Just after a major maneuver on September 8, the tiny CAPSTONE probe spinning around, uncontrollably. It took almost a month for Advanced Space engineers, with NASA, to restore the situation and regain control.
Fortunately, CAPSTONE is still on its way to the Moon.
She spins, she spins…
We remember that just a few days after takeoff, the small CAPSTONE probe (25 kg, 20 x 20 x 30 cm) had already put the ground teams through hell, which had spent several days sending commands to restart the spacecraft. ‘board computer. They had arrived there, and for more than six weeks, the small vehicle had continued its journey towards its very special lunar orbit.
Indeed, CAPSTONE performs a long-distance maneuver, which saves a maximum of fuel, to be able to enter lunar orbit thanks to a large ellipse. The last chapter will be played on November 13, with the arrival around the Moon… If all goes well! Indeed on September 8, just at the end of its last trajectory change, CAPSTONE had entered “safeguard mode”, in uncontrolled rotation. And this time, it took almost a month to find the solution.
Take his time
In the first days after the anomaly, ground controllers from Advanced Space (which manages the probe for NASA, in a public-private partnership) first re-established communications, as well as the orientation of CAPSTONE for that the latter does not run out of energy. Not knowing what caused the probe to spin, they preferred to leave it rotating until they were sure.
And they did well, because one of the management valves of one of the eight mini-thrusters was blocked without being able to close: if the teams had pressurized the propulsion system, the leak would have immediately generated even more movement. Isolated, this problem could be solved by using only the other thrusters… And on October 9, the American authorities explained that they had regained full control of CAPSTONE.
Groping correction
Luckily, this uncontrolled rotation, which the teams took a long time to understand, simulate and solve (it must be said that debugging a system a few hundred thousand kilometers away without being allowed to make mistakes does not help much ) took place in an interval without a crucial maneuver.
CAPSTONE will therefore be able to continue its mission and inject itself into lunar orbit… If there is not a new development by then! The teams are now confident and believe that the small probe the size of a suitcase will be able to carry out its mission. Recall that with the delays of Artemis-1, it is possible that it will be the only American lunar mission this year…
Source : space news
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