Skylab's Body Mass Measurement chair, the facility of the Body Mass Measurement experiment (M172), is shown here in this 1970 photograph. The M172 experiment determined the body mass of each crew member and observed changes in body masses during flight. Knowledge of exact body mass variations throughout the flight in significantly aided in the correlation of other medical data obtained during the flight. Mass measurements under zero-gravity conditions were achieved by the application of Newton's second law (force equals mass times acceleration). The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.

Astronaut Karen Nyberg,Expedition 36 flight engineer,performs a Space Linear Acceleration Mass Measurement Device (SLAMMD) Body Mass Measurement test in the U.S. Laboratory.

ISS020-E-015853 (30 June 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 20 flight engineer, uses the IM mass measurement device to perform the PZEh-MO-8/Body Mass Measurement Russian biomedical routine assessments in the Zvezda Service Module of the International Space Station.

ISS019-E-014216 (6 May 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 19/20 flight engineer, uses the IM mass measurement device to perform the PZEh-MO-8/Body Mass Measurement Russian biomedical routine assessments in the Zvezda Service Module of the International Space Station.

ISS019-E-014222 (6 May 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 19/20 flight engineer, uses the IM mass measurement device to perform the PZEh-MO-8/Body Mass Measurement Russian biomedical routine assessments in the Zvezda Service Module of the International Space Station.

S73-20622 (March 1973) --- Scientist-astronaut Joseph P. Kerwin, science pilot of the first manned Skylab mission, demonstrates the Body Mass Measurement Experiment (M172) during Skylab training at the Johnson Space Center. Dr. Kerwin is in the work and experiments area of the crew quarters of the Skylab Orbital Workshop (OWS) trainer at JSC. The M172 experiment will demonstrate body mass measurement in a null gravity environment, validate theoretical behavior of this method, and support those medical experiments for which body mass measurements are required. The data to be collected in support of M172 are: preflight calibration of the body mass measurement device and measurements of known masses up to 100 kilograms (220 pounds) three times during each Skylab mission. The device, a spring/flexure pivot-mounted chair, will also be used for daily determination of the crewmen?s weight, which will be manually logged and voice recorded for subsequent telemetered transmission. Photo credit: NASA

iss053e059889 (Sept. 28, 2017) --- Astronaut Joe Acaba calculates his mass inside the Columbus laboratory module using the Space Linear Acceleration Mass Measurement Device (SLAMMD). The device generates a known force against a crew member mounted on an extension arm with the resulting acceleration used to calculate the subject’s mass.

ISS035-E-017874 (8 April 2013) --- NASA astronaut Chris Cassidy, Expedition 35 flight engineer, performs Body Mass Measurement activities using the Space Linear Acceleration Mass Measurement Device (SLAMMD) in the Columbus European Laboratory aboard the Earth-orbiting International Space Station. Since crew members can?t weigh themselves in zero-g, they use this method as the next best thing. Skylab astronauts, the first NASA crew members to fly in space for over a month at a time, some 40 years ago, used a body mass measurement device that was somewhat different from this.

ISS023-E-052104 (26 May 2010) --- Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi, Expedition 23 flight engineer, uses the IM mass measurement device to perform the PZEh-MO-8/Body Mass Measurement Russian biomedical routine assessments in the Zvezda Service Module of the International Space Station.

ISS021-E-014503 (12 Oct. 2009) --- NASA astronaut Nicole Stott, Expedition 21 flight engineer, uses the IM mass measurement device to perform the PZEh-MO-8/Body Mass Measurement Russian biomedical routine assessments in the Zvezda Service Module of the International Space Station.

ISS037-E-006475 (3 Oct. 2013) --- NASA astronaut Michael Hopkins, Expedition 37 flight engineer, performs Body Mass Measurement activities using the Space Linear Acceleration Mass Measurement Device (SLAMMD) in the Columbus laboratory aboard the Earth-orbiting International Space Station.

