The Phantom Torso was designed to gather data on ISS crew Radiation exposure. What was its fate?

enter image description here

  • 10
    $\begingroup$ They could have left off that creepy smile. $\endgroup$ Commented Dec 17, 2023 at 23:52
  • 13
    $\begingroup$ @OrganicMarble ... what, and used a hockey goalie mask? $\endgroup$
    – Woody
    Commented Dec 18, 2023 at 0:11
  • 1
    $\begingroup$ I was an ISS payloads Operation Controller from 2016-2019. In all my dealings with HRF (Human Research Facility), I never heard anything about a phantom torso payload. So the answer is it's probably not still on board. $\endgroup$
    – Doresoom
    Commented Jan 25 at 19:18

1 Answer 1


Is there still a legless phantom crew member on ISS?

As far as I can tell, no.

For that particular torso, no, it was returned.

The torso was launched on Expedition 2 with STS-102 from Cape Canaveral and landed with STS-105.

But then the legless phantom split into several paths:

  • 1998 an original legless phantom was sent up on a STS mission.
  • 2001 FRED went up on STS-102, and then was dissasembled for its return
  • The Russians built their own version for the Shuttle-MIR missions
  • Joint ESA, ROSCOSMOS and JAXA versions went on to do several missions on the ISS through to 2011 (last on Kibo; overall 7 years inside and outside the space station)
  • Modern versions, including female parts, flew on the Orion missions.

This is from the wayback machine:


Operational Requirements

The crew was only required to transfer and activate the Torso and equipment, check its status every 7 to 10-days, download data (using the Human Research Facility - 1 laptop) every 7 to-10 days, and to change the battery every 20-days. At the completion of the experiment, the crew disassembled the Torso for its return on STS-105.

Operational Protocols

The crew set up the Torso in the U.S. Destiny Laboratory and activated all the associated hardware. Once activated, the Torso, CPDS, and TEPC collected data continuously, without crew intervention. Data downloads were sent to the Telescience Center at Johnson Space Center for distribution to the investigators.


The Organ Dose Measurement Using the Phantom Torso (Torso) employed a model human head and torso (Rando phantom), imbedded with over 350 detectors (thermo-luminescent detectors) and five silicon diode detectors, over five depths to measure absorbed dose to specific organs during shuttle flight. A tissue equivalent proportional detector and a charged particle directional spectrometer were placed within 1.5-feet of the torso during these ISS measurements.

Results/More Information

Organ Dose Measurement Using the Phantom Torso (Torso) results were combined with results from various experiments on previous missions to validate NASA's organ dose database for astronauts. Preliminary results suggest that organ dose and dose equivalent can be projected to a +/- 25 percent accuracy using a combination of dosimetry and radiation transport models. This accuracy envelope is greatly improved relative to the current accuracy of organ specific cancer risk projections, estimated at +/- 500 percent. Further analyses and incorporation of these radiation results into operational planning for exploration is ongoing.

Overall, the dose rates measured in Torso were in good general agreement with other measured values and with the models used to predict these values. The largest differences observed between measured data and the simulations were 15 percent. In addition, a model which considers orbital altitude, attitude, and solar cycle emissions agreed within 25 percent of the measured data. It was determined that the majority of radiation energy deposited in human tissues (about 80 percent) was due to galactic cosmic radiation. This is due to spacecraft material providing effective attenuation of the protons trapped in the Earth's magnetic field. The data indicated an average radiation quality factor (a measurement of how damaging a type of radiation is to tissue) of 2.6 and that the quality factors do not appreciably change with depth in the body. Finally, this experiment indicated that the contribution to both skin and organ doses from secondary neutrons is not negligible (Expedition 2 Postflight Report).

Organ Dose Measurement Using the Phantom Torso (Torso)02.06.09

Brief Summary

Organ Dose Measurement Using the Phantom Torso (Torso) measured the amount of radiation that a human received during an extended space flight. The measurements were taken using an anatomical model of a male head and torso that contains different types of radiation sensors. This experiment is important for future human long-duration space exploration.


The Phantom Torso experiment is the first to also measure the effects of radiation on organs inside the body, especially blood-forming organs. The Torso is a "phantom" because it is not human, but so close to being human that scientists cannot tell the difference between a human X-ray and an X-ray of the Phantom. The Phantom Torso is similar to torsos used to train radiologists on Earth, and is equivalent in height and weight to an average adult male. Covered with a Nomex "skin", the interior is horizontally sliced into 34 sections 1-inch (2.3 centimeters) thick. Each slice is embedded with two kinds of detectors: passive detectors, which use no power and will be read after the torso returns to Earth; and active detectors that will measure real-time radiation doses on the brain, thyroid, heart and lung area, stomach and colon. Data collected from the active detectors is transmitted by the crew on board the International Space Station to scientists on Earth every 10 days. Passive detectors on the Nomex will be used for comparison. Radiation measurements on the ISS exterior will be taken. Data will be downlinked every 10 days.

2009 The Phantom Torso returns:


The Phantom Torso is back, and he has quite a story to tell. He's an armless, legless, human-shaped torso, a mannequin that looks like he's wrapped in a mummy's bandages. Scientists at the European Space Agency call him Matroshka, and like his NASA counterpart Fred, this mannequin is an intrepid space traveler. Now that he's spent four months on the International Space Station, scientists are learning about the space radiation that Matroshka endured.

enter image description here

similar question asked:



Fred the 'phantom torso', is a dummy in space. Made from human bones, plastic organs and artificial skin, Fred's mission is to measure the amount of radiation to which astronauts are exposed.

