ISRO considering doing more docking tests with Spadex satellites

India’s space agency ISRO has delayed the undocking of its two Spadex satellites as it considers a plan to do more docking tests.

The original plan was to have the chase satellite complete only one docking with the target vehicle, after which the two satellites would separate and spend the next two years doing different work. That plan is being reconsidered.

[Isro chairman V.] Narayanan said in Sriharikota that they have to think of the money involved in such projects and utilise it to the maximum. “Now we are in the process of reviewing when to do the undocking, the power connections and when to totally separate them again and dock again. All these processes are going on. We do not want to undock and leave it,” the Isro chairman said.

“We have loaded five kg of propellant on both the satellites. The propellant is needed for docking and undocking exercises. Currently we have 60 to 70 per cent of the propellant (as of January 29) remaining in the spacecraft. There are going to be a lot of experiments in the docking, undocking, power connection exercises and it is not a one time exercise,” he said.

Sources at ISRO also suggest there may be issues with the docking that still need analysis.

India’s Spadex mission completes docking

India’s space agency ISRO today announced that its engineers had successfully completed the autonomous docking of its two Spadex satellites, the chase vehicle making proper contact with the target vehicle and then linking together.

Manoeuvre from 15m to 3m hold point completed. Docking initiated with precision, leading to successful spacecraft capture. Retraction completed smoothly, followed by rigidisation for stability. Docking successfully completed

The docking needed to be completed before January 20th or the lighting conditions would have caused a delay until March.

Next engineers will demonstrate the spacecraft have linked electronically. Eventually they will then undock and spend up to two more years in orbit operating separately.

Spadex’s unmanned docking faces possible two month delay

India’s Spadex mission, launched to test autonomous unmanned docking procedures necessary for many of that country’s future space plans, now faces a possible two month delay in orbit before the final docking can take place.

On January 11, 2025 the chase vehicle completed its closest proximity maneuver, getting within three meters of the target vehicle, after which it backed away as planned. ISRO engineers are presently analyzing the data before proceeding with the actual docking.

The problem is that this docking must occur by January 20, 2025. After that the lighting conditions will not allow another attempt until March.

It seems ISRO is not concerned about this situation, and would rather get things right, even if it means that delay.

ISRO moving ahead with Spadex docking

India’s space agency ISRO has announced that it now moving ahead with the autonomous docking of its two Spadex spacecraft presently in orbit, but it will wait until after the docking to post when it had occurred.

With the Indian Space Research Organisation’s (Isro) SpaDeX space docking experiment missing two publicly announced schedules on January 7 and January 9, the space agency has decided to complete docking before making a public announcement.

Isro had earlier announced that the docking would be a public event but after two consecutive postponements, a senior Isro official said that the docking “is on track” but the space agency will now “dock and inform” the public about the exercise.

I suspect they realized the uncertainty of the real docking schedule made making the schedule public too difficult. This remains a test, and so many things can occur along the way to slow things down.

ISRO delays its unmanned docking in orbit two days

India’s space agency ISRO today announced that it has decided to delay the attempted unmanned autonomous docking of its two orbiting Spadex spacecraft two days, from January 7 to January 9.

“The docking process requires further validation through ground simulations based on an abort scenario identified today (Jan 6),” Isro said Monday. Multiple sources told TOI that “there was nothing concerning” with the Space Docking Experiment (SpaDeX) satellites and that the additional simulations are being carried out to validate the docking process.

This follows the pattern at ISRO since its present head, S. Somanath, took over in 2022. He pushes hard to get missions launched, but simultaneous demands caution and testing along the way to make sure the mission is a success. For example, when he took over he quickly added a number of unmanned test flights for India’s Gaganyaan manned capsule, to take place before the manned mission.