ISS037-E-006478 (3 Oct. 2013) --- NASA astronaut Michael Hopkins, Expedition 37 flight engineer, performs Body Mass Measurement activities using the Space Linear Acceleration Mass Measurement Device (SLAMMD) in the Columbus laboratory aboard the Earth-orbiting International Space Station.

Vincent W. Converse of Rockford, Illinois proposed Skylab's student experiment ED-74, Mass Measurement, to measure mass in a weightless environment. This chart describes Converse's experiment. Mass is the quantity of matter in any object. The gravitational force between an object and the Earth is called weight, which is a result of the Earth's gravity acting upon the object's mass. Even though objects in Skylab were apparently weightless, their mass properties were unchanged. Measurement of mass is therefore an acceptable alternative to measurement of weight. The devices used in this experiment provided accurate mass measurements of the astronauts' weights, intakes, and body wastes throughout the missions. In March 1972, NASA and the National Science Teachers Association selected 25 experiment proposals for flight on Skylab. Science advisors from the Marshall Space Flight Center aided and assisted the students in developing the proposals for flight on Skylab.

ISS031-E-157943 (26 June 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, uses a body mass measurement device (BMMD) in the Zvezda Service Module of the International Space Station.

ISS038-E-008293 (25 Nov. 2013) --- NASA astronaut Rick Mastracchio, Expedition 38 flight engineer, uses a body mass measurement device (BMMD) in the Zvezda Service Module of the International Space Station.

ISS016-E-033800 (27 March 2008) --- NASA astronaut Garrett Reisman, Expedition 16 flight engineer, uses a body mass measurement device (BMMD) in the Zvezda Service Module of the International Space Station.

iss071e113128 (May 22, 2024) --- Expedition 71 Flight Engineer and NASA astronaut Matthew Dominick works in the International Space Station's Columbus laboratory module performing maintenance on the Space Linear Acceleration Mass Measurement Device, or SLAMMD. The human research device applies a known force to a crew member then calculates body mass using a form of Newton’s Second Law of Motion, force equals mass times acceleration.

S85-26553 (Feb 1985) --- STS-40/SLS-1 payload specialist Millie Hughes-Fulford sits strapped in the special device scientists have developed for determining mass on orbit. As the chair swings back and forth, a timer records how much the crewmember's mass retards the chair's movement. Dr. Hughes-Fulford will be joined by three mission specialists, the mission commander, the pilot and a second payload specialist for the scheduled 10-day Spacelab Life Sciences-1 (SLS-1) mission. The flight is totally dedicated to biological and medical experimentation.

ISS032-E-010109 (27 July 2012) --- Japan Aerospace Exploration Agency astronaut Aki Hoshide, Expedition 32 flight engineer, uses a body mass measurement device (BMMD) in the Zvezda Service Module of the International Space Station.

ISS032-E-010111 (27 July 2012) --- Japan Aerospace Exploration Agency astronaut Aki Hoshide, Expedition 32 flight engineer, uses a body mass measurement device (BMMD) in the Zvezda Service Module of the International Space Station.

ISS032-E-010119 (27 July 2012) --- NASA astronaut Sunita Williams, Expedition 32 flight engineer, uses a body mass measurement device (BMMD) in the Zvezda Service Module of the International Space Station. Japan Aerospace Exploration Agency astronaut Aki Hoshide, flight engineer, is visible in the background.

ISS016-E-033799 (27 March 2008) --- Russian Federal Space Agency cosmonaut Yuri Malenchenko, Expedition 16 flight engineer, uses a body mass measurement device (BMMD) in the Zvezda Service Module of the International Space Station.

ISS034-E-009703 (23 Dec. 2012) --- Newly arrived Expedition 34 Flight Engineer Tom Marshburn, NASA astronaut, uses the Body Mass Measurement Device in the Zvezda service module aboard the International Space Station on Dec. 23, 2012. Marshburn, along with Canadian astronaut Chris Hadfield and Russian cosmonaut Roman Romanenko arrived the orbital outpost on Dec. 21 to join three other crewmen already onboard.

