As detailed in our closing weblog publish, for the primary time in our yearlong prolonged venture we had a lack of communications with Ingenuity from the downlink of Would possibly 3 (Sol 427) and Would possibly 4 (Sol 428). After every week of anomaly investigation, two sols devoted to information assortment, and the heroic efforts of the Perseverance and Ingenuity operations groups, I’m more than pleased to record that we have got reestablished dependable communications with Ingenuity. In line with all to be had telemetry, the helicopter seems wholesome, and we’ve resumed a changed type of operations. Assuming iciness recommissioning actions whole nominally, Ingenuity’s twenty ninth flight might happen in the following few sols.
Telemetry from Ingenuity showed that the lack of communications used to be because of inadequate battery state-of-charge (SOC) going into the evening, which ended in a reset of our venture clock. This day by day SOC deficit is prone to persist at some point of Martian iciness (till September/October).
Demanding situations like those are to be anticipated: After masses of sols and dozens of flights past the 5 flights at first deliberate, the solar-powered helicopter is in uncharted terrain. We at the moment are working some distance outdoor our unique design limits. Traditionally, Mars could be very difficult for spacecraft (specifically solar-powered spacecraft). Every sol might be Ingenuity’s closing.
Under is a abstract of our anomaly investigation during the last two weeks, our increased iciness chance posture, and the conceivable paths forward for Ingenuity all through iciness and past.
Sol 427 and 428 Lack of Communications
We have now reached the purpose in Martian overdue fall/early iciness at which Ingenuity can now not strengthen the power calls for of nominal operations. Beginning at the night time of Sol 426, we consider Ingenuity began experiencing in a single day battery brownouts (drops within the battery’s voltage), which reset the electronics. Because of the seasonal lower in to be had solar power, will increase in airborne mud density, and the drop in temperatures, the power call for to stay the electronics powered and heat all the way through the evening has surpassed Ingenuity’s to be had power funds.
Under is a plot of the environmental prerequisites at Jezero Crater. The black line is a climatological style of airborne mud density (referred to as “tau”) over a Martian 12 months, and the anticipated day by day insolation (quantity of Solar’s rays attaining the photo voltaic panel) illustrated within the inexperienced dotted line. We at the moment are within the a part of the Martian 12 months with height tau, mixed with falling insolation. Now not proven on this plot is the extra development of decrease moderate day by day temperatures, which additionally provides to Ingenuity’s power call for. We think to be on this difficult iciness power paradigm till round Sol 600, at which level we think to go back to being power-positive from sol to sol.
Whilst in iciness, each and every evening we think our battery SOC will fall low sufficient to the place:
- Chilly Biking Parts: Our heater thermostat can now not stay the battery (and surrounding electronics) at their programmed setpoint (e.g. minus 13° F / minus 25 ° C). In consequence, we think that Ingenuity’s electronics are attaining in a single day ambient temperatures of roughly minus 80 °C (minus 112 °F).
Affect 1: This bloodless biking each and every evening items a life-time chance to our digital elements.
and
- Cleared Challenge Clock: The battery can now not strengthen our voltage regulators and venture clock. This nightly brownout resets (or clears) our venture clock.
Affect 2: Every morning when Ingenuity warms up, fees its tired battery, and makes an attempt to activate its laptop, it’s booting in step with a misaligned alarm agenda, which is out of synchronization with Perseverance.
When Perseverance tried communications with Ingenuity at the morning of sols 427 and 428, Ingenuity didn’t reply as it used to be waking up on the fallacious time. The group reacted by way of uplinking a full-sol seek process with the Helicopter Base Station (HBS) onboard Perseverance to try to keep in touch with Ingenuity all through one in every of its misaligned alarm widows, which succeeded.
Since Sol 429 and each and every sol since (except Sols 444 and 445, which didn’t include helicopter actions), we’ve been in day by day touch with Ingenuity by way of the use of an identical morning seek actions all through what we consider to be the perhaps occasions when Ingenuity can be sufficiently charged to try booting its electronics. Those morning seek actions reprogram the helicopter’s venture clock each and every sol, which, at some point of that sol, allows further scheduled actions to use the power that we do have to be had. These days, we achieve sundown with ~68% SOC, with an estimated want of no less than 70% to stay the entirety powered in a single day. Our 2% SOC deficit is anticipated to develop to a 7% deficit when we achieve iciness solstice (Sol 500 in July), at which level prerequisites will begin to support.
All telemetry downlinked up to now means that Ingenuity is wholesome, with out a indicators of wear from the in a single day bloodless cycles. This morning-search adopted by way of night time actions is our new standard for the instant long run.
Iciness Chance Posture
Our newest fashions recommend that without reference to changes to our in a single day thermostat technique, it is going to be extraordinarily difficult and even unattainable to stay our electronics core module (ECM) elements heat and inside their nominal temperatures in a single day. Even supposing element failure has at all times been a chance that we have got carried since rover deployment, that chance is now magnified. ECM elements had been typically stored heat in a single day by way of our battery heater (generally set to five°, minus 4°, or minus 13°F, or minus 15°, minus 20°, or minus 25°C). We think that ECM elements at the moment are thermal-cycling right down to the ambient in a single day temperatures of minus 112 °F (minus 80 °C). We do have restricted ECM element checking out to signify that make a choice elements might live on throughout the iciness, however we can’t expect how all of the ECM will fare all the way through iciness. Chilly-soaking electronics is assumed to have brought about the tip of the Alternative and Spirit Mars rover missions.
Iciness Operations and Past
Given our increased chance posture, our focal point within the closing a number of sols has been to prioritize information downlink from Ingenuity to the HBS. We have now a handful of Heli-to-HBS switch actions left prior to all distinctive information are copied from Ingenuity to the HBS. In particular, we’re copying flight efficiency logs, electronics logs, and high-resolution colour photographs from the closing 8 flights which are nonetheless onboard Ingenuity.
In spite of everything vital logs are transferred, the group will continue with a recommissioning segment all through which we can reestablish Ingenuity’s flight-readiness given our ongoing in a single day cold-cycling. Like all through the era demonstration segment, we can carry out a high-speed spin prior to continuing to flight. Will have to Ingenuity obtain a blank invoice of well being, we might be in a position to execute a brief sortie to the southwest in Flight 29. This flight will support our radio hyperlink for about the following 4 to 6 months whilst Perseverance samples on the river delta.
Within the period in-between, the Ingenuity flight tool group shall be making ready a chain of upgrades to allow complex navigation options. Those new functions will lend a hand Ingenuity ascend the river delta and proceed its missions as a ahead scout for Perseverance previous iciness.
Subsequent Steps
The Perseverance and Ingenuity operations groups have completed an peculiar task in reestablishing dependable communications with Ingenuity. As of Sol 446, the group has transferred ~3,500 megabits (Mb) of information from Ingenuity to the HBS on Perseverance. There are roughly ~400 Mb of information last on Ingenuity of noncritical logs and pictures that shall be transferred opportunistically, whilst the group forges forward with recommissioning efforts this week. If the telecom hyperlink between Perseverance and Ingenuity stays strong, and Ingenuity receives a blank invoice of well being, we are hoping to execute Flight 29 within the subsequent a number of sols.