Update on Lucy: panels generating more than 90% of expected power
According the Lucy science team, the spacecraft’s solar panels are generating more than 90% of the expected power at this stage of the mission, despite the fact that one panel did not deploy completely and has not latched in final position.
“We’re very happy to report that we are getting most of the power we expected at this point in the mission,” said Joan Salute, associate director for flight programs at NASA’s planetary science division. “It’s not 100%, but it is fairly close. So that is great news.’
In an interview with Spaceflight Now, Salute said the power output from the solar arrays appears to be “most likely above 90%” of the expected level of 18,000 watts. “We don’t know if it’s a latch problem, or that it is only partially deployed,” Salute said.
If correct, there is an excellent chance the mission will not be seriously hindered, even if they cannot get the panel fully deployed or latched. At the same time, there are worries about firing Lucy’s main engine for major course corrections with the panel unlatched. The first major course correction is scheduled for mid-November.
The engineers are presently reviewing their data. One option might be to order the spacecraft to re-attempt a full deployment, in the hope that the process will complete during that second attempt.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
According the Lucy science team, the spacecraft’s solar panels are generating more than 90% of the expected power at this stage of the mission, despite the fact that one panel did not deploy completely and has not latched in final position.
“We’re very happy to report that we are getting most of the power we expected at this point in the mission,” said Joan Salute, associate director for flight programs at NASA’s planetary science division. “It’s not 100%, but it is fairly close. So that is great news.’
In an interview with Spaceflight Now, Salute said the power output from the solar arrays appears to be “most likely above 90%” of the expected level of 18,000 watts. “We don’t know if it’s a latch problem, or that it is only partially deployed,” Salute said.
If correct, there is an excellent chance the mission will not be seriously hindered, even if they cannot get the panel fully deployed or latched. At the same time, there are worries about firing Lucy’s main engine for major course corrections with the panel unlatched. The first major course correction is scheduled for mid-November.
The engineers are presently reviewing their data. One option might be to order the spacecraft to re-attempt a full deployment, in the hope that the process will complete during that second attempt.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Question:
What generally are the criteria for selecting a power source for these type of probes?
–I always wonder why radioisotope thermoelectric generators are not used as a matter of course. How much of these decisions are political vs. engineering?
How much power does the Hubble telescope consume?
Wayne: The criteria appears to be cost and the probe’s location. Closer than Mars generally they choose solar power, because there is an ample supply and I suspect solar panels are cheaper overall. From Jupiter and beyond the radioisotope power generator is the only choice, because solar power is insufficient. From Mars to Jupiter it appears it becomes an either/or depending on many other factors.
Don‘t forget the Juno probe, which uses oversized solar panels to get it‘s power in orbit around Jupiter.
Mr. Z.,
Thank you. That’s about the most rational explanation I’ve heard.
Radioisotope Power Systems page at NASA
https://rps.nasa.gov/
tangential but interesting….
“Presidential Memorandum on Launch of Spacecraft Containing Space Nuclear Systems”
D.J. Trump, issued August 20, 2019
https://rps.nasa.gov/news/36/presidential-memorandum-on-launch-of-spacecraft-containing-space-nuclear-systems/