Fred is spending the next four months on board the International Space Station with the astronauts. Although no astronaut has ever been diagnosed with space radiation sickness, excessive exposure could lead to health problems.

Further info:

Matroshka experiments on ISS (post-FRED):

enter image description here

Four MATROSHKA exposures have been performed outside (MTR1) in the PIRS module (MTR 2A in 2006), in the Zvezda module (MTR 2B from 2007 - 2009) and inside the Japanese Experimental Module (MTR-KIBO from 2010-2011).

Matroshka outside the ISS, 2004-2005:

enter image description here


Matroshka AstroRad Radiation Experiment (MARE) on Exploration Mission 1

enter image description here

enter image description here

Other FRED links:





NASA has always used cadavers in their research for safer capacities for the crew

This torso is used to document radiation exposure during long term space flight. Recently, they made limited use of cadavers in testing during the development of the Orion spacecraft.

Twitter link:


enter image description here

1998 Phantom torso:

NASA expanded space radiation research in the late 1990s, by designing a human torso phantom (nickname FRED), which was exposed to space radiation in the year 1998 aboard the Shuttle-MIR space flight

FRED is the first fully instrumented Alderson RANDO phantom torso (with head) in a flight inside the single module SpaceHab during STS-91 Shuttle-MIR mission. The phantom was composed of a human male skeleton and tissue-equivalent polyurethane resin. The soft tissue comprised of 8.8% hydrogen, 66.8% carbon, 3.1% nitrogen and 21.1% oxygen, with a density of 1.0 g/cm3; and the lung is composed of 5.7% hydrogen, 74.0% carbon, 2.0% nitrogen, and 18.1% oxygen with a density of 0.320 g/cm3.

The phantom body was sectioned into 34 equal slices (2.5cm thick) from the head to the thigh. A total of 59 detector cases were placed into critical organ/tissue positions and were designed to provide measurements for: the brain, thyroid, bone surface, esophagus, heart, lung, stomach, liver, spinal cord, bone marrow, descending colon, bladder and gonad

The phantom was fixed onto a rack at the starboard side in the SpaceHab module onboard the Space Shuttle. The shuttle Discovery was launched on June 2, 1998, and landed on June 12, 1998, for total flight duration of 9.8 days

The Institute for Biomedical Problems in Moscow developed a water filled spherical phantom with a 35cm diameter. This phantom was placed at three different locations onboard the space station MIR in the years 1997 – 1999. The phantom is rather simple, having only four detector channels, positioned in right angle in one plane inside the phantom.

(more advanced spherical phantom (MATROSHKA-R) flown in 2004) The MATROSHKA-R (MTR-R) phantom is a multi-user unit for studies of the depth dose distribution of the onboard radiation field inside the compartments of the ISS.

most comprehensive phantom experiment is the MATROSHKA human phantom experiment; headed by ESA and with cooperation from 16 international research organizations.
The objectives of the MATROSHKA experiment is to determine the empirical relations between measurable absorbed doses and the tissue absorbed doses in a realistic human phantom exposed to the radiation field in orbits of the ISS; particularly the depth dose distribution at different organs of astronauts during an extravehicular activity.

The MATROSHKA facility consists of a RANDO human phantom, a base structure and a container. The phantom body consists of natural bones embedded in tissue-equivalent polyurethane resin, with different density for tissue, lungs and organs. The phantom body is made up of 33 slices, each with 25mm thickness, stacked together over a mandrel to stabilize the whole body. The phantom was covered in a poncho and hood with sewn on polyethylene stripes and detectors to measure the skin dose and for thermal protection. The phantom was enclosed inside a carbon fiber reinforced plastic container, with a mean mass thickness similar to the astronauts spacesuit during EVA, and to protect the phantom against space vacuum, debris, and material off-gassing. The phantom was launched to the ISS in 2005 and was transferred into the Russian module Zvezda of the ISS. The MATROSHKA phantom facility was installed outside the Zvezda module, simulating measurement of an astronaut during EVA. The MATROSHKA experiment spent 616 days in orbit, both inside and outside the Russian module.



2005 ESA:


Last Matroshka experiment:


Space radiation measurement of the Kibo module using the Matryoshka facility, which has jointly been performed by Russia, ESA and JAXA since May 2010, was completed on March 11, 2011.

  • 2
    $\begingroup$ There are photos of the versions that flew on Orion here en.wikipedia.org/wiki/StemRad#StemRad_MD which are less colourful than the the rendered images but equally uncanny. $\endgroup$ Commented Dec 18, 2023 at 10:50
  • 1
    $\begingroup$ I'm surprised that that got official funding, remembering the popular objection to the nude images on the Pioneer plaque. $\endgroup$ Commented Dec 19, 2023 at 8:29
  • $\begingroup$ I'm wondering how much of a coincidence it isn't that the two names I most commonly use for phantom card players (eg: a "player" who just turns over the next card without looking at it in Hearts, Spades, or Cards Against Humanity) are "Fred" and "Rando". $\endgroup$
    – T.E.D.
    Commented Dec 19, 2023 at 14:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.