﻿ Astronomy Picture of the Day [1]Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2023 May 14 [2]An astronaut is seen hovering over the Earth. In the top part of the image, the astronaut is seen against the darkness of space. In the lower part of the image, the Earth is bright blue with white clouds. Please see the explanation for more detailed information. To Fly Free in Space Image Credit: [3]NASA, [4]STS-41B Explanation: What would it be like to fly free in space? At about 100 meters from the cargo bay of the [5]space shuttle Challenger, Bruce McCandless II was living the dream -- floating farther out than anyone had ever been before. Guided by a [6]Manned Maneuvering Unit (MMU), astronaut McCandless, [7]pictured, was [8]floating free in space. During [9]Space Shuttle mission [10]41-B in [11]1984, [12]McCandless and fellow [13]NASA astronaut [14]Robert Stewart were the first to [15]experience such an "un[16]tethered [17]space walk". The [18]MMU worked by shooting jets of [19]nitrogen and was used to help deploy and [20]retrieve satellites. With a mass over 140 kilograms, an [21]MMU is heavy on [22]Earth, but, like everything, is weightless when drifting in orbit. The MMU was later replaced with the [23]SAFER backpack propulsion unit. Tomorrow's picture: red eagle __________________________________________________________________ [24]< | [25]Archive | [26]Submissions | [27]Index | [28]Search | [29]Calendar | [30]RSS | [31]Education | [32]About APOD | [33]Discuss | [34]> __________________________________________________________________ Authors & editors: [35]Robert Nemiroff ([36]MTU) & [37]Jerry Bonnell ([38]UMCP) NASA Official: Phillip Newman [39]Specific rights apply. [40]NASA Web Privacy Policy and Important Notices A service of: [41]ASD at [42]NASA / [43]GSFC, [44]NASA Science Activation & [45]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2305/freeflyer_nasa_3000.jpg 3. https://www.nasa.gov/ 4. https://www.nasa.gov/mission_pages/shuttle/shuttlemissions/archives/sts-41B.html 5. https://apod.nasa.gov/apod/ap950809.html 6. https://en.wikipedia.org/wiki/Manned_Maneuvering_Unit 7. https://www.nasa.gov/image-feature/nasa-celebrates-50-years-of-spacewalking 8. https://youtu.be/RvnC--JjDBw 9. https://apod.nasa.gov/apod/ap990411.html 10. http://en.wikipedia.org/wiki/STS-41-B 11. https://en.wikipedia.org/wiki/Nineteen_Eighty-Four 12. https://www.nasa.gov/press-release/astronaut-bruce-mccandless-ii-dies-at-80 13. https://www.nasa.gov/astronauts 14. https://www.nasa.gov/sites/default/files/atoms/files/stewart_robert.pdf 15. https://youtu.be/7K5DiKsZhTk 16. http://www-istp.gsfc.nasa.gov/Education/wtether.html 17. https://apod.nasa.gov/apod/ap990801.html 18. https://youtu.be/92ZRVlKuc0U 19. https://periodic.lanl.gov/7.shtml 20. https://apod.nasa.gov/apod/ap121209.html 21. http://en.wikipedia.org/wiki/Manned_Maneuvering_Unit 22. https://apod.nasa.gov/apod/ap220206.html 23. https://apod.nasa.gov/apod/ap011002.html 24. https://apod.nasa.gov/apod/ap230513.html 25. https://apod.nasa.gov/apod/archivepix.html 26. https://apod.nasa.gov/apod/lib/apsubmit2015.html 27. https://apod.nasa.gov/apod/lib/aptree.html 28. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 29. https://apod.nasa.gov/apod/calendar/allyears.html 30. https://apod.nasa.gov/apod.rss 31. https://apod.nasa.gov/apod/lib/edlinks.html 32. https://apod.nasa.gov/apod/lib/about_apod.html 33. https://asterisk.apod.com/discuss_apod.php?date=230514 34. https://apod.nasa.gov/apod/ap230515.html 35. http://www.phy.mtu.edu/faculty/Nemiroff.html 36. http://www.phy.mtu.edu/ 37. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 38. http://www.astro.umd.edu/ 39. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 40. https://www.nasa.gov/about/highlights/HP_Privacy.html 41. https://astrophysics.gsfc.nasa.gov/ 42. https://www.nasa.gov/ 43. https://www.nasa.gov/centers/goddard/ 44. https://science.nasa.gov/learners 45. http://www.mtu.edu/