Could An Astronaut Throw Something From Orbit To Earth?
Why Space Exploration Stack Exchange recommends it
Space Stack Exchange users link it when answering how hard something must be thrown from the ISS to deorbit, and for its worked delta-v figure of about 90 m/s.
Recommended by 3 people across 3 different months, 2018 to 2024.
What it is
Scott Manley works out whether an astronaut could throw an object from the ISS hard enough to bring it down to Earth within one orbit. He uses orbital mechanics, the delta-v needed to drop the periapsis into the atmosphere, and examples such as discarded Russian hardware and the lost tool bag.
What people said
Recommends user3715778 · 2018-06 · Space Exploration Stack Exchange · on “How hard do you have to throw something off the ISS to make it deorbit?”
There is a great video by Scott Manley , which specifically addresses your question: Could An Astronaut Throw Something From Orbit To Earth? [this video] The short answer is no, humans can not provide enough delta-v by muscle power to deorbit an object by throwing it from ISS.
Recommends Ghedipunk · 2018-11 · Space Exploration Stack Exchange · on “Assuming a spacecraft is traveling in a constant rate and our Astronaut will exit it to a space walk, will she be "left behind" by the spacecraft?”
@BladeWraith, not quite. If the astronaut were 1 meter away, in a homogeneous gravity field, they would co-orbit each other, or, more likely, oscillate in distance to each other. Better visualization: [this video] -- And, atmospheric drag depends entirely on the relationship to surface area hitting the atmosphere relative to weight... which _usually_ correlates to an object's density. Spacecraft being intentionally light, and usually quite hollow, a spacewalking human is more dense than the ISS, so will experience less atmospheric drag.
Recommends Justin Braun · 2021-03 · Space Exploration Stack Exchange · on “Why does it take so long for ISS garbage to fall out of orbit?”
Related: This video explains what tools you'd likely want to use to help you eject the garbage pallet faster. [this video] With that said, one might consider pushing it off as hard as possible as way to boost the station's orbit.
Cites user12102 · 2018-02 · Space Exploration Stack Exchange · on “Was this large pieces of "space junk" just released from the ISS in the "nadir and retrograde" direction?”
According to Space.com's 02-Feb-2018 article Cosmonauts Break Russian Spacewalk Record During Space Station Antenna Repair [LINK] : The cosmonauts spent the day replacing an electronics box for a high-gain communications antenna outside the Zvezda service module. Instead of holding on to the outdated piece of equipment, the cosmonauts tossed the original electronics box overboard, dooming it to burn up in Earth's atmosphere. According to this answer [LINK] the orbital mechanics is such that if an object is hand deployed (read "tossed") from the ISS in the nadir plus retrograde (read "down and backwards") direction, it will not intercept (read "hit") the ISS again. Is this in fact the way thi
Cites user12102 · 2018-02 · Space Exploration Stack Exchange · on “What kinds of things have been tossed out of the ISS?”
According to Space.com's 02-Feb-2018 article Cosmonauts Break Russian Spacewalk Record During Space Station Antenna Repair [LINK] : The cosmonauts spent the day replacing an electronics box for a high-gain communications antenna outside the Zvezda service module. Instead of holding on to the outdated piece of equipment, the cosmonauts tossed the original electronics box overboard, dooming it to burn up in Earth's atmosphere. caption: An old electronics box drifts through space after Russian cosmonauts tossed it away from the International Space Station during a spacewalk on Feb. 2, 2018. Credit: NASA TV GIF: [LINK] edit: According to Scott Manley's video [this video] this is 1998-067NM 43203 ISS
Cites user12102 · 2018-06 · Space Exploration Stack Exchange · on “How hard do you have to throw something off the ISS to make it deorbit?”
@user3715778's answer [LINK] is correct. Throwing will not make enough of a difference in the orbit to reenter Earth's atmosphere de-orbit promptly. Let's run the math using the vis-viva equation [LINK] : $$v^2 = GM \left(\frac{2}{r} - \frac{1}{a}\right)$$ periapsis apoapsis semi-major apoapsis altitude (km) altitude (km) axis (km) velocity (m/s) initial 400. 400. 6778. 7668 final 80. 400. 6618. 7575 difference 93 world's record 45 edit: Scott Manley gets [this video] about 90 m/s as well. According to this Quora answer [LINK] the fastest thrown ball was in Cricket with a speed of about 161 kph or about 45 m/s, which is about half of the speed necessary to promptly de-orbit. This would definitely
Cites user12102 · 2018-08 · Space Exploration Stack Exchange · on “How was "toolbag-sat" imaged in space? (from Scott Manley's video)”
In Scott Manley's video Could An Astronaut Throw Something From Orbit To Earth? [this video] at about 02:00 he includes a sequence of images that shows the famous tool bag that was lost from the ISS and entered Earth orbit. Question: How was this image sequence made, who made it, and from what location was it imaged? edit: The toolbag is mentioned in What kinds of things have been tossed out of the ISS? [LINK] and in further detail in this answer [LINK] . There is separate mention [LINK] of a lost tool box as well. [LINK] Scott Manley says [this video] that this tool bags lost from the ISS took only 9 months to reenter the atmosphere and result in a fireball over the pacific.
Cites user12102 · 2018-08 · Space Exploration Stack Exchange · on “What kinds of things have been tossed out of the ISS?”
Scott Manley says [this video] that one of these tool bags lost from the ISS took only 9 months to reenter the atmosphere and result in a fireball over the pacific.
Cites Woody · 2021-11 · Space Exploration Stack Exchange · on “If you release a tool outside the ISS in space will it remain at the "same" place forever?”
Great question to illustrate small but measurable effects of orbital mechanics! NO, even if both wrench and ISS are idealized point masses in the same circular orbit. The mass of the ISS imposes a non-trivial gravitational acceleration on the wrench. If the wrench is dropped within EVA distance of the ISS, mutual gravitation will displace it on meter-scale distance within a few orbits. Surprise with such a small mass, but this is a 3body problem! NO if the circular orbits are non-coplanpar since they would intersect. NO, if coplanar eliptical orbits have the same period but different eccentricities. The pair would do a retrograde orbit around each other. NO because of atmospheric drag. The I
Cites Schwern · 2023-01 · Space Exploration Stack Exchange · on “How much does it cost to return 1 kg from the ISS to the Earth? What are the parameters influencing this price?”
There is (almost) no air in space and (almost) no drag. The ISS is moving horizontally at 27,600 km/h around the Earth in orbit. If you chuck something out the airlock, let's say at 100 km/h, it will now orbit slightly lower at 27,500 km/h and be hazardous space junk. You have to slow it down a lot until its low enough to be slowed by atmospheric drag. Same reason we can't just "throw" our trash into the Sun; you have to cancel the Earth's 100,000 km/h orbital velocity around the Sun. See Can An Astronaut Throw Something From Orbit To Earth [this video] .