion Miles Away

Nasa Voyager 1 Voyager 1 thrusters Image source
Theresa Hayes | 05 December, 2017, 05:08

NASA's Jet Propulsion Laboratory compared the feat to successfully starting up a vehicle that had been sitting idle in the garage for 37 years. Voyager 1 reached interstellar space, which NASA described as "the environment between the stars", in 2012.

In order to continue communicating with its handlers here on Earth, Voyager 1 needed a slight adjustment.

Yet Voyager 1, NASA's furthest-travelled spacecraft, has just fired up a set of thrusters that haven't been used for 37 years. They are located on the back side of the spacecraft in this orientation. Over time, the thrusters require more puffs to give off the same amount of energy. Voyager 2 is close on its heels - almost 11 billion miles from Earth. It took more than 19 hours - the one-way travel time for signals - for controllers at the Jet Propulsion Laboratory in Pasadena, California, to get the good news. Chris Jones, Robert Shotwell, Carl Guernsey and Todd Barber analyzed options and predicted how the spacecraft would respond in different scenarios.

Voyager 2 is also on course to enter interstellar space, likely within the next few years, and now, its attitude control thrusters are still functioning well.

The twin Voyagers provided stunning close-up views of Jupiter and Saturn.

Last week, ground controllers sent commands to fire backup thrusters on Voyager 1, our most distant spacecraft.

A set of thrusters aboard the Voyager 1 spacecraft, the only human-made object in interstellar space, have been successfully fired up after 37 years without use, U.S. space agency NASA said. The MR-103 thrusters, delivered by Aerojet Rocketdyne, are meant to fire in pulses to spin the spacecraft and retain its 12-foot (3.7-meter) antenna directed towards Earth, but engineers have observed plenty of firings were required recently designating the jets were ceding some of their interpretation. The same kind of thruster, called the MR-103, flew on other NASA spacecraft as well, such as Cassini and Dawn. It orients itself by firing several 10-millisecond puffs with its thrusters - problem is, the ones it regularly uses haven't been performing as well after four decades in space.

As of August, Voyager 1 was almost 13 billion miles from Earth, and Voyager 2 about 11 billion miles out.

You can then imagine their mixed incredulity and glee when, on November 29, they received data that Voyager 1's backup thrusters worked flawlessly in a test run.

The plan going forward is to switch to the TCM thrusters in January, it said. To make the change, Voyager has to turn on one heater per thruster, which requires power - a limited resource for the aging mission. The "attitude control thrusters" have been in decline since 2014, and are now wasting more propellant than ever. They will likely also conduct similar tests on the backup thrusters on Voyager 2.