# How long does trash jettisoned by hand from the ISS fall before burning up on reentry?

NASA proposed a policy for the jettison of trash from the ISS space station.

This article notes that a recent ISS space station spacewalk by Russian cosmonauts involved one man jettisoning by hand a replaced electronics pack. The pack was shoved by arm and hand downwards to Earth. See the link to a YouTube video showing the dramatic toss.

How much time and distance does that package take to fall before disintegrating/burning-up?

Also: Is the point of burning-up too far to see the flare by camera from the space station?

– OON
Commented Mar 9, 2018 at 8:32
• could you perhaps provide the relevant time of the video? Commented Mar 9, 2018 at 8:32
• @derwodamaso: Problem solved. Commented Mar 9, 2018 at 8:33
• About colliding with ISS: Not a chance: The release rate seems to be about 1.5m/s retrograde. After just one orbit, the junk will be back up to the same altitude, but ahead in the orbit by 3.1 seconds, this is about 24 km ahead in the orbit. The junk descends down from 400km to 393km, so will experience a bit more drag. online calc says it will decay to reentry in 84% of the time as compared to starting in ISS orbit. That's significant, but not huge. Commented Jul 25, 2021 at 15:59

The higher the altitude, the longer the orbital debris will typically remain in Earth orbit. Debris left in orbits below 370 miles (600 km) normally fall back to Earth within several years. At altitudes of 500 miles (800 km), the time for orbital decay is often measured in decades. Above 620 miles (1,000 km), orbital debris normally will continue circling Earth for a century or more.

The space station orbits at around 400 km altitude, so that would fall into the category "several years". The part was tossed backwards w.r.t. the station, which increases the rate of decay.

• In the video it looks like it was thrown more retrograde than "downwards" this deorbits it quicker than throwing it downwards iirc. Commented Mar 9, 2018 at 9:21
• @Dragongeek right, corrected that Commented Mar 9, 2018 at 11:06
• Also, throwing it backwards, with drag reduces the chances that it's orbit will take it back into collision with the ISS. Throwing it straight down virtually guarantees that it will eventually reconnect with the ISS. Commented Jun 21, 2018 at 19:31
• 400 km is actually more of a "Several months" as opposed to years. Trash is light and not very aerodynamic, it should have a higher drag then the space station. Not sure exactly, but most likely a year tops. Commented Aug 24, 2018 at 17:47

It depends

The ballistic coefficient of the thrown object will vary and that what's going to set the rate of decay.

There is two factors to that coefficient:

• The surface area of the trash
• The mass of the object

Few years ago a cosmonaut threw an USB key from the ISS. It was wrapped in a plastic bag to increase the surface and the rate of decay. See video.

One last thing: The astronauts don't throw the objects towards nadir (down), they throw objects retrograde (towards the rear). This will in turns slow the orbit of the trash and ensure there is sufficient horizontal separation when the object gets back again on the next orbit (minus orbital decay).

• Nice pointing out the dependencies. Minor remark: NASA's FAQ does not mention these dependencies, thus I guess the stated estimates apply either generally or for the most common types of debris. Commented Mar 9, 2018 at 11:11
• The CBM "taco" corner shield that was lost last year on EVA took a little less than a year to reenter. Being made mostly of foam and fabric, it had a very low ballistic coefficient, though. Commented Mar 9, 2018 at 15:17
• @uhoh While I am aware your question was intended as humor, the answer is actually interesting. To quote the linked article: The memory stick in question contained videos and scripts from last year’s 70th anniversary celebration of the Victory Day in Russia. This event commemorated the 70th anniversary of the capitulation of Nazi Germany in 1945, and was the largest and most lavish celebration ever held in Russian history. Commented Aug 24, 2018 at 20:54
• @BasilBourque Thank you for clearing that up, and for reminding me to take advantage of links provided.
– uhoh
Commented Aug 25, 2018 at 1:06
• Doesn't the direction thrown also affect the decay rate? Commented Jun 26, 2023 at 16:02