Astroscale’s ADRAS-J Satellite Takes Up-Close Photo Of Discarded Rocket Stage

Although there is a lot of space in Earth orbit, there are also some seriously big man-made objects in those orbits, some of which have been there for decades. As part of efforts to remove at least some of this debris from orbit, Astroscale’s ADRAS-J (“Active Debris Removal by Astroscale-Japan”) satellite has been partaking in JAXA’s Commercial Removal of Space Debris Demonstration (CRD2). After ADRAS-J was launched by a Rocket Lab Electron rocket on February 18, it’s been moving closer to its target, with June 14th seeing an approach by roughly 50 meters, allowing for an unprecedented photo to be made of the H-2A stage in orbit. This upper stage of a Japanese H-2A rocket originally launched the GOSAT Earth observation satellite into orbit back in 2009.

The challenges with this kind of approach is that the orbital debris does not actively broadcast its location, ergo it requires a combination of on-ground and on-satellite tracking to match the orbital trajectory for a safe approach. Here ADRAS-J uses what is called Model Matching Navigation, which uses known visual information to compare it with captured images, to use these to estimate the relative distance to the target.

Although the goal of ADRAS-J is only to study the target from as closely as possible, the next phase in the CRD2 program would involve actively deorbiting this upper stage, with phase start projected to commence in 2026.

Thanks to [Stephen Walters] for the tip.

23 thoughts on “Astroscale’s ADRAS-J Satellite Takes Up-Close Photo Of Discarded Rocket Stage

      1. Most of them probably not. Lost screws, a space glove, wrecked remain of a smashed satellite, and a (supposedly) manhole cover would be hard to see if you’re not flying close to them.

        1. The manhole cover could never made it to orbit, it’s physically impossible to get into orbit from a single “impulse” from earth. Orbital mechanics will always put you back on earth. So even if that manhole made it to space (doubtful), it no longer is there.

          1. I mean, if you have enough velocity you can go get a gravity assist from somewhere, e.g. the Moon, and end up in Earth orbit for awhile. Not that we think it did, but still.

  1. A case can be made that a ground-based laser is a much more effective way to de-orbit space debris.

    A pulsed laser in the nanosecond range can deliver very high peak power (gigawatts) in a spot less than a meter in diameter at a range of 1000 km. That kind of power density ablates the surface of the space junk, causing atomic ejecta to come off at thermal velocities, like a rocket exhaust. It will impart momentum to change the velocity of the orbiting junk.

    A UV laser in the sub-nanosecond range will work best, something like the National Ignition Facility’s laser, but much smaller and firing at a much higher rate.

    Though the peak power is high, to ablate the leading surface, the average power is low, not enough to melt the target, and not enough to structurally disrupt it and cause more junk pieces.

    The ground-based facility should be located on a high mountain to get above most of the beam-distorting atmosphere, and near the equator to reach all orbits. Chimborazo would be good. Or Kilimanjaro.

    Any given target would pass over the site and would be worked on for a few minutes per pass, roughly twice a day. Though it might take months to drop the velocity of a target enough to re-enter, the facility could work hundreds of targets per day, enough to de-orbit a tons of junk per month.

    It won’t happen though, because it also would make an excellent offensive weapon, and would meet vigorous opposition in being built. On the other hand, several might already be deployed, waiting for use, but their owners won’t tip their hand until needed…

    1. Cool. Thanks for that.

      They propose using CW lasers. That’s easier, but thousands of times less efficient than the ablative approach: Their 40 kW CW laser would produce less than a quarter millinewton of force on the target. Not insignificant, but it would take years to decelerate a notional 1-tonne target to reentry.

      The same 40 kW average power, but in sub-nanosecond pulses, would produce thermal ejecta in the range of rocket velocities, with similar specific impulse. Even after accounting for inefficiencies, you could expect forces in the 1-newton ballpark, vastly increasing the throughput of the system.

  2. Maybe a Coke & Mentos sponsored de-orbit (fizzdown) of the week? ;)
    Some sort of pusher bottle/thrust unit
    with internal storage and mixing capabilities.

  3. I’m confused… what’s the point of making a separate rocket stage that ends up in orbit with the payload? Can’t that last stage just be part of said payload? Would that not shave off some weight by eliminating the separation mechanism and attachment points?

  4. While we still have a system where private space industry can pollute and the cleanup is paid for by tax money, we will have an increasingly polluted space.

    Privatize profit and socialize expenses is the current strategy.

    It gets even worse. ADRAS-J is moving additional tax dollars to the private sector to clean up problems the private sector is making worse.

    It’s like the worst consultancy hell.

  5. So anyone can grab any debris in the space? or it is more like hey that debris is mine cos I put it there! Imagine a big operation to recover space junk and suddenly the “owner” appears. What about the digital and technical data in there? quite interesting, I think a should go and grab the Apollo lunar module…unless never been there (insert X files’s soundtrack here)

    1. Oh, that’s an idea. I hear there are thousands of satellites up there with kilowatts of solar power each, plus a whole lot of argon and krypton Hall thrusters too. Maybe you could round them all up, and use them to launch to the Moon, or Mars.

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