2 weeks ago
16
Throughout the 5 months of troubleshooting, Voyager's crushed squad continued to person signals indicating the spacecraft was inactive alive. But until Saturday, they lacked penetration into circumstantial details astir the presumption of Voyager 1.
“It’s beauteous overmuch conscionable the mode we near it,” Spilker said. “We're inactive successful the archetypal phases of analyzing each of the channels and looking astatine their trends. Some of the temperatures went down a small spot with this play of clip that's gone on, but we're beauteous overmuch seeing everything we had hoped for. And that's ever bully news.”
Relocating Code
Through their investigation, Voyager's crushed squad discovered that a azygous spot liable for storing a information of the FDS representation had stopped working, astir apt owed to either a cosmic ray deed oregon a nonaccomplishment of aging hardware. This affected immoderate of the computer's bundle code.
“That took retired a conception of memory,” Spilker said. “What they person to bash is relocate that codification into a antithetic information of the memory, and past marque definite that thing that uses those codes, those subroutines, cognize to spell to the caller determination of memory, for entree and to tally it.”
Only astir 3 percent of the FDS representation was corrupted by the atrocious chip, truthful engineers needed to transplant that codification into different portion of the representation bank. But nary azygous determination is ample capable to clasp the conception of codification successful its entirety, NASA said.
So the Voyager squad divided the codification into sections for retention successful antithetic places successful the FDS. This wasn't conscionable a copy-and-paste job. Engineers needed to modify immoderate of the codification to marque definite it volition each enactment together. “Any references to the determination of that codification successful different parts of the FDS representation needed to beryllium updated arsenic well,” NASA said successful a statement.
Newer NASA missions person hardware and bundle simulators connected the ground, wherever engineers tin trial caller procedures to marque definite they bash nary harm erstwhile they uplink commands to the existent spacecraft. Due to its age, Voyager doesn't person immoderate crushed simulators, and overmuch of the mission's archetypal plan documentation remains successful insubstantial signifier and hasn't been digitized.
“It was truly eyes-only to look astatine the code,” Spilker said. “So we had to triple check. Everybody was looking done and making definite we had each of the links coming together.”
This was conscionable the archetypal measurement successful restoring Voyager 1 to afloat functionality. “We were beauteous definite it would work, but until it really happened, we didn't cognize 100 percent for sure,” Spilker said.
“The crushed we didn’t bash everything successful 1 measurement is that determination was a precise constricted magnitude of representation we could find quickly, truthful we prioritized 1 information mode (the engineering information mode), and relocated lone the codification to reconstruct that mode,” said Jeff Mellstrom, a JPL technologist who leads the Voyager 1 “tiger team” tasked with overcoming this problem.
“The adjacent step, to relocate the remaining 3 actively utilized subject information modes, is fundamentally the same,” Mellstrom said successful a written effect to Ars. “The main quality is the disposable representation constraint is present adjacent tighter. We person ideas wherever we could relocate the code, but we haven’t yet afloat assessed the options oregon made a decision. These are the archetypal steps we volition commencement this week.”
English (US)