ISS039-E-008066 (30 March 2014) --- NASA astronaut Steve Swanson, Expedition 39 flight engineer, participates in body mass measurement/Russian biomedical routine assessments in the Zvezda Service Module of the International Space Station. Looking on is Russian cosmonaut Alexander Skvortsov, flight engineer representing the Russian Federal Space Agency (Roscosmos).

ISS034-E-009700 (23 Dec. 2012) --- Newly arrived Expedition 34 Flight Engineer Tom Marshburn, NASA astronaut, uses the Body Mass Measurement Device in the Zvezda service module aboard the International Space Station on Dec. 23, 2012. Marshburn, along with Canadian astronaut Chris Hadfield and Russian cosmonaut Roman Romanenko, arrived at the orbital outpost on Dec. 21 to join three other crewmen already onboard.

This chart shows, on the top row, artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii, masses, densities and surface gravity as compared to those of Earth. These numbers are current as of February 2018. On the bottom row, the same numbers are displayed for the bodies of our inner solar system: Mercury, Venus, Earth and Mars. The TRAPPIST-1 planets orbit their star extremely closely, with periods ranging from 1.5 to only about 20 days. This is much shorter than the period of Mercury, which orbits our sun in about 88 days. The masses and densities of the TRAPPIST-1 planets were determined by careful measurements of slight variations in the timings of their orbits using extensive observations made by NASA's Spitzer and Kepler space telescopes, in combination with data from Hubble and a number of ground-based telescopes. These measurements are the most precise to date for any system of exoplanets. In this illustration, the relative sizes of the planets are all shown to scale. https://photojournal.jpl.nasa.gov/catalog/PIA22094

STS-40 Payload Specialist Millie Hughes-Fulford along with backup payload specialist Robert Ward Phillips familiarize themselves with Spacelab Life Sciences 1 (SLS-1) equipment. The two scientists are in JSC's Life Sciences Project Division (LSPD) SLS mockup located in the Bioengineering and Test Support Facility Bldg 36. Hughes-Fulford, in the center aisle, pulls equipment from an overhead stowage locker while Phillips, in the foreground, experiments with the baroreflex neck pressure chamber at Rack 11. The baroreflex collar will be used in conjuction with Experiment No. 022, Influence of Weightlessness Upon Human Autonomic Cardiovascular Control. Behind Phillips in the center aisle are body mass measurement device (BMMD) (foreground) and the stowed bicycle ergometer.

This still image features a free-air gravity map of the Moon's southern latitudes developed by S. Goossens et al. from data returned by the Gravity Recovery and Interior Laboratory (GRAIL) mission. If the Moon were a perfectly smooth sphere of uniform density, the gravity map would be a single, featureless color, indicating that the force of gravity at a given elevation was the same everywhere. But like other rocky bodies in the solar system, including Earth, the Moon has both a bumpy surface and a lumpy interior. Spacecraft in orbit around the Moon experience slight variations in gravity caused by both of these irregularities. The free-air gravity map shows deviations from the mean gravity that a cueball Moon would have. The deviations are measured in milliGals, a unit of acceleration. On the map, purple is at the low end of the range, at around -400 mGals, and red is at the high end near +400 mGals. Yellow denotes the mean. The map shown here extends from the south pole of the Moon up to 50°S and reveals the gravity for that region in even finer detail than the global gravity maps published previously. The image illustrates the very good correlation between the gravity map and topographic features such as peaks and craters, as well as the mass concentration lying beneath the large Schrödinger basin in the center of the frame. The terrain in the image is based on Lunar Reconnaissance Orbiter (LRO) altimeter and camera data. Credit: NASA's Scientific Visualization Studio <b><a href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA image use policy.</a></b> <b><a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a></b> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. <b>Follow us on <a href="http://twitter.com/NASAGoddardPix" rel="nofollow">Twitter</a></b> <b>Like us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a></b> <b>Find us on <a href="http://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a></b>